Bert

Ok... many people recommend an LS tranny for a turbo app for the longer gearing, but I don;t understand why this would be better than, say, a gsr tranny with shorter gearing. It seems to me that shorter gears would get you into the higher rpm range sooner, so the turbo would spool up sooner, so you'd make peak power sooner. The revs should also drop less after a shift, keeping you closer to the sweet spot of the rev range. Also, wouldn't being able to launch at a lower speed (but constant rpm as compared to the LS tranny) make for less wheel spin and most likely a more controlled and better (at least on street tires) launch?

Thanks for any input!

dbman96

If you shift quickly, lower gears ARE better. The problem is when you drive a turbo teg with a GSR (or in my case a Type-R) tranny, you run through the gears REALLY fast... boost hits and OOPS there's redline. The LS tranny just buys you a little more time before you have to hit the next gear. Plus for driving around on the freeways and stuff it gets you down to a nice low RPM when you're cruising and the turbo means you still have tons of power on tap when you need to move out.

Bert

Hmmm.... that makes sense (having a little longer to shift) but it seems like it could be overcome with a little practice. Do you find the TR tranny to be a problem in your set-up? The argument I've heard most often is that lower gearing makes for a worse launch somehow, but after some thought that didn't really make sense. The main reason I ask is I'm trying to determine how much switching to the dark side would cost me... if I can keep my GSR tranny with JDM FD, Quaife, ACT clutch and Spoon flywheel that would cut down cost greatly.

VTC_CiViC

A tighter tranny (GS-R, ITR) makes launching more difficult because of how fast the rpms build. So fast in fact that it makes it VERY difficult to maintain traction, whereas a taller geared tranny will climb the revs just a bit slower, making it that much easier for your tires to fight for grip. A GS-R tranny is already kinda long for a Teg anyways compraed to an ITR/Si tranny, so I'd stick to the GS-R tranny with an LSD and you'll be set.

dbman96

I don't really drag race so I'm not a good one to ask - I know I get better launches and corner exits with the built-in LSD though! Only downside for me is cruising at 4500 on the freeway.

TurboSedan

Lower gearing also hurts acceleration.

rtype11

less shifting quicker ET, longer gears you stay in boost longer, you guys with short gears and short power band have slower ET then lets say an LS (tranny) with constant torque from 3500 - 7000rpm, more useable power.

Bert

If lower (numerically higher final drive) gearing hurt acceleration, then launching in 2nd should be faster than launching in 1st, which obviously isn't true. Extreme example, I know, but just to illustrate.

rtype11, unless the ls tranny can finish the quarter in third (can it? what's 3rd at say 8k?) It should be the same number of shifts. Wouldn;t shorter, closer gears gear allow you to stay where ever you want in the rev range (as long as you were able to shift quickly enough?)

dbman96

From what I know though, regardless of what tranny you have you're going to hit 5th gear in a quarter mile if your car is reasonably fast - so if you've got 4 shifts in there it doesn't much matter when they are.

rtype11

a type r with LS tranny will finish in 4th, my LS with much higher than stock Red line also finishes at over 120MPH in 4th.

rtype11

I dont think I have to reply anymore to this thread, my first post says everything I have to say.

LsTurbo91

can you swap the gears in the 94-00 LS tranny in a 91 cable? I freaking end my 4th at 100mph - 6800rpm. Im pretty much assed because I can't switch to a hydro

Turbo_Teg

my friend has a turboed b16 with a ls tranny and his 3rd gear goes up to 110-120, somewhere around there. i really dont know if he uses the 4th gear in a 1320.

june

What tranny code is th ls tranny in cable??? I bought a A1 tranny and it has about the same gearing as my Y1 tranny with lsd...The guy saidit was a ls tranny...I need one for my turbo setup..
Thanks june.....

TurboSedan

Ok, you've got to be the biggest ******* idiot. Noone starts in 2nd gear *******, duh. Before you post some stinky ****, do some research first. Lower final drive yields higher top speed ability, but hurts acceleration. Higher final drive helps acceleration, but hurts top speed. Sorry to flame, but having a bad day at work.

DIRep972

iTrader: (1)

Ever ridden in a muscle car, supra, or any of the bad *** japan TT's.. All those cars Long gearing, U can be going 110 in third in my friends RX7.. U know why? cause they have enough torque power to push the longer gears with out it making a difference in accelleration.. Thats why with turbo cars they make so much torque you really wont benifit from shorter gearing and it might even hurt u since its harder to drive..

heres an example: im running 4.5psi in my turbo LS, my friend is running 6.5psi on his turbo GSR.. We raced from a 10 punch and I was in the lead all the way till the top of third.. U know why, cause I had more time to go with out shifting and more usable power... But third gear where he actually had time to stay in boost for a sec his extra horsepower was able to pull on me..

Bert

The problem is that you do not understand the terminology and apparently have poor reading comprehension. As I clearly stated "If lower (numerically higher final drive) gearing hurt acceleration,.." So, to make it even clearer, what is generally referred to as lower gearing is achieved by using a numerically higher final drive. So, as I originally stated, what you call higher gearing but most people call lower gearing should help acceleration.

Hence my question, why does higher gearing (numerically lower final drive) improve quarter mile times on a FI app. The answer seems to be that there is already an over-abundance of torque, which negates the presumed benefit of increased torque multiplication of a numerically higher final drive. With the increased torque being effectively unusable, the effects of increased, quicker shifting outweigh any benefit derieved from the increased effective torque.


[Modified by Bert, 11:47 AM 11/20/2001]

Turbohatch

The only problem with ls trannys is they aren't strong at all

TurboSedan

Oh and now I see the light. Seems like since you are so smart you could have researched this and come to the conclusion as it seems you already have.

InfamousRS

What about the kaaz settup? They have a long ratio kit for the Teg trannys I believe? Does anyone know if they will benifit anything? How much do all those gears cost?

Finest

Longer gears = more time under boost.

Doesn't help when you can only build 5psi in 2nd gear before you hit redline. With a longer gear, you'll be able to build upwards of 8-12psi before shifting. It's that extra second or two that helps put more load onto the turbo, thereby building more boost.

It's not rpms that builds boost, it's engine load.

Bert

Interesting... do you know engine load is so important? My simplistic thinking was that turbine speed would be a function of how much air was being forced across it, with the amount of exhaust being expelled obviously being a function of engine rpm.

Edit: I think maybe what I was missing was that a lower but constant flow spools the turbo more effectively than shorter bursts of higher flow. I had always heard people refer to their turbos as spooling at x rpm, but it seems that if engine load is a major factor it should spool at a lower rpm in higher gears. Is this the case?


[Modified by Bert, 6:14 PM 11/20/2001]

ajbones

97civicferio wrote;

A bad day at work does not justify your abusive and insulting manner.


[Modified by ajbones, 8:58 PM 11/20/2001]

bigTom

it doesnt matter what tranny u are using... the turbo will spool at the same rpm... and i dont know where this whole beliefe of ls tranny's being better ofr turbo came into play... yes u can stay in boost for longer but who really cares... u want to finish the qt. mile as quick as possible... and a shorter gearing obviously will do this... look at the differant between ls and itr trannies in an all-motor application... the itr tranny will be faster... the same goes for turbo... and for whoever says u have to shift to fast of u have no time... thats the point! any quick car u have to shift pretty damn quick... so u think .10 or .20 of a second is gonna make that much of a differance... except makeing u slower?

Rain_man

97CivicFerio, you are an ***. You made the mistake and not even an apology for your poorly excused behavior.

But I guess I'd have bad days at work if I was a bitch too.