OK, I can't hook anymore. Last year with less power I ran 1.66 60' times, now 1.75 is my best, mostly 1.80's. WTF? Tried launching with less boost, but it hooks for a foot or two, then spins hard. Like sideways. I'm running 28x11.5 et streets. Last year was 26x8.5 et drags. Its a bigger tire this year, but drags hook better. What can I do? I've got two airbags, drag shocks(front and rear), pinion snubber, stock arms. NO wheelhop, just spin. Tried different burnouts too. Maybe this track just sucks compared to where I was going last year. Ideas?
What happened to my 60' times!!??
- Thread starter turbosam6
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Don't say that. I just spent $360 on these! Friday I went back and cut some cool sideways 1.99 60' times. This sucks. I ran 7.7 94 mph with my 200 lb buddy riding shotgun, and a 1.94 60'. That would be flyin if it hooked. Take off the weight, and compensate for the traction, and that should be 7.30 or so. Aaarrgghh! Can I do anything to hook on these et streets? Guys run 1.6 all the time on DR's, and these are better.
I can add: ET Streets ARE NOT ET Drags. Regardless. I ran the 26x11.50's for just over a year, and NEVER 60's anywhere near what I did with a cheap (borrowed) set of 26x8.5 ET Drags.
There's just no comparison. And unless the track is in perfect condition (NHRA national meet) , the differences are huge.
There's just no comparison. And unless the track is in perfect condition (NHRA national meet) , the differences are huge.
- Joined
- May 28, 2001
- Messages
- 16,737
Traction??
3 things I see that could be part of the problem
1. The drags were 26" tall and the streets are 28".. that difference will change the net torque you are applying to the ground.
2. The snubber could be causing the rear tires to unload...
The chassis pitch rotates and plants the tires.. the snubber then hits and stops the chassis from working and then the tires unload, causing the spin after the initial launch..
3. If the car is going sideways, I'd look at the posi condition, tire pressure and air bag pressure. Even if the car is spinning the tires, it should go strait..
3 Suggestions..
1. Lose the snubber and tune the chassis w/ the proper components such as shocks and springs, control arms w/ good bushings, and the proper pinion angle.[like 3-4*]
Snubbers are 60's technology and were used on leaf spring cars. You have a 4 link car.. when was the last time you saw a snubber on a pro stocker or a comp elim car??
2. Put the car on a set of scales and w/ it at race wt, including driver, see what the wheel loadings are. To a degree, you can control that w/ the air bags..
3.Experiment w/ tire pressures.
I did a series of tire tests w/ Jerry Francis of MT. We found:
ET Streets were marginally BETTER than an equal sized Drag.!
That both tires liked the 14-16 psi inflation.
That both tires liked an equal amt of heat buildup from a burnout.
Jerry reported he wanted to see the tires at a temp of 10 to 15* hotter than the track surface.
NO dry hops! The burnout forces oil out of the rubber and to the surface of the tire. This makes the tire sticky. Dry hops remove some of the oiled surface.
Do not spin the tires while in the "puddle" of the burnout box. doing this throws water into the wheel house and this water then drips off onto the track IN ftont of the tires when staged.
Back into the water, roll forward to"high ground", and do the burnout. We used a 3 sec count to keep all burnouts the same length. Counting: one thousand one, one thousand two, ETC.
LASTLY Don't try to compare two different tracks two different years!!
3 things I see that could be part of the problem
1. The drags were 26" tall and the streets are 28".. that difference will change the net torque you are applying to the ground.
2. The snubber could be causing the rear tires to unload...
The chassis pitch rotates and plants the tires.. the snubber then hits and stops the chassis from working and then the tires unload, causing the spin after the initial launch..
3. If the car is going sideways, I'd look at the posi condition, tire pressure and air bag pressure. Even if the car is spinning the tires, it should go strait..
3 Suggestions..
1. Lose the snubber and tune the chassis w/ the proper components such as shocks and springs, control arms w/ good bushings, and the proper pinion angle.[like 3-4*]
Snubbers are 60's technology and were used on leaf spring cars. You have a 4 link car.. when was the last time you saw a snubber on a pro stocker or a comp elim car??
2. Put the car on a set of scales and w/ it at race wt, including driver, see what the wheel loadings are. To a degree, you can control that w/ the air bags..
3.Experiment w/ tire pressures.
I did a series of tire tests w/ Jerry Francis of MT. We found:
ET Streets were marginally BETTER than an equal sized Drag.!
That both tires liked the 14-16 psi inflation.
That both tires liked an equal amt of heat buildup from a burnout.
Jerry reported he wanted to see the tires at a temp of 10 to 15* hotter than the track surface.
NO dry hops! The burnout forces oil out of the rubber and to the surface of the tire. This makes the tire sticky. Dry hops remove some of the oiled surface.
Do not spin the tires while in the "puddle" of the burnout box. doing this throws water into the wheel house and this water then drips off onto the track IN ftont of the tires when staged.
Back into the water, roll forward to"high ground", and do the burnout. We used a 3 sec count to keep all burnouts the same length. Counting: one thousand one, one thousand two, ETC.
LASTLY Don't try to compare two different tracks two different years!!
Et Streets aren't ET drags, but 1.94 60 fts suck for ET streets.
