gears
 

Ok so here's my question.... going to install 4:10's in my cobra and im just wondering what brand gears to go with. The car will see 500-600 HP when I get done. I am also going to get an x3 tuner AM sells a kit w/gears and the tuner but they dont say what brand gears the are. Any help would be great!!!

Dont think you should be running that steep a gear with a s/c cobra. 3.73 I believe is what is more common.

The pros here should be able to confirm this or not.

To stay safe, I say stick with FRPP or Motive gears. I don't really have anything bad to say against Richmond. But stay away from Yukon, if they even make gears for the 8.8 Ford.

All gears should be fine. If you wanna go by brand then go FRPP or if you wanna go for cheapest go for motive.

Btw welcome to the forums, make a introducing post and tell us about you and your car!

Thanks guys!!

FRPP 1st choice. Then Motive. Stay away from Richmond gears. The quality is ok, but they whine horribly. A buddy of mine that builds and races mustangs had two sets in his old mach 1 and they were so damn noisy. As for 4.10 or 3.73, depends on if you have a NA cobra or a Termi.

One more question I have a strut tower brace so the JLT cai is out....what cai options do i have that go into the fender??? and the car is n/a still...

If your n/a you should be using 4.30gears.

Confused.....if your cobra is n/a then 4.10/4.30. If you are planning on that much power then that is too much gear though. Are you planning on racing, driving on the street, or both?

it is going to be a track car

oh boy...

Track car. what kind of track 1/4, 1/8th, auto-x, road course? From your S/N I'm going to assume auto-x.

I think you need to look up your transmission and factor what rear ratio you need to put you in the ideal rpm range for the track...most cars in auto-x stay in 2nd gear between 50-65+ mph...if your shifting your wasting time.


I'd suggest doing some more research. Otherwise you will just be wasting money.

Im going road coarse have been auto x-ing for about 8 years now movin up in the world :) Changing trans out for T56 in a couple months

I have never heard a set of Richmond gears "whine" that were installed properly. Thier quality is second to none and if break a set of thier gears, you've done a days work and you might as well go to the house.

I have a set of Richmond 410's in my car and they are quiet as a church mouse.

He's an ASE Master Mechanic so im sure they were installed correctly being as he's been a mechanic for over 30 years, and has been building mustangs for about 15. *shrugs* I've never had personal experience with Richmond, just rode in his Mach when he had Richmonds in it, and they whined quite badly. As for the quality, I'm sure they're a fine manufacturer. He got a second set, same thing, then went to FRPP and not a peep. That's why i bought FRPP.

If you're going to be pushing 500-600hp you will hate 4:10s or higher for a road course set-up.

If you go with 4:10s or up you'll be doing nothing but peddling like crazy in first and second.

I tried putting 4:10s in my '04 Cobra after the KB, but ended up hating them. The car pulled hard, damn hard, but it would just light up the tires from first to second and halfway through third with NT555Rs in dry weather. And it's built to be a track car.

The car now has FRPP 3:73s and drives like shes on rails. It'll still light up the tires, but peddling actually controls it, unlike with the 4:10s it didn't matter how much you peddled it.

With the T-56, if you go Viper-Spec or the Cobra-Spec, the gears are pretty short as it is so I personally would recommend 3:73s. I only know one person with 4:10s out of about 30 guys and his car is a strictly trailer queen drag car. Everyone else I know has 3:73s or the stock 3:55s.

If 3:73s just sound to low, then try 3:90s and see if they work for you. But I think 4:10s is just too much.

I had 4:10's in my gt that was about 400hp and they were perfect so you may be right about going to 3:73s or maybe 3:90s thanks.

If he's road racing, you want the taller (or is it steeper) gear behind a T56. The ratios in a T56 are not the same as in the 5 speed (1st is only 2.97). Also, combine the fact that it's a 4V which doesn't produce the same low end grunt as a 2V, you will need the help. Especially a modified 4V which will be producing even less torque down low. Go with the 4.30 or up.

Now if you go FI, then it depends. A blower will need something less, like 3.73s or 4.10s but a turbo/centrifugal will need the higher gears like a 4.30.

But. even a centrifugal supercharger at 600hp will suck ass with 4:10s. Once that power curve kicks in it'll spin like crazy on a road course. On a prepped drag strip, no, but a concrete or asphalt track hell yes. Especially with dirt and everything else all over it.

Hell the C6.R used in LeMans uses a 3:73 rear end and it only has ~500hp.

4v needs gear so don't go less then 4.10s unless your running turbos or some super high HP #'s.

The editor of MM&FF uses 4:88 gears in his red '98 cobra (DOHC Superfly) which has been featured several times in the magazine. In the most recent thing I remember reading about the car, he ran only one second slower per lap than he did in a Ford GT. I don't remember the power output of the car but yeah, 4Vs need gear.

But if I remember correctly his car only has a little over 300hp, right?

360rwhp, w/ a T-56 trans. I found the article I was thinking about. It also states that his lap time was 0.71(s) faster than the Ford GT.

http://www.musclemustangfastfords.co...sts/index.html

My point is I don't think that going with 4:10 or even 4:30 gears would be so bad for this guy, even with so much power, just have to learn how to control it.

While the power curve will kick in, the car will be slugglish beforehand. It's a trade-off between being able to accelerate and not having wheel-spin. I guess if you don't plan on driving it on the street, a lower ratio would help as generally while racing, you aren't worried about staying in the rpm band.

As for the vette, remember that they don't car about acceleration in Le Mans. It's about speed and the larger the ratio, the lower your speed. The V8 is enough for acceleration (and isn't much more than a modified LS7).

I know that, but in road racing you don't ever get out of the powerband. Hell, half the time you're running at least 3k RPM if not closer to 4-5k. That's how I drive at least.

Autocrossing, sure I'd use a steep gear because top end isn't needed and really the only time you're out of powerband is at the start or in very tight sequences, but on a road course you'd almost always be in the powerband (at least with the way I drive).

And with 500-600hp and probably close to 500-600tq I think acceleration is going to be well enough for the car.

That depends. If that power comes on later, you will feel something similar to turbo lag. Think of the exotic cars. They are dogs off the line, until they hit their powerband.