In need of some help and advice from you experienced drivers. This is my first time using slicks. I am using 22x8x13 MH with Lensos. The car is a full interior DC Integra that probably weighs around 2800 LBs with driver. The car has an all motor b20vtec that makes 239 whp SAE and 153 tq with an ITR LSD tranny and traction bar. Tires were at 12 psi and launch RPM was at 8500. I preloaded the clutch and as soon as green light , i full throttled it. It actually dropped to 7000 before rising again resulting in a 1.986 60ft. 1/8th was 8.368 at 84.5 mph and 1/4 was 12.9 at 107 mph. Does this sound about right , or am i doing something wrong ? Maybe wrong size tires ?

 

Tire might be a bit small also try dropping the pressures more i usually run mine around 8psi.

 

best advice i can tell you is go get as much seat time as you can, get comfortable in the car. get to know the car, make small changes, not big ones, and you will get it.

 

Did the car spin or bog on the launch?

 

lower psi. Play around with diffrent PSI's in your tires. I usalley ran min @ 7-8 depending on the track conditons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acura_b18c1 &raquo;</TD></TR><TR><TD CLASS="quote">In need of some help and advice from you experienced drivers. This is my first time using slicks. I am using 22x8x13 MH with Lensos. The car is a full interior DC Integra that probably weighs around 2800 LBs with driver. The car has an all motor b20vtec that makes 239 whp SAE and 153 tq with an ITR LSD tranny and traction bar. Tires were at 12 psi and launch RPM was at 8500. I preloaded the clutch and as soon as green light , i full throttled it. It actually dropped to 7000 before rising again resulting in a 1.986 60ft. 1/8th was 8.368 at 84.5 mph and 1/4 was 12.9 at 107 mph. Does this sound about right , or am i doing something wrong ? Maybe wrong size tires ? </TD></TR></TABLE>

holy crap you are launching high on that tire pressure. i'd lower it down to about 8 psi. and check it often as the pressure will change with moving the car and even just sitting the pressure can rise. lower your launch RPM as well. making that power you shouldnt have to launch that high. we are making 228 with a gsr N/A and using 24.5x9.5x13's and launching at about 8100 hooking up with 1.6 60's.

change around the tire pressure and lower the launch rpm. you are only on 22's so i'd launch a LOT lower. seriously try like 7000 or 7500 with about 8psi in the slicks.

Good luck!! let us know how you do on the next outing!!

 

ya the tire pressure is pretty high. I usually tell customers to start out at about 10psi if you're not familiar with your track conditions and running with slicks. once you get the feel of the track, your car and how the car hooks, start dropping the tire pressure only .5 psi at a time. See how the car reacts with that much change. Dont do drastic drops in PSI like 2 psi. The changes are so dramatic, you wont be able to know where your sweet spot(tire pressure) for your car weight, power and driving style.

Tire pressure is different for each car. You'll see some guys run 6-7psi on high hp cars while some lower HP cars wont work well with that setup. i've even ran 9-10 psi on a 140hp SOHC on 22x8x13 and was cutting 1.7s everytime. but if I dropped to 8-9psi, the car will bog too hard and the car is having a hard time pushing a tire that flat.

Keep in mind tire pressure can affect the mph also on the top end. If the tire is too flat and your car has a harder time pushing a flatter tire at top end, it will result in a slightly lower mph. Remember that flatter the tire, the more resistance it has. The higher the tire pressure, the easier it is for the car to push the car, especially if its not making that much HP.
So you really have to find the proper tire pressure for your car, your hp and track conditions.

 

hmm .. i will try to play around with the PSI the next time i go to the track. i will also try different launch rpms according to the PSI , but i dont understand how in the past situation , if i m launching at 8500 and it boggs to 7000 , how would launching at 7000 or 7500 help ?

 

i dont know if youre on a rev limited, but 8500 is pretty high for what you have. With the tire pressure you have, the high RPM launch, that tire must have been spinning pretty good and not hooking up like it should. But with that, you could have spun too much, hit the rev limit and brought down the rpms and caused it to bog.

like h22 said, the launch rpm is just too high. experiment with soemthing lower. Thats what racing is all about. testing and experimenting and finding out what is best for your car.

