traction help..........

T

TURBOV6

"SECRET PARTS"
Staff member
Joined
May 28, 2001
I need to get better traction of what I have right now, the rear consists of stock springs, Bilsteins shocks, air bags on both sides and 275-50-15 BFG drag radials on stock GN rims.

My first run I did not heated up the tires with 25lbs of air in the tires, building boost at the line about 3lbs the car creaps forward. 60ft was a terrible 2.5 range

Next run heated the tires alittle (dry burnout) and with 20lbs of air in the tires, got alittle better 2.3 60ft

Third run and same as the 2nd run but got a little better 60ft 2.1.

All these run my air bag was at 5lbs on each side(was told from a friend to let the car squat), the scary thing is when i'm launching the car off the line the car will lose control (spin, fish tail off a few feet off the line) so I have to ease off the gas, so when I do this I get a shower et's.
 
Originally posted by TurboV6
was told from a friend to let the car squat
Click to expand...

Quit listening to your friend... He evidently wants your car to go slow... You want to keep the rear stiff (see web page in my sig for the reasons). Add more air to the air bags. You still may have too much air in the tires. I think I read that someone runs them around 17psi for the best traction.

hth's
ks
 
I have read in a couple of write ups on the BFG Drag radials that theyneed a lot of heat. I know that BFG says differently, but you might want to try some big smokey burnouts and see if that helps. Worth a try right.


zak
 
talk to UNGN about launching on drag radials.......my feeling is you are tilting windmills trying to race with DR's...get some race tires!.....you should also preload your suspension with your air bags, like 15 lbs in pass side and 5 in driver side....if you spin at all, you are going slow!!!!
 
There are about 50 do's and don'ts that are associated with drag radials. The MFG's should send out a card with the do's on one side and the don'ts on the other. The BIG do's are keep the tires as clean as possible. The BIG don'ts would be Never park or drive on dirt, crushed rock, gravel or grass if you can avoid it. After the first burnout of the evening, this is especially important. The pores get opened by the burnout (think of millions of suction cups) and dirt will clog these pores (think of a million suction cups with no stick)

Lesser do's and don'ts are:
Do a burnout (staionary and launching) on concrete to check the tire contact patch (for tire and airbag pressures)
If the tire is light in the middle (common for underinflated 275's on a 7" rim) you aren't using the center high traction band. Somewhere around 18-20 psi will provide the best patch with a stock rim (lower with a wider rim)
After the burnout check the tread. If rolled up balls of rubber are present, the burnout was too long.
Get a linelock. It will helps the brakes (by letting them stay cool) and will be easier on everything.
Don't listen to people that tell you to lower drag radials down to 13 psi. Sure your 60 fts will improve vs. awful, but 275/50 drag radials aren't designed to work at 13 psi on a stock 7" rim (maybe on a 10" rim) Most of the traction comes from the tire distortion (deflated basketball traction) rather than the "millions of suction cups" method the engineers intended. If you try all of these and run at a dirty track with no prep or sweeping, forget about making drag radials hook better than 1.90's and go to a slick tire.

A far as car setup goes, squatting is for corvettes and 240Z's (and puppys). Lower the air pressure in the tires to 18 psi, crank up the right side air bag to 25 psi (leave the driver side at 5 psi), do a burnout until you see smoke in your rear view mirror and launch by rapidly flooring the accellerator, waiting an instant, then releasing the brakes. After flooring the gas pedal hold it there. If it goes up in smoke, come off the gas and reapply full throttle. If it still spins come off the pedal further, next time. Pedalling a turbo car doesn't work. It screws up the fueling and the turbo spool and the tire never "plant". You want to use the engine to fully plant the tires. Make the suspension push them into the ground (the opposite of squatting)
 
I run about 20psi of air on passenger side air bag,10psi on drivers side air bag, 12psi of air in both tires(BFG Drag Radials,275/50-15)on the stock GN wheels,do a really big smokey burnout,and i usually average around a 1.80 60ft and have gone high 11's low 12's in the 1/4

Mike
87GN 11.72/114
 
HOW MUCH , air in the Bags for MT ET STREETS 10.5 x 15??
and how much in the slicks. TIA
 
Originally posted by SVTR1
HOW MUCH , air in the Bags for MT ET STREETS 10.5 x 15??
and how much in the slicks. TIA
Click to expand...

I have always run my slicks around 13-14psi with good success. For the airbags, I usually start off with 20psi in the passenger side and 10psi in the drivers side and adjust from there. My best ever 60' was done @ 9psi DS and 22psi PS.
 
Originally posted by xtreme6mwm
12psi of air in both tires(BFG Drag Radials,275/50-15)on the stock GN wheels,do a really big smokey burnout,and i usually average around a 1.80 60ft and have gone high 11's low 12's in the 1/4

Mike
87GN 11.72/114
Click to expand...

12psi? Is'nt that kind of low?

And thanks everyone for the help, I will need it for this Saturday's race.

And also I still new in launching techniques I try to creep up to the first white light and then start to build boost then move on to the second white staging light. Should I start to build boost rolling in to the staging lights?
 
IMHO, 12psi is way too low for a drag radial to run safely at high speeds. It's not a drag slick with screws, so pressures that low can be dangerous.

I wouldn't recommend going below 18psi. So you should be fine with the 20psi that you are currently running in the rear. Be sure to air up your front tires to about 38-40psi.

Also, like a few have already mentioned, you might want to increase the airbags to 10psi (left) / 20psi (right), then adjust the pressure according to the way the car feels as it launches off the line. Increase or decrease pressure in the left bag.

Good luck this Saturday at the Import Races!

Keith
 
I don't believe anyone was talking about running 12 lbs air in a radial......those pressures are for bias ply, soft sidewall, slicks or DOT slicks..........
 
alot of people get the wrong impression when it come to a given tire, bigger is not always better. I would tell some one who has a problem hooking you may want to look into a taller tire, these cars make so much on the bottom, alot of them have a hard time hooking, after you move the car like 20-30ft, then basically any good tire will work from then on. I recommend somethin like a 30 x 12.5 x 15 mickey thompson. these car on a basically stock motor do not like to be turned an rpm's

even with like a 7.50 1/8th tune up the motor will quit making HP around 4800-5200 rpms, however the motor will continue to turn rpms up till the limiter. so, the longer that you can keep an engine of this nature within its "powerband" the longer the shortblock can stay together. And give you many troublefree 7.50 passes
 
ah yes, I see........don't think 12 lbs in a radial would be good....18-20 works
 
Hey fellas,just wanted to clarify about my 12lb statement on drag radials,when i got to the track that day i never checked the air pressure from the week before,which usually i keep around 14lbs,but this day was a little colder and the car left really hard (1.70 60 ft) and i didn't check the pressure til after the pass,and that's when i started running 12lbs,it didn't feel any different than 14 or 15lbs going through the traps, some say unsafe, yea probaly,but what a ride
Mike
87 GN 11.79/114
 
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