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Another cam thread - different set-up

Muskrat

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I was just going piggyback off cheeky's question, as a lot of the information there pertains to this - so no need to double post that stuff - but I didn't want to have info for two different setups in the same thread, confusing people.

Starting from the inlet my set-up will be:

Evo MAS to Dejon Tool 1g 4" intake.
8-blade HX35 w/ BEP .55 a/r turbine housing
ETS intercooler system
stock TB
Cyclone IM
DSM Graveyard Frankenstein head or similar local build
8.5 CR
FP cast manifold
MAP or Punishment Recirculated external waste-gate/o2 housing
2.5" turbo back exhaust (considering building a 3" in the future. Car already has the 2.5")

The turbo seems to like to live at a 2.5-3.0 pressure ratio, so I'm thinking of running a dual stage setup with waste gate spring set at a 2.5 PR (about 22 psig) and being able to bump it to 3.0 (about 30 psig) with a solenoid and mbc.

Of course I'll have all the necessary fuel mods for this. Walboro 255HP, 850 cc injectors, and Aeromotive fpr.

My power goal is 350-400 whp which IIRC I should meet at about 25 psi, if my assumptions are close. But if I do go for the two-stage setup I'll be able to have a good "around town" setting, and then get it on a dyno to max out the setup.

I'm looking for quick spool up, and a broad power band. This will be a weekend warrior and auto/rally cross car.

I'm tempted to see what I can do with stock cams, but at the same time I'm fairly sure they will choke me off at higher RPM's, and I'd rather not have to pay for more dyno time than I need.

I'm sure I don't want/need more than a 272 duration cam, and am questioning if even that might be more than I want. I've been looking hard at the fp1x which seems to be a little more aggressive than a 264, with higher lift. I've also been thinking about something like a 272 intake/264 exhaust (opposite of the standard 264/272) to maximize intake potential, but still keep exhaust gas velocity up for optimized spool.

I've got some time before I need to make this decision, but looking for some input to help clear things up.
 
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cheekychimp

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Funnily enough that setup isn't vastly different from the one I have on the project car except I don't have a Cyclone Manifold (yet) and I have slightly higher compression. I'm using the HX35/40 in the same housing but internally gated. Although the HX35/40 is rated for more power, a lot of people say the .55 A/R means you don't get all the benefit of the 40 wheel so it won't produce significantly more power than the straight HX35 in that housing. That said I think the HX35 turbo should be capable of over 400 hp at 25 psi if properly tuned.

From what I have gleemed so far, you should really see the benefits of the 272/272 combination over 400 hp, especially IF you intend to utilize the top end and in my opinion even with a quick spooling turbo there isn't a great deal of point in fitting a bigger turbo if you aren't going for top end. If you only want the lower power threshold and low end to mid range response however, I'd be tempted to go with your original idea of using stock cams or the 264s. I don't think you will suffer greatly from using the 272s but at that pressure ratio I think you will end up seeing more power. Not a bad thing but you might find the reliability gremlins coming in at the 400+ hp mark.

Edit: Actually, looking over my figures again, I think you do need 272s or you are just choking that turbo. An 8-blade HX35 in the BEP .55 A/R housing should make 20 psi at about 3500 rpms on 272s and there are a number of cars putting down 500 hp with that setup (at 30 psi). Your 2.5 exhaust might also choke things though. I do have a full 3 inch turbo back with no cat (not required by law here), I forgot about that before.
 
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DR1665

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OOh! Camshaft discussions. So tasty! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

From what little research I've done on the 4G63 front, it seems the bulk of aftermarket cams available OTC in the US cater to the predominately masturbatory pursuits of the drag racing community. <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> You either get a barely noticeable over stock "street" cam or you get something designed for WOT and redline. The market is flooded with echo chamber champions running huge turbos and high lift/duration race cams. Supply? Meet demand. It's all about e-peen top end, imo.

To each his own, but it makes things harder for those of us looking for bottom end/mid-range torque, such as is needed in autox/rallyx/stage rally.

We run smaller displacement, turbocharged engines. At 14.7psi, we're running 200% VE; at 30psi, we're sitting on 300% VE. In vacuum conditions, we're still subject to reversion. We could use the additional lift offered by the aftermarket, but not with all that duration. There aren't many HL/SD profiles out there, but here's my two favorites for comparison and conversation.

<b>Kelford 1-TX258</b>
lift (i/e): 413/413
duration (i/e): 208°/220°

<b>Piper MITS1BP300 Rally</b>
lift (i/e): 453/453
duration (i/e): 265°/265°

<b>FP1X/1X</b>
lift (i/e): 412/396
duration (i/e): 204°/204°

<b>HKS 272/264 invert option</b>
lift (i/e): 405/385
duration (i/e): 272°/264°

WELL! You learn something new every day, don't you? I still think I'd opt for the Kelfords in a rally car with a restrictor and a smaller turbo, as I suspect I'd see better intake velocity (torque) down low, but look at the FP1X combo! That's downright raunchy. If you had a fast-spooling, larger turbo that could feed those valves quickly, I bet they'd really rock.

