Drag racing tire question....
Thread Starter
MBWorld Fanatic!
Joined: Oct 2002
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SL65, E55T, Pending S65
Drag racing tire question....
Quick question for all you serious drag racers.
Why would you lower the tire pressure on radial tires for the strip?
On smaller rim sizes it seems like it would allow more flex in the side wall resulting in better transfer of energy but in an 18" or 19" rim size the sidewall is so small that this does not appear to happen.
Does lowering tire pressure really increase the tire patch and result in more traction?
I have hear of many people running at 22 and 25 psi on the rears for the strip for radial tires.
My experience with road racing tells me the under inflation results in cupping of the tread.
Does this really help?
Schiz
Why would you lower the tire pressure on radial tires for the strip?
On smaller rim sizes it seems like it would allow more flex in the side wall resulting in better transfer of energy but in an 18" or 19" rim size the sidewall is so small that this does not appear to happen.
Does lowering tire pressure really increase the tire patch and result in more traction?
I have hear of many people running at 22 and 25 psi on the rears for the strip for radial tires.
My experience with road racing tells me the under inflation results in cupping of the tread.
Does this really help?
Schiz
MBWorld Fanatic!
Joined: Jan 2004
Posts: 7,092
Likes: 13
From: Salt Lake City (but not Morm)
2003 E55 & 2014 GL550
Few guys at the track told me the same thing. That running drag radials real soft (like in the upper teens psi) does nothing for your times.
I guess the only arguement for reducing pressure is larger contact patch correct?? I bet there is a "too far" point were performance is reduced, but we all need to figure out what the point is.
Just my humble.
I guess the only arguement for reducing pressure is larger contact patch correct?? I bet there is a "too far" point were performance is reduced, but we all need to figure out what the point is.
Just my humble.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2002
Posts: 1,428
Likes: 2
SL65, E55T, Pending S65
I have run 60' times as low as 1.79 on stock RE050's in my SL65. Using standard street pressure.
This was a well prepped track, my typical times in the SL65 are 1.85 60'.
You are probably right, laws of diminishing returns here. I tried running different pressures at the drag strip on my E55T am saw no noticeable differences in 60' time between 22 and 36 psi.
I think I will just stick to the low side of stock pressure for 19" rims.
Schiz
This was a well prepped track, my typical times in the SL65 are 1.85 60'.
You are probably right, laws of diminishing returns here. I tried running different pressures at the drag strip on my E55T am saw no noticeable differences in 60' time between 22 and 36 psi.
I think I will just stick to the low side of stock pressure for 19" rims.
Schiz
