ET Street Radials on a 6 speed.

[94-6spd]

A buddy of mine has a LT1 6 speed Firebird Formula with a set of 315/35/17 et street radials. The car will dead hook at a 3K rpm launch at 18-20 psi. (Bogs) The car is a bolt-on's car that only runs 8.30's to 8.40's in the 1/8th. The 60' times are barely 1.9's on a dead hook.

Here is the problem, I think the car should go quicker et's with a higher rpm launch and a better 60'. When he raises the rpm it'll smoke the tires and get a 2.?? 60' time. He has all the aftermarket suspension parts. Torque arm, LCA's, panhard bar, and subframe connectors. Don't get me wrong the car runs good for what it is but should go quicker with a better launch. What could we change to be able to launch at a higher rpm? Do you think tire pressure would help? Oh, the car does still have the sway bar on the front for when he auto x's the car. Any help or .02 is appreciated.

[z289sec]

A buddy of mine has a LT1 6 speed Firebird Formula with a set of 315/35/17 et street radials. The car will dead hook at a 3K rpm launch at 18-20 psi. (Bogs) The car is a bolt-on's car that only runs 8.30's to 8.40's in the 1/8th. The 60' times are barely 1.9's on a dead hook.

Here is the problem, I think the car should go quicker et's with a higher rpm launch and a better 60'. When he raises the rpm it'll smoke the tires and get a 2.?? 60' time. He has all the aftermarket suspension parts. Torque arm, LCA's, panhard bar, and subframe connectors. Don't get me wrong the car runs good for what it is but should go quicker with a better launch. What could we change to be able to launch at a higher rpm? Do you think tire pressure would help? Oh, the car does still have the sway bar on the front for when he auto x's the car. Any help or .02 is appreciated.


Dumb idea but, does that car have the factory traction control system? I know some guys with the new Challengers and Roush supercharged Mustangs that have reduced there E.T.'s substantially by enabling the factory TCS. All the Mustangs were stick cars. Just a thought.

One in particular would barely manage a low nine, high eight second 1/8 mile, but it ran 98 mph out the back door, so it was making plenty of power. With the TCS on it was able to run in the 7.4xx range. Took a lot of grunt out of it initially but didn't blow the tires off.

[94-6spd]

No, this car isn't equipped with traction control. With another friends Z06 we would do better with it off. That surprises me that the Mustangs and Challengers do better with it on.

[Big Cliff]

What about slipping the clutch.......I would think that a 1.8x 60ft should be easy slipping it. No low pro sidewall is going to be able to hold the clutch dump.

[Jason Moulton]

Radials and stick cars are a tough combination. With too much RPM they will spin or wheel hop. Too little and they bog. A lot of people will "slip the clutch" instead of "dumping it".
If you want to dump the clutch on most cars, a bias tire will work out much better.

Thanks,

Jason Moulton

[94-6spd]

Radials and stick cars are a tough combination. With too much RPM they will spin or wheel hop. Too little and they bog. A lot of people will "slip the clutch" instead of "dumping it".
If you want to dump the clutch on most cars, a bias tire will work out much better.

Thanks,

Jason Moulton

I agree that it's a tough combination but this is a low hp car with a 315 wide tire. Aren't there people out there with trans brakes hitting the tires hard and not spinning or hopping? :confused: I believe that there is a way to make this car work better. Will try slipping the clutch a little next time out.

[5678TA]

i tried radials when i was running in the mid 12's.. 275/50-15 and she didnt want any of it. it would spin most of first and do a nice spin in second.

but somehow it was damn consistent. i would dial 12.45 and run 12.45-12.47 with 60ft's in the 1.81-1.84 range. never went 1.80 or lower though.. any rpm above 2k would result in the same spin off the line and it would still turn the same 60ft. i just stuck with 4k on the radials. :smt102

i even tried different length burnouts and it was all the same. but it could just be the car because even on hoosier qtp's it only 60ft's in the 1.7x.. spinning hard.

[Jason Moulton]

I agree that it's a tough combination but this is a low hp car with a 315 wide tire. Aren't there people out there with trans brakes hitting the tires hard and not spinning or hopping? :confused: I believe that there is a way to make this car work better. Will try slipping the clutch a little next time out.

Yes, transbrakes are being used, but a converter is different than a clutch.

Radials like a relatively hard load applied, then maintained. They do not like to be "shocked" as the case when "dumping" the clutch.

A word of caution when slipping the clutch, obviously with those tires, that is hard on that component as well. (I have to say that you know!:))

Thanks,

Jason Moulton

[MrNova]

so for my 5speed on the street a drag radial wouldn't be a good choice???

[5678TA]

the radials would be good for street usage but not for drag..

[Jason Moulton]

so for my 5speed on the street a drag radial wouldn't be a good choice???

For street driving, the radials will handle and ride better than the bias ET Streets. For the best results with a stick and a DOT tire on the dragstrip, the bias ET Street would be preferred.

Thanks,

Jason Moulton

[Green&Silver95]

when you take the car to the track just unbolt the front sway bar and try that. also you might wana try a hoosier radial the side wall is a little softer.

[wazslow]

They work fine if you can get some practice on them. I had an 03 cobra with upper pulley, catback, and cai. Bone stock ford suspension with a 275 x 40 x 17 MT drag radial on the stock rims. Car would go 1.66 60's all day and I was still bogging it a little. Its all about the driver, and practice! You CANT just go and dump the clutch and think they will hook though.

[GrannySShifting]

practice practice practice. Ive cut 1.80-1.82 on factory 275/40 tires, and been best of 1.47 on a 275 drag radial with a low 400 hp ls1 car. Just a matter of getting the suspension right and hitting tire right

[Collinsautomotive]

Does this car have Lower control relocation brackets ? IF not get a set. That will take the prodive right outta the rear suspension. If he roads races as you mentioned in your original post get a set of bolts in LCA brackets so you can take them off. Toss the front sway bar links to when your at the track.