Cams are a bit down on my list. Car needs to go back together and driven before I bother with making more power, but this is definitely one of the first orders of business once that time arrives. I think I'll pick up a well-sorted set of cams before I mess with a turbo upgrade.

EDIT: Also, considering how valve sizing plays into the whole lift/duration picture, I think I'd probably want something custom; maybe lift in the .300"-.350" range, sticking with marginally less aggressive 208°/220° durations advertised by Kelford.

Still, at 50% more expensive than the FP grinds, cost would really become an issue.

EDIT2: I forgot about the restrictor. The Kelford cams are for handicapped rally cars running inlet restrictors, which limit top end, but accelerate the intake charge at low- to mid-range. MACH (supersonic intake charge velocity) happens much sooner on a restricted engine, meaning it wouldn't make sense to have the additional lift. They remain my favorite grind.
 
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Muskrat

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Great info, thanks.

As far as power band, I'm hoping the cyclone and 8.5 cr will help make up some down low torque, and am looking for a broad power band from the mid to high rpm range. Like DR, I'm not looking for something that's super peaky.

DR: did you have a type-o on the Kelfords lift? Looks like you put the "Spec" cam duration (aka 258 intake/264 exhaust)

Since I am planning to upgrade the valve springs in the head, the FP1X is looking more and more appealing.

Also, I'm not sure what the max allowable lift for our engines is, but I think the Piper's might be cutting it close. Piston choice might be crucial with those.
 
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SleepinGVR4

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Danville, Pennsylvania
What about the GSC Power-Division S1 Cams?

*(Intake: 268 , 230@1mm 11mm valve lift) / (Exhaust :268 , 230@1mm ,10.5mm valve lift)

*taken from Garfield's website.
 

DR1665

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</font><blockquote><font class="small">Quoting Muskrat:</font><hr />

Great info, thanks.

<hr /></blockquote><font class="post">
No worries. I love this sort of discussion.

</font><blockquote><font class="small">Quoting Muskrat:</font><hr />

As far as power band, I'm hoping the cyclone and 8.5 cr will help make up some down low torque, and am looking for a broad power band from the mid to high rpm range. Like DR, I'm not looking for something that's super peaky.

<hr /></blockquote><font class="post">
That's so bizarre to consider 8.5:1CR as a bump. Coming from the 2GNT community, I took my stock 9.6:1CR 420A to 10.5:1CR. I did a double take when you mentioned 8.5:1 being a bump toward torque. Most 420A turbo guys looking to run more boost will run 8.8:1CR slugs, but I know some running the 10.5:1CR. Higher CR is a bit more efficient on its own, making the same power at reduced boost pressures, but you start out closer to the edge.

The rule of thumb I picked up was +4%bhp for each point compression. Example: 200bhp @ 7.8:1CR would be 208bhp @ 8.8:1CR.

</font><blockquote><font class="small">Quoting Muskrat:</font><hr />

DR: did you have a type-o on the Kelfords lift? Looks like you put the "Spec" cam duration (aka 258 intake/264 exhaust)

<hr /></blockquote><font class="post">
Oops! My bad. The headings are links to specs on manufacturer websites. I grabbed the wrong numbers on the Kelfords. Just updated the post to show the proper .413 lift on both intake/exhaust. Given this development, the FP1X would actually be a bit less aggressive than the Kelfords.

</font><blockquote><font class="small">Quoting Muskrat:</font><hr />

Also, I'm not sure what the max allowable lift for our engines is, but I think the Piper's might be cutting it close. Piston choice might be crucial with those.

<hr /></blockquote><font class="post">
Max allowable? I'm not sure, but I've heard it said a good lift target is 50% of valve diameter.That's why I was thinking about something custom, with .300"-.350" lift on a 208°-220° duration. Coming from the land of all motor nutjobs, I've learned all too well the lessons of reduced low RPM intake velocities at the valves.

I'd rather have the bulk of my power and torque down low, say, 1500-4000rpm, than up high, where it only gets used above 5000rpm.

Once 195/2000 goes back together, I'll be starting with speed density through a Cyclone into a lightly massaged (read: gasket-matched, cleaned up a bit - not ported) stock head, feeding a 14B and ported O2. I'm sticking with the stock DP and crush-bent 2.5" catback until after I've played around with interfooler plumbing a bit. (Looking to increase volume with a "boost tube" in-line between SRT4 FMIC and TB.)

Brakes, suspension, and seat time come first for me with this car. Been a GVR4 owner going on five years and have all of 30 minutes seat time in anger. sh*t's got to change. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> Once I've shaken down the chassis and have a sense of how the car drives, I'll be looking into the E316G and cams to turn up the wick a bit.

Good discussion. We need more of these.
 

cheekychimp

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Wow, didn't realize how much I didn't know until going over this a couple of times after the past few days. I wonder if FPs would have suited me better in my setup over the 272/272 combo especially given that I have always said over here I rarely get above 5000 rpms.