 

oo i understand . well , my rev limit is set at 9500. I tried 7000 and it bogged to 6000 , i tried 8000 as well , before trying 8500 . All previous launches before 8500 resulted in 2.0 + 60fts . thats y i didnt understand what was going on either because thats a very high rpm to launch at . i figured the psi might be high but its not like i was spinning the tires . and 22x8x13 is not to big of a tire so i didnt even think it was going to bog .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acura_b18c1 &raquo;</TD></TR><TR><TD CLASS="quote">oo i understand . well , my rev limit is set at 9500. I tried 7000 and it bogged to 6000 , i tried 8000 as well , before trying 8500 . All previous launches before 8500 resulted in 2.0 + 60fts . thats y i didnt understand what was going on either because thats a very high rpm to launch at . i figured the psi might be high but its not like i was spinning the tires . and 22x8x13 is not to big of a tire so i didnt even think it was going to bog . </TD></TR></TABLE>

you might have some other problems going on with the car then if its bogging like that. those kinds of things are pretty hard to diagnose over the internet. if you say you've tried launching lower and it bogs you defineltly have something wrong.

does it do the same thing on street tires? because at 8500 rpm on 22's making that kind of power and at 12 psi you should be roasting those slicks...

anything else thats going on with the car? noises? shaking? anything?

 

no there is no shaking or any kind of problems and the power band is tuned very smoothly. when i use bfg drag radials i cant get any kind of traction if i full throttle the launch at 3,000 rpm which is why i find it unusual that im bogging when i launch at 8,000 rpm on little slicks like this

 

bump for some more discussion

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acura_b18c1 &raquo;</TD></TR><TR><TD CLASS="quote">bump for some more discussion </TD></TR></TABLE>

man i don't even know what else to tell you.. are you launching off a 2 step? maybe you are like Will said Hitting the rev limiter and its coming back down..

lower the tire pressure and get a good burnout. then launch lower at like 7000. try different launch RPM's and tire pressures.

make sure your Rev limit is set to what you think it should be?

what are you tuned on? Hondata?

 

no i m not using 2 step .. car is tuned with s200 .. i am 100 % positive that the rev limit is set at 9500 because thats where i shift at each gear .. when i launch at 8500 , it immediately drops to 7000 and then it goes .. i understand this might be hard to explain over the internet .. i guess i was jus hoping to find someone else whos been through this before to give me some pointers .. i guess i ll jus lower the psi and try again .. Its jus weird because everybody is telling me to get larger slicks ( i m using 22x8x13 ) .. lower the PSI ( i was at 12 psi ) but i didnt even spin the tires .. it actually bogged .. o well , thanks for everything .. i ll keep this thread updated when i try again

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acura_b18c1 &raquo;</TD></TR><TR><TD CLASS="quote">no i m not using 2 step .. car is tuned with s200 .. i am 100 % positive that the rev limit is set at 9500 because thats where i shift at each gear .. when i launch at 8500 , it immediately drops to 7000 and then it goes .. i understand this might be hard to explain over the internet .. i guess i was jus hoping to find someone else whos been through this before to give me some pointers .. i guess i ll jus lower the psi and try again .. Its jus weird because everybody is telling me to get larger slicks ( i m using 22x8x13 ) .. lower the PSI ( i was at 12 psi ) but i didnt even spin the tires .. it actually bogged .. o well , thanks for everything .. i ll keep this thread updated when i try again </TD></TR></TABLE>

Good luck with it!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acura_b18c1 &raquo;</TD></TR><TR><TD CLASS="quote">no i m not using 2 step</TD></TR></TABLE>

are you part throttling it up to 8500 and launching? if so, i could see why it might bog on the launch.

 

well , i m part throttling it but as soon as green light , i full throttle it as i release the clutch .. i m not sure if that might be the cause of it but i do the exact same thing on bfg drag radials at 3000 rpm and it does bog at all

 

I had the same problem with my ITR when I was using my OEM 4.4 FD cutting 2.0 60ft's, and after I went 4.785, I was cutting consistant 1.8 60ft's

 

hmmm, i never went below 11.5 -12 psi on my 22x8x13's, maybe i should have tryed i thought i was in the "sweet zone" I cut 1.7's w/ 190ish hp in a 2090 lb h22 sedan, launching at 8-8200 rpms.