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Theoretical utlimate street motor - 2k full boost goal.

tsitalon1

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Dec 29, 2010
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309
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Montgomery Al
So this might not be in the right section.... /ubbthreads/images/graemlins/laugh.gif

So for the longest time i've wondered if it was possible to build what I call an ultimate 4g63 street motor. So assuming money is not a factor (which it is for me right now) I wonder if the below goals can become a reality. Keep in mind I'm talking about custom work.

93 octane pump gas
No meth, water, NOS, or any other adder
2.0L (not stroker)
400 BHP (not whp)
2k full boost
Flat torque curve (almost flat /ubbthreads/images/graemlins/smile.gif)
Semi quiet exhaust


Here's what I imagine could do this: /ubbthreads/images/graemlins/smile.gif

10:1 compression
Custom pistons to help with detonation
Custom Ball bearing or variable vane turbo (evo3-16g size?)
Kiggly mivec or cyclone manifold
15-20psi boost

Ok I'm ready....Flame me away guys /ubbthreads/images/graemlins/ooo.gif
 
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SouthCaliVR4

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North county San Diego
comp ratio too high for boost levels. full boost by two k is gonna be too small a turbo for upper end hp goals.
 

tsitalon1

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Dec 29, 2010
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Montgomery Al
Maybe!

I'm no engineer, but I believe they have coatings to help with detonation.

I think a variable vane turbo could spool by 2k and hold 7.5k, do you have any experience with VV turbos? I don't.

We might even be able to switch to direct injection...see below:

web page

I'm trying to think out of the box /ubbthreads/images/graemlins/smile.gif
 
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SouthCaliVR4

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No can't say I do but, I do have experience with high compression turbo motors. 9 to 1 & 15 lbs of boost & I was right on the ragged edge of timing issues. when I moved to Cali w/91 from washington's 92 I had to redo my whole setup. which of course led me to rebuild the whole car but I digress.

thing is, you'll be right on the edge & it's easy to pop a motor with knock.
 

belize1334

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Nov 18, 2003
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Bozeman, MT
You might look into the EvoX turbo. It's sized like a biggish 16g but its twin scroll, which aids with spoolup, and it's pointed in the right direction. But you'll definitely need a custom manifold to make it work. Even then 2k rpm is a really low goal for full boost. I think you'll want to reconsider the 2.0L setup. Going 2.4 will help you alot with getting early spoolup. It'll also mean lower boost for the same power, which will also help with the detonation issues. Or you could twin charge it... I've thought long and hard about having the superchager feed the turbo. That way the total airflow is completely dependent on the supercharger choice, but the efficiency follows the design of the turbo once it spools.
 

tsitalon1

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Dec 29, 2010
Messages
309
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Montgomery Al
Quoting SouthCaliVR4:
No can't say I do but, I do have experience with high compression turbo motors. 9 to 1 & 15 lbs of boost & I was right on the ragged edge of timing issues. when I moved to Cali w/91 from washington's 92 I had to redo my whole setup. which of course led me to rebuild the whole car but I digress.

thing is, you'll be right on the edge & it's easy to pop a motor with knock.



I didn't mean to suggest you weren't experienced or knowledgeable. I don't know your experience, I was only asking because people sometimes regurgitate something they've read or heard but do not have experience in. I apologize if it sounded that way.

Did you have any coatings on those 9:1 pistons?

Are there no high dollar coatings that could allow 10:1 and our normal timing maps to work on 93 octane?

Does anyone know how to do the math to find out how much boost we would need at 10:1 compression to obtain 400bhp on 93 octane?

Belize: Funny you mention the Evo X turbo as i sold mine a little more than a year ago, shortly before I sold my Evo X. Lol.

This is all speculation on my part, again throwing out the cost factor. So how well do variable vane turbos perform? Or how much faster would a EvoX or Evo316g size turbo spool if it was retrofitted with ball bearings and on a 10:1 motor?