Now, when Muskrat started this thread he said he didn't want to piggy back off mine but I sort of wish he had. Since this is moving on nicely can I step back a fraction and ask you to apply what you know to a more stock setup. You said above: -

Quote:
Once 195/2000 goes back together, I'll be starting with speed density through a Cyclone into a lightly massaged (read: gasket-matched, cleaned up a bit - not ported) stock head, feeding a 14B and ported O2. I'm sticking with the stock DP and crush-bent 2.5" catback until after I've played around with interfooler plumbing a bit. (Looking to increase volume with a "boost tube" in-line between SRT4 FMIC and TB.)



This is very much what I am aiming towards with my other car. AMG intake manifold to increase that volume you spoke about, higher compression, some port matching, extrude honing, ceramic coating etc, short route hard intercooler piping and possibly a 2G/EVO III head. I'm not looking to go larger than an EVO III 16G and I want to start with the Small 16G. I was leaning towards a stock cam profile to start and possibly a 264/264 setup at a later stage. What are the cam choices you are considering for a smaller frame turbo? For this car I am definitely looking for low end and midrange but one of the main criticisms of the standard cyclone manifold is that whilst it is great for low end and mid-range it flows less than other manifolds and drops off after about 6500 rpms. Since the AMG intake manifold doesn't and was designed for a car that had a higher redline, it also seems silly not to take advantage of that extra volume which could help give the car a nice broad power band.
 

Rausch

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^ Don't forget that the AMG intake was designed for naturally aspirated car with a much lower VE than a turbo engine on boost. I don't know the differences between the two (Cyclone and AMG) but I'd have to imagine that the AMG mani would move about the same volume, maybe a bit less, than the Cyclone, no?
 

cheekychimp

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I'm not 100% sure. I'm still trying to work a lot of this stuff out for myself. The whole concept of a forced induction engine is that it compresses air thereby forcing more of it into the engine. I would think therefore that this would mean that the intake manifold on a turbo car would not need to be as large as that on an NA car to move the same volume of air. Movement itself I would hazard a guess has a great deal more to do with cam profiles given that the AMG and turbo heads don't appear significantly different. I remember previously I suggested the AMG cams might be more aggressive and worth trying in a turbo application and I think you questioned whether this would work due to differences in overlap and duration. I have yet to get to the bottom of this.

The plenum on the AMG is huge however and given it will be filled under pressure, I would suspect it to move significantly more air, cams permitting. It would be very interesting to swap in the intake manifold without any other changes, just to see if it makes any real difference. However I am reliably informed that this will require some modification of the intercooler piping since the AMG manifold significantly alters the position of the throttle body and I don't really want to do my piping twice just for the sake of conducting an experiment.
 

Muskrat

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Cheeky, if your looking for low end power, I'd actually go with a standard cyclone, not the AMG.

Here's some comparison pictures. Also pay attention to Curtis' comments: click (I know you've seen this before, you posted in the thread /ubbthreads/images/graemlins/smile.gif )

I was always under the impression that for our cars increasing the intake plenum volume will shift the power band up the rpm range, and for our cars you only really need to to if you're pushing a lot of air. Also, with the larger main runners, your intake air velocity will be lower with the AMG than the Mitsu cyclone, negating some of the down low torque benefits. I'm still working through the reasoning for WHY. I think have the general idea, but I'm not confident enough to put it in words and post it yet /ubbthreads/images/graemlins/smile.gif. So if someone knows better, speak up.

I was under the impression that, like curtis' custom larger plenum cyclone intake, the AMG would REALLY only benefit a high horsepower car, looking to broaden their top-end power band. Beyond that, the regular cyclone is more than sufficient. Especially for the relatively stock car you're planning.

The AMG WILL move more air, but it's a question of where in the RPM range it does it, and is it usable. I suspect, however, it moves LESS air in the lower RPM ranges.

Where did you see the cyclone tails off after 6500 rpm? Everything I've seen says the cyclone flows slightly less up top, but it's as near as makes no difference to a 1G.


Edit: Here's a quick paint drawing of what I'd generally expect the dyno graphs to look like, if the only thing changed was the intake.


 
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DR1665

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Quoting cheekychimp:

Quoting DR1665:

Once 195/2000 goes back together, I'll be starting with speed density through a Cyclone into a lightly massaged (read: gasket-matched, cleaned up a bit - not ported) stock head, feeding a 14B and ported O2. I'm sticking with the stock DP and crush-bent 2.5" catback until after I've played around with interfooler plumbing a bit. (Looking to increase volume with a "boost tube" in-line between SRT4 FMIC and TB.)



This is very much what I am aiming towards with my other car. AMG intake manifold to increase that volume you spoke about, higher compression, some port matching, extrude honing, ceramic coating etc, short route hard intercooler piping and possibly a 2G/EVO III head. I'm not looking to go larger than an EVO III 16G and I want to start with the Small 16G. I was leaning towards a stock cam profile to start and possibly a 264/264 setup at a later stage. What are the cam choices you are considering for a smaller frame turbo? For this car I am definitely looking for low end and midrange but one of the main criticisms of the standard cyclone manifold is that whilst it is great for low end and mid-range it flows less than other manifolds and drops off after about 6500 rpms. Since the AMG intake manifold doesn't and was designed for a car that had a higher redline, it also seems silly not to take advantage of that extra volume which could help give the car a nice broad power band.



Wow, Paul. Two questions:

1. Is this car mostly daily driver, highway cruiser, or track beast?
2. How will you determine if these mods are worth it?

