To kill a drag radial...
03-17-2002, 08:09 PM
#1
To kill a drag radial...
Saturday I went to the track with a few of the guys for an import meet. My nitrous was not working, I had an electrical gremlin 
The water injection didnt seem to help so it was disabled for most of pass's.
My boosted times were as follows..
On my 205/50-15 BFG gForce drag radials on 15x7 Kosi K1 rims
13.443ET @104.906MPH 2.132 60'
FWIW,Corrected for enviormental factors 85f 57% 29.98"
13.2 @ 103
On my 225/50-16 Dunlop SP5000s on 16x8 RX7 rims
13.562ET @ 107.040MPH 2.204 60'
I did my first two runs on my street tires @34psi and got 13.8s with "street" trim. Then I put the DR's @ 22psi on and set the AGX's to full stiffness and did a few pass's. I eventually set the DR's to 18psi and did a lot more pass's, maybe ~20. I then started to notice that my 60's were getting worse, so I looked at the DR's and saw that the leading edge's of the tread blocks had ~1/8" thick layer of rubber ply pealing off? So I switched back to my street tires @22psi and did a few more runs. With all setups I did short tire cleaning burnouts.
With the DR's I would get decent hole shots ~2500rpms, but when I shifted into 2nd the tires would spin for at least one half to maybe a full second and torque stear to the right! Where as with my street tires on the later runs would hook ok out the hole, but bairly chirp 2nd and hook? My best 60' with the DR's was 2.095 on one of my early runs at 22psi. In the later runs with the DR's @18psi I was getting ~2.175's. With the streets a best of 2.204.
My first conclusion is that I had the pressure in the DR's a bit too low @18psi because the outer blocks were worn more. My second is that 205/50-15 is WAY to small for the power I am putting down. Time for some slicks!
I do have a few questions I hope some one can answer. Would VHT cause the tire tread layer pealing? When I nailed my 2nd gear shift with the DR's, just after the tires stopped spinning I would hear a low pitched groaning noise, could this be the clutch letting go? (or was my car begging for mercy)
I'll try and get a few pic's of the DR's treads for yall to see, cause their toast I think!
The water injection didnt seem to help so it was disabled for most of pass's.My boosted times were as follows..
On my 205/50-15 BFG gForce drag radials on 15x7 Kosi K1 rims
13.443ET @104.906MPH 2.132 60'
FWIW,Corrected for enviormental factors 85f 57% 29.98"
13.2 @ 103
On my 225/50-16 Dunlop SP5000s on 16x8 RX7 rims
13.562ET @ 107.040MPH 2.204 60'
I did my first two runs on my street tires @34psi and got 13.8s with "street" trim. Then I put the DR's @ 22psi on and set the AGX's to full stiffness and did a few pass's. I eventually set the DR's to 18psi and did a lot more pass's, maybe ~20. I then started to notice that my 60's were getting worse, so I looked at the DR's and saw that the leading edge's of the tread blocks had ~1/8" thick layer of rubber ply pealing off? So I switched back to my street tires @22psi and did a few more runs. With all setups I did short tire cleaning burnouts.
With the DR's I would get decent hole shots ~2500rpms, but when I shifted into 2nd the tires would spin for at least one half to maybe a full second and torque stear to the right! Where as with my street tires on the later runs would hook ok out the hole, but bairly chirp 2nd and hook? My best 60' with the DR's was 2.095 on one of my early runs at 22psi. In the later runs with the DR's @18psi I was getting ~2.175's. With the streets a best of 2.204.
My first conclusion is that I had the pressure in the DR's a bit too low @18psi because the outer blocks were worn more. My second is that 205/50-15 is WAY to small for the power I am putting down. Time for some slicks!
I do have a few questions I hope some one can answer. Would VHT cause the tire tread layer pealing? When I nailed my 2nd gear shift with the DR's, just after the tires stopped spinning I would hear a low pitched groaning noise, could this be the clutch letting go? (or was my car begging for mercy)
I'll try and get a few pic's of the DR's treads for yall to see, cause their toast I think!
03-17-2002, 10:26 PM
#2
Senior Member
Join Date: Aug 2000
Posts: 2,807
Around what rpm were you finishing the 1/4 at? Generally with slicks your 60ft and ET drops but you lose alittle more trapspeed vs DR's/street tires. Given your trapspeed and tire size you should be finishing around 5400-5600rpm in 4th gear. Man you killed some DR's hehe good job!
03-17-2002, 10:43 PM
#3
Turtle turtle... Moderator
iTrader: (25)
Join Date: Aug 2000
Location: San Bruno, Petaluma, SF Bay area
Posts: 4,857
haha....hate to say i told you sooo....but rmemeber Matt? i told you 205's werent gonna do!! anyways i have some 225/50/16 drag radials or i might juss go with some 245's. dunno
Thread
Thread Starter
Forum
Replies
Last Post
Maxima_Joe
4th Generation Classifieds (1995-1999)
16
11-25-2015 08:19 AM