Soon2BMaxed

my times at high school drags......(very long)
well well well,where do i start....
ok, saturday i was leaving my house to drop my little brother off at the mall and i bottomed out pretty bad on the end of my driveway that has a decent slope to it. well later that night after i was driving for awhile i start to notice this loud buzzing noise whenever i hit 4k to 4400. WELL, sunday comes and after my first run the buzzing gets LOUD and it sounds like i have an exhaust leak. i look under the car see my gasket between the y-pipe and cat fluttering around and it turns out thats where the noise is coming from. now with that said.....my times absolutely sucked (even in the nice cool weather we had all day)

my runs are as follows:

1st run
60ft. 2.393
330 6.569
1/8 9.992
mph 71.74
1000 12.932
1/4 15.431@89.82

2nd run
2.298
6.410
9.823
72.10
12.757
15.254@89.90

3rd run
2.323
6.409
9.815
72.55
12.741
15.224@90.59

whats weird is this (a previous run back in jun in 80+ weather)

60ft. 2.389
330 6.472
1/8 9.873
mph 72.86
1000 12.792
1/4 15.263@91.71mph

so basically, i ran a 2.29 60ft versus a 2.38 and ran only 1 hundredth of a second faster but 1.81mph slower!?!? and this is WITH full exhaust.

SO my theory is this.
when i bottomed out i nailed my cat pretty hard (i know this because there is still gravel wedged in the cat brackets) maybe i knocked the honeycomb loose and its blocking airflow? maybe its blocking it so bad that it worked my gasket loose when i drove the car hard? later today i will rip apart the cat and look inside. if the honeycomb is in there crooked or anything then i am knocking it out, hopefully my car won't stink too bad.


Trevor


p.s. upside to this was later that day i met up with charles and went for a ride in his G35. all i can say is YUMMY

Dave B

Well that sucks. It sounds to me like the exhaust leak you might be experiencing is causing most of your problems. Still check the cat though. What's really perplexing is that you're nearly .4 and 2mph slower WITH the y-pipe. I can't imagine an exhaust leak would cause that much of a problem. Conditions yesterday were awesome with temps in the upper 60s, ultra low humidity, and good pressure. I talked to the Grand Prix guys who ran out there on Friday and they said the track was absolute crap. On full blown slicks, the best 60' for any GTP was a 1.91. This guy usually pulls 1.7s at his track up north.

Now I'm a bit worried about going to KCIR this Wednesday.


Dave

kratz74

Those times are awfully close either way. Could be blocked but only partially if at all. B/c the times and trap speeds are too close together .

Soon2BMaxed

well, just checked the gasket and it was pretty loose. i must not have tightened it very well the last time i was under there. i could only check the side of the cat towards the y-pipe because the other end was too rusted to the stud and it was fine anyways. that buzz is gone for the most part but the gasket still makes a little buzzing noise that you can only hear when you're under the car. but overall the leak is gone. i still dont see what is wrong with my car. its really weird but my top end just feels a little weaker than usual and its been like that for the past week or two but i thought it was just my butt dyno. i'm totally clueless. i might come out with you wednesday.


Trevor