I just got a 98 z28 A4 w/19K miles, it's bone stock to the lid except the guy before me had a flowmaster muffler put in with stock tubing and tips. My disappointment is that I made 4 passes at the track not too long ago and couldn't do better than a 14.2??? 60ft times were 2.2's and I couldn't trap higher than like 97. Any ideas as to why so slow? Car was ran at memphis motorsports track in pretty hot weather, don't know the DA here but just trying to find out anything that could affect the times this much??? Sorry for the long post!

 

Don't be man cause at this time of the year ya shouldn't expect alot from a stock car besides DA' is a killer factor on the track & the sixty foot is main thing to break through man

it's a matter of time man to see cold & freash air so keep it up !!

peace

 

To give an example:

I raced last August in 80 degree weather and ran 14.4 @ 98 with a lightly modified 97' T/A.

I raced in October in 50 degree weather and ran 13.65 @ 100 with the same modifications. Cool weather is your friend. You can cut a 1.9x 60' time if you practice. Clean the tires off a bit, don't smoke them a lot. Foot brake at the line to about 1,500 rpm (if it's an auto) and on the 3rd yellow, let her rip!

 

thanks for the info. Anymore advice welcome!!

 

Hot summer weather = slower times.

Coach

 

yea july sucks for et's and high mph's.

not to thread hijack or sound like a dumbass.....but what is DA?

 

What was your 1/8 mile ET and mph? any other details of the time slips?

14.2 seems high for a stock 98 even in the heat, did you hot lap? Not letting the car sitting a long time in the staging lane? This will help keep the car a little cooler.

 

DA = Density Altitude.

Figure each 1000 foot of DA is about .1 to .15 of elapsed time. Obviously lower DA is better

14.2 is not all that bad during summer months. The 60 foot time holds a 13 second time if you can hook up better (I got a 2.06 60 foot on my stock Goodyear GSC 16 tires at 27 psi).

Derek

 

here are two of my runs. One is the best of the night and one is the worst.

Best run: Worst Run:
r/t= .165 r/t= .406
60= 2.220 60= 2.179
330= 6.089 330= 6.138
1/8= 9.248 1/8= 9.383
mph=78.79 mph= 76.56
1000= 11.956 1000= 12.165
1/4=14.261 1/4= 14.538
mph= 97.79 mph= 94.86

my worst run had the best 60ft time?? Maybe I hotlapped? dont' remember but the mph seems low given it was hot as hell??
The best run was also my first run of the night and same goes as my worst run being the last. had two more runs one was another 14.2 and one was 14.4

 

Seems to be down on power a bit, but we still don't know DA and elevation, gearing and a few other things to give an informed answer.

 

gears are 3.23, wish I could find out the da here in Memphis! If anybody knows please feel free to chime in. Thanks to everyone that has replied so far..

 

thanks, now the next ?
how do you figure DA? like instrument or gauge, what?

 

Instruments are best (I use a Kestrel 4000 handheld, like $239 I believe, and it tells temp, humidity, dewpoint, wind speed, DA and corrected DA. Nice to have for reference and help since I bracket race.
You can also figure DA from actual weather conditions with a formula, or check out the national weather service for a list of airports and such located close to you and they log the last rolling 24 hours of weather conditions, including DA.

Derek

 

DA/ET Calculator

Something useful from a ferd site.

 

thanks a lot!! makes me feel a little better anyways. Does anyone know how realistic this site actually is?? If it is correct my 14.2 @ 97 weather and sea level corrected would be a 13.6 @ 101..

 

Given you're mods a 13.6 in good weather is definetely realistic.

 

It's not going to be dead on, but it should be within reason. Here in hot & humid FL, I see cars drop as much as 3 MPH going from the winter time to the heat. Did you factor in your track's elevation? You can google the track to find out information like that, then use data from weather.com or a site like that to get all the weather conditions. The rest is up to you...

 

my 98z with just drag radials in april was a 13.8 ride aug was around a 14.0-14.1...nitrous is your friend no matter what the weather is lol. Dont be to disappointed as everyone has chimed in its pretty much normal.