Street gearing

[custom442]

I have a medium built 383, I'm guessing somewhere between 460-490 hp/tq. The engine isn't bolted in the car yet, but will be in a few weeks. I'll use the stock TH200 for now to go from point A to B.Before the summer ends I'd like to have the engine dynoed before the drivetrain is ordered. The idea is to be able to utilize first gear instead of jumping from 1st to 2nd too fast.

What's the best rear gear ratios to get the most out of 1st gear if my redline is about 5,800-6,000rpm? For 2004r vs. th350? The goals are to hit 60 mph in first gear, and not launch too hard (it's for the street). Gas mileage is a non-issue at this point, so the only reason I'm considering the two different transmissions is for the different gear ratios.

Edit: I'd also use a ratchet shift for manual control so shift points aren't a concern.

 

[jrm81bu]

If you really want to be able to hit 60 in first gear a th350, 2.41 rear gears and 26 in tall tires will do it. But why do you want to run 60 in first.

 

[adumb]

maybe to not have a shift in the middle of his 0 - 60 time? that's the only reason i can think. having just switched from 2.41 to 3.42, even though my engine isn't built as high as your specs, i would advise to have something numerically higher than a 3 in the back.

 

[XbeasleyX]

3.08 with a 26.3" tire and a 2004r you'd hit 60 at roughly 6500 rpm.
TH350 would get you 5950 rpm.

 

[shotgun]

Can't make an educated responce without more info on the engine, car etc.

What carb?
What intake? Single or dual plane?
What is the power band of the cam?
Etc etc.

Goals for the car?

Having said that, I do alot of Pontiac 400 which are very similar to 383s.

A mild 400 with a th350 and 3.23/3.42 make a great all around combo.

You can always play with tire diameter to "fine tune" it.

 

[custom442]

Can't make an educated responce without more info on the engine, car etc.

What carb?
What intake? Single or dual plane?
What is the power band of the cam?
Etc etc.

Goals for the car?

Carb is a 750 cfm Holley street avengner (a 4150 electric choke with extra goodies)

Intake is an edelbrock RPM air gap.

Powerband on the cam specs is 'supposed' to reach 5800 rpm. Here's the actual specs from compcams - http://www.compcams.com/Cam_Specs/CamDe ... d=160&sb=2

The goals for the car are - 80%+ street driving, it'll see the 8th mile more than the quarter (there's a strip close to where I live). I'd like it to handle some twisties decently well, which will be worked into the suspension much later. It'll take a road trip every month or two (about 300 mile round trip) to galveston from north houston. Other than that, just normal driving with the occasional WOT runs from stoplights. A weekend/fair weather driver.

 

[custom442]

If you really want to be able to hit 60 in first gear a th350, 2.41 rear gears and 26 in tall tires will do it. But why do you want to run 60 in first.

The goal is to be around 60. I know it's not going to be perfect. If it comes close, that's fine too. I just don't want to be 'launching' the car hard on the street or shifting early with too strong of gearing.

Thanks for the suggestions everyone, looks like the most likely choice is th350 and around a 3.00 rear.

 

[custom442]

3.08 with a 26.3" tire and a 2004r you'd hit 60 at roughly 6500 rpm.
TH350 would get you 5950 rpm.

What about a th350 with 3.00 gear and 27", or 28" tire?

 

[dogsht]

For your setup and goals/use I would recomend a street strip build 200-4r with a 2,800 stall lock up converter. $1,500 ish plus $300 for the converter but you will be very happy with your transmission and car. You really won't be as happy with and achieve your goals well with a three speed. IMO

This will work well with a bigger taller tire on the back to get decent safe traction on the street with that power. Ideally a drag radial.

 

[shotgun]

I think you are over-cammed for your goals.You need more low end torque to do what you want. If a cam swap is out,maybe advance yours.
Still will not be ideal.

You could go 2500 stall,th350, 3.23 with 27.5" tire and be at max rpm in second at the end of the 1/8th running 7.8z and 12.20 in the 1/4.

You can gear for the 1/8 or the 1/4 , not both.

The steeper first on th200 (2.74?) will net you a 1/10th in the 1/4.

My concern will be cruising anywhere with higher stall and low gears. You will be below 2500 alot of the time so the convertor will be slipping.Heat kills!!

Oh, put some sticky tires and killer stall, say 4500 and you would have a mid 11 second ride.