Tire Pressures, Trackcross Tire Pressures Options

[BENBRO02]

My son and I are going to a track cross tomorrow at Summit Point. My son's BMW is not ready so I plan on driving my 914 and letting him drive my Acura. Please give me recommendations on tire pressures for the 914. I have never had it on a track. It has a stock suspension without sway bars, 205-55-15 tires (300 treadwear rating) on 4 lug Fuchs. It will only be 50 degrees.

[Krieger]

I would use the stock recommended tire pressures. Set them 26 front, 29 rear in the am before you drive anywhere.

[BENBRO02]

My son and I are going to a track cross tomorrow at Summit Point. My son's BMW is not ready so I plan on driving my 914 and letting him drive my Acura. Please give me recommendations on tire pressures for the 914. I have never had it on a track. It has a stock suspension without sway bars, 205-55-15 tires (300 treadwear rating) on 4 lug Fuchs. It will only be 50 degrees.

Thank you

[infraredcalvin]

Agree with stock.

Question is if you've ever been on the track? If not, or not much, concentrate on the course, your sight (looking ahead), shifting points, etc. have fun, don’t worry about that till you’re hooked and buying real tires....

[BENBRO02]

Agree with stock.

Question is if you've ever been on the track? If not, or not much, concentrate on the course, your sight (looking ahead), shifting points, etc. have fun, don’t worry about that till you’re hooked and buying real tires....

I've done 5 track days and was amazed at the lack of grip because of the cold weather. I ended up letting my son drive the 914 and I drove the Acura. It was a great father & son activity. We were in different classes but our afternoon times were only 0.038 second apart. 2 observations from my son. The 914 needs a front sway bar and a sport seat.

[infraredcalvin]

I’ve got same sizes but with 460 tw tires on mine now, I feel your pain with lack of grip, doesn’t take much to warm them up, and they get greasy shortly thereafter. Finishing cleaning up some track wheels, then I’ll fit some 200 tw tires (trying to stay in certain class).

Did you take the seat bottom out of the 914 seat? Have a harness bar too? That might temporarily help the seat issue. I agree with sway bars, I run both front and rears among a bunch of other stuff, I just need to continue working on the driver.

[BENBRO02]

I’ve got same sizes but with 460 tw tires on mine now, I feel your pain with lack of grip, doesn’t take much to warm them up, and they get greasy shortly thereafter. Finishing cleaning up some track wheels, then I’ll fit some 200 tw tires (trying to stay in certain class).

Did you take the seat bottom out of the 914 seat? Have a harness bar too? That might temporarily help the seat issue. I agree with sway bars, I run both front and rears among a bunch of other stuff, I just need to continue working on the driver.

Taking the seat bottom out is a good idea, my son is 6'2" so we took the top off so the helmet wouldn't hit. Thanks for the tip.

[wndsrfr]

Bottom seat cushion out, use a 1/2 inch foam pad. Highly recommend Bridgestone RE71 tires when you start looking...I just ran them at Roebling... got the same lap times as I did with Hoosiers, surprised me. Get them shaved to 4/32 from Tire Rack...

[Racer]

bottom cushion removal is a longtime trick. Without foam though, you get to sit on fiberglass. Trade off is slightly more bolstering and head room.

I find that my left knee often ends up locking the drivers door by the end of my run. Likely part of my trying to brace myself.

[RARE 6]

Agree with stock.

Question is if you've ever been on the track? If not, or not much, concentrate on the course, your sight (looking ahead), shifting points, etc. have fun, don’t worry about that till you’re hooked and buying real tires....

Sound advice, though it sounds like you're now hooked. Line, braking points, apexes etc. all are more important and will shave lap times whatever tires you used. Fastest time I ever turned at Woody Creek in the -6 back when we were consistently posting top class times in PCA DE events was on used Dayton Thoroughbred street tires pulled off a Ford Torino because we were dead broke at the time. Came close with all the other back in the day cool tires (XWX, Pirelli, BFG Comp TAs, etc) but apparently had all those other driver elements dialed in with the Daytons that particular afternoon.
Get a front sway bar and some lower springs in the back. Those will make a huge difference. Now that you're hooked, remember that the last few hundreths of a second off your lap times will be exponentially more expensive than the first few full seconds.

[wndsrfr]

Saw your pic that you posted in the Paddock area... post it here also and you'll get more recommendations really nice action pic.
Think about a front sway bar... your son has the driver's side completely unloaded.... nice.

[914Toy]

Many of my track colleagues used to aim for hot tire pressure to be at 34 lbs pressure, starting with 28 lbs (ambient around 80 degrees) cold tire pressure - trial and error adjustments to final preferred hot temp.

[infraredcalvin]

A simple approach to begin with is to make sure you’re using the entire tread. Tires have several markers on the edge (usually little triangles). The wear area from your session should touch the point of the triangle. Mark a line with chalk across the corner of the tire edge to more easily see the wear area from the most recent session. If the chalk is worn off at the tip of the arrow, you’re close to the right pressures.

[BENBRO02]

Here's the picture of my son at speed.