No disrespect, but damn. That's one hell of a convoluted shopping list, my friend! /ubbthreads/images/graemlins/jawdrop.gif

My reasoning for the "boost tube" is a little bit different from what you're thinking, Paul. I'll get to that in a second, but first, consider how bi-modal intake manifolds like these are concerned with maximizing low- to mid-range torque without necessarily compromising top end power. Down low, there is a smaller volume (CFM) of air moving through the runners to fill a vacuum. Increased runner length (and reduced runner volume) improves torque by accelerating smaller volumes (CFM) of air at lower engine speeds.

The flip-side to this is, these smaller runners can only accelerate the charge to a point. Once the overall volume of intake charge exceeds the capacity of the runner, it becomes a restriction in the system. This is when the second set of runners come into play. The primaries are maximized and the potential restriction is removed.

Now, from quick glances at the pictures in that other thread regarding the AMG/Cyclone, it looks like the Cyclone's primaries are longer than its secondaries, while the AMG has both sets apparently the same length. This makes sense to me, as the Cyclone is designed for turbocharged applications, while the AMG was all motor, baby.

Why do we want the Cyclones on our turbocharged cars? Low- to mid-range torque. How do we get this? Longer primaries accelerating the reduced CFM intake charge prior to system pressurization. Once the turbo wakes up, who gives a sh*t how many runners we've got or how long they are? It's all pressurized. There is no more natural aspiration. The engine is not sipping a Mint Julep through a straw anymore. No sir. Now it's chugging off a 3-story beer bong. f*** all. The secondaries are shorter to move higher volumes of pressurized air right to the intake valves.

The AMG, on the other hand, does not see positive manifold pressure. My theory - as I'm no engineer and am basing this all off all motor DSM experience - the AMG has larger primaries because it has a higher basic compression ratio, meaning it makes more torque off the line (offsetting the reduced intake velocities realized by the larger runner diameter, initially), and the activation point is later than that of its turbocharged cousin because there is no hair dryer suddenly pressurizing the system, meaning the point of restriction occurs later. Both sets of runners need to be the same length in order for the intake charge to be flowing at the same rate when it reaches the valves.

Now, for my "boost tube" ideas, consider this: As soon as the throttle plate closes, the intake manifold goes to maximum vacuum instantaneously. Turbo lag is a function of compressor acceleration, true, but there is also the time it takes to pressurize the entire intake system; compressor housing to intake valve. I'm looking to increase the volume of the system before the throttle plate. A larger intake manifold plenum does so after.

Barring any real data (this is all hypothetical at this point), as MY car will spend a LOT of time at part-throttle in the 3000-5000rpm range, I'm willing to explore how such a setup impacts performance. I'm not as concerned with initial spool-up as I am having a steady supply of of pressurized charge on tap when I go from 70-40-90%TPI. I also suspect it might retard BOV function a bit, but that's just something I'll be looking to compare when the car is back together.

All things being equal, increasing intake manifold volume is going to shift the powerband upward, possibly increasing turbo lag. Think back to all the intakes you've seen on full-time dragsters with ginormous turbos on them. They generally feature increased plenum volume and short, straight runners. They run WOT and aren't concerned with power below, what, 4000rpm?

Back to your list, I like the idea of a modest bump in compression. In fact, if you've got access to high quality petrol over there, I'd give it serious consideration if I were you, sir. You'll need to do a bit more in the tuning department, but so long as you don't get crazy, it makes for a more efficient engine below 100%VE (read: boost).

I love the idea of Extrude Hone services, but I'd bump that (and the ceramic coating) to more of a P3 at this point. I favor building the simple solution to the complex. Far more elegant, imo. If you really want wring every last drop of potential out of that mill, bolt up the Extrude Honed/coated bits after some dyno time with the basic setup so A) you can determine if it was worth the money for you, personally, and B) you can help others make the determination for themselves. Last time I looked into Extrude Hone, it was something like $600 for an intake manifold. And for what, 15hp? Pass.

Getting back to CAMS, which ones would I use for a small frame turbo? Um, I think I'd go with the FP1X or the Kelfords. Both seem intended for use below 6000rpm with turbo flow rates above stock. Probably a great match for the likes of an E316G.

Don't sweat the Cyclone falling off above 6500rpm. Unless you're building an all-out race car, your engine probably spends less than 1% of it's time there. On the street or below about 120mph, who gives a sh*t about top end? It's all about a fat torque curve through the midrange in my book.

We now return to your regularly scheduled programming.
 

cheekychimp

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Damn, so much information here, I don't really know where to start but here goes.

First I am sorry, I have no idea why I said the cyclone falls off at 6500 rpms. You are quite correct the cyclone flows exactly 1 CFM less than a USDM 1G intake at WOT. It isn't even worth talking about. I think I may have something in my notes that relates back to when I was thinking about putting a cyclone on a 2.3 litre but given the completely different airflow characteristics of the stroker that is a completely different kettle of fish. So again, I'm sorry.

