Anyone tried a gear change?

[christians87]

Thinking of putting a 3.73 in my car. Figured it would make the car more fun on the street and also help with spool a little. Has anyone ever tried a gear change in our cars? If so, what were your thoughts and comments? Thanks guys.

 

[toofastforyou]

Thinking of putting a 3.73 in my car. Figured it would make the car more fun on the street and also help with spool a little. Has anyone ever tried a gear change in our cars? If so, what were your thoughts and comments? Thanks guys.

I tried that before. I went from the stock 3.42's to some 3.90's, then 4.10's, and eventually went back to the stock 3.42's and the et's got better...:redface:
I've even heard of some guys wanting to put in some 3.23's but I've never heard of any results, good or bad, with these...

Claude. :wink:

 

[TurboBuRick]

Yep, best to stay with the stock 3.42 ratio.

 

[christians87]

I dont really run my car to often at the track and when i do its an 1/8 mile track so im not to worryed about ets. How did the car drive with the lower gears? Like on the interstate and around town? Also did it seem to spool quicker? Thanks

 

[toofastforyou]

I dont really run my car to often at the track and when i do its an 1/8 mile track so im not to worryed about ets. How did the car drive with the lower gears? Like on the interstate and around town? Also did it seem to spool quicker? Thanks

Frankly, I did not see as big of a difference as one would think...Yes the engine will rev a little higher, but it goes back a while, so I don't remember exactly by what margin. Save yourself some trouble and KEEP the STOCK gears...

Claude.

 

[TurboBuRick]

If looking to improve spool, I would think more about a converter upgrade rather than a gear change.

JMHO

 

[STGMAN]

Gear change

I tried a 373 and a 391 gear and all it did was make the car spin the tires harder. Save your money and get a higher stall. Call Dusty Bradford and he will hook you up!

bob aka stgman

 

[whitehot1]

The factory got it right when they put the 3:42 gears in the GN's nothing more needs to be done unless you have a non-posi rear.

I made the mistake of changing the gears to 4.10's and it was just a waste of money.

Spend your money in other places that need improving and that will give you better results in performance.

 

[Unsafe6]

Some guys used to go with different gears when running a 29" + tall slick, other than that, I would leave them alone.

 

[SPOOLFOOL2]

I went to a 3.73 gear when I put the 28" tall (275/60/15) MT DRs on many years ago. The final gear ratio works out to about 10% lower than stock. I like it for streetability. I'm able to spool my dbl BB 62/65 turbo with a tight (2900 RPMs @ 0 lbs boost) converter. The thing spools faster than a stocker. Very fun around town. Car gets over 20 mpg on the freeway. Runs a 10.87 @122 going threw the traps at 6100 rpms. I'm guessing that I could pick up a tenth by going back to the 3.42 gear, but it's not worth it to me to give up the advantage of being able to walk a fast car from a light, without having to build boost at the line.

IMHO, A 3.73 gear and at least a 28" tall tire, is a match made in heaven for a street car. And yes, you can run a little tighter converter. The taller tire will help you hook better on the crappy street too.

I would NOT do it if your trying to better your ET in the quarter mile, or run smaller than a 28" tire.

This combo used to be more popular fifteen years ago.

Happy spooling.

Mike Barnard

 

[mikestertwo]

IMHO, A 3.73 gear and at least a 28" tall tire, is a match made in heaven for a street car. And yes, you can run a little tighter converter. The taller tire will help you hook better on the crappy street too.

I would NOT do it if your trying to better your ET in the quarter mile, or run smaller than a 28" tire.

I agree with the above statement. If your going to run a tall tire the 3.73's work great. I ran 11.90's with slicks on a stock long block back in the day with them. If your running a smaller tire stay with the 3.42's

 

[tom j]

What about the high HP(800rwhp) cars, has anybody gone to like a 2.73 gear. I wonder if the et would fall off that much.

 

[Dusty Bradford]

The lower gear will help the car launch. It allows you to launch at a lower boost and 60' a little better. The downside is the low rpm Buick can run out of it's rpm range easily in the 1/4 with the gear change which can slow the car down.

You have to gear the car to match it's trap rpm needs. If the car has enough power to run out of gear at the track, the lower gear really isn't helping.

 

[toofastforyou]

3.23's for use with a TH 400...

The lower gear will help the car launch. It allows you to launch at a lower boost and 60' a little better. The downside is the low rpm Buick can run out of it's rpm range easily in the 1/4 with the gear change which can slow the car down.

You have to gear the car to match it's trap rpm needs. If the car has enough power to run out of gear at the track, the lower gear really isn't helping.

Given the great amount fo torque these turbo V6 engines makes, I always wondered if someone has tried using some 3.23's...
I'm asking this because I do drive the car on the street and I still have the 200-4R transmission on my car. Even if it's been "built" by Eric Schertz (Dynotech) with the best parts, everyone including Jack Cotton tells me that sooner or later, the 200-4R will reach it's limits and I might have to go to a TH400 one day.
-My first question is : Would using 3.23 gears compensate for not having an overdrive...
-My second question is : Will that (going to 3.23 gears) hurt my 1/4 mile et?

Thank you,

Claude. :wink:

 

[JDSfastGN]

I run 3.23s in my car. I went this route so that I could trap in the low 120s unlocked on my 17" wheel/tire combo without having to shift into OD. Now that I have an efficient NL 9.5" PTC it wouldn't be as big a worry but i'm still happy with the gear change. It keeps my rpms at the track with 28s down near 5100 through the traps at 122+. Again I mostly did it so I could run at the track on 17s that are only 25.7" tall and not have to shift to OD. 3.23s do load the car slightly more and would actually aid slightly in spoolup in theory.

 

[SNOWBIRD]

Claude ,I tend to agree with jack ,that 200 will really be taxed behind your new engine.I KNOW you will keep the boost low to run mid nines.

 

[jasjamz]

Using the TCI racing calculator, the 28" tall tire makes the car act as if it has a 3.18 gear in the rear. Going to a 3.73 with the 28" tire is like having a 3.46 gear. If you were going to do that, couldn't you just go back to the 26" tire and see how the car performs? Just brain storming at work...

 

[JDSfastGN]

Using the TCI racing calculator, the 28" tall tire makes the car act as if it has a 3.18 gear in the rear. Going to a 3.73 with the 28" tire is like having a 3.46 gear. If you were going to do that, couldn't you just go back to the 26" tire and see how the car performs? Just brain storming at work...

If I thought my gear was too tall with the 28s and 3.23s i was just going to run a 27" tall slick instead, but so far I like it.

 

[Mr.Spool]

pretty interesting thread.i run the 4.10's in the rear on a 30 inch tire now with a built motor,however on the stock motor i ran a 28 inch drag radial with the 4.10 rear. the car was quicker and faster through 1100 ft,required nearly no load to 60ft the car (1.58 60ft on a 1psi footbrake launch on bfg drag radials).i have never gone back to the stock gear and yes i did need od to complete the pass but found it a much useable gear (car didn't fall on its face like with the 342 gear and would backhalf 25mph).the turbo spooled faster (ta49) as the car got up into the rpm range much faster with much better driveability and responsiveness.the combo is very important as that can be said for all cars,if the rpms climb way ahead of the turbo the combo will not work,with that being said i like the tighter housings vs the larger ones.inmo on the street there is no comparison

 

[mygn276]

I am running 3.23. Let the turbo do its job.