Michael Cook Posted June 22, 2016 Report Share Posted June 22, 2016 I want to take my 14' to test track, 1/8 mile. Not going to heat tires with burn out. Michelin pilot SS. What pressure can I run in rear tires?? Link to comment Share on other sites More sharing options...
mark.barton Posted June 22, 2016 Report Share Posted June 22, 2016 I want to take my 14' to test track, 1/8 mile. Not going to heat tires with burn out. Michelin pilot SS. What pressure can I run in rear tires??First off, I'm not a drag racer nor an expert by any means, but in general, higher air pressures equal better traction with a radial tire. Max tire pressure for the MPSS tires is something like 50 PSI. Do not exceed the max pressure printed on the tire. My best guess would be to start at 40 to 42 PSI and adjust from there. Mark Link to comment Share on other sites More sharing options...
Frank S Posted June 22, 2016 Report Share Posted June 22, 2016 My best results on Michelin Pilot PS2s (275-35x19 on ten-inch-wide wheels) was at five pounds under daily-drive pressures. 32 - 5 = 27. Pilot Super Sports (275-40x18 on nine-point-five-inch wide wheels) didn't seem to show any effects with five-pound differences from daily-drive 32 psi. Did yield a 2.012 60-foot on one run. The Michelins do respond to a mild cleanup/burnout. If hundredths-of-a-second are important to you, raising front-tire pressures to near the recommended maximum can be beneficial. Link to comment Share on other sites More sharing options...
Michael Cook Posted June 25, 2016 Author Report Share Posted June 25, 2016 Thank you Link to comment Share on other sites More sharing options...
Michael Cook Posted June 25, 2016 Author Report Share Posted June 25, 2016 First off, I'm not a drag racer nor an expert by any means, but in general, higher air pressures equal better traction with a radial tire. Max tire pressure for the MPSS tires is something like 50 PSI. Do not exceed the max pressure printed on the tire. My best guess would be to start at 40 to 42 PSI and adjust from there. Mark Link to comment Share on other sites More sharing options...
Michael Cook Posted June 25, 2016 Author Report Share Posted June 25, 2016 I really don't know about over pressure.. thank you Link to comment Share on other sites More sharing options...
msb64 Posted June 25, 2016 Report Share Posted June 25, 2016 First off, I'm not a drag racer nor an expert by any means, but in general, higher air pressures equal better traction with a radial tire. Max tire pressure for the MPSS tires is something like 50 PSI. Do not exceed the max pressure printed on the tire. My best guess would be to start at 40 to 42 PSI and adjust from there. Mark I heard the same thing too about radial tires, but my strip results do not agree, maybe a drag radial is a different animal. If I drop my Nitto 285 18 555Rs down to around 15 lbs, I get the best grip off the line. I have tried everything from around 26 lbs and down, and the lower I went the better the traction was. Even at low pressure and a hard launch my car will knock the tires loose off the line, and at pressures above 15 lbs even the bottom end of 2nd gear does the same thing. I am probably close to 700rwhp & tq though, my best 60 foot with the nittos is a 1.72, but that is hard to do and is usually closer to a 1.9. I am getting pretty good at pedaling the car though Link to comment Share on other sites More sharing options...
mark.barton Posted June 26, 2016 Report Share Posted June 26, 2016 I heard the same thing too about radial tires, but my strip results do not agree, maybe a drag radial is a different animal. If I drop my Nitto 285 18 555Rs down to around 15 lbs, I get the best grip off the line. I have tried everything from around 26 lbs and down, and the lower I went the better the traction was. Even at low pressure and a hard launch my car will knock the tires loose off the line, and at pressures above 15 lbs even the bottom end of 2nd gear does the same thing. I am probably close to 700rwhp & tq though, my best 60 foot with the nittos is a 1.72, but that is hard to do and is usually closer to a 1.9. I am getting pretty good at pedaling the car though Like I said, I'm not an expert and haven't drag raced in decades. Fact is the last time I drag raced, bias ply tires were still the norm and I used wrinkle wall slicks on my Plymouth. I was basing my info on what I've learned from track days which has more to do with lateral grip than absolute straight line traction. Mark Link to comment Share on other sites More sharing options...
