turbo's and rear gears

[Turbo V6 Camaro]

hello

First about the car. its a 1997, 3800 II 3.8L Turbo Camaro. with a best Dyno of 456 RWHP and 509 RWTQ. so far i only have 9 track runs in the 1/8 mile. best of 8.05 @ 87MPH with 10.5 psi (can hold 16-18 on pump gas)

Drivetrain is: PI Vigalent 3800 Stall, Rossler stage II 4L60E tranny and 10 bolt rear with 3.23's/LSD.

The clutches in the rear are about gone. so i have to rebiuld.
i was going to upgrade to a EATON carrier and possibly up the gears.

However i have gotten some mixed info.

being a V6 i dont have tons of low end TQ to get off the line so i was going to go with 3.73 gears. then i was told that was to much gear for a turbo and to stay with 3.42 and no more. i have heard different things from different poeple, And i'm really confused.
can someone please explane to me why i can/can't go with the 3.73's? or why the 3.42's are better?
i know my max 1/4 mile with the 3.73 will be about 10.7 or so.... but my goal is only 10.99 (with 26" tires)

i know the GN's came with 3.42's does anyone ever upgrade those ?

 

[Turbo V6 Camaro]

TTT

come on guy's while the motor are different alot of the same stuff still applies i just want to learn a few things

 

[UNGN]

Our motors make peak HP at 4400-4800 RPM and will nose over at 5K. With 3.42 gears and 26" tires, 5K RPM is about 112-114 mph.

If we want to run consistantly faster than 112-114 mph in the 1/4 with the stock motor, we go to taller tires (or a cam and ported heads).

What was the RPM of your Peak HP and how fast do you want to run in the 1/4 mile?

This is what you base your rear gear selection on and nothing else.

 

[Turbo V6 Camaro]

Our motors make peak HP at 4400-4800 RPM and will nose over at 5K. With 3.42 gears and 26" tires, 5K RPM is about 112-114 mph.

If we want to run consistantly faster than 112-114 mph in the 1/4 with the stock motor, we go to taller tires (or a cam and ported heads).

What was the RPM of your Peak HP and how fast do you want to run in the 1/4 mile?

This is what you base your rear gear selection on and nothing else.

http://www.turbov6camaro.com/dyno/run.pdf << only thing is those was with the M5

let get some auto dyno graphs these are all at 10 psi, for some reason i had troulbes with the tach (note messed up TQ)

my goal for the car is a 10.99

BTW more info on my mods www.turbov6camaro.com/mod.htm

thanks for the info thus far

stock they peak at 5200 mine seems to peak as soon as the turbo spools

 

[SHADOWII]

Congradulations!

Just want to say, "nice ride"!

IMHO, I agree w/UNGN and your goal of 10.99 is well w/in reach.

 

[UNGN]

stock they peak at 5200 mine seems to peak as soon as the turbo spools

Your high HP/Torque run is messed up. The torque and HP are still climbing when the test cuts off (well before 5K RPM)

From the looks of things, your HP peak will be about 5500 max.

You don't want to pick rear gears based on ET, but on MPH. 4.11 gears might give you a better ET (with big slicks and a perfect launch), but you'll only run 108 or so in the 1/4.

If you want to run solid 10's, assume 125 mph trap speeds.

125 mph with 26" tires and 3.42 gears is about 5600-5900 RPM depending on how loose your converter is (locked up you'd be on the lower end).

3.73 gears would be 6100-6500 RPM at the same 125 mph (great for an LS1, 1000 RPM over your HP peak...not good.)

From the looks of things, I'd keep the gears you have and forget about 3.73's

 

[Turbo V6 Camaro]

Your high HP/Torque run is messed up. The torque and HP are still climbing when the test cuts off (well before 5K RPM)

From the looks of things, your HP peak will be about 5500 max.

You don't want to pick rear gears based on ET, but on MPH. 4.11 gears might give you a better ET (with big slicks and a perfect launch), but you'll only run 108 or so in the 1/4.

If you want to run solid 10's, assume 125 mph trap speeds.

125 mph with 26" tires and 3.42 gears is about 5600-5900 RPM depending on how loose your converter is (locked up you'd be on the lower end).

3.73 gears would be 6100-6500 RPM at the same 125 mph (great for an LS1, 1000 RPM over your HP peak...not good.)

From the looks of things, I'd keep the gears you have and forget about 3.73's

the dyno lost the tach sig every time at 5k rpms on any run over 330 RWHP

i have 3.23 right now so 3.42 would be a good upgrade? (i have to rebiuld the rear anyway.)
http://media.putfile.com/Emerald-Coast-1-22-05 << you can here the motor take off that the turbo hitting LOL. the first run with me was my best and the last run you see of me was my worst of the night

www.turbov6camaro.com/track << more videos with my crappy camera

htanks again for the help and coments

 

[steve davis]

KEEP THE 3.42 GEAR.THATS ONE THING THE FACTORY DID RIGHT. MY NEW COMBO I WILL GET INTO THE MID TO LOW 10,s. AND I AM STAYING PUT WITH THE GEARS.JUST MY .02C

 

[John Wilde]

I would keep the 3.23 especially if you are going to run a short tire.
Most guys trying to run in the 10s with 3.42s have 28 inch tires.

Nice car BTW!!!

 

[Turbo V6 Camaro]

I would keep the 3.23 especially if you are going to run a short tire.
Most guys trying to run in the 10s with 3.42s have 28 inch tires.

Nice car BTW!!!

thanks

ahhhhh car setup sucks when it's just your hobby...... what to do what to do

if i went 3.42 and 28" tire whats the point? doesn't that cancle each other out ?

 

[John Wilde]

thanks

ahhhhh car setup sucks when it's just your hobby...... what to do what to do

if i went 3.42 and 28" tire whats the point? doesn't that cancle each other out ?

The 28inch tall tire will have more side wall and you will be able to launch the car harder.


Go here and you can play around with some numbers.

http://tciauto.com/tech_info/calculators.htm

 

[Turbo V6 Camaro]

The 28inch tall tire will have more side wall and you will be able to launch the car harder.


Go here and you can play around with some numbers.

http://tciauto.com/tech_info/calculators.htm

so.... looks like i ma stay with 3.23's cause i'm not going 28 inch tires anytime soon

 

[Ormand]

What's the gearing in the Turbo TA? Seems like that might be a closer match to the Camaro than a GN. The GN is such a brick, it really runs into big air resistance at the end of the quarter, compared to a TA.

 

[TTA850]

Stock TTA gearing is 3.27 and works very well. When I first put my car together I went with 3.08 gears and a 26" tire, best 60ft was 1.47 and was trapping 125mph at 5600rpm. Went to 3.42 gears, 28" tire and slight change in the converter and now trap 125mph at 5900rpm with 60fts around 1.49(also 200lbs heavier).

I'd stay with gears similar to what you have now, no more than 3.42

HTH,
Steve

 

[Turbo V6 Camaro]

Stock TTA gearing is 3.27 and works very well. When I first put my car together I went with 3.08 gears and a 26" tire, best 60ft was 1.47 and was trapping 125mph at 5600rpm. Went to 3.42 gears, 28" tire and slight change in the converter and now trap 125mph at 5900rpm with 60fts around 1.49(also 200lbs heavier).

I'd stay with gears similar to what you have now, no more than 3.42

HTH,
Steve

i can get an almost new set of 3.42's for 20 bucks plus shipping..... so If it was your car.... would you go with 3.42's or stay with the stock 3.23

i think i'm around 3600# right now without doing any huge wieght stuff (still got spare and thing in the car.... lol) roll bar and turbo add some wieght.

i wish i would have ran a 1/4 mile kinda hard to go off the 1/8 mile stuff

thanks again for any input thus far

 

[UNGN]

I would just keep the gears you have (3.23's). When you get the car dialed in, you're going to break that rear end the first time you put slicks on it, so I wouldn't spend too much money on it.

 

[Epitome]

No big long explaination...but....stay with the 3.23s if you want to use the 26" tall tire.....use 3.42 if you go to 28". Your statement that you don't make great torque down low because it's a V6 is wrong. That is our whole game, torque down low. Now if you don't brake boost before you launch....that is a different story

 

[Turbo V6 Camaro]

No big long explaination...but....stay with the 3.23s if you want to use the 26" tall tire.....use 3.42 if you go to 28". Your statement that you don't make great torque down low because it's a V6 is wrong. That is our whole game, torque down low. Now if you don't brake boost before you launch....that is a different story

that the thing car rolls on me over 3000 RPM with a 3800 stall... have to figure out why

 

[UNGN]

that the thing car rolls on me over 3000 RPM with a 3800 stall... have to figure out why

Try the E-brake to see what your true stall is. If it still doesn't go past 3K you may need to have the converter restalled.

PS: There is no reason for not testing the stall with the E-brake at the track (hint, hint).

 

[Turbo V6 Camaro]

Try the E-brake to see what your true stall is. If it still doesn't go past 3K you may need to have the converter restalled.

PS: There is no reason for not testing the stall with the E-brake at the track (hint, hint).

i never would have ever thought about using the ebrake at the line....... now do you use both or jsut the ebrake?