Lets just think out the box and see where it leads us /ubbthreads/images/graemlins/smile.gif
 

cheekychimp

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Apr 19, 2004
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East Sussex, U.K.
southcali really summed up your main obstacles in one sentence, but rather than just flaming you, let's talk about outside the box like you said.

First why boost by 2000 rpms? Believe me, I am the biggest advocate of low down power here but you will literally never be off boost. That's not ideal in a street car in my opinion. Make that lower limit 3k and it is far easier to achieve, better to drive, better mileage yada yada yada.

That said, my idea would be a sleeved 4G64 block with a 4G63 head using stock or stock sized pistons on 162 mm rods. Long rod 2.0 litre which will be great for that long flat torque curve and you will be able to rev it out. You will want to rev it out because you will need a short ratio 3.909 box or lower (mine is 4.3) which will help with low end, spool up and horsepower. You want a modified cyclone intake, possibly custom cams and a borg warner EFR 7064 turbo on a twin scroll exhaust manifold.

I think the 2k full boost thing is unrealistic without the vv turbo but I honestly believe that the above setup on my car (I only lack the 4G64 block, turbo and cams) would give you everything you asked for with full spool by 3 grand.

Paul
 
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SouthCaliVR4

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no worries, I took no offence, just stating fact, I have zero exp with variable vane turbos. For you're spool goals that could be a possibility.

As for compression ratio, I liked having the higher ratio, better drivability off boost better mpgs. I have seen 10 to 1 motors with a turbo & even superchargers but they where only pushing 3-5 pounds of boost. Would the coatings help, quite possibly but you're talking some serious cylinder pressures at 20psi on a 10 to 1. I'm not sure that even cold you could avoid knock without pulling so much timing that it hurts your output more than a lower ratio or lower boost level.

I'm gonna make a couple calls on this & see If I can dig up some more info.
 

5OF2k

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Mar 28, 2012
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colorado springs, colorado
High comp and turbo/forced induction motors arent impossible, quite the opposite really. The trick is having a tuner and fuel capable of supporting the engine's needs. The higher the compression and boost, the greater the need for a fuel thats able to deter detonation and provide enough octane to support said chlinder pressures.

There are mlre than a couple high comp DSMs here in CO, as in 10.5:1+, all running well over 20psi, all on e85.

It can definitely be done and it makes some serious power, when done right FWIW.

-Jake
 

EMX5636

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Jun 28, 2008
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Bucks County, PA
I second the compression agreement. I'm 9:1 and run 28-31psi without meth depending on temperature. I personally know a couple people running 30ish psi on a 10:1 engine. Not a big deal, and response/off boost driving is much nicer. Just gotta find a good tuner and make sure he understands your setup.

I use KP Tuning and he's done a lot of high CR high boost engines (both on and off meth/E85).
 

calcaliente

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Aug 8, 2012
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Oakland
So could you run 40 PSI on a 8:5:1 motor? on 93 pump?
 

EMX5636

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Quoting TheGat:
So could you run 40 PSI on a 8:5:1 motor? on 93 pump?



I think there is a set of pistons laying around my old work that would probably let you run 40psi on pump gas. You'll never want to drive it out of boost though. 6.7:1 custom Venolia's from back in the late 90's. lol
 

calcaliente

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Aug 8, 2012
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Oakland
Quoting EMX5636:
Quoting TheGat:
So could you run 40 PSI on a 8:5:1 motor? on 93 pump?



I think there is a set of pistons laying around my old work that would probably let you run 40psi on pump gas. You'll never want to drive it out of boost though. 6.7:1 custom Venolia's from back in the late 90's. lol





Hahahah crazy! But my buddy built his evo with 9:1 and his swallows 30lbs and spikes to 35psi sometimes. So i figured i could shove 40lbs in mine since its 8:5
 

