Gearbox Ratios.

[cheekychimp]

Okay, as some of you no doubt know, I'll be running a custom ratio gearbox that was put together by John Teeter. It uses GVR4 RS gear stacks with a GGSX final drive and matching rear pinion gear and a custom 'overdrive' 5th gear for either a stupid max speed or hopefully some reasonable highway gas mileage. Take a look at these ratio comparisons.

Gear/Ratio/Speed at 7500 rpm/Percent change/Speed at 2500

Hybrid GGSX/GVR4 RS

1st 2.571 53 18
2nd 1.6 85 38% 28
3rd 1.16 118 28% 39
4th 0.862 158 26% 53
5th 0.617 221 28% 74
Final 3.9525

Magnus dog box

1st 2.6 54 17
2nd 1.8 78 31% 25
3rd 1.17 119 35% 38
4th 0.81 172 31% 55
Final 3.8667

A comparison of speeds at 7500 rpm

GGSX/GVR4 RS

1st gear 53
2nd gear 85
3rd gear 118
4th gear 158

Stock US tranny

1st 36
2nd 65
3rd 98
4th 132

Stock GVR4 RS tranny

1st 39
2nd 62
3rd 86
4th 115

I'd like some input/suggestions/comments/flaming on how driveable you think this gearbox is going to be on the street ... before I tell you what I learn't today !!!

 

[Ted Andkilde]

Having been a position to fondle your turbo yesterday, nohomo /ubbthreads/images/graemlins/smile.gif, at the DSG -- I might be a little concerned that 1st gear might be a bit tall.

That turbo is _REALLY_ big Paul.

How about a 30 shot to get it spinning?

Cheers, Ted

 

[cheekychimp]

Thanks Ted ... any more takers ... vastly overgeared ... not enough ... completely unstreetable?

 

I agree first gear might be a bit tall. Are you planning some "dime store anti-lag"? Is your new motor a 2.3/2.4?

This excel sheet may save you some typing in the future and may also be fun to play with.
excel sheet

 

[teet]

I drive

speed at 7500 rpm
43
69
95
128
165

every day

RS 1-4...US 5th...on standard US final drive.

I really like the tall 1st gear for stop and go traffic. Starting is OK...and my motor is SICK (I hope its my motor). Can't make more than 12 psi before 4k rpm kinda sick...drinks 2 quarts every 1500 kinda sick...

so will it be streetable?

You said you were looking at the Magnus box...and thus the gear ratios are near the magnus. Are those ratios streetable...ask Magnus /ubbthreads/images/graemlins/wink.gif

I didn't "design" anything /ubbthreads/images/graemlins/wink.gif I had parts...I told you what they would do when put together...you decided you wanted to buy them. I hope this isn't going to turn into a "teeter led me astray" type of posting.

John

 

[Ted Andkilde]

Quote:
Thanks Ted ... any more takers ... vastly overgeared ... not enough ... completely unstreetable?



Well, just doing some envelope scratch calculations your 1st is roughy 35% taller than RS gearing, 45% taller than USDM.

You're running a built stroker motor, so using the patented scientific wildass guess or s.w.a.g., you'll have at least 20-25% more off boost torque than stock.

The bigger question is, will the carbon/carbon clutch be happy with a bit of slippage? Or is it a lightswitch?

IMHO, if it'll slip happily you'll be fine.


...t

 

Paul, I'm confused. According to vfaq, link, the GGSX has a 5.208 final not a 3.9525. Is the VFAQ wrong?

edit...
Nevermind, I got it.
The vfaq shows:
for ggsx a 1.680 primary and a 3.100 secondary. l.68 x 3.1 = 5.208
for evo/rs a 1.275 primary and a 4.260 secondary. 1.275 x 4.26 = 5.435

what you have is a 1.275 primary and a 3.100 secondary. 1.275 x 3.1 = 3.9525
and the ggsx rear matches that ratio because it is dependant on the secondary.

that was tough.

 

[teet]

Paul's tranny uses the 3.1 secondary gearing.

and the 1.275 primary

result

3.95 final gearing

notice what changes in the various drivelines to come up with the various final drives.

 

Thanks teet, you posted that while I was typing my edit.

 

FWIW, strictly playing the numbers game and knowing nothing about part compatibility a stock dsm tranny coupled with a 2g at secondary I think would be ideal.

speed at 7000rpm with a 23 inche diameter wheel:
1st 34.32
2nd 62.84
3rd 94.91
4th 127.04
5th 158.89

This is very similar to the evo/rs with swapped 1g ratio, but has a first gear to match a stock galant.

But this has nothing to do with what you asked.

 

[cheekychimp]

Quote:
I didn't "design" anything I had parts...I told you what they would do when put together...you decided you wanted to buy them. I hope this isn't going to turn into a "teeter led me astray" type of posting.



John,

Calm down. Quite the opposite !!! I think you are being pretty humble about the fact that you came up with a collection of OEM parts for $800 that rivals the ratios of a custom box that costs over 6 times as much. I started this thread because I have complete confidence in this box and your ratios and having spoken to someone running a very similar motor and setup to mine I have confirmed that I made a good decision. I had received comments in the past however that this was completely unsuitable for the street so I thought it would be interesting to lay it open to discussion.

From what I have seen on this forum so far there is a strong sense of unwillingness to try anything new because "so and so said this ..." or "I heard this ..." and I just wanted to set the record straight ... that is ALL !!!

For the record my motor will be a 2.3 litre stroker running a 9.0:1 compression on a fully built, balanced and lightened rotating assembly. Headwork, modified Forrester intake, phenolic resin intake and throttle body spacers and dual port actuator are all designed for torque AND to get the HX-35/40 hybrid Holset turbo spooling as quickly as possible.

I spoke to a guy over on the DSMLink forums running an FP3052 on a similar engine with an external wastegate. He has a Magnus Dogbox and I asked him about the ratios. This was what he said.


Quote:
Gear ratios are great. The new engine is a completely built 2.4L 6 bolt, running 455hp at 13.5PSI of boost (fp 3052). At this moment the car lets loose in first and second gear. Even though the ratios are so high. Im not talking launches either, im talking once boost hits all our tires are spinning

So at 455hp, I was running racing hart cp 035s on crappy kuhmo tires 17inch 215s and they let loose in first and second. So I switched to falken 451, 235 18inch gram light 57pros. Im hoping that even with the increase in hp(by going to 20ish psi), countering it with the much heavier rear brakes, slightly heavier rims all around, wider tires and much stickier compound i will get 2 gear back.

All in all I have zero troubles with the gear ratios, in terms of fourth gear. I hardly use it in the city,

Hope this helps some



I have no idea if the Holset is going to produce as much power as his FP3052, but I'm hoping it won't be an issue. This was an e-mail I got from David Hall on the Bullseye site

Quote:
Actually, I'm not certain the HX-35 would be enough turbo for what you are trying to do. The HX-40 would certainly do the trick. We have a customer that has already put down 549 at the wheels at only 20 psi. He seems to be hitting 20 pounds at around 4000 rpm. Bear in mind, he has just about every mod available. You can find some pictures of his car here

http://pictures.bullseyepower.com



The HX-35/40 hybrid is also supposed to spool faster than the standard HX-40.


So is this all BS or is this thing going to really shift?

Paul.

 

[Hertz]

Quote:
Stock US tranny

1st 36
2nd 65
3rd 98
4th 132




I don't think that is correct. Here's what I have for USDM Galant VR-4:

1st - 2.846 - 35.55mph
2nd - 1.684 - 60.09mph
3rd - 1.115 - 90.75mph
4th - 0.833 - 121.47mph
5th - 0.666 - 151.93mph

Unless maybe your numbers are for a "regular" Galant?

If you have Excel https://www.galantvr4.org/rhertz/maxspeed.xls you can test out your different gear combinations...

 

[teet]

Ok. I've been spending too much time over on the RX7 boards. they're...umm...JACK@#$es. OMG. you think people here are overkill on being negative to something new. I posted how i was putting the calipers from a Cayenne turbo on my RX7 (with 14 inch rotors) and I was called all kinds of stupid.

Anyways

for my calculations I used about a 22 inch diameter wheel. All depends on your tire diameter what your total speed could be...

also you are dividing by the transfer case in column D...which you shouldn't do...you should just divide by the primary, secondary and gear ratio.

john

 

[Larry Parker]

I want high final drives.... Where to look first?? EVO 1,2,3 guys over seas should know but I cant fnd any info out there!!!

LP

 

[cheekychimp]

Quote:
Ok. I've been spending too much time over on the RX7 boards. they're...umm...JACK@#$es. OMG. you think people here are overkill on being negative to something new. I posted how i was putting the calipers from a Cayenne turbo on my RX7 (with 14 inch rotors) and I was called all kinds of stupid.



Was that an apology? ... /ubbthreads/images/graemlins/grin.gif ... if so gracefully acepted ... /ubbthreads/images/graemlins/rofl.gif

Funny that you mentioned the Cayenne Turbo brakes ... the guy on the DSMLink forum was unable to give me updated dyno figures for the 20 psi he intends to run because his car was down to fit the EXACT SAME rear brakes. On a side note I followed one of these the other night and he floored it away from a junction on me. For such a big car those things really shift. What sort of power are they putting out?

Paul.

 

[steve]

The Cayenne V8 is rated at 340hp 310ftlb.
V6 is 247/229.

 

and the TURBO is rated at 450hp or so /ubbthreads/images/graemlins/smile.gif

 

So the first gear in a galant gsx can hit 53 mph? If thats the case how much are they from the dealer? Also, how strong are they?

 

I have a hybrid WQNK box modified to work with US xfer case and rear. I gotta say, it's steep, and I love it.

I'll measure tonight, but I think 1st goes over 50, 2nd-4th are pretty close, and 5th gear may go up to 200mph (no, not testing that).

 

Quote:
This excel sheet may save you some typing in the future and may also be fun to play with.
excel sheet



I'm not sure if any of you saw this or maybe there are too many numbers on it. Either way there is a lot of info on it. It is similar to Hertz's but has side by side comparissons of many different combos.