Same numbers and mods as I have in my sig i put down 25rwhp less on a mustang dyno. They put the car under load and the dynojet doesnt. Good for tuning, not so good for numbers. So its a combo of your weak exhaust and numbers from a mustang dyno.

 

The other cars were a LS1 with a cat back that put down 315 and a stock LT1 caprice that put down 240ish.

 

Ok i still dont know what to do with this car. Not only did it have a weak dyno pull, but over the summer the best i ran at the track was a 13.9 and the thing has been getting progressively worse gas mileage (160 to a tank). But it seams to run fine, idle great and when i pulled it on the dyno the hp line kept climbing and and the tq curve was a nice even line just low.

 

what brand converter is it?
you have a big issue somewhere...my friend ran that cam with shorties and no tune...he went low 12's at 112

Sounds like possibly a mechanical problem or a crappy tune

 

If its a cheap restalled convertor that might be eating up some power. And a dyno tune, longtubes, and true duals will definatly help out.

 

What kinda of mechincal problem would cause such a power and MPG loss awhile maintaining showing no other problems

 

What kind of converter for the 4th time. The BBKs are pulling hp, what kind of y pipe do you have, and do you have and KR?

 

I have no idea what converter it is i got it with the car stall is 2500, the y pipe is bbk and no i have no kr

 

mechanical problems
converter going out
trans slipping
valve springs
wrong push rods
bad bearing, water pump,alt, ps
fuel reg/pump
ignition problem?
what have you checked so far....things don't just bolt together and work well
its a system, everything has to be in top shap for the sytem/car to run right

With your mods and a o.k. converter I would say 325 rwhp would be a resonable goal

Just my opinion, but i'm no genius

 

trans is new,valve springs are new,pushrods new hardened from combination motor sports, new plugs wires cap & rotor, coil, (if there was a ignition wouldnt the hp fall of at high rpm?)

 

i meant ignition system in general plugs wires

What do your a/f/ look like?

I have been on the dyno and picked up 30-40 h.p. b/c my fuel press was too low

could be many many things

 

it sounds like the combo is on the car needs an af ratio check during the run. i would say you have a different problem than not enough parts. the parts you have on are not killing it. run a scan tool on it and watch the fuel trim numbers and get the fuel pressure. the low mpg says something and so does the hp numbers.

mdacton may be right.. seen fuel filter cause great torque numbers but die at high rpm. start with the basics before you change anything

 

That's REAL low man...I got Borla exhaust and a MSD Coil and I dyno'd 279.4 RWHP and 302.1 RWTQ