Racah15

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Colorado springs CO
Boost doesn't depend on compression ratio. Technically, yes it does to a point, but not like you guys think. Also, I don't know why you guys are trying to achieve boost numbers? Boost is unrelative to horsepower. Technically, yes it is, to an extent, but not so much. When you change to a more aggressive cam, you will gain flow, and lose boost. Better head performance (porting etc) can also lead to more flow less boost. So why would you want to boost 40psi? Boost is just a measurement of how much excess air pressure is in your intake manifold. You can run 25psi on a crappy cam, stock head setup on a 16g, but you probably will be beaten by a guy running 20psi on an an efficient head and cam combo with the same turbo because he may be pushing 10lbs/min more than you. Plus, we're not even talking turbos here. 40psi on a 16g?(not physically possible), 40psi on a gt4202r? Gt47? I'm sorry but it's a pet peeve of mine when people want boost numbers, not flow numbers. You want a certain hp? You go by lbs/min, not psi. Just like when people tell me they have a 57 trim turbo. Oh yeah? My stock 2g t25 is a 60 trim, that does not mean it's bigger or flows more.

If you really want the ultimate street motor, try out a 2.6L 4g64. That will get you the spool numbers you want on a 16g. You won't be boosting 40psi, and you won't be revving out to 10k, but if you want spool, try it out. I haven't done, nor do I know anyone that has, but if .3l changes spool time pretty good, another .3 should be double the fun /ubbthreads/images/graemlins/smile.gif
 
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CutlassJim

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Manchester, NH
Quoting Racah15:
Boost doesn't depend on compression ratio. Technically, yes it does to a point, but not like you guys think. Also, I don't know why you guys are trying to achieve boost numbers? Boost is unrelative to horsepower. Technically, yes it is, to an extent, but not so much. When you change to a more aggressive cam, you will gain flow, and lose boost. Better head performance (porting etc) can also lead to more flow less boost. So why would you want to boost 40psi? Boost is just a measurement of how much excess air pressure is in your intake manifold. You can run 25psi on a crappy cam, stock head setup on a 16g, but you probably will be beaten by a guy running 20psi on an an efficient head and cam combo with the same turbo because he may be pushing 10lbs/min more than you. Plus, we're not even talking turbos here. 40psi on a 16g?(not physically possible), 40psi on a gt4202r? Gt47? I'm sorry but it's a pet peeve of mine when people want boost numbers, not flow numbers. You want a certain hp? You go by lbs/min, not psi. Just like when people tell me they have a 57 trim turbo. Oh yeah? My stock 2g t25 is a 60 trim, that does not mean it's bigger or flows more.

If you really want the ultimate street motor, try out a 2.6L 4g64. That will get you the spool numbers you want on a 16g. You won't be boosting 40psi, and you won't be revving out to 10k, but if you want spool, try it out. I haven't done, nor do I know anyone that has, but if .3l changes spool time pretty good, another .3 should be double the fun



Smartest thing said in this whole thread. I also find that %90 of the people who build their engines for more powa have no concept of airflow vs boost.
 
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tsitalon1

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Dec 29, 2010
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Montgomery Al
Please lets stop talking about 40psi. This is not even the direction i was trying to discuss.

Lets try to get back on track /ubbthreads/images/graemlins/smile.gif

If 2k full boost is absolutely not possible, I could live with 2.5k.

I'm adverse to the Stroker motor because in my past, i purchased a Magnus 2.3, and while it was a beast, it literally vibrated the car to pieces with it's second hand harmonic vibrations.

I've never felt a 2.6, so as long as i can rev it to 7k and it's as smooth as a stock 2.0, that would be fine.

So lets dream a bit....

Where would we expect a 2.6 with 9:1 compression, 93 octane and and EvoX turbo and manifold to reach full boost? 2.5k, or would we have to increase compression to 10:1?

I would assume it could easily reach 400bhp and hold a relatively flat torque curve.

Thoughts?
 

tsitalon1

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Dec 29, 2010
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Montgomery Al
Yes, but would prefer it to be flat from 2.5k all the way to 7k.

I don't care how much boost it would require. If i can get that spool on 10:1 and 400bhp at 10-15psi, that would be fine..
 
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