I know tire pressures at the track is a top secret subject, but I’m not a racer just a guy who can’t afford anymore tickets so I am looking for advice I can use at my track days.

My bike is a ’06 ZX-14, suspension set up for me by RaceTech and I’m running Michelin PP2CT’s 190 55 on the rear. At the last track day I had on the same tire but in a 50 series and the turn in was not crisp and easy, I had to focus on it. I’m hoping the 55 series works as claimed and the bike turns in easier. I have read the front tire pressure, or front to rear pressure difference does affect the turn in ease.

The track guys always tell me to run 30 psi front and rear. Can anyone provide me some advice on the ZX-14 front tire pressure on the high speed Auto Club Speedway track. I’m thinking of trying 31/32 F and 30 R.

Cruderudy that's always the tradeoff isn't it, bump the pressure up and they roll in crisp but are skittish midturn, drop the pressure and they stick like rails in the corners but initial turn in feels like you're manhandling a bread truck. I don't do the track days with mine just the fast canyon stuff but 30/30 sounds a touch low on street legal tires, even for track. The 14 is heavy and needs a little more pressure me thinks and likes the front pressure to match the rear. I'd be tempted to start with 34/34, check your turn in and then slowly drop the front and rear until you nail the feel you are looking for. I'm betting you find your sweet spot at around 33/33 or 32/32, just a guess as every rider is different.

Just a thought, I'm using 37/37 street on my '06 and turn in is good with excellent stability and fair gas mileage on the freeways. I haven't noticed any loss of grip, get down into toe scraping lean angles but the roads I take are pretty good on traction, no sketchy worn out asphalt.

Thanks Kruz,

The last track day I saw 6-7 psi increase from the 30 psi cold to after the 1st 20 min session was over. I think even 36-37 may be to high for the track. I think Kawi recommends 42 psi cold to make sure the wheel rim does not bottom out on road hazards and pot holes, have not checked the tire pressure after a fun street run ... really need to do that. I have checked the temps with my IR thermometer and the rear is usually around 115 F and the front ~112 F.

This track is really clean and nice/smooth. I think the full track bikes on race tires are starting with ~20-22 psi cold and 28 to 30 psi after the warmers come off. That's why I'm thinking about a 1-2 psi delta over the rear tire pressure at cold. Last time after the tires warmed up and the pressure went up to ~36 psi the front turn in was not quick and crisp. I'll report back after the track day in a few weeks on the pressures I ended up happy with.

Yea, those track tires are whole different animals as you know, 20/22 on a sport tire like an S-20 or Pilot Power 3 would leave you with a mass of melted gooey rubber after one lap. I wasn't recommending 37/37 for track on the 14, just general all around riding on the street, it's a decent compromise. 32 or 33 psi is where I'm thinking you'll find the sweet spot on track, just a guess.

6 to 7 psi sounds about right for a delta, ask your tire tech rep from Dunlop or Michelin what they recommend. They get paid to share secrets.

I went with 28 front and rear on Bridgestone BT-003. This is a slow track with some pretty tight corners.

Was MUCH safer than 43 psi. The bike squirmed all over at street pressure. I went off into the grass and thank God I didn't loose it.

Never saw my tire roll off rubber like that in street use. Go 28 cold, front and rear. The heat will cause the tire pressure to increase a lot more than it would on the street if its a warm day. I don't recall ever feeling like the turn in felt sloppy at low tire pressure. It will on the street but track is all different.

So here is what I ended up at for tire pressure on Auto Club Speedway. I started the day and the 1st session 31 psi cold F and R, at the end of that 20 min session the R was 140 F and 37 psi and the F was 125 F and 37 psi. I set both of them to 30 psi warm and it Was the ticket!!

Bike handled great, turn in with the new 190/55 Mich PP 2CT Rear was much better. Before the day I also re-set my sag to 30 mm F and 35 R, kept the factory rebound and damping settings. I really had a much better track day and my lap times were quicker than the last day at this track. Probably even move up to Group 2 next time to get out of the group with slow riders.

In one session I was blasting down the main straight at 150, I usually down shift to 5 and take the first L/R combo at ~100 (the fast guys take this at 140 ,,) when I saw the 5 or 6 bikes ahead of me about to enter this turn really breaking hard and really slowing down fast. Thanks to the great breaks on my big girl there was no drama but there sure could have been! In front of these bikes were a pair of riders, by that I mean a guy on a L bike and his GF on a Ninja 250, doing about 50 freeking mph, everyone was breaking right or left around them to avoid them. This section of the track is super safe so I went high and right above them without incident.

To end the story, I left early because it was just too hot, when It got to 100 F in the shade in the pit garages I split. When I got home and got the bike off the trailer and into my garage I checked the cold tire pressure and both F and R were at 26 psi. I usually run 36-37 on the street but now I have a good starting point for my next track day in the fall, when it cools off a bit.
Cheers

Cruderudy,
I fling love your name! It elegant and rude, well selected my bro!
Stay out of the thermal nuclear heat.
Wman