I was running 13.5-13.9 all day at around 102-104MPH with an average of 2.2++ 0-60' until this run..Why the loss in MPH?Did the 60' times affect the MPH??

R/T..1.078
60'..1.899<---best of the day
330..0.615
1/8..8.707
MPH..78.41
1000.11.419
1/4..13.693
MPH..99.44 <----?????

Daz and Confused
L98,TPI,3.27,Auto,Yokohama AVS (rears)

 

The better 60' time should have netted you a better ET but it won't change your mph. Mph is a direct result of hp. Many things could have effected it. External forces things like head wind, barometric pressure ect may have changed. Vehicle changes like shift point rpms, valve spings starting to float the valves, tire pressures, oil temperatures can all effect engine hp.

It's possible you may be starting to hurt something in the engine causing it to lose hp.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
LS6 Big Block buildup now in progress

Best results before the engine blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!

Member of the Calgary Drag Racing Association

 

At this run there was long wait in line...and my car's temperature is at 200 plus..Would that cause the 3 mph??

Daz

 

Quite possible. High temperatures will decrease hp. That's why most drag racers like an engine at around 160 and a max of 180. When the coolent is hot the oil is also. The tranny oil is cooled by the rad and it was probably hot. All these hot fluids could have caused the decrease. Once you made the run, the oils hot even hotter and couldn't be cooled enough.

The only way you can tell is to go back and race again with a colder engine temperature.

 

did you take air pressure out to get this 60 ft time? If so it would have decreased your MPH

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

 

vorteccar,
Yes I did,from 25psi to 20 psi..I ran a couple more times after but didnt go under 2.2..Would locking up the converter help?

Daz