07Txlex

Sorry if my skills as a camera man weren't up to par... LOL No really I had fun, both of your cars sound badass!! Gernby u finish off that 12 yet? lol

Gernby

iTrader: (1)

The video was fine. Thanks for recording it for me.

Unfortunately, the 12 was finished...

caymandive

iTrader: (2)

Your car sounds very good.

combfilter

iTrader: (3)

Actually, the other cars out there were running good also. Faster mustangs then before and we saw this tubro diesel big *** 4x4 extended cab truck running 8.7's It was funny as hell.

Gernby

iTrader: (1)

I've been running every sort of mathematical model I can think of to figure out what my estimated 1/4 mile times would be, and the results are all over the place. If you guys have any input, please visit this thread.

lobuxracer

iTrader: (2)

They're models. The only way to know for sure is to complete the 1/4 mile. That's why we race on tracks not on calculators.

Gernby

iTrader: (1)

I agree with your point, but I would really like to figure out what these numbers really mean. It seems to me that the most consistent measure of performance on a track would be the difference between 1/8 and 1/4, since it would reduce the variables the most for similar cars.

I don't want to poke at you specifically about it, but this track experience makes me believe that dynos are FAR better than tracks for grading engine performance.

lobuxracer

iTrader: (2)

If you keep focusing on times, you would be right. If you focus on trap speeds, you would not be right at all.

Gernby

iTrader: (1)

I understand that trap speeds are important, but my trap speeds varied as much as my times. They ranged from 74 to 83 MPH. I've never had a dyno test vary that much!

lobuxracer

iTrader: (2)

You do have to learn some consistency, but the longer drive (1/4 mile) will take some of the guesswork out of it.

Gernby

iTrader: (1)

I just got back from the dyno, and the results weren't particularly good. However, I don't think the poor results were necessarily due to the exhaust. It's been 3 months since my last dyno, and the weather conditions are very different now. It was a cool, beautiful day here on November 3rd, '06 when I did my last test, and today is a very cold, rainy day. In theory, the SAE correction would even out the difference, but the shop's climate sensors still seem to read the same figures. Plus, the shop is keeping all their doors closeed now, and is running huge gas heaters to keep warm. Surely the O2 content in the building is much lower than it was in November when they had a fresh breeze blowing through.

The most interesting data from the test was the change in shape of the torque curve. It is much flatter and smoother now. However, I'm concerned by the resulting AFRs, which are all over the place. BTW, my piggy-back ECU was disabled for both of these runs. I've been trying to figure out how the closed up shop with heaters might have played a role in the AFRs. I would have expectedt he AFRs to appear even more rich due to the reduced O2 levels. As an afterthought, I wish I had monitored ignition timing via OBDII to see if the ECU was pulling any.

EDIT: the red line is from 3 months ago, and the green line is from today.

caymandive

iTrader: (2)

Hmmm so this test is still inconclusive. Also how did they monitor your Air/Fuel? Sniffer in the tailpipe? If so those things are notorious for reading all over the place and differently on different days. At least you still got increases throughout the whole power band.

jsquared

the green line is today? so you lost power?

Gernby

iTrader: (1)

You read the graph wrong. The plot shows decreases throughout the whole power band. According to the dyno, I lost 3 peak HP, and 7 peak ft-lbs.

It was a sniffer type WBO2, but the readings were very consistent 3 months ago, and psuedo consistent today.

caymandive

iTrader: (2)

Ok crap I should have looked a bit closer. I just looked at it and assumed you made more power. Man now it's really inconclusive.