Trouble switching from street tires to DR's

[blufin]

After drag racing on street tires for over 4 years, I've gotten pretty good at launching on them. After the Pirelli's wore out, I decided to switch to an 18' vette wheel with Mickey's on them. The 2 times I've had them at the strip have been horrendous. My best 60' on street tires was in the 1.6's, and with the DR's, the best has been a 1.8. The last outing a few days ago was nothing but 2.0's.

I've been trying to launch the same way I was launching on street tires; slipping the clutch. The car feels like it falls on it's face. It feels like as soon as I start moving, the engine cuts power. All nannies are off. I feel a brief stutter then the power comes on. Gonna have to learn a whole new way to launch. Gotta be a lot more aggressive I guess.

Even the burnout isn't easy. The car wants to stall. I know, more throttle. Well when I do that, it doesn't want to go above 4k rpm's. All nannies are off.

This is gonna take a lot of seat time to re-learn how to launch. I want my street tires back!

[HRD_WRK]

Sorry man-but it'll be worth it once you get adjusted. You've always had killer 60s-never knew how you got by without wheelhop.
I think you're right though-get more agressive sooner. I've taken up Autox also and have had to 'relearn' myself how to launch-but back on street tires when there's no sticky and often sand/debris. I'm learning to accelerate by fast feathering in lieu of mashing-its a fine line-especially with 370s.

You've got a lot of torque with your SC-you'll be squatting harder soon-suspension and alignment will be more important.

Looks like we'll both be hitting the track next spring.

Good luck.

[xjer22x]

Originally Posted by blufin

After drag racing on street tires for over 4 years, I've gotten pretty good at launching on them. After the Pirelli's wore out, I decided to switch to an 18' vette wheel with Mickey's on them. The 2 times I've had them at the strip have been horrendous. My best 60' on street tires was in the 1.6's, and with the DR's, the best has been a 1.8. The last outing a few days ago was nothing but 2.0's.

I've been trying to launch the same way I was launching on street tires; slipping the clutch. The car feels like it falls on it's face. It feels like as soon as I start moving, the engine cuts power. All nannies are off. I feel a brief stutter then the power comes on. Gonna have to learn a whole new way to launch. Gotta be a lot more aggressive I guess.

Even the burnout isn't easy. The car wants to stall. I know, more throttle. Well when I do that, it doesn't want to go above 4k rpm's. All nannies are off.

This is gonna take a lot of seat time to re-learn how to launch. I want my street tires back!

its totally different. everything needs to be amplified with DR's.

Burnout - start in second gear, bring it up to 5500rpm and drop the clutch and keep the rpms up over 5000rpm. Its the only way to properly heat them up. I would even look into a line lock if you dont have it already. Water will be your friend to get the burnout started.

On the launch, i was bogging way too much... so i started launching @ over 5000rpm and feathering the clutch at that RPM. Worked out way better.

it will take a little bit of practice but will be well worth it once you get the hang of it.

[Bad70supreme]

I ran slower on DRs as well! The issue I had now with a sticky tire was a heavy car and under geared! All the tire did was amplify the issue. It's worse with stick car, no stall to keep the engine in the power band. I hope you have axles and a good clutch to take the abuse you need to give it. That's why I went th400, less issues to deal with and in the long run more reliable.

[etmx183]

I had the same problem with my Turbo Street bike when I switched tires. I used higher tire pressure up to the point of spinning. Than I would slowly reduce pressure to the fine point of little spin with good launch and great 60'. A good launch has a little spin to it is what I've learned. Good Luck, it will be worth the headache when you get it all dialed it.

[blufin]

Originally Posted by Bad70supreme

I ran slower on DRs as well! The issue I had now with a sticky tire was a heavy car and under geared! All the tire did was amplify the issue. It's worse with stick car, no stall to keep the engine in the power band. I hope you have axles and a good clutch to take the abuse you need to give it. That's why I went th400, less issues to deal with and in the long run more reliable.

