Engine NEW TRACK TIMES :(

NEW TRACK TIMES

Check out my signature......my time in my sig is without JP Header & ES Motor Mounts. Needless to say, here's how my best time slip looked with these two new mods tonight:
r/t: .542
60': 2.421
330': 6.756
1/8: 10.347
1/8 mph: 67.53
1000: 13.476
1/4: 16.104 :cry:

TRACK CONDITIONS: Strong Headwinds (15mph), 85 Degrees, 70% Dew Point, and about 70% humidity.
I also removed my spare and sub box like last time but this time I ran with a 1/4 tank of 93 octane instead od a 1/4 tank of 89 octane.
Last time I went there was almost no humidity and it was about 55 degrees outside. Does anybody know why my times were so crappy this time??? Im thinkin cuz of the humidity and temp.
Oh yea my friend with a WRX(turbo back exhaust and boost controller) ran a 14.0 flat at 15 PSI. I thought he would do a little better than this, too.
I expected to run a 15.7??, but I guess I will have to back again in the fall when it gets cooler again.

The header will actually hurt your 1/4 mile time usually, becuase it makes power, but sacrifices torque, which is what gets your car moving. Also the 93 octane fuel probibly hurt you some too, its poven that 87 octane makes more horsepower than 93 in cars that dont have forced induction or rediculous compression. I ran a 16.0 with my header and all other bolt-ons, thats the best i've done yet, but i never ran it without the header.

Actually, our cars will run the best with 89 octane because of the higher compression of the 10:1. I just wanted to see what it would do with 93.

Do you know what elevation the track is at? What kind of tires do you have?

The elevation is 770ft above sea level, and Im not worried about the tires because i ran with the sames ones the other time at the same psi. Its the Kumho HP4's (my winter tires). I used these because they are about 5 lbs lighter per wheel compared to my 17's with 215/45/17 kumho ecsta 711's. Granted, the 711's are stickier, but i think that the 5 lbs per wheel makes up for the stickier tires.

89 not 91? weird....

you can't replace weight with stick. I would have stick over weight anyday. 20lbs isn't going to change your 1/4 mile time as much as you want to think. now 100lbs that will make a tiny difference but not much.

I had a stock 2003 corolla and i ran 16.1 in the 1/4 with the same forcast.

BTW the myth about 91 burning the sludge in your engine is fake. It doesn't matter what grade you useing it won't "clean" it out like people want. If you think about it, it makes sense.

Yea but i thought that 5 lbs rotational weight equalled about 50 lbs in the car.

Im not sure of exact numbers... but its something like that

Truthfully, I can't see that 89 or 91 octane would even help power. I'd think 87 would be better than anything. Engines make the most power with very slight detonation. High octane fuels burn slower. That allows some engines (namely V6 or V8 or FI) to advance spark timing and compress the air/fuel more before ignition. Our engines don't do that, so it would make sense that 87 is best because it ignites and burns faster.

Trav

well, to me, with 89 in the car, i get better gas mileage. My car also seems to run better with 89 compared to 87. I think it is because of our high compression (10:1)

Winter tires are much less efficient on dry pavement. Mine also runs better on 91 than 89. More torque, power and better gas mileage.

10:1 will run most efficient on 89 I believe (proven this by street racing the same car 3 times on tanks of 87 vs 89 and 89 is better every time).

As for your times, get some sticky tires. 5lbs of rotational mass won't make up for the difference in a sticky tire. Oh and the conversion for rotational mass that I was told is that you double the rotational weight to get resting weight.....so if you save 5lbs per wheel then you have effectively taken out 40lbs of crap in your car :wink: And taking out 100lbs of crap gets you .1 off your 1/4 (about), you would only be saving .04 seconds off your ET by using those tires but you have less traction so they are probably hurting your ET cause of your crap launches.

so, next time i guess that i will run on my 17's since they are stickier.

Chris it has to be more than double. By dropping 5 lbs per rim thats 20 lbs so with that equation you are only cutting 40 lbs and that is really nothing at all. I noticed was more of a difference when I put my rims on in terms of losing acceleration compared to adding 100-200 lbs of speaker equipment. I would say 5x because I have heard 10x but that would suprise me.

That's just what I heard at school (mechanical engineering department), I don't know the actual conversion but I'm sure that it could be found on the net in about 5 minutes if you really wanted to look it up :wink:

Which I did and was not very happy about my finding. 3/4 not even double lol. Oh well these rims will be nice either way. Now I just have to get my clutch and flywheel on

uhem, HIJACK

And your point being?????.............

lol, just being a smart-ass you know :wink:



Anyways, what Tyler found is significant to what you are doing at the track, rotational weight is only 1.75 of resting weight (what Tyler found). So that 5lbs per rim you saved really only got you 35lbs off your car, lol. Stickier tires would do you a world of difference :wink:

Exactly so in fact that was very relative and screwed me seeing im spending 1800 for wheels and tires to drop weight when I was originally thinking it would make more of a difference. I did find out though that flyhweel weight in first gear decreases weight by an average of 37x's so if you drop 5 lbs on a flyhweel it is like dropping 185 total car weight That is only in first gear. The percentage drops with each gear but still nice to know. So to hijack the thread again does anyone know the weight of the stock flywheel.

The stock flywheel is something like 14lbs or maybe 18, not sure. It's on the newcelica.org site though, in their clutch/flywheel sticky :wink: