3.23s vs 3.42s

JDSfastGN

JDSfastGN

Well-Known Member
Joined
Jun 16, 2001
Well im pretty sure im going to need a new ring and pinion and im not sure if i should keep with the 3.42s or go with a 3.23. ive read the debates on here but am not sure yet. I run 25.7" tall tires on the street and it would be nice to be able to run them at the track without buzzing to 5900 through the traps, but then again i like using my big 28" tall slicks at the track for the sidewall wrinkle etc... Is there anybody running a 3.23 in a GN? I really like the 3.23. According to the racing calculators on TCIs site, i would be at 5500 going through the traps on my 17" wheels, where as now im at 5950. I guess shifting into OD is a viable option with the 3.42s, but it seems that when i have the car tuned optimally for the track that OD is a little lean and starts to knock a bit. I can always lock the TC but i don't want to punish the TC everytime i go to the track (im not always there for a new best). i'm also worried about my 60 fts being slower with less gear, but i can't imagine that small amount of change would really have much of an effect on the car with as much torque as it makes. I know TTAs came with a 3.27 and some would say apples to oranges when comparing the two, but honestly other than the aero differences its pretty much the same package, the TTAs are no lighter than a GN from what ive seen. Thanks guys
 
I'm in the same boat. I am running a 3.70 gear with 28" slicks now and want to go to a 3.40 or 3.25 with 26" slicks. I'm looking for someone with experience running the lower ratio.

Thanks, Chuck
69 Camaro, 3.8T
10.83 @ 125
 
I would stick with the 3.42's. In the TTA at 70 the RPM's are at 2100. In the TR at 70 they are at 2200. Both according to a scanmaster. The T takes off a lot harder outta the hole then the 3.27's do and there is hardly no noticeability in the rpms at highway speed. So, unless you need the less rpms, like you mentioned, at the end of a run stick to the stock ones.

Jason
 
thanks guys, yeah ive read about quite a few cars going faster with 3.23s even when still running a 28" tall slick. Im pretty sure im gona go with a 3.23 now, as it makes sense to me, but i guess only the timeslip will tell :D Chuck how much does that camaro weigh? I've heard a lot of good stuff about higher gears(3.08/3.23s) in lighter hybrids.
 
The good thing about a turbo car with a fat and very flat horsepower curve is that you can use a taller gear to stay in the sweet zone of the curve longer. Shifting into OD doesnt ever seem like a good idea to me. You're no longer multiplying torque...you're dividing it, when you go over a 1:1 ratio. I would shoot for whatever gear gets you to about 500rpm above peak hp through the traps....while in a 1:1 gear, like 3rd.
Hearing about those rpms at 70mph makes me wonder whats up with my car. Im not getting lockup for a few different reasons, but Im at about 2200 at 65 while cruising on a flat highway. Seems like the converter isnt slipping all that much. Where should I be with lockup?
 
they don't slip a huge amount while cruising, you would probably see a 200-250 rpm drop around 65
 
If your not running the tallest tire possible then i would definitely consider the 3.23's. I run a 26" tire on my car (255/45-16 drag radial) and i run out of gear on the street really fast running a non lock up and 3.42's. The car likes the 29" slicks a lot. The rpm reduction is 10-15% and its stays in the meat of the power curve longer. Higher boost launches are required but there is a gain in performance in almost every application i have played with in the last 10 years by going with a tall slick. Therefore if you rarely run slicks and usually only 26" radials, i would go with 3.23's. Theres not much to be gained on the launch on the street because of the lack of traction. Running the 3.23's will help at 115+mph on the street with 3.23's. Shifting to OD is a huge drop of over 30% and not reccomended for racing. Running a multidisc lockup will further lower your rpm 7-10% and keep you from running out of gear in 3rd. OD should always be avoided when racing imo. Look at everyhing as a % when collecting your data about gear ratios. This will avoid confusion when comparing applications. 3.23:3.42 is 5.5%.
 
Going to 3.25

I've decided to go with the 3.25 in my 9-inch. It sounds like the right way to go.

Chuck
 
I would definitly like to know how that turns out for ya Chuck, i got home yesterday and finally got to take apart the rearend completely and of course the gears are perfect... spotless. I had figured that the pinion gear had slammed back into the carrier but it appears it was just a weak carrier and it grenaded itself. I may try and see if i can have the gears magnafluxed but ive very closely inspected them. So even though i think 3.23s would help i can't justify spening an extra 200$ when i can put that towards my wideband setup/or a bigger turbo :D .
 
Shifting into OD doesnt ever seem like a good idea to me. You're no longer multiplying torque...you're dividing it
Click to expand...
Hmm, seems to me that you are also "dividing" torque when you switch to a taller rear gear. The 3.42 multiplies torque by a factor of 3.42 to 1, while the 3.23 multiplies by a smaller factor. Very similar to dividing, in my book. But I agree that shifting into OD is not a good thing, not under power, and not unless you really have to. The "best" geat depends on how much power you're making, and what you want to do with the car. If you run almost always in the 1/8 mile, then the best gear may be different from what you would want for the 1/4, and neither of them may match up with the best gear for the street. Just do whatever floats your boat. Try it for a while, and if you don't like it, somebody else probably will.
 
Ormand said:
Hmm, seems to me that you are also "dividing" torque when you switch to a taller rear gear. The 3.42 multiplies torque by a factor of 3.42 to 1, while the 3.23 multiplies by a smaller factor. Very similar to dividing, in my book. But I agree that shifting into OD is not a good thing, not under power, and not unless you really have to. The "best" geat depends on how much power you're making, and what you want to do with the car. If you run almost always in the 1/8 mile, then the best gear may be different from what you would want for the 1/4, and neither of them may match up with the best gear for the street. Just do whatever floats your boat. Try it for a while, and if you don't like it, somebody else probably will.
Click to expand...

I really wouldn't call it dividing as much as i would just call it "less" multiplication. You are still multiplying torque in any gear that is greater than 1-1 i would think, no matter 3.42 or 3.23 when you hit OD and go to .67 ratio, you are putting a lot of load on the motor (EGTs raise) and a lot of load on the clutch pack even if you have a 3 clutch upgrade. But i agree completely about what may be the best gear for one situation may not be for another,
 
Gears

I run a set of 3.30 in my 64 3.8 turbo skylark. The best 60 ft on BFG's was 1.49 with a turbo 350 trans. It all depends on how much boost and the weight of your car. I was going to go with a 3.08 just to see how much I would gain. I also went with a larger cam and lost some bottom end and only gained 200 rpm. So if i would of stuck with the larger cam I would of had to up my gear back to a 342. To me it just is not worth it to loose your streetability. One thing that you have to remember is your 200 trans has a better first gear than a turbo 350, so JMPO go with the 3.23 gears. It is alot easyer to just change your tire height later in the long run.
 
turbo96max said:
bumping an old thread. did the op try the 3.23?

im trapping well into 4th running 275-4-17 tires and wonder if a gear change will be a good option as it was mentioned in a thread i created looking for info on others experience

http://www.turbobuick.com/forums/th...n-4th-looking-for-advice.420332/#post-3485425
Click to expand...
I would switch gears for sure in your application. Id also switch the trans planet to get a taller 1st and closer ratio. Your gains in the beginning of the run will be even greater than out the back


BPE2013@hotmail.com
 
Jason Kramer went back to the 3.42 gear.the car will require more launch boost to 60ft the same.you will be taking torque away and will have to make it up by boost to leave the line in most it's a real lame gear and is noticeably slower on the street.with a short tire it can be made to work.
 
Another thing that seems to be missed alot is the huge advantage of rollout of the taller tire.provided there is enough power to turn the tire.
 
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