msb64 Posted June 26, 2016 Report Share Posted June 26, 2016 No worries Mark, I am far from an expert myself, just passing on what has worked for me. Slicks are the way to go for best launch, but your drive train better be up to the hp/tq levels you will be pushing them to. I've got my rear end and driveshaft covered (including driveshaft safety loop), but I am pretty sure that my tsb replaced clutch would toast in no time. Michael, if you are not going to do a burnout, just drive around the water box if you can, do not drive through it. Street tires (front and back) can retain water and you will bring it up to the start line and make it even harder for yourself to get traction. Also, many places will set up cones and not let you run in the groove (main rubber track) because street tires will tear up the softer race tire rubber laid down. Running out of the groove definitely makes it harder to get best possible grip, but it is what it is. Resist the temptation to bring the rpms up high at launch, instead bring it up to around 2200 rpm or so and do a rapid smooth release on the clutch, do not just dump it. Instead of stomping on the gas pedal, squeeze down on it rapidly, you might have to do the same going into second gear too. If you have never ran against a tree before, don't wait till you see the green light come on, that is way too late. You need to launch a fraction of a second after the last yellow light comes on. That all has to do with the width of the staging beams, where you stage in them (deep or shallow), your reaction time and your cars reaction time. Like the NHRA Mellow Yellow moto says "Go On Yellow", just remember that would be the bottom yellow on the tree. If you do drop your tire pressure, keep in mind they can vary throughout the day depending on how warm you get the tires, by driving or even just having them sitting in sunlight. If the sun is on one side of the car while you are waiting, the pressure can increase by as much as a few pounds. Let us know how you make out, just don't take it too seriously and you should have fun. If you or someone you know has a gopro that you can use, set it up inside the car and you can check out what it was like after the fact. Link to comment Share on other sites More sharing options...
Helge Ruchelski Posted June 27, 2016 Report Share Posted June 27, 2016 Link to comment Share on other sites More sharing options...
msb64 Posted June 27, 2016 Report Share Posted June 27, 2016 No kidding. It is always nice to hear how people make out. In many cases it is kind of like reading a book that is missing the last chapter Link to comment Share on other sites More sharing options...
mark.barton Posted June 28, 2016 Report Share Posted June 28, 2016 No kidding. It is always nice to hear how people make out. In many cases it is kind of like reading a book that is missing the last chapter +1 Mark Link to comment Share on other sites More sharing options...
Michael Cook Posted July 1, 2016 Author Report Share Posted July 1, 2016 Not good. 8.7 and air pressure at 26. I could not grip. Need to learn. Link to comment Share on other sites More sharing options...
mark.barton Posted July 1, 2016 Report Share Posted July 1, 2016 Not good. 8.7 and air pressure at 26. I could not grip. Need to learn. Did you try adjusting air pressure between passes? Mark Link to comment Share on other sites More sharing options...
Michael Cook Posted July 2, 2016 Author Report Share Posted July 2, 2016 I tried 32 first pass and 26 second pass. Could I start in second gear at 6000 ??? Link to comment Share on other sites More sharing options...
Michael Cook Posted July 2, 2016 Author Report Share Posted July 2, 2016 Or maybe try 15 Link to comment Share on other sites More sharing options...
Michael Cook Posted July 2, 2016 Author Report Share Posted July 2, 2016 Or try 15 Link to comment Share on other sites More sharing options...
