well, i for one had fun, but it wasn't b/c of my times unfortunately something's wrong with my car dammit!!! my times were worse than in November...i raced Zapata the first 2 times and Xenon7 the third time...Zapata kept creeping up on me both times...Xenon just hauled ass past me!!! here are the slips in time order...im car #7037, and that's my number for the rest of the season...first run against Zapata:

 

2nd run against Zapata:

 

3rd run against Xenon7:

BTW, temp was 60 degrees with lots of humidity...i had just over half a tank of gas...spare and jack in the car

the 3 of us had intakes only (Zapata and Xenon7 have AEM, while i have Xephyr)

 

Good job on the runs and I'm sure with your new tires those times will change! Sadly Scooter it's 2:16AM and I am still at work

 

:thumbsdn: :shakehd: :angry:

im sorry man

 

Nice reaction times

 

i had the same problems reaction times at first because I would stage as soon as the staging light would light up. Now I roll forward ~10 inches and my reaction times are WAAAYYY better.

 

I never worry about reaction times unless I am running brackets.

Usually, I stage as shallow as possible to help ETs when doing time trials...

That 10" will be about half a tenth.

 

I had an awesome time! First time to the track. Scooter and I went against each other twice and he came away empty handed both times. I had the spare tire out of my trunk. I had 1/2 tank of gas left and i weight 195 lbs. I don't think the spare made the difference because it can only be like what 10lbs at most? Tire pressure was 40psi on all four tires. I don't agree with taking pressure out of the front tires because it really kills acceleration in the top end. I did not brake torque. I gate shifted all 3 runs. 1>2>3.

My car number is 7033.




I don't know why my time as so shitty. It was my first time so i was a bit nervous. Scooter was a little annoyed that he was ahead up to 1/8 mile and then i caugh him and passed him. He swore he was going to get me the next time





I improved my 60ft time so that helped my overall time. However, Scooters 60ft time was better than mine and i still beat him Cracked that 15 second mark. I am very happy because the temp was 65 with 75% humidity.



Went against a guy in the 3.0L v6 accord. Every stat improved since my first run.

BTW, none of the other CLS broke 15


My woman came with and run her subaru awd outback station wagon. n/a 4 banger that weighs 3500lbs. Her first run was agains a VW GTI vr6 w/turbo. I don't know how much boost. He had every seat out except driver. Last week he ran 12.001 so the car is very very fast.

 

can anyone shed any light as to y my times were kinda sucky...disregard the first run b/c i fudged it up trying something

the 2nd and 3rd runs were torque braked bout 2K

 

I know that there is a small reduction is torque to the road with the 225/50-17 vs the stock 215/50-17. (Just to be clear, I'm not saying that this IS the cause, just that it is a possible factor -- consider it to be "info" to weigh [food for thought, etc, etc])

Pilot A/S link:

http://tires.michelin-us.com/assets/...lotsportas.pdf

Diameter: 26.1 revs/mile (at 45 mph): 795


Stock MXMs link:

http://tires.michelin-us.com/assets/..._pilotmxm4.pdf

Diameter: 25.5 revs/mile (at 45 mph): 819


Using the revs/mile ratio between stock and the 225s, there is a difference of 3%. This is like changing the gear ratio by 3% with subsequent reduction in torque in gears 1, 2, and 3 (for quarter mile purposes).

So, it would be like having a 200 lb-ft at the wheels, become 194 lb-ft at the wheels (or a 3% loss in “effective” torque). Looking at another way, if an AEM CAI (or equivalent gains an average of +4HP [not peak]) and -0.03 * 200HP = -6HP, you would negate the gains of the CAI with the increase in diameter.

Finally, I have a chart of tire weights, and I would love to see Michelin (and others) put in the weight of the tire. As a rule, the Michelin’s are a bit on the heavy side and will help you in the longevity and resistance to punctures, but can drop more equivalent HP from increased weight. The bigger tire alone will probably weight more.

(Can someone weigh his or her 225/50-17 A/S tires at the tire dealer in the future???)

