jdblack1

There is a local event and I would like to attend. I have a few ideas but I need some experienced help.

I've got a couple things to do to be able to pass tech: battery tray and tires

my car
89 CRX Si
filter on tb for an intake
D15B2, yeah yeah I know, but it's rebuilt and got me driving
Stock springs and shocks.
gutted
front upper strut bar
13" Steelies

Here's where I need help
my ignition timing is full advance and I'm burning good
I'm going to fill my front tires to about 42psi and the rears at 40psi. I've read about the chalk idea so I'm going to try that. I also have one of those infared pyrometers. How can I use that to help with my tire setup?
I can also make me a rear upper strut bar. Would that help alot? I don't care about the ghetto look I'm primered anyways.

Also I'm about to buy new tires and I just read this elsewhere


Tirerack has these in the yokohama's, but will they fit? I don't know the stock width of these rims.

Any help or advice is great

Thanks

CivicSiRacer

my car
89 CRX Si
filter on tb for an intake
D15B2, yeah yeah I know, but it's rebuilt and got me driving
Stock springs and shocks.
gutted
front upper strut bar
13" Steelies

Sounds like you are in D or E-Prepared. Definitely not Street Mod for SCCA. The stripped interior throws you out of SM.

Air pressures sound good for now.

TO use the pyrometer you have to measure your tie temps as soon as you get off the course. Having someone else do this is easier. You want to measure the outside, middle and inside tread. For the front tires you want the temperatures even across the tire. Low temp in the middle means add more air. Low temps on the shoulders (edges) of the tire means take out some air. You don't measure the rears. You adjust the tire pressure to your liking of oversteer/rotattion. TOo much rotation and bring the air pressures closer together. Not enough rotation and add or subtract more air pressure.

The CRX is throttle lift oversteer happy. I know it happened to me alot

FourthGenHatch

You have an Si but with a DX engine? How come?

stephan

He specified it was rebuilt, musta blown the stock engine.

FourthGenHatch

I know he said that but I would think you would have to convert it to DPFI if you went Si > DX.

jdblack1

I spun bearings in the stock motor. The D15B2 is running on my MPFI. all I did was switch longblocks

Thanks for the help guys.

Any more ideas

jdblack1

Well today was my big day.

That was fun as hell

I got put in STS and I ran against a 94+ vtec prelude and a 97 Imprezza 2.5RS.

My best time was 45 secs their's were the lude at 43 secs and the Imprezza at 41 secs.

I got 4 runs in within about 40 minutes so I was happy. I stayed ready during the wait.

1st 47
2nd 46
3rd 45
4th 46

1stGenCRXer

Looks like you were fairly consistant. What changes did you make to the car and your driving between runs? Also what kind of tires were you using?

jdblack1

The best tires I could find local were these H-Rated tires
Firestone Affinity 175/70/13. They were brand new.

My first run I was all over the track, and a friend told me to let out of the throttle a little. I did and found better control during the 2nd and 3rd runs. The 4th I let out to much and lost some time

Tire pressure, since my tires were new after the 2nd run I could see that I wasn't putting all of my tread down so I dropped all my psi's 2 psi. 40 in the front and 38 in the rear. It helped because my third run was a lot smoother and faster, even though I bogged out of a turn.

I'd like to do this again, but I think I should have been in DSP. I also want to make some changes to the car.

1stGenCRXer

Yeah, believe it or not, the fact that the tires were brand new probably hurt you a little. Everytime brand new rubber is asked to provide traction, all it really does is scrub off the release agent, then it'll start gripping.

I take it you didn't use chalk or white shoe polish or anything for your tire pressures, just venturing a guess, but I would bet you'd get slightly better rotation in tight turns and the esses if the rear pressures were dropped a couple pounds more. The most pressure I've ever really been able to get a honda to use in the rear is about 36 [street tires]. If those front tires start gripping harder, you may be able to go back up in pressure there.

Driving smooth is the key when you're starting, and it sounds like you had a pretty helpful spotter, keep it up.