[Barricade81]

I've heard a few different replies anytime I ask what the horsepower/torque limit is on the Ford Racing 7.5" Posi-Trac. I've heard everything from "Don't go over 300hp with one," to "Don't even bother with one, you'll be lucky to keep 250hp in one", and I've also talked to a guy who had a supercharged 2000 V6 making 450 at the crank on the 7.5" rear.

Anyone have any more info? 450 sounds like a lot to run through the 7.5" without getting an 8.8" instead, but the guy owned the car and said it's been rock hard reliable for him, so I won't doubt him. But if I get to those power levels I'd like to know at what kind of power I should ditch a 7.5 and get an 8.8

[6ER THEN I 8ER!]

Originally Posted by Barricade81 I've heard a few different replies anytime I ask what the horsepower/torque limit is on the Ford Racing 7.5" Posi-Trac. I've heard everything from "Don't go over 300hp with one," to "Don't even bother with one, you'll be lucky to keep 250hp in one", and I've also talked to a guy who had a supercharged 2000 V6 making 450 at the crank on the 7.5" rear. Anyone have any more info? 450 sounds like a lot to run through the 7.5" without getting an 8.8" instead, but the guy owned the car and said it's been rock hard reliable for him, so I won't doubt him. But if I get to those power levels I'd like to know at what kind of power I should ditch a 7.5 and get an 8.8

you can put quite a bit of power on a 7.5 as long as you build it right...the only real upgrade to an 8.8 is just the added knowledge that it can handle whatever you throw at it (well to a certain extent lol)

[walt1120]

Originally Posted by Barricade81 I've heard a few different replies anytime I ask what the horsepower/torque limit is on the Ford Racing 7.5" Posi-Trac. I've heard everything from "Don't go over 300hp with one," to "Don't even bother with one, you'll be lucky to keep 250hp in one", and I've also talked to a guy who had a supercharged 2000 V6 making 450 at the crank on the 7.5" rear. Anyone have any more info? 450 sounds like a lot to run through the 7.5" without getting an 8.8" instead, but the guy owned the car and said it's been rock hard reliable for him, so I won't doubt him. But if I get to those power levels I'd like to know at what kind of power I should ditch a 7.5 and get an 8.8

well it would probably be alot less hassle and cheaper to just swap to an 8.8. plus with an 8.8 you know that you have plenty of room to work with as far as power levels go. you would probably be nervous on every launch if you kept the 7.5 and that wouldn't be any fun worrying the whole time.

and your friend with all that power probably has some pretty pricey upgrades. most likely a Detroit locker and possibly some stronger axles, which in the end would cost you alot more then just swapping in an 8.8

[mustangmike!]

there is no limit, you can put 1000 on it and it hold up, just depends on how you drive it You can blow a 7.5 on stock power to ..

[9986paulk]

The differental is the real weak point. A Ford racing t-lok, I don't know what they'll hold up to. The detroit tru-trac should be good to around 450. A stock 8.8...well I don't think they're all that amazing. Sure a little stronger, I might say 375. But swapping for just a stock 8.8 is basically less of a benefit than swapping for a detroit differentail. Though, once you upgrade the 8.8, it would be out of the question which is stronger.

I do believe the 7.5 and 8.8 share the same axles though.

[ReverendDexter]

Originally Posted by 9986paulk I do believe the 7.5 and 8.8 share the same axles though.

They share everything but the center-section.

+1 on just swapping out the carrier for a stronger unit and keeping the 7.5. Upgrade to some stronger half-shafts while you're in there, and you'll end up with a plenty-strong rear axle that weighs less than an 8.8 and causes less drivetrain loss.

[mustangmike!]

lol just get a 31spline 8.8 w/ Detriot

[9986paulk]

yep, thats well over $1k for the 8.8, gears, tru-trac, and install.

[Codeman]

I agree with everything on here. A tru trac is more than strong enough for the majority of ppl on here. JT launches with a high stall convertor, DRs, and 17 psi procharger using a 7.5 and a tru trac and he has no problems. He said the only thing he is worried about is breaking an axle, and they have aftermarket harder ones for when that happens.

[ESG-642T]

Originally Posted by Codeman I agree with everything on here. A tru trac is more than strong enough for the majority of ppl on here. JT launches with a high stall convertor, DRs, and 17 psi procharger using a 7.5 and a tru trac and he has no problems. He said the only thing he is worried about is breaking an axle, and they have aftermarket harder ones for when that happens.

Let him put the new dr's on and launch it at 3.3-4k if he can stall that high... Then we'll see

I like knowing my 8.8 isn't going anywhere

[Barricade81]

Originally Posted by Codeman I agree with everything on here. A tru trac is more than strong enough for the majority of ppl on here. JT launches with a high stall convertor, DRs, and 17 psi procharger using a 7.5 and a tru trac and he has no problems. He said the only thing he is worried about is breaking an axle, and they have aftermarket harder ones for when that happens.

Well if there are guys with those power levels then I'd be fine with the 7.5" I'm not building a monster drag car by any means, so if it can stand up to those types of setups I feel a lot better about it. Of course I haven't done anything on the rear end yet, so I might still go with an 8.8" It'll depend on what type of prices I can get.

[Codeman]

What are your goals for the car?

[Barricade81]

Originally Posted by Codeman What are your goals for the car?

450-500 at the wheels. It'd my DD for now, but it won't be once I start to really dig into the engine.

[walt1120]

Originally Posted by Barricade81 450-500 at the wheels. It'd my DD for now, but it won't be once I start to really dig into the engine.

pretty high goal for a v6, be prepared to spend some dough

[Barricade81]

Originally Posted by walt1120 pretty high goal for a v6, be prepared to spend some dough

I am This is probably the only 'stang I'll ever own, so I'm going to have fun with it.

[Codeman]

If you are going for those numbers get an 8.8. Sure you can make the 7.5 work. But if you are making that steam you wont be able to launch hard at the track even with a tru trac. Just get an 8.8 and add gears. Then when you start making more power update and add the tru trac with 31 spline axles.

[Barricade81]

Originally Posted by Codeman If you are going for those numbers get an 8.8. Sure you can make the 7.5 work. But if you are making that steam you wont be able to launch hard at the track even with a tru trac. Just get an 8.8 and add gears. Then when you start making more power update and add the tru trac with 31 spline axles.

Yea I'll just go with the 8.8 at this point. The prices I've found for the 8.8 differential isn't that much more than the 7.5 anyway.

[JTs03v6]

Running 400rwhp through a detroit locker in a 7.5 and have -0- worries it will brake. I do worry about my stock axles.

The only benefit I can see from an 8.8 is you can upgrade to 31spline axles. The 7.5 can be upgraded to hardened axles though.

[Codeman]

That is true on the ^. I just wanted OP to see both sides.

And if you can find a cheap 8.8 then go for it is what I say. But I could not find a cheap one.

[stangcharger]

As long as you don't beat it often at the track even a factory 7.5 rear will be fine. With prolly 10 total times to the track from 301rwhp-436rwhp never had an issue. Still on 7.5 rear with just 3.73 and posi added, no upgraded parts yet.