Out of date tire weight link (if someone had some more complete and newer ones, please do let me know):

http://www.miata.net/faq/tire_weights.html

 

Eric,
Excellent analysis as usual. However, scooter is still on stock tires so i don't think the tire size had anything to do with his slowness. Scooter did mention that he was running at 34 psi on all four tires. I suspect that the lower tire pressure really hurt his top end acceleration; which is the exact place where i pulled past him. Hmmmm I wonder what pressure Xenon7 had his tires?

 

zapata, why are you running your tires @ 40psi? acura recommends 32psi. you'd be better off at 35psi cold, more traction and a better ride.

 

Mea culpa 3/22/2002! Yes, those virtual tires wouldn’t change much (At least a before-and-after test match is possible after 3/22)

The other "option" that's not generally available at the "track" due to time and crowding issues, is the "swap drivers" option. (this at least gets rid of the driver technique and weight issues.

(Did everyone use the D1->D2->D3 with same shift points?????)

I know that a 5PSI drop in pressure on my Toyos makes the car feel rather sluggo (and the gas mileage sucks too).

When I look at the times, it looks like Scooter is always behind and the (added weight?) or (lower torque/hp?) or (drag/losses) just widens the gap with distance (as it should)...

The famous (or infamous) NHRA link for “web racing”: http://www.prestage.com/carmath/calc_etmph.asp

This is going to be a great, "hey, can I borrow this item" (if its claims are met):

http://www.gtechpro.com/competition.html

 

Ack, 35psi makes the car feel SLOOOOWWWWW. Especially during the winter the tires are cold. During the summer i kick down the tire pressure to 35psi because i know they will expand rather quickly. Also, the majority of my driving is smooth highway so i just need good MPG and drive quality isn't a huge issue for me.

 

Eric,
I think if scooter looses again he may want to swap cars(NO BRAKE TORQUE!!!!!) and see how the times are affected. The first run he didn't floor it in first gear until he was at 5k rpm. However, he didn't didn't repeat that techique but still lost 2 and 3 runs.

What would explain his intial lead and then losing the lead between 330ft and 1/8 mile?

 

Sure wouldn't help (firm grasp of the obvious) "staying" off WOT until 5K.

If the ride heights are all the same, tire wear is the same, the main issue would be drag as a function of speed (such as):

1. Aero issues (should be the same unless someone is lowered)
2) Tire drag or other drag related to axle/wheel speed. (The tire pressure would affect the drag losses in the tires as the speed increased. There was a drag calculator for tires, but I can't find it right now)

and ???

 

Eric,
Hmmmm will i have a moon roof visor. I'm not sure if he does. Although i think that would be in his favor--if he didn't have one--and we both of spoilers. Both of our cars are the same height.

 

check my sig...spoilers are a wash, moonroof visors are a wash, and all other accessories don't amount to weight...

here's where the weight differs...i had my spare, jack, and some tools in my trunk...tools weigh bout 10 pounds...dunno how much spare and jack weigh...i weigh 215, so that's about 20 pounds difference there between Zapata and myself.

and i SS'ed with no VSA and torque-braked about 2K.

those seem to b all the differences...any insight???

 

what are the chances the Xephyr intake performs better in colder weather, while the AEM performs better in warmer weather???

it was 60+ degrees with lots of humidity.

 

Anything is possible -- I don't know

You would want to make sure the K&N filter is clean...

 

More similarities than differences...

The 20lbs -- not enough for .2 seconds (no rocket science required)

D1->D2->D3 vs. SS (yes/no)?

Zapata says you lead to the 60ft and the time slip shows it (no gear change yet [yes/no]?) (The lead is small there too...)

If he was using the D1->D2->D3, he would hang on to 1st longer (only accounts for a small lead at a single point).

I recall a number of folks reporting the best times with D1->D2->D3 vs. SS or Auto...

You didn't mention the gas tank level...

< -- >

Previous and additional guesses:

The shift method (SS vs D1,2,3) or some minor shift timing difference between trannies.

Tire pressures.

K&N dirty (have you checked your filter lately?) < ---------

Production variances…

Without the driver swap, the 60ft is so close, that IMO, I call it a wash (due to technique, etc).


$0.02