1G 26” slicks tire pressure?

[awdmonster1904]

How’s it going

I’m trying to figure out some things regarding the tire pressure on a bias plys.

background **
Back in the day i would run 13 psi front 8 in the rear on my et drags 24.5 slick with good results
This was on 35R 1.44 60ft it just worked
Launch at 6 k

Fast forward to now
On my last track event test and tune. Did a launch at 15 psi front 17 in the rear thinking it would spin a little since I just wants to get a shaker pass snapped an axle passenger rear. This is on et drags 26” on 6766
Launch at 6.5-7 depending on track


Just trying to get some feedback much appreciated
What pressure would y’all recommend in bias ply 26”

 

[97gsxIA]

For my bias-plys I usually show up at the track with 15 on all four. I'll do a pass to see how they react to the track and the temp of the day then adjust down. I usually end up around 10.
As far as front/rear- I find that to be largely more dependent on weight distribution and suspension then a standard formula. So you-do-you on that one.

If you've never used slicks before, be prepared for some looseness through the large end of the track. She's gonna float. And a good shake-off through the waterbox will do wonders.

Good luck my man.

 

[awdmonster1904]

For my bias-plys I usually show up at the track with 15 on all four. I'll do a pass to see how they react to the track and the temp of the day then adjust down. I usually end up around 10.
As far as front/rear- I find that to be largely more dependent on weight distribution and suspension then a standard formula. So you-do-you on that one.

If you've never used slicks before, be prepared for some looseness through the large end of the track. She's gonna float. And a good shake-off through the waterbox will do wonders.

Good luck my man.

I’ll try this method thanks for your feed back
What’s your setup?

 

[97gsxIA]

My car used squat HARD and I have a welded center diff so I used to run a little lower pressure up front to keep as much traction as possible up front when the torque shifts to the rear. I never ran lower pressure in the rear.
Most rear end parts break from when the car's tractions jumps from front to back (and back again) off the line. There's lots of things you can do to combat this- pulling the slack out of the driveline at the line, spring selection, rebound settings, tire pressure, weight distribution, and even things like preload on rear diff bearings etc.
Here's a good example of what I mean:

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That being said, I have changed a lot of shit in my setup and what worked for me before might not work for me this year, and may definitely not work for you depending on what you have done to your car.
Just some things to consider.

Good luck!

 

[awdmonster1904]

I’ll try out 15 psi and see how the car reacts

 

[bastarddsm]

I'm usually 12-15 in hoosier qtp 26". regardless, you'll need to get good with your left foot, or you'll need a large supply of driveline parts.

 

[twicks69]

Going to the bigger tire will be beneficial above 150mph, but it will put more load on the drivetrain. Thanks for posting the old video of my POS eclipse breaking everything out back. That was a result of running coilovers with too soft of a rear spring (which I changed to a 500# spring preloaded to 1000# initial), along with a 4 spider center diff (you can see the viscous coupler at work in the video on the rodeo hops before everything exploded). I also had better launches by softening the rear dampening with the higher rear spring rate, and running a harder front dampening with the 675# front spring at static initial.

I typically would be in the 11.0-15.0psi range depending on conditions and stability.

Oh, and the video of everything exploding was a result of the stock rear diff cover breaking the mounts, then rotating and breaking the rear axles, ring and pinion, damaging the fuel tank, rear subframe, etc. Great fun carnage!

 

[awdmonster1904]

Going to the bigger tire will be beneficial above 150mph, but it will put more load on the drivetrain. Thanks for posting the old video of my POS eclipse breaking everything out back. That was a result of running coilovers with too soft of a rear spring (which I changed to a 500# spring preloaded to 1000# initial), along with a 4 spider center diff (you can see the viscous coupler at work in the video on the rodeo hops before everything exploded). I also had better launches by softening the rear dampening with the higher rear spring rate, and running a harder front dampening with the 675# front spring at static initial.

I typically would be in the 11.0-15.0psi range depending on conditions and stability.

Oh, and the video of everything exploding was a result of the stock rear diff cover breaking the mounts, then rotating and breaking the rear axles, ring and pinion, damaging the fuel tank, rear subframe, etc. Great fun carnage!

Thanks for the feedback Tim I’m going to
Test again the weekend of 2/13
My wife got me one of these t case she purchased from a friend but need to swap out the output shaft with i need to order from you