Okay, last time I went to the track, my best was this:
2.320 60'
9.461@77.17 1/8 mile
14.481@98.48 1/4 mile

Tonight, my best was this:
2.185 60'
9.288@77.18 1/8 mile
14.328@97.90 1/4 mile

The weather was cooler than usual, with a slight breeze. The only changes were tb bypass and adjusting the tire pressure to 35psi front/30psi rear vs. 30psi all around. All my runs tonight were .5-1mph slower than before, though I cut better et and 60' times. What could be causing this drop in top end? I have an auto, and my launch technique is rolling the throttle smoothly to keep from spinning. Not sure if it matters much, but when I flip my manual fan switch to high, my voltmeter drops from midline to near redline, though someone told me the meter tends to read a volt low. Could the fan be draining my weak battery and negating the benefit?

 

Okay, here's another thought...I didn't bleed the coolant when I did the tb bypass. Would that affect anything? BTW, I barely dripped any coolant when doing it, so I seriously doubt the opti got wet.

 

your times look about right considering the bad sixty foot.

what are you talking about "drop in the top end"?
your top end looks pretty consistant, you gained 21 mph on both runs, from the 1/8 to the 1/4.

get some drag radials and you will see high 13's

what was the water temp during the run?

jesse

 

in your case,the slightly lower top end (which is NOTHING to worry about) is due to better traction,wheel spin falsely raises mph,so guys that spin then start hooking get all freaked out by a mph drop.

your times are decent for whats done to the car,get some good tires and watch the et drop.

 

Also if you lower the tire pressure you get a bigger contact patch between car and track, and bigger patch means more friction, which slows your car down. This is the reason why some guys go with skinnies up front.
Basically get the fronts to the highest safe PSI, and the rears to the best hooking PSI and you will have a good combo.

 

thanks for the responses. Maybe I'll reset the tire pressure to 30psi all around so I can make sure everything else is running alright!

 

the reason why your times might be slower than some of the other fbody cars is because the track at campbell is never really prepped well. i was disapointed with my times too. my best is a 14.6. all stock, just like it came from the factory. ive herd of people going high 13.0's stock. i assume its the tracks fault, as everyone else seems to think so too. lemme know when u go next, i wanna clock my car again with the cai.

 

those are decent times, with 2.73's? How was your launch? Did you spin at all? I know I lowered the psi in the rear tires to 25 psi, on my best runs . I would get them gears swapped out. I noticed a night and day difference when I went from my 2.73's to 3.73's.

 

You did not listen to:

Radial tires aren't meant to be run at lower pressures like slicks. Bump the tire pressure up a notch, say to like 40 PSI. I used to run my street tires at 45 PSI.

 

The reason you have a lower MPH is because you finished the race faster. So, the car has just a little less time to accelerate. It's a pretty normal thing to happen when you lower your 60ft times.

 

That's about what I ran stock with my 2.73's (and the auto back then). 14.0-14.1 with 2.1x-2.0x 60 ft @98-99 MPH.

Seems ok. You might be rolling it a little too slow though... something to work on.