poor dyno numbers? and poor exhaust

Just had my car dynoed in Lincoln Ne today. On a Mustang dyno it only put out 281hp and 283tq at 5800 rpm. The technician told me that my exhaust was too restrictive, that I need a cross over pipe and I should get some better headers. He also told me that after all the bolt ons, exhaust and the predator programmer and everything else I only gained about 20rwhp. Whats the deal with that. I knew that there was a difference between a dynojet and a mustang dyno, even with the drive train loss should it still be this low?
Mabey I just expected to much?

Ram Air Hood, Cut out air box, K&N filter
predator programmer
edelbrock shorty headers, no cats, 2.25in dual exhaust, slp loudmouth2x2
SLP 25% underdrive pulley
Mizierre electric water pump, 180 thermo

I made 333rwhp and 327rwtrq, with slp long tube headers, hooker catback exhaust and a whisper lid. i mean im lowered and have a clutch and short shifter but that dont do shit. Idk man mine did ok

shortys are worthless on these cars. you would see a good gain from LTs and a ORY.

Do you have a lid? Try porting your TB. Pick up a LS6 Intake.

Yeah dude we are both 2000s and i have that much more power you need LTs and what cast heads do you have? I have 241

Only mods you have that make power is the loudmouth and pulley. Mustang dynos are pretty unforgiving. My car went from 372 on a dyno jet to like 360 on a Mustang dyno. I dont really give a damn about dyno #s anyway, low ETs are where it's at.

I've seen stock cars put down more than 281 RWHP Hell I made 300 at the wheels on a Dynapack with only a lid and a catback at 109K miles and using the original clutch. But I agree with the above poster that Dyno numbers mean very little. Dyno's are tools for tuning nothing more. Too many people see them as bragging rights but in reality the car with the most Horsepower is not always the winner.

These comments are true, had a friend with a 99 z28 made 2 less rwhp than me and he never even got within 2 cars of me and we have raced from all speeds all gears and about 50 times he never catchs me unless i let him go first. He also has been driving stick far longer than me and hes really good. He also knows his car hes had 3 z28s all 98+ and all m6 and 1 evo that ran an 11.09.

The guy also told me that corrected for the weather it should have been about 295hp. I just have a stock lid with the runners cut out of the top.
I ran an 8.918 @83mph in the 1/8 mile at mid america motorplex, I was running faster than most if not all the fbodys (mostly camaros)and the new/newer mustangs that were there that night,a BMW M3 an even my best friends 06 GTO(stock). So I talked to my buddy that did my duals and we talked about getting the crossover pipe if not going to a xpipe or even back to a 3 inch single pipe to a y at the mufflers.
I am going to ditch the shorty headers. I am now looking at the SLP LT headers or Pacesetter Armor LT headers. Depending on the witch headers I get will probably determin what type exhaust I am going to go with. Im thinking that the SLP LT headers would go really great with some AFR heads in a year or so. I have heard that the stock y pipe is better than a dual set up? I may just go with a 3inch pipe that way if I decide to rear mount a turbo later some of the work will already be done.
If money wasnt an issue what headers would you guys get?

If money is no issue than the American Racing headers looks like one of the nicest header/Y pipe set ups out there. After that definately Kooks. For a budget go with ceramic coated Pacesetters. Skip the SLPs. American Racing headers seems to have the nicest Y pipe and they also have the high velocity merge collectors (HVMC). A little info here with pics on page 2 of this thread. http://www.ls1tech.com/forums/showth...9&page=1&pp=20

If your gonna run duals I'd prolly go with the kooks, they can be found from most of the sponsors. The American Racing ones get here. http://www.lmperformance.com/15430/1.html

I am going to ditch the shorty headers, and the dual exhaust. Im going to go with qtp ceramic headers and a 3inch pipe back to a big single turbo. Im not going to run the turbo at max because the motor isnt built for it yet. Right now Im looking for an Air to Air inter cooler.
thanks for your help