Now I'm not completely sold on your theories regarding the AMG Cyclone but both of you make sensible arguments for your reasoning so I'd like to explore those further. I did a little bit of research on the interwebz last night to get some figures. Now I know the internet is not the most reliable source of information but I'll treat these figures as semi accurate until someone shows them to be incorrect. Here is the run down:-

1989 Galant VR4

Bore x Stroke 85mm x 88mm
195 bhp @ 6000 rpm
203 ft/lb @ 3000 rpm

16V Galant GTi

Bore x Stroke 85mm x 88mm
143 bhp @ 6500 rpm
127 ft/lb @ 5000 rpm

Galant AMG

Bore x Stroke 85mm x 88mm
167 bhp @ 6750 rpm
141 ft/lb @ 5000 rpm


Now why have I done this? It was something Driggsy brought up in his post: -

Quote:
Now, from quick glances at the pictures in that other thread regarding the AMG/Cyclone, it looks like the Cyclone's primaries are longer than its secondaries, while the AMG has both sets apparently the same length. This makes sense to me, as the Cyclone is designed for turbocharged applications, while the AMG was all motor, baby.



Now first off, I'm sorry, but I don't subscribe to the theory on the runner length. I have a spare AMG plenum section sitting here and I just measured the runners somewhat unscientifically by pulling a piece of string taut against the inside radius of both sets of runners and for this short section the difference was 2.5 inches vs 5.5 inches ... hardly identical, and since the lower runner is going to follow a wider radius all the way to the head (with the second section of the runners attached) I think we can see that disparity getting larger. Now I actually expected the longer runner to match the diameter of the standard cyclone runners (i.e. 38 mm) but in fact it is the larger 43.5mm runner which is the longer one. Now if you are right about the higher compression ratio, I expect this manifold might be better suited to a higher compression turbocharged motor. Some members have installed cyclone manifolds on 8.5:1 CR engines and have experienced knock at the switch over point due to the more aggressive timing maps in the 1G ECU designed for lower compression engines. This may also have something to do with the changes in the design of the AMG cyclone.

What does interest me is that whilst the AMG car produces more power higher up the rev range (which is what you predicted) it makes MORE torque at the same rpm as the GTi which suggests that that manifold doesn't hinder low end (at least on an NA car). Now again, the AMG also had a higher CR but compared with the Gti the difference was less than the difference between the USDM 1G and 2G turbo cars so I don't think that this alone can account for the differences. Cam profile and timing might however and I STRONGLY suspect that the correlation between timing, cam profile and the AMG manifold is going to be critical in getting good results here.

Now regarding the runners and butterflies themselves, something else that I have been told but I have yet to confirm is that whilst the standard cyclone has both sets of runners open past the activation point, the AMG actually SWITCHES runners at activation. Now I have some issues with this. If the shorter runner was the larger diameter one it would make some sense but seeing as the shorter runner is the 38mm one which matches the size of all 8 of the standard cyclone runners, then at the WOT the AMG would effectively be using half the runner volume of the standard cyclone. It doesn't make sense and yet, since air follows the path of least resistance, I wonder if the longer set of runners are actually flowing any air (or at very least any significant amount of it) once the short runners are actually open. Perhaps closing the first runner increases velocity in the shorter one? Another issue that Curtis brought to my attention with the design of the hybrid cyclone manifold is that heimholtz ram effect has a significant effect on velocity and flow. If the first runners are closed upon activation of the butterflies I am unsure at this stage if you would just get dormant air sitting in those runners or if turbulence would take air in and out of those runners creating any other effects inside the manifold plenum.

If the AMG cyclone (with or without the correctly matched camshafts) creates more torque at the same rpms in an NA car, I would still expect it to benefit a forced induction engine. Now what would be really useful here is if someone had put a standard cyclone on an NA motor and we had figures to compare. In the absence of that, the next best thing is throwing the AMG intake on a turbocharged engine that originally came with the standard cyclone. If it is a flop, I'll just throw the AMG cyclone on the GTi in the UK. I can't see that being a problem (if I can figure out how to activate it).

To answer some other questions. The shopping list isn't so hard to come by out here in JDM land. I have parts left over from the first build lying about and I have picked up some other pieces pretty cheap. Ken has EVO III heads on his shelf and EVO III (9.0:1 CR) pistons are available at Mitsubishi Hong Kong. I take your point on the extrude honing but I actually do think it is worth it. To answer your other question, this will be a daily driver primarily so it isn't just about making power this time around. If it was I'd just step up to a larger turbo. It is more about power delivery and efficiency and from what I have heard, extrude honing does have an effect on performance without effecting driveability. I don't intend to extrude hone an entire head. I am thinking about extrude honing the plenum section of the intake manifold and leaving the butterfly section alone and extrude honing the exhaust manifold and compressor/turbine housings. I have a tubular O2 housing so I think that should be smooth enough. Ceramic coating will be to keep exhaust gases hot from the time they leave the head until they leave the downpipe. Mugen has tuned a number of Honda engines in Asia and on the face of it the prices do not seem worth the modest power increases (10-15 hp in some cases) but anyone who has driven the cars says the figures do not do justice to the power delivery.

