[bulloch27]

First hand experience here.... you run out of gear with 4.10 and 28" tire at 118 mph. I run the eighth so I'm good with it but the few times i've run the quarter I run out of gear in the traps.

[Shaun03GT]

I have first hand expierience with 4.10s and stock tire size. Trapped 117mp as i was going through my shiftlight went off. I spin my motor to 6300-6400. That plays a big roll. With a 28" tire it'd be like 3.73s almost and id be able to do atleast 125mph

[bulloch27]

I agree, the increased RPM will you give you more. I should have added that I'm still running the stock RPM rev limiter and don't turn past 6000 unless I absolutely have to.

[Shaun03GT]

Yeah so that's where I make up for the extra mph. 4.30s would be so nasty. If it was only 1/8 mile is definitley do them.

[bulloch27]

You can choose to run the 1/8th on a 1/4 mile track Shaun!!!!!!!!!!!

[Eagle2000GT]

Originally Posted by bulloch27 You can choose to run the 1/8th on a 1/4 mile track Shaun!!!!!!!!!!!

Obviously, you do not play the same game as me. Whether I win or lose I enjoy the heads up race. I've been down the track only a few times this year and some of them have been against rails. But I have raced heads up a Mach 1, a new model GTO, a new Charger SRT, a new SS Camaro, a 95 Trans Am, a 90 something Corvette, and a Pontiac G8. I beat all of them except the G8. I was disappointed he got me .4 seconds on reaction time (I was pretty slow.). But I lost the race by .05 seconds (five one-hundreth of a second). My car was faster yet he beat me. It was also the most exciting race I've had in a long, long time. I was closing in and damn near got him. Once in fourth I could see the gap closing and we finished side by side. After that run, he told me he'd never seen a Mustang catch up like that. Damn, exciting race.

Heads up racing. That is what we used to do. For a lot of you reaction time doesn't seem to count. It does in a real race.

[Shaun03GT]

When I go to the track, if Im racing a random car, I dont really care if I win or lose to be honest. If its my dad or a friend, its fun. Ill let my dad jump on the light, then take off. I never really focus on R/T. Just try to get a good launch.


So what do you guys think? I could really set this car up for 1/4.

4.30's
28" QTPs on 15" wheels
MSD 2 step
26 Spline Input shaft

6,300rpm with that setup at the top of 4th is 122mph. Which will be more then enough for the stock motor. By the time I hit those trap speeds, Ill have a built motor spinning to 7k which would be 135mph. That gives me PLENTY of head room. Ill hang onto my 3.73s just in case.

Heres where Im getting my calculations for speed/tire

MOTOR - A Rear Axle Calculator

[bulloch27]

Originally Posted by Eagle2000GT Obviously, you do not play the same game as me. Whether I win or lose I enjoy the heads up race. I've been down the track only a few times this year and some of them have been against rails. But I have raced heads up a Mach 1, a new model GTO, a new Charger SRT, a new SS Camaro, a 95 Trans Am, a 90 something Corvette, and a Pontiac G8. I beat all of them except the G8. I was disappointed he got me .4 seconds on reaction time (I was pretty slow.). But I lost the race by .05 seconds (five one-hundreth of a second). My car was faster yet he beat me. It was also the most exciting race I've had in a long, long time. I was closing in and damn near got him. Once in fourth I could see the gap closing and we finished side by side. After that run, he told me he'd never seen a Mustang catch up like that. Damn, exciting race. Heads up racing. That is what we used to do. For a lot of you reaction time doesn't seem to count. It does in a real race.

I have no idea where you came up with this. I said you can run the 1/8th instead of the 1/4. I said nothing about reaction times or bracket starts. I'm glad you ran against a rail. Do you know that you can run against a rail in the 1/8th too. My point was that if he wants to run 4.30 gears and runs out of gear in the 1/4, he can simply run the 1/8. I prefer the 1/8 because of slower speeds, I'm not a huge fan of crossing the line at high speeds and trying to get stopped while making sure the dipshit in the other lane doesn't drive through my ass end.

[JTs03v6]

Pretty simple really...your centri is rpm dependant, so the highest gear you can hook on the faster you'll go. I was going to go with 4.56 if I kept the d1sc on the car.

I vote 4.30 and wind it out to 6500rpm 1st- 2nd, 6200rpm in 3rd, and just ride out 4th

[stal94gt]

My vote is 4.10's with a 26 inch tire. Or if your willing to buy new tires 4.30 gears with 28's on the street it does not matter the gear and tire combo

[Shaun03GT]

I'm really thinking of just putting money into it for the track. 4.30, 28" tires, 2 step, 26 spline input shaft, lca and uca. Car would be a beast out of the hole. I need more money!

[DickH]

maybe just be cheap and remove weight. its really really cheap and it should help with the mph

[bulloch27]

Don't neglect the 31 spline axles!!!!!!! Much more fun as a track car than a daily driver in my opinion anyway.

[stal94gt]

what did you calculate as your mph with 4.30's and 28 inch tires? i just did a similar swap and it really helped out. dialing in rpm for the track really improves track times. plus running a 28 inch slick makes the launch so much softer and it hooks better. you get more sway down the strip but that can be controled and you get used to it. im setting up a compleatly new combo for my self this winter, getting rid of all my current suspension and going with a full baseline pro launch setup in the back, k member, A arms for the front with new shocks and struts. i imagine once im done i will see 60 ft times in the 1.4-1.3 range. building for street and building for strip are 2 totally diff paths and im done messing around trying to keep best of both worlds.

[JayC]

Originally Posted by JTs03v6 Pretty simple really...your centri is rpm dependant, so the highest gear you can hook on the faster you'll go. I was going to go with 4.56 if I kept the d1sc on the car. I vote 4.30 and wind it out to 6500rpm 1st- 2nd, 6200rpm in 3rd, and just ride out 4th

This is the answer! Even with butt loads of torque my car loves the 4.10/28" tire set-up. If I was running a centri I would not hesitate to drop 4:30's in there!

[Shaun03GT]

Originally Posted by bulloch27 Don't neglect the 31 spline axles!!!!!!! Much more fun as a track car than a daily driver in my opinion anyway.

Rearend is all built. 31 splined and cobra diff with carbon clutches.

Originally Posted by stal94gt what did you calculate as your mph with 4.30's and 28 inch tires? i just did a similar swap and it really helped out. dialing in rpm for the track really improves track times. plus running a 28 inch slick makes the launch so much softer and it hooks better. you get more sway down the strip but that can be controled and you get used to it. im setting up a compleatly new combo for my self this winter, getting rid of all my current suspension and going with a full baseline pro launch setup in the back, k member, A arms for the front with new shocks and struts. i imagine once im done i will see 60 ft times in the 1.4-1.3 range. building for street and building for strip are 2 totally diff paths and im done messing around trying to keep best of both worlds.

With 4.30s and a 28" tire gives me 122mph at 6300 and about 125mph at 6500.

Your car will be a beast with that setup man.

Originally Posted by JayC This is the answer! Even with butt loads of torque my car loves the 4.10/28" tire set-up. If I was running a centri I would not hesitate to drop 4:30's in there!

Exactly! I think I'm leaning towards the 4.30s. I'll probably run 28" mt street radials when my toyos are done.