Better traction for drag racing

[Boostn]

Hey guys,

I have a 68 mustang coupe. I have ran best of 11.9 at 117mph. I have done that time with 125 and 175 shots of nitrous.

I am running on flex-a-forms fiberglass leaf springs and 255 profile 16 inch wheels M/T ET street drag radials. Mustang weighs about 3100lbs. I couldn't go any faster since I would lose traction when I upped to 175 shots of nitrous. My mustang wouldn't squat much with those fiberglass leaf springs, so I think they are not good for drag racing, but I don't have any wheel hop. I am thinking I need to get opinions of how to improve my rear end suspension and wheel sizes to get better times. It is still on 8in axle.

I just had it dynoed for fun and free this morning. It planted down 300hp without nitrous which I am happy about that for only 9:1 compression 5.0L fuel injected engine with T-5. I tried again with 225 shots of nitrous, but I broke traction and didn't have enough nitrous for 2nd run after airing down the tires. So I will try again later.

Just wanted to get better track times with new rear end set up. Any ideas and info would be helpful

 

[Robdogg67]

Caltracs typically are mentioned as the best traction assist for traditional suspension but I'm not sure how they would work with composite springs, maybe call them and ask. I'm running Caltracs and love them with 4.5 leafs on 9" with 3.70 gears.

 

[brianj5600]

What about the front suspension?

 

[DukeGnarley]

there's a thread from a while back labeled "how to drag race your classic" search for it, there's plenty of good tech info in there.

 

[dennis112]

Caltracs and Rancho 9 way adjustable shocks in rear. Set the shocks to 5.

6 cylinder coil springs and cheap 90/10 drag shocks in front. Set the shocks on their lightest setting, if they are adjustable. Run narrow tires on the front. Remove one of the end links off the front sway bar.

Move the battery to the trunk. Remove any excess weight from the car, such as the rear seat, spare tire, jack, and what ever.

 

[Blue Oval Man]

You stated that the car doesn't squat much when you leave the line. That's great. You don't want the rear to squat, for maximum traction you want the front to rise. As others here have said, caltracs are great, but if you have little squat and no wheel hop it sounds like you would be better off working on the front suspension. Opentracker has a set of upper control arms and spring perches with roller bearings that work great, six cylinder springs and adjustable shocks and remove the sway bar for racing should help with your times, although they sound fairly respectable as is.
David

 

[Taranis]

When I bought my flex-a-forms, the guy said that the caltracs work well. I can't testify to this, though as my car hasn't been driven since I put them on.

 

[67Dylan]

What does your 60' times look like? What pressure are you running in the tires? Are you getting the tires plenty hot?
I agree about the front end, work on getting that set up properly and it will pay good dividends IMO. I've seen cars go 10's on 8" tires, it ALL comes down to suspension set up.

 

[Edbert]

Another vote for caltracs here. There are cars running high 8s on leafs with them.

 

[brianj5600]

Another vote for caltracs here. There are cars running high 8s on leafs with them.

There is an orange Camaro running 7's with them.