Michael Cook Posted July 6, 2016 Author Report Share Posted July 6, 2016 OK... I tried 20 psi seemed to work but only 94.9 mph in 1/8 mile. It could be driver era. Having o2 senor looked at tomorrow. Will run again. Link to comment Share on other sites More sharing options...
msb64 Posted July 6, 2016 Report Share Posted July 6, 2016 If you project your 1/8 mile mph to 1/4 mile mph, you are looking at around 123 mph. Allowing 4000 lbs for car and driver, that would put you around 580 rwhp, which should be just about right for for a 2014. Your ET is off a fair bit, but most likely that would all be in the first 60 feet, you never mentioned what your 60 foot time was. One thing is for sure, its a tough car to drive quick with street tires, at least it is for me. The best ET I have had with the Nittos is a 7.29 1/8th mile, the car does a lot better in the 1/4 mile. Its fun to run down quick cars in the top end, so far the best I have had is 127.05 mph. The average high 10 second strip car with slicks and a working suspension is usually only running 122 mph in the 1/4 mile. Link to comment Share on other sites More sharing options...
Michael Cook Posted July 6, 2016 Author Report Share Posted July 6, 2016 Wow.. that's great time. My et 2.5 my first 60 ft. Getting o2 sensor first bank looked at now. I can't wait to run again.. Thank you again.. Link to comment Share on other sites More sharing options...
msb64 Posted July 7, 2016 Report Share Posted July 7, 2016 As long as you have fun that is all that really counts, sounds like you are enjoying it. There will always be someone faster at the track, and that can include trucks, motorcycles and snowmobiles. My very last run at the track was against one of the latest AAA Superstock Super Cobra Jet Mustangs, there wasn't a smudge on it. His 60 foot was 1.36, 1/8mph was 118.40 and 1/8 et was 5.90 sec. (1/4mile 9.20 seconds @ 148.55 mph). If you have a gopro or can borrow one, set it up inside the car looking forward and capture some strip runs. It makes for some interesting videos to watch in the off season. Sure wish I had brought my gopro for the last meet, would have been nice to watch that SCJ fly again. Watching your videos can also help you notice things like shifting, tire spin, pedaling the car etc. Link to comment Share on other sites More sharing options...
Michael Cook Posted July 7, 2016 Author Report Share Posted July 7, 2016 Could I run 95 octane ?? Link to comment Share on other sites More sharing options...
msb64 Posted July 8, 2016 Report Share Posted July 8, 2016 You can run 95 octane fuel, but you need to have a tune that will take advantage of that extra octane. If you can get that octane fuel easily, and if it is practical to run all the time, then I would get a tune built for it. I run nothing but 94 octane E10 in my car, and had VMP build the tune for my SCT tuner. You can also have them supply you with a lower octane tune and load it in the tuner as well, just in case you travel to areas that only have lower octane fuel, like 91. My older X3 tuner holds up to 3 custom tunes at a time, and changing the tunes only takes minutes. The tuner also works as a good diagnostic tool as well, for reading and clearing trouble codes. The newer X4 is even better, advanced real time data display, data logging capability and holds up to 10 custom tunes. It is at the top of my things to get list Link to comment Share on other sites More sharing options...
Michael Cook Posted July 8, 2016 Author Report Share Posted July 8, 2016 So it has to be retuned... Link to comment Share on other sites More sharing options...
msb64 Posted July 9, 2016 Report Share Posted July 9, 2016 If you want to get the maximum gain from the more expensive and higher octane fuel then yes. Keep in mind that the hp gain may not be a lot though, unless you jump up to a really high octane like race gas, 91 to 95 might only gain 10 - 20 HP or so. What a custom tune does do for you though, is allow for any upgrades or modifications that you have made to the car, as well as adjust it for your requirements. Make sure that you let them know everything that has been done to the car, including any power adders such as blower changes, intake upgrades, throttle body upgrades, pulley changes, injector changes, exhaust alterations, gear ratio change etc. Supply them with the octane rating and type of fuel(s) you will be using, as well as your elevation above sea level. They can recommend plug and gap changes, possible injector upgrades as well as pump boosters etc, depending on how much boost you plan on running. This way they have enough information to build you what should be a good & safe tune. If you want to go beyond that and chase the last remaining HP with the configuration you have, then you will have to do some dyno sessions and data log the specific parameters that your tuner requires. Link to comment Share on other sites More sharing options...
Michael Cook Posted July 9, 2016 Author Report Share Posted July 9, 2016 Thank you. I see the tuner I want, bama x4 tuner. Link to comment Share on other sites More sharing options...
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