To finish on another theory of mine. I think there is something to be gained by looking at the changes in configuration and development of these engines over time. The cyclones were used on 1G engines with lower CRs and larger ports where the cyclone was necessary to increase velocity at lower rpm. I still do not fully understand how the AMG cyclone was able to do this on an NA engine using a larger primary runner than the turbo variant. Obviously the NA runner holds more volume than the turbo runner (i.e. more air) but I don't see how velocity was achieved. I do think that velocity was the key to the upper rpm range of the AMG engine however and it's ability to hold torque to a higher rpm limit. I think it is significant however that as soon as the 2G heads were developed for the Evolution Lancers the Cyclones all disappeared. One explanation is that the convergence point of the dual runners at the ports to the head meant a larger port opening was required. Since the AMG runners converge about 3/4 of the way down the runner, I think there is considerable scope to modify or redesign that section to taper down to a 2G port size. Whether it would actually produce any benefits is another issue but I think it could be done. My gut feeling however is that a cyclone manifold of any type is superfluous on a 2G or EVO head.

ONE part I would desperately like to get my hands on however is a head from your USDM Hyundai 2.4 dohc engine. The head reportedly has 2g style runners with 1G intake ports and a smaller combustion chamber. If anyone knows of the whereabouts of one, I'd like to give that a try.
 

DR1665

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You hear that? That was the sound of my cerebellum fusing.

This is gonna degrade quickly into something barely legible to anyone not a seasoned engineer, imo. Not that I'm an engineer, by any means, nor that our conversation is inherently riddled with quantifiable data, but because it's a reach beyond the limits of my abilities to craft a comprehensive post. That is, as much as I'd like my entire post to be a continuous thought, I'm afraid this will be a series of loosely (at best) connected comments. Damn, I miss cohesion.

* I don't think the top end of the Cyclone matters at all to those of us seeking low- to mid-range power. I've no facts to back this up, but I'd be willing to bet this is a one or the other scenario. Not so much as black and white, but a gray area which shifts up or down the tach. Increased power down low means a compromise on top end and vice versa. Still, I concur the bit about 1CFM over the USDM OEM manifold, based on my digital travels.

* Comparing VR4-GTi-AMG is a step in the right direction, but there's more to the equation than bore, stroke, peak hp/tq, as you implied in your comments, Paul. Right off the bat, I'd be curious about specific compression ratios across the line, and all the stuff we're discussing is going to impact not only peak hp/tq, but the curves thereof to boot. It's hardly apples to oranges.

Each of these engines was engineered to serve a specific purpose. We can't mix and match the "best" parts of each into some kind of Super Sirius any more than we can add up the peak gains associated with random aftermarket parts advertised on the web. The AMG manifold was designed to make the most of the AMG spec sheet. That's not to say we wouldn't realize gains from its use on another engine, but doing so introduces compromises reducing the overall gains. Does that make sense? Am I saying that right?

* AMG runner length - Prior to this discussion, Paul, it's safe to say I've had all of five minutes experience casually thinking about the AMG manifold. Maybe an hour or two cumulatively considering the Cyclone. It was just a theory, but I still think the runners are sized with overall velocity given volume at the intake manifold. As I mentioned, turbochargers pretty much make all this discussion moot, as they change all the variables radically.

Did you apply your unscientific measurement process to the Cyclone to compare the length of its runners? Apples-to-apples, sir. /ubbthreads/images/graemlins/wink.gif I agree it's very unscientific - I'd be more interested in actual volume of the runners - but if the ratio of primarlyLength to secondaryLength is the same, I guess I'm at a loss. It still seems to me the runners are routed so as to ensure even airflow at the intake port when both sets are open.

* What really throws me is the suggestion the AMG manifold alternates runners, as opposed to supplementing, like the Cyclone does. The higher compression ratio is going to give the AMG lump a torque advantage across the board and it has no compressor pressurizing the intake charge, so I would suspect it would make use of the larger runners most of the time, only opening the smaller "secondaries" to allow for additional flow in the top end. (Anchoring bias in full effect!)

Do we know the activation point of the AMG manifold? Do we know - for sure - the AMG does *not* open both sets of runners at the same time?

Assuming the AMG really did alternate between primary/secondary, I suppose the smaller runners could be benefit extreme low end for crowded city streets, switching to longer, larger runners tuned for top end highway cruising (AMG is German, after all) at an earlier point than the Cyclone. This makes some sense to me, but without confirmation of the either-or functionality and/or activation point, I'm just talking out of my ass.

If it turns out this really is the way the AMG operates, I'd avoid it on a turbocharged car unless there was a way to implement the Cyclone's supplementary functionality; that is, use the smaller 38mm primaries through about 2500rpm before opening the larger secondaries to flow a lot of boost.

* Please do a before & after with the Cyclone/AMG, Paul. That would be wicked awesome. This is about so much more than just peak numbers; we're talking about the shape of the curves. Like I said, I've got just a couple hours experience fiddling around with the Cyclone and even less time with the AMG. I know the Cyclone supplements the primaries when activated, but I can't speak to the operation of the AMG.

Confirmation of how and when the AMG activates would provide more insight into its purpose. If it truly operates either-or, it might be a wicked solution for a 4G63 running a 14b below about 5000rpm (which is of interest to me).
 

cheekychimp

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CRs are 9.8:1 for the GTI, 10.4:1 for the AMG and trusty 7.8:1 for our old friend the VR4.

