3.73 gears too much?

[Loco5.0]

My car has 3.73 gears & a 2500 stall. I'm adding a single T76 turbo setup
C4 3 speed trans
26" tires
shift at 6k

Are the 3.73s too much?

 

[QDRHRSE]

Should be perfect with an AOD.

 

[Fast63]

He has a C4, not an AOD...

at 6000 rpm in 3rd, you'll be able to go 124.48mph, so if you plan on going faster than that in the quarter mile, then they are too much.

So at 3000 rpm, you'll be cruising at 62.24mph, or 3133rpm at 65. If that cruising rpm bothers you, then you need a different gear.

Hope that helps

 

[strtrcr50]

Turbo cars also like a load against them. I'd go to a 3:55 or 3:08. can you get a lockup converter for your trans?

 

[Loco5.0]

He has a C4, not an AOD...

at 6000 rpm in 3rd, you'll be able to go 124.48mph, so if you plan on going faster than that in the quarter mile, then they are too much.

So at 3000 rpm, you'll be cruising at 62.24mph, or 3133rpm at 65. If that cruising rpm bothers you, then you need a different gear.

Hope that helps

No, I am around 3200 RPM when I am doing 75-80.

 

[Jmunk]

Those gears would not bother me with your setup.

 

[NKau]

No, I am around 3200 RPM when I am doing 75-80.

Then either you don't have 3.73's, your tach or speedo are way off, or you have an overdrive transmission and don't know it

 

[mavmavv]

Personally, id go 3.55.

 

[Loco5.0]

Then either you don't have 3.73's, your tach or speedo are way off, or you have an overdrive transmission and don't know it

It's a C4 3 speed w/manual valve body. No OD. Tach could be off, but then so would my Auto Meter tach since they read about the same.

 

[Fast63]

It's a C4 3 speed w/manual valve body. No OD. Tach could be off, but then so would my Auto Meter tach since they read about the same.

Then you've exhausted the only other option. Your speedometer is off.

Unless your tires really are not 26 inches in diameter.

The formula doesn't lie my friend.

 

[Loco5.0]

Then you've exhausted the only other option. Your speedometer is off.

Unless your tires really are not 26 inches in diameter.

The formula doesn't lie my friend.

The speedo very well could be off. I don't have anything to test it. The tires definitely are 26" though. I wasn't saying you're wrong. You could be right, but I can only go by what I see & what info I have.

 

[NKau]

The speedo very well could be off. I don't have anything to test it. The tires definitely are 26" though. I wasn't saying you're wrong. You could be right, but I can only go by what I see & what info I have.

If you know your tire height, gear ratio, and RPM, you can calculate what speed you are running at various RPM's by plugging in some different RPM numbers. If I had the formula, I'd give it to you......but I don't

 

[SuperStang83]

I'd go with higher gears if you are going turbo. 3.27s would be a good choice.

 

[Fast63]

There are different formulas, but the one I like the most is this:

RPM = MPH x 88 divide by the circumference of your tires in feet x Transmission gear ratio x rearend gear ratio.