I would believe you, my car traps 119 cam only 3650 race weight, 3850 when I drive it, Im a big ******..lol. I had the same problem about a yr ago. I went from running 11.8s at 113 to 12.7 at 103. My car would take off normal then just fall on its face. No engine knock or check engine light ever came on.. After going through everything, rearend, tranny, and the geometry of the suspention several times and nothing working, we decide to do a compression test. When we took the valve covers off, there it was, a broken spring. Thank goodness, I had put dual springs on cause the broken spring was hung up on the inner spring.. Hope you find your problem soon..

 

Im taking it to a tuner on saturday to see what he can come up with

 

Hope it's nothing serious man..

 

I would also check the MAF and o2.

Friend's car went from running 7.2-7.4 to 8.x, cleaned a piece of lint off the MAF wire and replaced a bad o2 sensor and went back to running mid-low 7s

 

Get a tune for that stall. You didn't describe the pass you made with the stall...were you spinning bad, hitting the rev limiter, shifting early? I cant see the time slips on my computer at work.

And good times for stock. I ran 12.9@110 with my 01 Z with a lid, 3.73s, lt's, stock rubbers, and a stock tune.

 

no it wasn't spinning and it seemed to be shifting fine.

 

Also is it possible you put the rear o2 sensors in instead of the fronts? They are different part numbers.

 

Different part numbers on OEM sensors because of the different wire lengths.
Otherwise all four are the same sensor.

 

I also have a surge at idle could that be do to the lighter converter

 

Please do not misinform people....in my opinion that stall is to small, i run an ss4000 stall with just bolt ons no heads/cam stock motor and have went 11.7....before i went 12.6 with 3.23 gears, stock converter...only mods being longtubes with exhaust....lid...and tires....and trapped 109 still...trapped 113 on my 11.7 run....you have something major going on...either your car isint running on all cylinders, maybe it cuts out or is shifting from first to third or something....or your third gear clutch is slipping ungodly bad....but theres something major

 

its not a top end thing... its an all the time thing. He lost 5 mph in the 8th mile. Thats significant.. my money is on tune/timing/afr issues. Potential spark plug issue. Bring it to ur tuner with a set of spark plugs handy. Have him check the tune, do a compression test, change plugs. Etc. You should be running close to, if not into the 11s at around 113 mph assuming u went 109 before those mods

 

Im going to check the plugs tonight. I would think if it had a bad plug it would run rough or throw a code. If its not the tune I guess it has to be in the converter. If thats the case out with 4l60 in with the th400.

 

This is not impossible. I have personally seen a bone stock A4 z28 with slicks ONLY run consistant 12.8 in 50 degree weather.

 

This is your best bet. People can beat you to death with what they think is wrong but a tuner should be able to give you a direct answer.

 

Good Deal. I'm sure your shifts points are way off . Hopefully once your tuned ,you should feel a world of difference than before. I also hope that you don't have any tranny issues . Keep us posted ,man.

 

lol definately not. people run 3200-3600 all day, some go even bigger than that. I personally have a 3400 in mine, and it dropped .5 second and gained 2mph as a result

To the OP- Have your tuner datalog it

 

Took it to the tuner today and we found that the maf was bad the car runs alot better im taking it to the track sunday i'll let you guys know the results.

 

Good luck! I'm intrigued to see what you run. I ran a 12.91 @ 108 untuned with headers and a messed up maf. No number after my cam & stall, due to my tranny taking a crap.

 

I don't know, It just doesn't seem like a bad MAF will drop you 10 mph. That's a lot of mph to lose if you ran at the same track & fairly same conditions. Most drop I have seen is with altitude changes, about 6-7mph..from 1000 ft to 4500 ft. Anything is possible I guess.

 

how did the maf go bad? you didn't remove it, did you?

i was going to ask how close your ypipe is to the chassis..