Which gears to run?

hummer784 · Dec 25, 2003

Well my plan for a 10 second ride is being put off due to a constant lack of funding, so now I will be rebiulding my 289. Here's the question, I have a cam just like comp's 280h grind and I want to know what gears I should run. I have a c6 trans and was going to be using a 2500 stall converter. The engine is mainly stock with the exception of a performer manifold, performer 600 cfm carb and some headers. For those of you who arent familliar with the cam its 236/236 duration and .528/.528 lift. Oh, the car isnt daily driven and it would be used for drag racing. Thanks!

Also, if anyone knows who makes a good off the shelf converter please tell me.

rbohm · Dec 25, 2003

i would run a 3.25-3.50 gear on the street, and build a second pumpkin with something like 3.89-4.11 for the strip.

hummer784 · Dec 25, 2003

Thanks rbohm, but I cant afford to build 2 pumpkins right now. I dont drive to far and have had cars with low gears before so I dont mind using them, I just didnt know what ratio to use. The info that comp had in their description was "lower gears", right now im running a 26" tire and was thinking of going to drag radial that would be about 28" tall. Thanks for all of the help so far!

302 coupe · Dec 26, 2003

3.70, 3.89 ....either should work well. I wouldn't go much higher with the 26" tire

Edbert · Dec 26, 2003

I put 3.70s in mine, our cams are close but yours is a bit more radical. I am also using 26 inch tires but I have the advantage of an AOD. If you are not planning on doing much cruising with the car then I'll agree with the 3.70-3.89 ratio, if you want to cruise around town then don't go over 3.50.

I have to ask though...why a C6 behind a 289?

EDIT: If you want to get that second pumpkin started cheap PM me. I've got an extra 9-inch center section and a pair of 28s to go with it after upgrading to my locker and 31s.

hummer784 · Dec 26, 2003

I dont know if it makes any difference, but I have an 8" rear end. In summit all I could see for gears are 3.55, 3.8 or 4.11. Which would be the best choice? The car would see in town driving but mostly stoplight to stoplight and track usage. Thansk guys!

wickedmach1 · Dec 26, 2003

Go with the 3.89's if it will not be a highway cruiser. Drop the C6 and go with a C4. Much lighter! Or, when you get the funds, do a AOD or T-5 conversion. You will then not have to worry about the RPM's at higher speeds. Check out the rear gear calculators on the mustang websites. I think you would want to stay around 2000 - 2100 RPM's @ 70 MPH with the 289. Much more and you will be putting to much strain on your valve train. Good luck.

hummer784 · Dec 26, 2003

I was thinking about going with a c4...but not yet. Would a c4 use less horespower then my c6? Also how much power would a c4 be able to hold? Thanks!

Fostang · Dec 26, 2003

hummer784 said:
I was thinking about going with a c4...but not yet. Would a c4 use less horespower then my c6? Also how much power would a c4 be able to hold? Thanks!

C4 yes it will use less power how muc power can it hold depends how much money is put into it but in stock form I've ran 400 hp and the damn thing is still going in a different car.

My uncle built it but as far as I know it was a stock rebuild or maybe not? :shrug:

Either way he didn't charge me and for someone that worked for the art carr race team back in the late 70's to have built it, I think I got a sweet deal.

260 hp estimate plus 150 hp nitrous.

rbohm · Dec 26, 2003

hummer784 said:
I dont know if it makes any difference, but I have an 8" rear end. In summit all I could see for gears are 3.55, 3.8 or 4.11. Which would be the best choice? The car would see in town driving but mostly stoplight to stoplight and track usage. Thansk guys!

i agree with wicked mach, go with the 3.80's or 3.89's something in that range for the street and strip.

hummer784 · Dec 26, 2003

Cool, thanks for all of the info I will be getting soem 3.80's soon. Also, what should I expect to pay to have the gears put in if I take the 3rd member and gears into a shop? Thanks!

6Stang7 · Dec 26, 2003

Well, I'm a torque freak, so I got 4.11's. However, I am going to be installing a 5 speed, so I will have overdrive to help. People say 4.11's are too much, and that 3.50's or 3.80's are better, but the difference between 3.80's and 4.11's is about 300 rpms, and about 500 between 3.50's and 4.11's(going 70 MPH in whatever gear your trannys 1:1 is, with 245/45/17 tires). I will admitt, I was a little scared with getting 4.11's. I read a lot of post in the 5.0 and 4.6 sections and one thing I got over and over was this. DON'T FEAR THE GEARS!!! Most people that got 23.50's, 3.80's, or 3.89's said was that they wished they had gotten 4.11's. In the end though, you need to decide what RPM you want to run at when you're cruising at freeway speed. Here is a nice little link that will help you find what gear raitos to go with....if freeway RPM matters to you, otherwise, I say go with 4.11's or 4.30's.

http://www.corral.net/tech/gearcalc.html

-Shaun

Fostang · Dec 26, 2003

I once had a 3.35 first gear t-5 with a set of 4.11's what a nightmare I tell you.

I quickly hated driving stick shift.

nothing but spin city. I absolutely could not race anyone because there was no traction.

I quickly tached up 6250 which was my rev limiter was no problem getting to it actually too damn fast. 3.80's much better.

6Stang7 · Dec 27, 2003

Fostang said:
I once had a 3.35 first gear t-5 with a set of 4.11's what a nightmare I tell you.

I quickly hated driving stick shift.

nothing but spin city. I absolutely could not race anyone because there was no traction.

I quickly tached up 6250 which was my rev limiter was no problem getting to it actually too damn fast. 3.80's much better.

Is it wrong that hearing that made me even more excited about installing my 4.11's and T-5??? :shrug:

-Shaun

Fostang · Dec 27, 2003

Have fun going up in smoke while the competition passes you up.

Loosing traction isn't too fun especially if the frist time to the track you run a 16.5 when a honduh runs 16.7 with a 1.6L engine

88 Fox GT · Dec 27, 2003

So put some more meat on the back and make the suspension squat down and hook better.

Fostang · Dec 27, 2003

Speed_Demon1965 said:
So put some more meat on the back and make the suspension squat down and hook better.

dat wat me be doin now oh yeah man.

6Stang7 · Dec 27, 2003

I really don't plan on racing my car very much, if at all. I want to have to ability to make a lot of smoke whenever I have the urge.

Besides, if I ever do run it at the track, I'll be sure to put a set of DR's on my spare rims.

-Shaun

Fostang · Dec 27, 2003

6Stang7 said:
I really don't plan on racing my car very much, if at all. I want to have to ability to make a lot of smoke whenever I have the urge. Besides, if I ever do run it at the track, I'll be sure to put a set of DR's on my spare rims.

-Shaun

They are no fun no doubt about it if you plan on doing burn outs.

I would be cruising up to 30 and just slam the gas and it would start to break traction.

6Stang7 · Dec 27, 2003

Fostang said:
They are no fun no doubt about it if you plan on doing burn outs.

I would be cruising up to 30 and just slam the gas and it would start to break traction.