Best gears for turbo application?

[61mmstang94]

How about 3.05's?

It might end up there but I'm not sure if I need to go that far so I would rather take smaller steps down until I get it where I want it since gears are cheap and easy to swap. Obviously my car still isn't the most practical daily driver, but I love being able to run this kind of gearing and smoothly cruise down the highway at practically no RPM and know it runs 9s@150+.

 

[2002mustanggt]

I like to know this too as my motor blew and getting new motor build done here soon. I can rev my motor to 7k and have t70 single turbo kit. I have 3.73 gear and like to put back 3.27 but my buddy/engine builder tell me to keep 3.73 and run 28" tall tires for the track, What should I do?

So far everyone says 3.27 is the best but my buddy says different, I will be about 600+rwhp with 5 speed and can now rev to 7k rpm.

 

[2002mustanggt]

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[GloomySVT]

I have 3.73 gear and like to put back 3.27 but my buddy/engine builder tell me to keep 3.73 and run 28" tall tires for the track, What should I do?

I was thinking about doing the same thing your buddy is mentioning. I'm running 3.73s myself and what I heard was, an easy way to go to a lower gear without opening up the rear end, is to run larger wheels.

Say I have 17 inch rims with 3.73s. If go to 18 inch rims, the car should act like it has 3.55s roughly.

 

[61mmstang94]

I like to know this too as my motor blew and getting new motor build done here soon. I can rev my motor to 7k and have t70 single turbo kit. I have 3.73 gear and like to put back 3.27 but my buddy/engine builder tell me to keep 3.73 and run 28" tall tires for the track, What should I do?

So far everyone says 3.27 is the best but my buddy says different, I will be about 600+rwhp with 5 speed and can now rev to 7k rpm.

You'll just be swapping them out later when you don't like them. I'm running a 28" tall tire at the track and I'm still thinking about going to a 3.27 from my current 3.31s. But oh well, the best way to learn is to go try it yourself and you'll want to swap them out. :thumbsup:

 

[2002mustanggt]

I was thinking about doing the same thing your buddy is mentioning. I'm running 3.73s myself and what I heard was, an easy way to go to a lower gear without opening up the rear end, is to run larger wheels.

Say I have 17 inch rims with 3.73s. If go to 18 inch rims, the car should act like it has 3.55s roughly.

Thanks for the info, I learn some today.:thumbsup:

 

[THAITED]

It might end up there but I'm not sure if I need to go that far so I would rather take smaller steps down until I get it where I want it since gears are cheap and easy to swap. Obviously my car still isn't the most practical daily driver, but I love being able to run this kind of gearing and smoothly cruise down the highway at practically no RPM and know it runs 9s@150+.

Do you have twin or single? Just curious cause that's one fast car you got there.

 

[61mmstang94]

Do you have twin or single? Just curious cause that's one fast car you got there.

Just a single 76mm but the car's pretty light. Without me in the car it weighs around 2900-3000lbs.This turbo wouldn't be going quite as fast in a full weight 3500lb car. Anyways, now that the weather is cooling down to where I like it I should be able to get a few more MPH out of it and I am finally going to start using my trans brake to get that horrible ET down more. This coming weekend I'm hoping to get my goal of a 9.0 1/4.

The only current video I have of this car was back the first time I took it to the track and ran a 10.4@147 off a 2.1 60'. Since then I have it down in the higher 9s and with the trans brake, cool air, improved driving and my extra 8-9 psi I am going to try I hope for a 9.0 at close to 155 or better if I really get my short time down to where it SHOULD be.

 

[saleensc281]

3.73s are too much and are hurting your cars performance. Try atleast a 3.31 or 3.27 with the 6-speed and you'll be much happier. You don't need to run 4.10s like the n/a, nitrous or blower guys for better performance.

Thanks for the info man, so me having 3:27s, 600rwhp and a 28in slick wont effect me in a negetive way then?

 

[2002mustanggt]

Thanks for the info man, so me having 3:27s, 600rwhp and a 28in slick wont effect me in a negetive way then?

I like to know the same .

 

[GloomySVT]

Thanks for the info man, so me having 3:27s, 600rwhp and a 28in slick wont effect me in a negetive way then?

It might spool even quicker lol. More load. :idea:

 

[61mmstang94]

Thanks for the info man, so me having 3:27s, 600rwhp and a 28in slick wont effect me in a negetive way then?

Look at it this way, you know a turbo car likes load and when you increase the load, the better your turbo setup is going to perform. Having slightly longer gears really helps with this, hence why 3.73s will actually hurt the performance compared to a 3.27. If you go with the 3.73s you're going to be shifting too soon and will run out of gear before you get to the end of the quarter most likely.

