Which tranny should my friend be using for his built 2.0 turbo lsvtec? We are expecting this car to trap around 130-140mph once the boost is cranked up. Should he run a longer geared LS tranny to stay in 4th gear at the end of the track with a 24" tire or go with a shorter geared vtec tranny? Just wondering what all of you guys run on a similar setup. Thanx

Matt

 

bump

 

up

 

what is your powerband?
how high do you expect to rev the engine?
what kind of power are you making?
what size tire?

will make it a bit easier to answer your question with your insight on those

 

sure have been alot of tranny threads lately..hehe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Arturbo &raquo;</TD></TR><TR><TD CLASS="quote">sure have been alot of tranny threads lately..hehe </TD></TR></TABLE>

yeah i am just going to start responding to everyone with 5 letters

XTRAC

or even better

forget about it and buy a GM so you can run an Auto

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ihaterice &raquo;</TD></TR><TR><TD CLASS="quote">what is your powerband?
how high do you expect to rev the engine?
what kind of power are you making?
what size tire?

will make it a bit easier to answer your question with your insight on those </TD></TR></TABLE>
Right now torque peak is at 5200 rpms, maximum power is at 7500rpms, the car is making 365whp right now and the tire used will more than likely be a 24" slick. The car ran 11.5@125mph on sunday running out of gear in 4th using a ls tranny and 21" drag radials. The engine will not be limited to 365whp though and once the boost is cranked up we are looking for at least 500whp or more.


Modified by SOHC_MShue at 2:06 AM 11/16/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">
Right now torque peak is at 5200 rpms, maximum power is at 7500rpms, the car is making 365whp right now and the tire used will more than likely be a 24" slick. The car ran 11.5@125mph on sunday running out of gear in 4th using a ls tranny and 21" drag radials. The engine will not be limited to 365whp though and once the boost is cranked up we are looking for at least 500whp or more.


Modified by SOHC_MShue at 2:06 AM 11/16/2005</TD></TR></TABLE>

Once you step up to the 24" you should be fine w/ the ls tranny....21s are freakin small as hell for that kinda power level...

 

The 21's were some borrowed tires he used last minute.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">The 21's were some borrowed tires he used last minute. </TD></TR></TABLE>

I would try the 24s before thinkin of any kind of tranny swap...It will probably bee a good combo..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99lspwr &raquo;</TD></TR><TR><TD CLASS="quote">I would try the 24s before thinkin of any kind of tranny swap...It will probably bee a good combo.. </TD></TR></TABLE>
Yea me and JDM S1eeper have been talking about it. This is for his car btw. I was just asking to see what people hitting 10 second 1/4s usually run.

 

go with a b16 on 25" slicks

 

any idea what his top speed in 4th gear would be at 8500rpms with a b16 tranny?

 

21inch wheels = 109
22inch wheels = 114
23inch wheels = 119
24inch wheels = 125
25inch wheels = 130

that's for the b16 tranny's 4th gear of 1.107 with a 4.4 final drive

i've always thought it would be ideal to use a gsr/ls 1st and 2nd with b16 3/4/5 gearing and just shift into 5th. 5th is already short as hell on this tranny. plus the RPM drops are less so it would theoretically keep you at full boost

 

Do you think shifting into 5th would be worth it considering the time it takes to make the shift? That is my friend's argument that he doesn't want to have to shift into 5th.

 

it's up to you

integra LS 4th gear of 0.966 paired with a 4.4 final drive shifting at 8500 ends at ___ with:

wheel diameter:
21 - 125
22 - 131
23 - 137
24 - 143

as you can see, the LS 4th gear is extremely long (even with a higher 4.4 final drive!)

as far as hybrid transmissions go, for b-series hydro you have one option for 1st gear (they're all 3.23) and you either have the gsr/ls mainshaft that has a 1.9 second gear and the b16/itr has a 2.105 second gear.

as far as boost goes, 2.105 is too short. shorter gears will always be faster with the one exception that traction is available. shorter gears (ie higher final drive) yields more tq being put to the wheels. Tires can only handle so much tq before they start to lose traction. wheel spin can be overcome by getting more traction (wider slicks perhaps) or decreasing power.

you can either run 500whp on a LS tranny or run 440whp on a b16 tranny. these number aren't accurate by any means but what you're doing by running an LS tranny, opposed to gsr or b16/itr is decreasing the amount of tq being put to the wheels.

but back to what i was saying, if traction is an obstacle in 2nd gear, then don't use b16/itr mainshaft
however using b16 gearing (closest stock ratios) your rpm drops will be less, thus keeping you in the powerband longer.

if it were me, i would try something like
b16 gearing with a 4.266 LS final drive....

b16 4th gear, 4.266 ls final drive, 8500rpm shift
21 - 112
22 - 118
23 - 123
24 - 129

for this scenario, i would think that that would be your best option.
ls 1st and 2nd, b16 3rd, 4th, and whatever 5th you desire

 

Thanx for the response

 

thanks for the posts. I think i'm going to stick with the stock LS for now with a taller tire. like a 24.5 when we up the boost

Its also a steet car and I enjoy the gearing for the daily ride. gas milage is great also

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMs1eeper &raquo;</TD></TR><TR><TD CLASS="quote">thanks for the posts. I think i'm going to stick with the stock LS for now with a taller tire. like a 24.5 when we up the boost

Its also a steet car and I enjoy the gearing for the daily ride. gas milage is great also </TD></TR></TABLE>

stock LS gearing with a 24.5 inch wheel, 8500rpm 4th ends at 150mph. stock b16 5th is something like that....IMO, LS is TOO tall

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bense &raquo;</TD></TR><TR><TD CLASS="quote">

stock LS gearing with a 24.5 inch wheel, 8500rpm 4th ends at 150mph. stock b16 5th is something like that....IMO, LS is TOO tall </TD></TR></TABLE>

id get that much more MPH outta 4th by goin from 21" to 24.5? Hmm..

Hey matt, lets try trapping 150mph this next season