I really really wish I had a lot more information on all of this. One of our New Zealand members stated that the facelift GTis they got were about 160 hp. That is a pretty interesting fact if it is correct. We make all this fuss about the AMG and yet on the face of it assuming there were no substantial differences between the pre and post facelift GTi engines, Mitsubishi had already achieved a 15 hp increase in power WITHOUT that fancy AMG intake manifold. What that would mean is that what AMG actually achieved with custom headers, custom intake, custom cams and higher compression was a poxy 7 bhp. As you said, it isn't JUST about peak horsepower and torque, but it makes the revered AMG tuners look a bit less incredible if Mitsubishi already achieved 160 bhp out of the 4G63 in NA form. I wish I had more information on the engine specs of the NZ cars.

I think I am going to rob a standard Cyclone intake off one of the old blocks at the shop. When the full AMG Cyclone gets here I will measure the full length of the primary and secondary runners in both the standard and AMG cyclone. I'll also ascertain how the butterflies on the AMG Cyclone work and if the runners work independently or in collaboration like their turbo counterparts. If you are really lucky and it gets here whilst I am still off work, I might cut some sheet metal to seal off the runners at the cylinder head end and measure the volume of both the primary and secondary runners in each manifold. I'm not sure what liquid would be best to use to avoid any corrosion of the butterfly assembly, any recommendations?

Good call on the activation point as well. I'll need to try and find that information from somewhere.

What is really doing my head in is why the longer runner in the AMG cyclone is the larger diameter one. Irrespective of HOW the manifold operates I would still expect the design to use a longer smaller runner for low rpms and a bigger shorter runner for top end. Of course, I take your point that being NA perhaps it uses the larger runner most of the time and only opens the smaller runner at significantly higher rpms when the first one is becoming restrictive. If that is true it really would seem the AMG manifold is a poor choice for a turbo application. Not that it would take much to alter the activation point OR if the runners do act independently to switch polarity so to speak to use the smaller runner at first and the larger one later but then everything is still ass over tit because your small runner is short which won't produce as much torque and your larger runner is now long. The latter might not prove a significant issue but the former would probably negate much of the point of running the dual runner setup in the first place.

I think once I have done the measurements on the two Cyclones, I will send them off to be cleaned up media blasted, powder coated and possibly get the plenum sections extrude honed. I'll gasket match and reassemble them when I get them back. I'll go check out what dyno options are available and see if I can get a discount for booking a number of sessions in bulk. If I can, I'll get the car dyno'd as it stands to use as a base line and document the actual increases in horsepower achieved with each mod or group of mods. I have two Small 16Gs so I can throw one on in the stock housing and then swap in one with an extrude honed turbine and compressor housing to see if it makes any difference. I cannot promise to be able to document every single mod individually (for instance the extrude honed housing will probably be ceramic coated as well, so we won't be able to see which process yielded the most benefits) but hopefully we will see how much is bling and how much is worth doing.

Somewhere towards the end of those mods, I'll swap on the AMG Cyclone and see what effect it has. If it isn't that effective I'll pull it and save it to put on the NA GTi and I'll swap on the Cyclone with the extrude honed plenum and see if that yields any power increases as well.

Going back to CAMS which is what this thread is about (although I do believe there is a genuine correlation between cams and intake manifold design which should be addressed), I'd be interested to hear what if anything you can tell me about the differences between NA and Turbo cams especially in relation to 'overlap' to find out if it is worth using a full AMG head. Logic states the parts matching would already have been done here and we would simply be using the turbo as a pump to flow more air. The compression ratio would require more thought and the activation point might need to be addressed as the point of restriction would be reached earlier but since the AMG was designed to rev a bit higher and hold torque longer, I have a feeling this approach might have some benefits if we aren't shooting for huge power.
 
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FlyingEagle

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Some random information could be gleened from posts inside this thread I just read. Nothing proven, but anecdotal right?

click
 

cheekychimp

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Actually that's pretty useful information thanks. I had been looking for info as to why the NZ facelift spec GTIs had 15 horsepower over the pre-facelift ones and it seems it was due to a hike in compression. That thread says the early GTI was a 9.5:1 compression, whereas my information said 9.8:1. I'll need to double check that.

But it means that the extra compression is responsible for most of the power increase between the early GTIs like mine and the AMG. Still means the Cams, IM and Header only accounted for SEVEN additional horsepower. I hope that the power and torque curves show a more serious benefit or it doesn't look like that manifold is worth much at all.

Did you notice at the bottom it said German Tuners had made 200 bhp on track cars. I'd like to see what mods they did. A 200 bhp NA Galant would be cool.

Edit: From that, it appears the AMG cams in addition to being hollow and lighter weight have a 260/264 duration and 394/374 lift.
 
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DR1665

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@Paul - The newly shared AMG specs make a lot of sense. To illustrate...

