I just want to make sure im on the right track. LAst year a ran a 13.6 @106 2.3 60foot(in hot weather). I did LT Race headers (only mod since last years run) and last night did a best of 13.6 @107 2.3 60foot(in cold weather). I was open header. Do you guys think (which i do) if i put exhaust on the car that my times should go down? Ill probably need a tune aswell, do you agree? Thanks

 

Tune, 60' time, weather are all factors.

 

2.3 60' .. ouch. general rule of thumb- 1 tenth in the 60' is =to 2 tenths in the 1/4. lower that 60' to 2.0 and youll see 13.0 maybe better

thats weird, i always hear that LT headers and ory will drop 3 tenths

 

If you were running the stock catback, without even a cutout, you wouldn't notice anything probably. Your exhaust has to have the ability to outflow your manifolds or headers before you'd gain anything, which the stock catback cannot.

 

He said he was running open headers

 

i was open header....lol

 

Crap

 

Get some M/T ET street drag radials and youll be getting way better 60s with better times

 

I agree.

 

Open headers are prone to mess up your fuel trims by
corrupting the O2 sensors' operation (fresh air reversion).
Headers can also affect this just by their thermal effect,
too cool for school (O2s go sleepy). In either case you
would be over-enriched if you have any positive fuel
trim action, and the stock PCM tune is too rich to begin
with. Get to a stable engine / exhaust configuration and
then make with the tuning. If the tuner discovers high
positive fuel trims still, after adding the rest of the pipe,
you will have to address the thermal side (wrap, 'vette
rear O2s, etc.).

 

i picked up nearly a half second and 3 - 4 mph when i went to headers and duals

 

Using some 3" diameter extensions beyond the header collectors would be a good idea.

 

I picked up .6-.7 seconds and 5 MPH with my LT's, TD's and lid. The ported TB and SFC's were done after my best runs. My best MPH was actually 108.5, but not on the 12.98 run. It's never been tuned....yet. It was a definite and obvious gain the first time I drove it. Most likely it's what JIMMYBLUE said. You turned a similar trap speed to mine....you've got low 13's to high 12's in you. My 12.98 was also a spinning launch. With DR's, I could have probably hit at least a 12.8. I didn't get a chance to put my buddies DR's on though. I do know that it was spinning enough for me to be surprised that I still hit a 12 on that run.

 

Full-Force, did you get tuned after the header / exhaust install? Or was that a bolt and go type of thing

 

exactly what i was thinking

 

bolt and go

longtubes are the biggest bang for bucks mod out there short of nitrous

 

so apparently from what you guys are saying. I need to get my exhaust hooked up in order for me to see a gain. I have a corsa catback on the car already, i just need a y pipe

 

Try it with the headers closed. My car lost 10 hp with the headers open when i dynoed it, and i closed the headers and got it back

 

There is an advantage to exhaust pulses being merged by a good Y or X merge, as scavenging occurs.
Other than that, even if you just add some 18" extensions from your collectors, this will help with the front O2 situation mentioned above.
Also, are your rear O2's cleared/deleted or simulated?

 

I (my car) experienced the opposite effect. Every setup is different.
And, I would hope none of us runs with headers closed.