What was your airbag pressure? You may have put air in the left side bag which is a no no. Left side air takes weight off the right side tire. Since axle rotation also takes weight off the right side tire, there isn't enough weight there to begin with. Taking any off makes things worse. Your car should respond exactly as you described: step sideways and spin.
Take the air out of the left side bag and crank 20-25 psi into the right side bag. If you need to run air in the left side bag, keep the difference 20-25 psi. See if that helps.
What was your airbag pressure? You may have put air in the left side bag which is a no no. Left side air takes weight off the right side tire. Since axle rotation also takes weight off the right side tire, there isn't enough weight there to begin with. Taking any off makes things worse. Your car should respond exactly as you described: step sideways and spin.
Take the air out of the left side bag and crank 20-25 psi into the right side bag. If you need to run air in the left side bag, keep the difference 20-25 psi. See if that helps.
I had 20 psi in the right side, 4-5 psi in the left side airbag. I know that taller tires will affect the torque mult. but I am also making more power this year, and the messed up part is the last 1.66 that I cut last year was on NO BOOST! I will lose the snubber, but I know the track was not prepped well. I'm gonna borrow some et drags and see what happens. Of course the tranny is starting to slip, so that doesn't help.
In addition to Chuck's comments, you may want to try adjusting your front shocks to rise less quickly. Could be that they're reaching full extension far too soon and starting down in the first 5 feet, thus unloading the rear tires...dunno if this is possible with ET streets though. In support of the comments above, comparing streets to slicks is like apples to oranges.
HTH
Jim
HTH
Jim
Two of the 11-second cars in my f-body club ran 1.5x short times on ET-streets this last weekend. The 11.1 car went 1.55 on a 28x12.5 tire and the 11.6 car went 1.57 on a 26x10.5 tire. This is not to say that ET-streets are better or worse than a similarly sized slick, it just shows that a daily driven street car can run a pretty good 60-foot if properly set up, even on the same tires it used to drive to the track.
Peter
Peter
HRpartsNstuff
Member
- Joined
- May 27, 2001
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- 844
I would agree that ditching the snubber may help out.
A 11.5 x 28 et street tire should net you better than 1.7's. Can you better describe what's happening right before it starts to spin? If you think it is squating & coming out hard, and then starts to spin, it could be bouncing on you. I have seen many cars do this with airbag pressures over about 15psi. It turns them into basketballs. We make airbag spacers that install under the bags & let you keep the same downforce (or body lift) while using a reduced pressure. This takes the basketball effect out & keeps it hooked up. It's the cheapest e.t. gain I have seen so far.
If you have the spacers installed, ditched the snubber, and checked the posi, and it is still spinning... Launch it harder! You may be launching below your torque peak so it hooks up & goes a few feet & your rpm's get into the powerband & those tires are gone! You have no more weight to transfer at that point & a marginal track/tire combo won't take the big change in HP. It's kinda like hitting the nitrous 3 feet out on an easy launch. Hit it harder (more boost) & closer to your torque peak and it should transfer more weight quicker & keep the tires planted firmly. I have seen cars with BFG drag radials pull the front wheels & run in the 1.4's!!! You might even want to try a race shock in the front that you can turn to 90/10 for race day.
PS- You might not benefit from launching it harder with the stock rear control arms & rubber. You might want to look at our bushing & boxing kit upgrades minimum to take the extra abuse. Make sure your axles & the rest is up to the task too. It is harder on stuff, but boy is it fun!
A 11.5 x 28 et street tire should net you better than 1.7's. Can you better describe what's happening right before it starts to spin? If you think it is squating & coming out hard, and then starts to spin, it could be bouncing on you. I have seen many cars do this with airbag pressures over about 15psi. It turns them into basketballs. We make airbag spacers that install under the bags & let you keep the same downforce (or body lift) while using a reduced pressure. This takes the basketball effect out & keeps it hooked up. It's the cheapest e.t. gain I have seen so far.
If you have the spacers installed, ditched the snubber, and checked the posi, and it is still spinning... Launch it harder! You may be launching below your torque peak so it hooks up & goes a few feet & your rpm's get into the powerband & those tires are gone! You have no more weight to transfer at that point & a marginal track/tire combo won't take the big change in HP. It's kinda like hitting the nitrous 3 feet out on an easy launch. Hit it harder (more boost) & closer to your torque peak and it should transfer more weight quicker & keep the tires planted firmly. I have seen cars with BFG drag radials pull the front wheels & run in the 1.4's!!! You might even want to try a race shock in the front that you can turn to 90/10 for race day.
PS- You might not benefit from launching it harder with the stock rear control arms & rubber. You might want to look at our bushing & boxing kit upgrades minimum to take the extra abuse. Make sure your axles & the rest is up to the task too. It is harder on stuff, but boy is it fun!
Thanks Paul. Actually the car has 90/10 fronts and 50/50 rears. I tried launching soft and hard. The DS files even show how I peddled it back to try and prevent spin. I'll call tomorrow to get the airbag spacers from you. I know these tires hook better than this. I also plan to get your control arms as soon as I can afford them, gotta get a transmission first. It does seem to transfer weight pretty well, so maybe the spacers will help.
