Drag Radial Pressure

**Nightmare00** · 06-30-2008, 05:12 AM

What is the lowest pressure recommended for drag radials? Tire size is 305-35-18 Nitto 555 Drag Radials. I was running 17 psi and still spinning off the line.... My best 60' time was 1.87.

A4 2000 Trans Am
3500 Stall
3.73 gears
445 rwhp 438 tq

**mike302** · 06-30-2008, 09:34 PM

I would say like 16-18psi, I run my nitto DRs with 17 psi

**LS2Tuner** · 06-30-2008, 09:41 PM

It all depends on what width rim you have them on. With that short of a tire anything under 15 will do NO good.

Also is you still have the stock springs and shocks on the rear they are a HUGE limiting factor. You need to go to the junk yard and buy a pair of used V-6 springs for the rear at the very least.

Your stock WS6 is VERY stiff and by NO means made for weight transfer or drag racing. Push on the rear corner of your car. . . . . . . . . . . . Stiff as a truck!

**Nightmare00** · 07-01-2008, 04:25 PM

I have not done anything with the springs... I appreciate the advise. Thanks.

**LS2Tuner** · 07-01-2008, 04:58 PM

No problem here to help.

So what are the width on your rear wheels?

**Nightmare00** · 07-01-2008, 07:17 PM

10.5

**LS2Tuner** · 07-01-2008, 07:26 PM

You should be close then @ 17psi. The key thing there is having an accurate low pressure gauge. You would be amazed to get a good accurate one and see how far off the cheapy regular gauges are at low pressure.

You can also go to a smooth concrete parking lot and set it at 17psi and do a minor rolling burnout and then look at your marks. If they are uniform all the way across in color your good. That would mean you have the most uniform contact area on the track. If it is darker on the edges then you know you have already went too low. And if it's darker in the center you can still go a little lower. . . . . . . . . . . . . . .

**98ta_ra** · 07-01-2008, 07:32 PM

Originally Posted by LS2Tuner

It all depends on what width rim you have them on. With that short of a tire anything under 15 will do NO good.

Also is you still have the stock springs and shocks on the rear they are a HUGE limiting factor. You need to go to the junk yard and buy a pair of used V-6 springs for the rear at the very least.

Your stock WS6 is VERY stiff and by NO means made for weight transfer or drag racing. Push on the rear corner of your car. . . . . . . . . . . . Stiff as a truck!

would changin to v6 springs actually help n e ones 60ft?? or me at least...i cant get lower than 2.01 ..i have a 98 trans am. as for my suspension, its all stock....

**LS2Tuner** · 07-01-2008, 08:03 PM

Originally Posted by 98ta_ra

would changin to v6 springs actually help n e ones 60ft?? or me at least...i cant get lower than 2.01 ..i have a 98 trans am. as for my suspension, its all stock....

Yes that is why if you read my post's I tell everyone to do this before they waste money on ANY other sus. mod.

**qwk93ta** · 07-02-2008, 03:06 AM

Originally Posted by 98ta_ra

would changin to v6 springs actually help n e ones 60ft?? or me at least...i cant get lower than 2.01 ..i have a 98 trans am. as for my suspension, its all stock....

I used V6 springs on my 93 T/A that would pull 1.7x 60' times.

**maxwax** · 07-02-2008, 03:35 AM

Originally Posted by LS2Tuner

You should be close then @ 17psi. The key thing there is having an accurate low pressure gauge. You would be amazed to get a good accurate one and see how far off the cheapy regular gauges are at low pressure.

You can also go to a smooth concrete parking lot and set it at 17psi and do a minor rolling burnout and then look at your marks. If they are uniform all the way across in color your good. That would mean you have the most uniform contact area on the track. If it is darker on the edges then you know you have already went too low. And if it's darker in the center you can still go a little lower. . . . . . . . . . . . . . .

That is a great example of how to tune your suspension. I do the same thing.

I run V6 springs in rear , no front sway bar, a drag bag with 13psi in right rear, and 255-60-16 MT/ET drag radials for 1.69 60' with a M-6.
I am in the process of building a bracket to relocate my TQ . Arm from the rear of the trans to the drive shaft tunnel, and it will be some what adjustable, up to +or- 4 degrees.

With the same set up I have netted a 1.85 60' time on sumotomo 315 -35-17 street tires.

**Nightmare00** · 07-02-2008, 05:45 AM

Originally Posted by LS2Tuner

You should be close then @ 17psi. The key thing there is having an accurate low pressure gauge. You would be amazed to get a good accurate one and see how far off the cheapy regular gauges are at low pressure.

You can also go to a smooth concrete parking lot and set it at 17psi and do a minor rolling burnout and then look at your marks. If they are uniform all the way across in color your good. That would mean you have the most uniform contact area on the track. If it is darker on the edges then you know you have already went too low. And if it's darker in the center you can still go a little lower. . . . . . . . . . . . . . .

Man thats great information!! I appreciate it. I'm going back to the track next week. I'll report back soon.

Thanks again.

**mike302** · 07-02-2008, 05:58 AM

Originally Posted by LS2Tuner

Yes that is why if you read my post's I tell everyone to do this before they waste money on ANY other sus. mod.

What would be a good suspention upgrade/set up for a 06 LS2 GTO, My cousin has one and that thing runs real good but he just can't make it run good at the track due to traction!

**LS2Tuner** · 07-02-2008, 06:11 AM

Originally Posted by mike302

What would be a good suspention upgrade/set up for a 06 LS2 GTO, My cousin has one and that thing runs real good but he just can't make it run good at the track due to traction!

What tire?

BMR drag bags.

Shit I was doing 1.55 60 fts with mine with the stock tq conerter and a set of 275/40/17 Mickey Et Drag Radials.