bmxsteve

I went to the track yesterday hoping to beat my last(and only time at the track)best time of 15.0@93.5mph. I still have the same mods. The first time I went to the track was only 3months after I bought the car. Its over a year later and I wanted to go back. I've noticed my car not pulling as well, and I wanted to verify this. I've changed plugs, cleaned the tb, air filter, gutted cat, but I didnt know if the improvement was mental or not.
So anyways, I went the track with nasty 75 degrees and a decent amount of humity. The best I got was a 15.2@90mph. My 60 foot sucked(2.3), yes, I understand that, but the track speed????!! My god, 90mph! I never hit over that. Its odd that a year a ago, when I was new to 5spd, and new to this car I could trap close to 94mph. I believe my shifts werent a factor this last time cause I still pulled off a 15.2@90mph and wouldnt a 15.2 car typically hit 92mph through the trap?
The only explaination I have is maybe something with my hybrid intake. I'm not using an upper tube from pr or wsp, rather a rubber tube I got from home depot. And the hose that runs off by the value cover isnt air tight into the rubber tube. But how much of an effect would this do to performance if air was getting in my system after the maf sensor? At this point I looking for any answers, im getting desprite. I want to dyno this week, I'll look at that and hopefully some of you knowledgable guys can help me.
Well thanks for listening to me and I hope someone can help.

Nismo87SE

The gutted cat is hurting you, its killing the exhaust velocity. Try running a test pipe instead or at least a high flow muffler. Also what were your 60', 330' 1/8 ET/trap info? Since you have a 95 I'd advise you to check the ECU and see if the knock sensor is functioning properly.

bmxsteve

I1: 2.369
I2: 6.445
I3: 9.814
MPH(I3): 73.258
E.T. : 15.209
MPH : 90.251

Also, the only code I have thrown was 0505, which means nothing, correct?
If put my car on the dyno, do you think we could point out the problem easier if we could see where my car is having trouble? Thanks

Dave B

The gutted cat is killing you. The odd shape of the converter internals makes for lots of exhaust turbulence. I don't what the infatuation is with removing cats on NA late model cars. A cat only sucks out 1-2 hp at most. Todays cats aren't like the ones from the 70s/80s. Either run a cat or get a test pipe. You probably lost 5-10hp gutting that cat, judging from your MPHs.


Dave

bmxsteve

Well, my car felt like it had a lost of power, so I did ever thing i could to find the problem, new ngk plats, cleaned tb, air filter, gutted the cat(thinking maybe it was clogged), changed the fuel filter. I was told by several respectable guys here on the org that there wouldnt be any side effects on gutting my cat. If this is the case, and it is in fact, just the odd shaped cat, i'll be more than happy to get a test pipe, not a problem! But that 90mph trap, geez, thats a dog! I dont know how much patience the dyno guy would have with me,(I get 3 runs, $50) but it would be cool if i could order a test pipe, dyno with the gutted cat on one run, and then throw the test pipe on there and see if there is a difference.

desertmaxima

iTrader: (5)

You might want to see how much they charge by the hour fro dyno tuning cause thas what yer gonna be doing and alot of shops dont let ya do pulls and wait while you change around stuff cuase you have to resetup everything. So he will probably tell ya go bye the hour to dyno tune. Good luck on yer dyno

bmxsteve

So a gutted cat can really hurt me 4-5mph through the traps, and .3-4 in the 1/4 mile???

Jime

iTrader: (10)

I wouldn't bet on that but its possible its hurting you depending on what you took out/left in. Some people just push a pipe right through the centre and leave it there so its just straight through. You could still do that. Only 4 bolts holding the cat on so it would be real easy to swap a test pipe between runs.
Good Luck