<b>My 97 2GNT Talon:</b>
10.5:1CR - Crower 2s (241°/241°, .388"/.357") - aggressive headwork - +1mm valves all around - machined intake manifold - 52mm TB - PnP ECU ("tuning")

<b>E39 Galant AMG:</b>
10.4:1CR - AMG hollow cams (260°/264°, .394"/.374") - headwork (unknown) - valves (unknown) - bi-modal intake manifold - TB (unknown) - AMG ECU tune

While I never put my Talon on the dyno, my friend Mark Bullett was running a similar setup at the time and did. I'm pretty sure he was putting down somewhere between 180-190hp to the wheels. You can see the AMG cams are even more aggressive than the ones I ran in my Talon, both in duration and lift. The AMG clearly wants to be a highway runner, with what I suspect would be a decent amount of overlap to aid in top end.

I still want to know - for sure - how the AMG activates. The headwork on my Talon was certainly more aggressive than what the AMG might have got. Low end was obliterated in favor of peak horsepower in my case. Compression helps out down low, but that cam profile shifts things up top. I was still clearly pulling at 8000rpm when the rev limiter kicked in. The bi-modal intake has to play a role in supporting both. Either-or operation still seems counter-intuitive to me. It would make more sense to tune the primaries for low- to mid-range, then open up secondaries to support airflow above 6000rpm.

Which is why the additional length of the larger diameter runners on the AMG makes perfect sense! Runner length aids in the acceleration of naturally aspirated intake charges. The larger diameter runners are a larger volume of air, so the additional length helps to accelerate the charge through them.

<b>Getting back to cams (which we should - sorry, Muskrat), you don't want to run the AMG cams, or any other aggressive cams designed for all motor applications in turbocharged engines.</b> All motor engines need the overlap in the top end to hustle things through. It's all about maximizing scavenging in the header and maintaining gas velocities into and out of the combustion chamber. Turbochargers don't need this.

Another anecdote, a good friend of mine up in Detroit a few years back was running a built 420A with an HRC S20G and stepped into a set of Crower 3 cams (254°/250°, .444", .437"). As these are the most aggressive (shelf) cams Crower makes for the 420A - a naturally aspirated application - they had more overlap (duration) and lift designed into them. Derek spent a couple months trying to tune them properly, but in the end, he had to dial most of the overlap out to minimize reversion. He sold the cams inside of 90 days or so.

Today, Crower offers 4 cam profiles for the 2GNT: 1, 2, 2<i>T</i>, and 3. To recap (for easy comparison):

<b>2GNT OEM (420)</b>
(221°/217°, .324"/.278")

<b>Crower 1 (420A)</b>
(234°/238°, .350"/.308")

<b>Crower 2 (420A)</b>
(241°/241°, .388"/.357")

<b>Crower 2 <i>turbo</i> (420A)</b>
(238°/236°, .409"/.403")

<b>Crower 3 (420A)</b>
(254°/250°, .444", .437")

Notice how the C2T compares to the others. Duration is increased over both stock and C1, but not by much, while lift makes a serious reach. The C2T profile was developed based on extensive conversations with the 2GNT community. Trust me, Paul. You don't want to run AMG cams on a turbocharged application.

Like I said earlier, the AMG bits were engineered for a specific application. It is certainly possible you could see gains from their use on a turbocharged engine, but while the AMG bits might have contributed a 30-40+bhp gain on the NA cars, the inherent design elements to benefit naturally aspirated lump might actually work against you on a turbocharged application.

Keep us posted.
 

cheekychimp

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Damn this thread rocks! I'm learning so much. Muskrat I apologize for your thread getting taken over like this but I hope you are following this and getting more information regarding cams from this as well. Now as far as the intakes are concerned, Rich (misterfixit) has informed me that late North European 4WS GTIs were configured with NA and the Cyclone manifold. He is checking engine specs for me but believes that these were 160 hp cars. Now if it subsequently transpires that these cars made 160 hp like other late model GTIs as a result of a 10.4:1 higher compression ratio it means that the Cyclone Manifold gives really no power just a healthy dose of low down torque. That makes sense! The turbo cyclone cars don't make any more or less power than similarly configured USDM cars (i.e. same size turbo, injectors and FMIC etc) they just make a healthy 40 ft/lbs lower down the mid range which points back to what you said Brian about the peak torque and power figures being not misleading exactly but not giving the whole story.

Now if this is the case and the 'turbo' cyclone manifold works on both turbo and NA applications, it suggests to me that the AMG cyclone may well work similarly well on a turbo engine especially if that cyclone operates the same as the 'turbo' one with the secondaries opening at higher rpms. I wish we had dyno graphs for some of these cars. If what you say about the onset of boost making runner design a bit of a moot point, the real crux of the issue appears to be if prior to 3000 rpms the AMG makes as much torque as the VR4 engine (this is going to be heavily influenced by cams and compression though). Surely once boost sets in the AMG will still work down low for turbo applications? We still have that additional length in the runner to increase velocity but we have more volume!

What we need is some dyno graps from guys with cyclones on an NA car and from an AMG car.
 
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Muskrat

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Go at it guys. I've been reading along, not much to add though at this point.

I think I have decided to give the FP1x a go in my build though.
 

DR1665

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Cheers, mate.

Do us all a favor and share a review on low- to mid-range on those FP1X when you install em?
 
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