To really figure out exactly what gear you need you'd have to run the car at the track and look at your RPM crossing the line. You want to cross the line at whatever the optimum RPM is and your gearing is what will change that.

For example, say you put 3.31s in your car and you are crossing the line at 7500rpm, but it would be more optimal to cross at 7000rpm. You would swap in 3.27s in hopes of getting it down closer to the 7000rpm target so you can go faster. If you were trying to get exact, then that would be the way to do it. But if you go with 3.27s you'll probably be close enough to what you want and from there you could make small changes to get it perfect.

Another example would be my own car. I went with 3.31s and a 28" tire...and they work alright. They load the turbo up good, the gears aren't too short, etc., but I would benefit from a set of 3.27s because I'm currently running out of RPM towards the end and it stops pulling before the finish line. So if I went with the 3.27s it would effectively allow my car to be at a little lower RPM and pull all the way through the finish line and my times would be better.

Hopefully my jumbled up explanation makes sense.

 

[2002mustanggt]

Thanks for info, I do really want to go back to 3.27

 

[61mmstang94]

Thanks for info, I do really want to go back to 3.27

Yeah, and when you drive it on the street you'll also benefit from lower RPM when driving around so it's a win, win situation. :beer:

 

[THAITED]

Yeah, and when you drive it on the street you'll also benefit from lower RPM when driving around so it's a win, win situation. :beer:

Thanks for the info, I'm hoping to keep top of 1st gear at 60 mph like the C6Z. This is a long shot for me since I have to save money but I will get there. One quick question, do you have a 4.6 or 5.1 stroker, thanks.:beer: BTW, how much HP are you putting out with that 76 turbo,thank you.

 

[61mmstang94]

Thanks for the info, I'm hoping to keep top of 1st gear at 60 mph like the C6Z. This is a long shot for me since I have to save money but I will get there. One quick question, do you have a 4.6 or 5.1 stroker, thanks.:beer: BTW, how much HP are you putting out with that 76 turbo,thank you.

Do you have a T56? With the right gearing you might be able to get pretty close to 60mph....you'll have to see after you get it done and start tearin' em up.

It's a pushrod 331 c.i. setup and I made 8XXrwhp on full boost through an auto. But so far I am still almost 8+psi from my max at the track as I have the boost controller down right now. I never place much emphasis on dyno sheets. How it performs at the track is how I've always determined if my cars run the way they should. But when I crank the rest of the boost out and get my 60' down I'm really hoping for some 8.9s at close to 160mph. As it keeps cooling down I'm sure it won't be a problem and when it happens I will surely have a camera so I can post it up.

I guess the only way for me to figure out what my power is would be to get an estimate by calculating what it would take for a car that weighs about 2900 lbs (w/o driver) to go the trap speeds I'm going but as long as I reach my goal I would care if it read 200rwhp.

 

[THAITED]

Do you have a T56? With the right gearing you might be able to get pretty close to 60mph....you'll have to see after you get it done and start tearin' em up.

It's a pushrod 331 c.i. setup and I made 8XXrwhp on full boost through an auto. But so far I am still almost 8+psi from my max at the track as I have the boost controller down right now. I never place much emphasis on dyno sheets. How it performs at the track is how I've always determined if my cars run the way they should. But when I crank the rest of the boost out and get my 60' down I'm really hoping for some 8.9s at close to 160mph. As it keeps cooling down I'm sure it won't be a problem and when it happens I will surely have a camera so I can post it up.

I guess the only way for me to figure out what my power is would be to get an estimate by calculating what it would take for a car that weighs about 2900 lbs (w/o driver) to go the trap speeds I'm going but as long as I reach my goal I would care if it read 200rwhp.

I have T-56, 03 Cobra.

 

[61mmstang94]

I have T-56, 03 Cobra.

Yeah, I don't know exactly what MPH 1st would top out in your car. Depends on the RPM you're able to turn and if you go with the 3.27s you'd probably be right around there.

 

[THAITED]

Yeah, I don't know exactly what MPH 1st would top out in your car. Depends on the RPM you're able to turn and if you go with the 3.27s you'd probably be right around there.

Thanks.

 

[GloomySVT]

Hey THAITED. From my experience in driving both cars, my dad owns both a Terminator and a C6 Z06, the Terminator requires you to shift sooner than the Z06, probably due to the final drive ratio. Here are some solid numbers for you if you're a numbers kind of guy:


Terminator T56
Gear
Ratio

1st
2.66

2nd
1.78

3rd
1.30

4th
1.00

5th
0.80

6th
0.63

Reverse
2.90

Final Drive
3.55

Corvette C6 Z06
1st
2.66

2nd
1.78

3rd
1.30

4th
1.00

5th
0.74

6th
0.50

Reverse
2.90

Final Drive
3.42

:beer: