Hey everyone, I went out to the drags this last Friday for the first time to see what I could pull here in AZ. The conditions were 75F at I think around 2000ft above sea level. The fastest time I got out of 4 runs was 16.017 @ 89.19mph. I know the R has pulled low 15's and was wondering if some of you have done this could give me some tips. I was using 92 octane gas, 45 lbs of tire pressure in each tire, and I took out the spare tire. Other than taking the spare out, I'm all stock (if you'd even consider taking the tire out a mod). I think I'm losing the most time on my starts. I tried launching at around 3k and dropped the clutch, but the tires did that jumping thing (they lose traction and gain traction a few times) before they actually gripped. I'm speed shifting the clutch (any powershifter's out there?). Heh, my GF told me to double-clutch and I'll go faster.... riiiiiiiiiiiiiiiight. She's seen F&F one too many times. Anyway, any tips for a first-time legal dragger?


[Modified by Striker, 11:38 AM 8/20/2001]


[Modified by Striker, 11:39 AM 8/20/2001]


[Modified by Striker, 11:43 AM 8/20/2001]

 

if i were you...id drop your tire pressure down to stock or in the high 20's in the front..not sure about the rear though.

 

I thought having a higher tire pressure will give you more speed, and having a lower tire pressure will give you more handling... no?

 

I would definatly lower the tire pressure. It sounds like if the front was hopping then you probably need to launch at a slightly higher RPM and feather the clutch.

 

What would you lower the tire pressure down to? By feather you mean easy the clutch out a little at first then drop it right?

 

...that wasn't very nice . You shouldn't be running 45 psi in your stock tires unless you are at an autocross. For normal street driving, the tires should be at 35F/33R, plus or minus a couple psi (depends on your preference). At the drags, you shouldn't really be running anything more than stock pressure, and if you want to improve your launches, you should probably drop it into the mid to high 20s. However, if you lower your pressure, it will reduce trap speeds. Try to find a balance that works best with your driving.

 

Bob, 35F and 33R? So are you going by what the inside of the door says? The tire itself says max psi is 45... so to get the best trap speed I inflated to 45. Why is it bad to have too much pressure in the tires?

Also, should I feather the clutch when launching at a high 2k rpm? Thanks...

 

Yes, the inside of the door says 35F/33R....you can vary it a couple psi to suit your tastes for daily driving. The problem with 45 psi is that the tire is so inflated that it reduces the contact patch and therefore reduces grip. 35 psi is fine for launching, but try 30 and see how you like it. You should be able to drop the clutch at atleast 4.5k without too much wheel hop. With some decent shifting, you should be able to get a high 14 second or low 15 second run at that altitude. (someone correct me if I'm wrong here)

 

Cool... I'll give it a try this Friday. I'll be happy to pull a low 15... that's a considerable improvement from 16.0. So I was probably pulling 16.0's because my tire pressure was too high therefore my starts were causing the wheel hop which decreased my start time... right?

 

....Yes. Try a 5k launch at 30 psi....the tires will spin a little, but they should grip without any hopping. If you get too much spin, try a 4.5k launch. If you get hopping, lower the psi a little and try it all over again. Just experiment with it.

 

What sort of 60' times did you have? I, too, ran terribly my first time at the strip.

 

You should definitely drop the tire pressure to around 21-22 PSI. Having to high ogf tire pressure will cause major hop and a whole lot of spinning. By lowering the tire pressure to around 12-22 PSI it should really help your traction out during launch.

This should help as well https://honda-tech.com/zerothread?id=54974

 

Well, we need your 60' times to really get an idea of how your getting off the line ....

Trick to getting fast times on street tire, 25 psi driver's side, 22 psi passenger, do a quick "scuffing" of the tires out of the water box - not a burnout per se, but a good scrubbing of them - stage, 5,500 rpm's, and "feather" the clutch (basically riding it) until it catches, then go ***** out to redline+ each gear.

2.20 60' times are optimum and just about as good as you'll get in a stocker on street tires. And don't forget you are at 2,000 ft., your times will suffer a little from the elevation.

 

Thanks for all your replies so far. My fastest 60' was 2.613. Why would you offset the left and right tire pressure? Driver weight?

 

there's your problem man...your 60 ft is horrible

should be in the 2.3xx range....if your really good a 2.2x is possible...

.1 sec in your 60 ft = .2 sec at the finish...just fyi

 

ok, so if I can get to 2.3, that's a .3 drop which should drop my 1/4 time to by about .6 or 15.4 right? Or if I'm good... 2.2, so a drop of .4, so a 15.2?

 

as a general rule yes...and low 15's would be good at the elevation you are at...high 14's would be very nice tho

 

Yes, gotta account for the extra weight in the driver's seat ......

A 2.6 60' is really not good ...... if you released at 1,500 rpm, you would get that kind of time. Or if you dumped the clutch at 5,000!! Use my method above, and you will get down in the 2.2 range with practice. That is where I always was on street tires, then I went to slicks .....

And with a 2.2 60'. you should be in the low 15 range at your elevation.

 

TypeR0207, you said above to launch at 5,500rpms with 25L and 23R but only w/ that tire pressure right? What about the rear tire pressure? should it be 23L and 21R?

 

put rears at max pressure...less rolling resistance

 

max pressure according to the tire or max pressure according to the inside of the door (45psi or 33psi, respectively)?

 

Everybody really gave a lot of good info. I fight the elevation bug everyday, I'm in Colorado and most R's run Low low 16's here stock, an occassional 15.9. The fastest run I've seen here was mine, bone stock with 2700 miles on her, I ran a 15.8 with a high 2.4 60' time. Our elevation at Bandimere Speedway is over 5000 feet! I ran that run with 40psi in the rear tires, 27ish in the fronts. So in my opinio, run about 26psi in the fron tires, 45 in the rears. I drop the clutch pretty hard at around 3500-4000 RPM's, you'll get some wheel hop but not too terribly bad. I do powershift also at the track, and shifted at about 8200-8300RPM's. Thats my 0.2.
I hope to get into the 15.6 territory at my lousy altitude with this combo.
HTH
M

 

What sort of trap speeds are high-14, low-15 sec. cars getting? Just curious... I already know my 60' times were terrible the one time I went to The Rock.

I did manage to get a .505 RT tho

 

First and only time I took the ITR out to the drags, my best was a 15.34 @ 89.75 mph with a 2.413 sec 60' foot. I only did 6 runs (first run was a 15.89)...my elevation is the same as yours (2000 feet). It wasn't my first time racing/dragging a FF car but it was the first time with an ITR. I think I can improve on my times but I don't think I can get into the 14's with my current setup. I had my tires at 30 psi up front and 35 in the rear (adjusting the tire pressure in the rear would not help that much with a stock ITR IMHO).

 

Hey Striker, what track were you at on Friday? I was at Firebird that same night. There was one other PY there too.

Just curious...