i have a 99 a4 z28, and when i took it to the track with only a borla cat back and an air lid, the car went 13.0 @ 108. i went to the track last night with an ls6 intake, kooks lt's, ory, and it was tuned by chuch @ HPE. One thing i think might be doing it is the stall i have. my dad rebuilt my transmission for me for graduation, and put a hughes stall in it. Anyways, it ran a 13.2 @ 104! whats the deal?

 

loss of traction is my first guess

 

Judging by the mph's, my guess would be the weather. I would bet it was much much cooler on the first day and it was very hot on the day with the 13.2 @ 104.

 

ya your right, it was about 50 degrees when i first ran it, and like 85 yesterday, but i didnt think weather made that much difference.

 

the reason i think it's that converter is, my 60 ft. was actually better last night than when i ran the 13.0 pass

 

How many passes did you make? How many trips to the track since the new combination. Point is, you should not try to make a decision based on a couple of passes on one night. Try 3 different nights, same track, same prep, same weather conditions etc.... or at least as close to the same on all that as you can get.

Then take an average and that should tell the story of whether the combination is off. And yes, the converter efficiency plays a big part in the overall performance! But don't try to pass judgement on it jsut yet, JMHO.

g

 

some tend to lose MPH with stalls, but you also added mods and tuned which should have shown an increase in MPH. (again, the weather could have affected the mph). what was your launch technique? if you were spinning, usually that is reflected in a higher-than-normal trap speed. what tires do you run and what pressures?

 

i was running 275 nitto's (street tire) @ 25 psi. The track was actually hooking up pretty good and i didnt really spin. As far as technique goes, i knew i would spin if i flashed it so i stalled it up as high as my brakes would let me, then rolled into it.

 

get some extra rims (try stock firebird or camaro 16inch rims) and e/t streets. heat them up and stomp on it. youll drop the e/t