Interesting questions

[Silvino]

I found out my tach is off from 300-500 RPMs. I can hit my rev limiter at about 8.4-8.5k rpms and my idle is about 200-300 rpms high. I was wondering how much this would effect my track times. I don't have my timeslip here but I had another horrible track trip and I figure this might be hurting me more than I think. If I shifted at what I thought was 8k rpms (and really 7.5-7.7 RPMS ..300-500 short of redline), how much would that effect my 1/4 time? I did a 2.3 60', 14.7 @ 95 MPH quarter at best on street tires. Do you think the missing rpms would bring me to low 14's like I should be getting? Anyonw know? ALSO, how do I adjust this thing back to what it should be. Is there an easy way to do so?


------------------
Silvino Orozco
'97 Integra GS-R w/JRSC,JR Fuel pump, AEM Cold Air Intake, Powerstop rotors/Axxis Metal Master brake pads, A'PEXi Dunk Exhaust, J&S Safeguard unit

[Marc]

Stock tachometers are notorious for being off a bit. Get an aftermarket tach. Remember the stock tach is off most at the bottom and top of the rpm band. It is most accurate when the needle is pointing straight up. Believe it or not there is a gravity effect on tachs. That's why on racing cars, the redline on a tach is always pointed at the top(12 o'clock).

------------------
Marc
1997 Civic EX, Supercharged

[CROM]

I hit rev limiter at about 8400 too....the easy way to adjust idle is messing with the Throttle cable, if your idle is too high, then loosen the cable about 1 or 2 turns on the cable bolt, this should work......if you dont understand what I am saying message back, and I will go into better detail....but this is very easy to do....You probably overtigthened the cable when you installed the supercharger

Man a 14.7 in the quarter, jeez, that must piss you off because i can do that hitting the rev limiter in every gear and peeling out in 1st and 2nd.......good luck

[This message has been edited by CROM (edited December 29, 1999).]

[This message has been edited by CROM (edited December 29, 1999).]

[Silvino]

Well that's what I'm getting at. I've not been hitting my highest RPM because I thought I was almost hitting redline when I wasn't. That's why I'm wondering how much time I'm missing. 300 RPMS in 1st, 2nd and 3rd could add up to a decent amount of time.
I was hoping someone would know how much.


------------------
Silvino Orozco
'97 Integra GS-R w/JRSC,JR Fuel pump, AEM Cold Air Intake, Powerstop rotors/Axxis Metal Master brake pads, A'PEXi Dunk Exhaust, J&S Safeguard unit

[sunny]

Sil, you could see a .5sec improvement in your 1/4 times but I don't think it will be that high. Reasoning: you probably spin on the 1-2 and 2-3 shifts anyway and getting the extra 3-500rpm would only worsen the spinning-no traction=slower times...the extra rpm should be beneficial on the 3-4 shift though. What you should really be paying attention to is your trap speed- that gives you a better idea of how much hp your car is making. What's the consensus on trap speeds w/setups similar to yours? A rough guesstimate by your 95mph trap says you're pushing around 190whp.

[sunny]

fogot to add this bit...I have a Field SFC and one of its features allows you to program a *beep* at any desired rpm. I set mine at 7900 (gives me 200rpm lag/reaction time to shift) and I've noticed that my tach is past 8k when I hear the beep.

[James151]

Hey Sil
I would recommend getting an autometer shift light that can take moduels that light up at certain RPM. The shift light is about $65 from summit and the pills are about $15. They are dead accurate and safer than trying to pay attention to the tach when racing. You could also get the mini shift light and keep a stealth look. Where we live I would stay away from attention grabbing tachometers. If you wanted to get an afetrmarket tach I would invest in a MSD 6AL and use the built-in tach attachment on the end of the box. It will give the most accurate reading and is easy to install, well easier than installing the J&S. send me an e-mail for more info.