I'm running a twin carbon street slayer but don't have axles yet. I think I may wait till I "need" them, ie, break the stock ones.

[dekan513]

man i finally made the switch like a month ago and as of probably 8 races now with them i suck . my problem seems to be either i try to do a easy launch and they bog me down really bad or when i get confident i spin. but im learning u need a ton of heat to make them hook. i dont think ive been doing a good enuff burn out

[xjer22x]

The burnout is a big part. Don't be afraid to out on a good smoke show.

sent from my galaxy s3. that would explain the errors.

[Pro Stock John]

Takes a while to change up the burnout and staging routine that's for sure.

[blufin]

I'm gonna spend as much time as possible at the track in an effort to get ready for winter. I was hoping for 10's with the current setup, but I may have to stab a cam in it if I fall short.

[redirish]

Originally Posted by xjer22x

its totally different. everything needs to be amplified with DR's.

Burnout - start in second gear, bring it up to 5500rpm and drop the clutch and keep the rpms up over 5000rpm. Its the only way to properly heat them up. I would even look into a line lock if you dont have it already. Water will be your friend to get the burnout started.

On the launch, i was bogging way too much... so i started launching @ over 5000rpm and feathering the clutch at that RPM. Worked out way better.

it will have a little bit of practive but will be well worth it once you get the hang of it.

I have the similar set up as you and only have a few runs so far! Everything xjer22x is recommending is working for me. I only launched at 3500rpm but will go higher next time. I understand the street slayer works best at higher RPM's Also go around the water and back in. I have a line lock and it works great for the burn out. I also have 4:10's now and that really helps to get her moving off the line.

I'm sure with practice you will be teaching others!

[Pro Stock John]

It's such a compromise hooking stock Pirellis at high horsepower levels, enjoy some decent tractiion and come out higher and on more power. I'm sure you'll drop a tenth maybe a lot more. I've run 325 DR's (1.35) and 28x10.5 slicks (1.38) over the years and I got tired of trying to hook stock tires, went 1.92 on them. No changes went 1.85 on 555R's. Now the 18 NTO5R's have gone 1.66 spinning on marginal track, so I still hope to do much better at some point.

[Fraxum]

Count me in on the cannot launch with DRs club . I also was better on Pirellis (in my last SS) than on NT555Rs on my 1LE, but nothing better than a mid 1.9 for me.

I have tried street launches and at 1,500-4000. The higher up I go I have to murder the clutch more to keep from spinning. Last time I lowered the pressure in my NT555R 305-45-18s to 22 pounds. That helped me get close to my best Pirelli time. I burn out in second bouncing off the rev limiter moving forward. I do get a nice plume of visible smoke.

In my last two runs last night my clutch slipped so much the motor kept revving all though first and second. On the way home it seemed better. Did i fry my clutch with only 4,000 miles on my car?

[xjer22x]

Originally Posted by Fraxum

Count me in on the cannot launch with DRs club . I also was better on Pirellis (in my last SS) than on NT555Rs on my 1LE, but nothing better than a mid 1.9 for me.

I have tried street launches and at 1,500-4000. The higher up I go I have to murder the clutch more to keep from spinning. Last time I lowered the pressure in my NT555R 305-45-18s to 22 pounds. That helped me get close to my best Pirelli time. I burn out in second bouncing off the rev limiter moving forward. I do get a nice plume of visible smoke.

In my last two runs last night my clutch slipped so much the motor kept revving all though first and second. On the way home it seemed better. Did i fry my clutch with only 4,000 miles on my car?

Nope, your clutch should be OK. What happened is your clutch fluid got hot. Look into a clutch reservoir seperating kit.

And realistically. You need a little more then just a roll out burnout. Ill look for one of my videos

*edit* here is a decent shot of how I warm them up. We suffer from poor track prep.



sent from my galaxy s3. that would explain the errors.