Michelin power one tire pressure at the drag strip?

[yzguyfl]

When running at the drag strip, what kind of pressure should I be running? I know the standard “what works for meâ€￾ but I have only been to the strip 2 times, and I have no idea what works for me! On the advice of the previous owner, I dropped it to 10 psi (he went down to 8), but in searching around a bit, I see people running 15 and over. I just want to make sure I’m not experimenting to low, and break the tire loose from the rim.

(I did spin the first time a bit when I had 20psi in it, but I did not burn out either)

 

[bisquit61]

I run 20 in my power 1 but the track is very sticky. It wil depend on your track surface. Some tracks I have to run much lower for traction. Start at 20 and keep going down until you stop spinning

 

[lankeeyankee]

I run cold 29 PSI at the track.
Those that run 8-10 PSI on a street tire think they are running slicks. A street tires carcass design is much different then a slick......

Here is how you check the proper tire psi for the tire, suspension, and rider weight.
Start off (in this case street tire) low 22 cold!! PSI. launch on some fresh asphalt white concreate works best.
Just launch the bike hard but not trying to break any records. The tire will leave a footprint.
OK.... here is what you need to look for.. The widest part of the darkest print left from the tire.

Not enough air psi will leave dark lines on the outter edge. so low such as 8 PSI you will find 2 narrow black marks with nothing between them.. The middle is to soft making no contact with the surface of the road.

To much air pressure will leave a dark narrow black mark.

The key is to get the widest darkest footprint/burnout.

I see hear this all the time at the track from street tire guys "I cant hook I am spinning" How much air psi are you running "Ohh around 8 PSI" ok bump it up to 20-25.. Wooooo Lahhhhh!



Slicks are designed to run around 8-10.5 PSI. not street tires!!!!!

 

[Professor]

Your wheelbase and the track is going to be a factor. With stock wheelbase I would run about 20-25 and not have any issues unless the track conditions were pretty bad. This was with Power Race and M/T shootout tires. Running about 61" I had to drop it to the 15-18 range. I ran a few shinko's and was never happy with the way they hooked up. I had to lower them 5lbs compared to the others. The Power Races were PR-4, PR-5, and Med-Soft compounds.

Running stock wheelbase, I could hook up a Pilot Power @ 20-22 at my home track. Compound should be close to the Power Ones.

 

[fiend]

I am sitting at 64.5" and have been running between 21 and 25 psi depending on track conditions.

 

[yzguyfl]

oh, forgot to mention, I am stretched 7.5" (not sure where that puts me as far as over all length) dropped 1" in the front, strap coming to drop another inch. My first trip to the strip, I ran it at 20 (was afraid to drop it lower), and did spin a few times, not even launching hard. But I did not burn out at all (first time at the track, and just got the bike wanted to get used to it). 2nd time, I dropped to 10 psi, did do a burn out, and did not spin at all. Still did not launch hard, but harder than the first time. (actually hooked and bogged)

I'll try 20 psi and a burnout next time.

 

[fiend]

How many passes can you usually get when you go? The key is to run as high a pressure as you can without spinning so if you try 20 and still don't spin go up to 22 the next pass. The higher pressure you are able to run the more mph you will have.

I run mid 1.5 60' as mine sits. The other thing to look at if you are spinning would be your suspension setup. Your sitting at about 65.5" with your stretch.

 

[lankeeyankee]

Also a factor to remember....
When doing a burnout the tire PSI will increase as the temp raises from the burnout equaling to longer burnout more tire PSI.
When I used to bracket race I would set the PSI right before I rolled out from the staging lanes onto the track.
I had a timer hooked up to a small LED When the burnout began the timer would begin keeping the burnout at the same RPM for the same time each time garunteed me a close tire PSI every time I rolled up to stage.
Ive seen a tire gain in PSI as much as 12-15 PSI with an increase in tempature.

When the sun dropped in later rounds so would the air temp and track temp and would increase the timer for the length of the of the burnout.

 

[yzguyfl]

How many passes can you usually get when you go?

Well first time, I got in 12 runs, but I had only had the bike a week, and was the first time at the track ever. So I was just getting used to the bike, the air shifter, the track and doing 140 mph on it! Second time I only got in 4 runs. (more people there, got there late, and had a long cleanup)

The key is to run as high a pressure as you can without spinning

oh, well I guess that helps explain my drop in mph from running 20 psi and going to 10 psi. Best mph at 20 was 141, with the norm being high 130's. At 10 psi it was all around mid 130's. I thought it was the extra 10 lbs in leather I was wearing the second time (Just a jacket the first trip, full leather and boots second trip)

The other thing to look at if you are spinning would be your suspension setup

I realize this is a loaded question, but what would be the first things to do/look at, if I go next time, spin at 20 psi with a burnout?

 

[lankeeyankee]

You may have more issues then tire PSI. Spinning isnt only beacuse of improper tire PSI. Is your rear shock set properly, is the track chitty, are you staging in the groove, is your body posture correct, are you sitting in the water box as your doing your burn out. I see so many inexpierenced riders making simple mistakes just in the burn out box. Ive seen people roll all the way back into the water as far as getting the front tire wet, Ive seen people spinning the tire while sitting in the water slinging water up under the under tail dripping on the tire as they are staging, I seen burn outs WAAAAAAAy to long...... Have someone video your whole process from your burnout to your launch, and may be able to help. So much goes into drag racing that many overlook.

 

[yzguyfl]

ok, I will, once I get a few more passes, and see what is gong on, then I will.
I did back into the water box, did not get front tire wet (actually backed in at an angle to keep the front tire out of the water trail the cars pulled out), rolled forward, burned out in 2nd until it started gripping, then released front brake, rolled forward (stalled it 2 times coming out of the burnout )

 

[lankeeyankee]

ok, I will, once I get a few more passes, and see what is gong on, then I will.
I did back into the water box, did not get front tire wet (actually backed in at an angle to keep the front tire out of the water trail the cars pulled out), rolled forward, burned out in 2nd until it started gripping, then released front brake, rolled forward (stalled it 2 times coming out of the burnout )

Backed in on angle? Stalled coming out of the box? Hmmmmmm. Hmm I betting you still have water sitting in the tread grooves. I dont know your setup or track qaulity.
Try staying out of the water box on 2 passes. Click it up into 2nd, stand up off the seat with your body weight slightly foward, front brake hard and let the clutch out spinning the tire at around 8K for 3-5 seconds leaning it back and forth making sure the whole tire surface is heating up, sit on the bike release the front brake come spinning out lowering the rpms to around 5500 and as soon as the tire grabs pull the clutch in and coast up and stage putting the bike back into first.

 

[yzguyfl]

several other cars drove through the whole box, many front wheel drive cars. In the "groove" area, there are long strips where water is dragged out. I backed in with my front tire off to the side of those strips, but angled the back tire so I hit some water. The water was not deep, actually normally not much in there.

I let it spin much more than 5 seconds, maybe 10ish, and I did tilt it back an forth a bit. When I started to let it roll forward, I did not pull the clutch fast enough and when it grabbed I stalled it

the last time I had no problem spinning, I was not hitting it hard enough, and bogged, I did not get enough passes in to get it down.

everyone was saying the traction sucked, but I was not spinning yet. I've only had 2 trips and want to get some practice and see what I can do. Next time I'll start at 20 psi, hit it a bit harder, do a burn out, and see if I can do better than a 1.9 60 ft

 

[yzguyfl]

and just because, some burnout shots

 

[fiend]

I'm guessing most of your problem is your suspension setup more than tire pressure. What is your sag set at? Do you still have the oem shock on it? What are your current shock settings?

 

[yzguyfl]

I'm not sure I have a problem yet. I have yet to spin after doing a burnout, but I have not been hitting it hard enough yet. Just trying to get some general info to know what to look for.

by Sag I'm assuming you mean the rear height? I think it is dropped a bit from stock, it has the adjustable lowering links in the back. I can't go much lower, as the tire will hit the license plate.
front is currently dropped one inch by raising the forks (I plan on using a strap to drop another inch)
I think it still has the OEM rear shock
I have no idea what the shock settings are. The previous owner did set it up for drag (street/strip), and seemed to have an idea of what he was doing, he had also raced drag only bikes.

 

[lankeeyankee]

Just by going lower doesnt mean more traction. You want the rear suspension to work. Its possible you arent using all of the travel of the shock under launch.

 

[yzguyfl]

ok, let me see what I can do with around 20 psi, and a burn out. See if I start spinning or pulling the wheel when I start hitting it hard enough. When I have a bit more practice (let me fix what I know is wrong first ), I'll post a vid an see if I'm doing anything else wrong.