Well, i finally had a good day to hit the track and see what kind of ET and MPH gains I would get in the quarter-mile!!

The sad part is that it was a very mixed bag of results tonight.


I got in about 5 runs and had a solid baseline from before the headers. Absolutely no other changes have been made to the car other than the headers since those last track runs.
I've got literally several hundred runs in my life, so I made sure that the gas level, and car prep (tire air pressure, no junk in trunk, premium gas, etc) were all exactly like last time.

The good news is that my 60' times were very noticeably better. A solid 1 tenth on one run!! wow! Then that was backed up with a couple of .04 - .06 UNDER my previous bests.

The bad news is that the ET was only better by .03 on two runs, and SLOWER on subsequent runs. The engine temp was never terribly overheated or abnormal. In fact, my two best runs were made RIGHT off the highway, get teched, numbered, BAM, make two back to back runs!
(14.12's at 96.5mph)

Previous bests were 14.15 and 14.17 at 98mph.

I've yet to compare the 330' times and 1/8th from the previous runs, they will tell if there were true gains and the car fell down at the top due to bad air or something.
The air did not seem bad at all, in fact, I thought it felt relatively close to the other runs!
I can post full times for tonight and the previous runs tomorrow night.


I hate crap like this.


.

 

at least you can change your sig now

 

that sucks. look at the good news though, you're almost at 13.xx with a NA 4000lb car .

 

Well, there are certainly things to consider. First, you went quicker than your previous best. You did make a solid effort to bring the car to the track in a close of condition as possible to your before best runs. It is interesting that your best pass was right off the road. Mine have always been with as cold of an engine and engine compartment as possible.

Did you happen to record the barometric pressure? Air pressure is very important as that is what actually charges then engine. The higher the pressure the better. Certainly cooler air is better and low humidity is better but absolute pressure is still king.

Also, fuel quality and engine "mood" is a variable. I look forward to the timeslip data. Did you ever post your baseline timeslip?

Here are 3 of mine

 

JBrady, Here's the numbers from my last pass, and the stock reference pass.
THESE ARE NOT FROM LAST NIGHT. These are from the torque converter installation.
---------------------------------------------------
old 60' - 2.259
new 60' - 2.046

old 330' - 6.273
new 330' - 5.916

old 1/8 - 9.49@75.5
new 1/8 - 9.104@77.34

old ET: 14.55@97.68
new ET: 14.15@96.92 (had 97.9 earlier)
----------------------------------------------------


PS. John, I totally agree with you. Pressure is King, Humidity is #2, air temps within reasonable range a close 3rd. Yesterday, the temp was around 80-84 I think. I don't have numbers for pressure and humidity. The only clouds were very thin and very high, so I expect air pressure to be average. (neither high, nor badly low)

 

HERE'S the runs from after the header installation.

First two runs, right off the interstate, teched, didn't even stop in the staging lanes! Just drove right up to the spot before the bunout box.

RUN 1 RUN 2
1.9582 - 1.9899 60 '
5.8171 - 5.8497 330'
9.035 - 9.055 1/8
76.31 - 76.38 1/8 mph
14.121 - 14.128 1/4
96.13 - 96.53 1/4 mph


3 "not as good" runs

1.98 - 2.01 - 2.01 ---- 60'
5.866 - 5.879 - 5.902 ----330'
9.102 - 9.099 - 9.129 ----1/8 et
75.5 - 75.7 - 76.28 -----1/8 mph
14.22 - 14.21 - 14.25 -----1/4 ET
95.73 - 96.16 - 96.15 -----1/4 MPH


Right now is the first time I've gotten to analyze these runs and compare them with previous runs. It's hard as hell to draw conclusions with results like this because the damn OBDII is so freakin unpredictable for us.

I will say this: Getting a consistent .05 - .10 in the 60' is hard to do, and shows very good promise. Air quality is LEAST determinate here.

Holding on to .05 improvement in the 1/8 mile is also a very good note.

Either the air pressure/humidity was NOT as good as I thought, thus hurting the 1/8 and 1/4 numbers,....or the OBDII is kicking in and screwing things up as the car goes down the track.

OH YEAH, I was running Shell 93 octane this time. I'm not sure about last time. Probably Speedway.92/93.

Air Pressure seems to have been about 29.98-30.02, <4mph wind.


PS> here's a good source for weather data.
http://www.erh.noaa.gov/data/obhistory/KFFO.html
http://www.nws.noaa.gov/

 

You should wrap the headers with insulation if you haven't done so. Cuting heat =more performance

 

perhaps. they are JetHot coated inside and out though.