All these bolt ons and only 207rwhp!! HELP ME :(

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ADRENLN said:
take your car to the track, then you should know. the altitude dosn't effect the track does it?

The nominal ambient air pressure at sea level is 29.9in-Hg (14.7psi); at this altitude it is typically 24in-Hg (11.8psi). Because the pressure is lower, there is less vacuum developed by the engine and less air/fuel mixture getting in the cylinders. That lowers HP and track times. It takes 2.5# of boost to compensate for the altitude and get the same power output you'd have at sea level (assuming you didn't have any parisitic losses). And for the comment about the dyno: they do it in 4th gear for a 5 speed (3rd for an auto). :bang:
 
my 99 cobra dynoed at 298 rwhp.with these mods, the dreaded mac longtubue headers that make my car smoke like a dog,o/r/h-pipe,mac back system,pulleys,3.27 gears.k/n air filter , and no computer tuning,just installed 62mm t.b.,4.10 gears i didnt like so changing to 3.73s.waiten it get pro m air mass than get chip.
 
hotrodman said:
my 99 cobra dynoed at 298 rwhp.with these mods, the dreaded mac longtubue headers that make my car smoke like a dog,o/r/h-pipe,mac back system,pulleys,3.27 gears.k/n air filter , and no computer tuning,just installed 62mm t.b.,4.10 gears i didnt like so changing to 3.73s.waiten it get pro m air mass than get chip.
62mm tb? Isn't stocker 65? :scratch:
 
there is somthing wrong with the machine. maybe it should have read 307 hp :shrug: once this gets resolved tho, it deserves one of these! :rlaugh: but of course not until you find your mysterious 100+ hp. i wish you the best tho
 
The altitude saps at least 20% of the power you would have at sea level, but I do think there is something wrong with the dyno too. Last time I was in there he was telling me that 96-98 GTs normally run 145 and 99+ GTs run about 185. There may be something else going on, but I wouldn't worry about it. I know someone with a T-bird that dynoed there at 245 SAE (about 200-205 STD) and ran 14.1 at the track just before it closed. My car was running great when it dynoed 211 and it would fry the tires then. You could always take a road trip to Arizona or Texas and see what you dyno at there... :nice:
 
I just ran my car at the last dyno drags a couple of weeks ago at the Dyno Edge and made 403 SAE and 340 uncorrected. Nearly identical to when I dyno'd last spring. I'd have to say the dyno is fine(at least when I was on it).
 
Well actually, the pressure altitude of where you are is a HUGE factor. I am a flight engineer on a P-3 Orion in the US Navy. Part of my job is predicting takeoff power for our 4 turbo prop engines. We lose 12 SHP (shaft horsepower) of every 100 feet in altitude above sea level. At 5500ft altitude that would equal roughly 660 SHP loss from each engine. Granted a turbo prop engine is a completely different theory then an internal combustion engine, but the environmental changes still apply. the higher the altitude, the farther apart the air molecules, which means less "O2" for combustion. Sorry for the brainiac explaination. :flag:
 
Barnaby said:
I just ran my car at the last dyno drags a couple of weeks ago at the Dyno Edge and made 403 SAE and 340 uncorrected. Nearly identical to when I dyno'd last spring. I'd have to say the dyno is fine(at least when I was on it).

Was that the Bullitt or the LX? Very nice numbers BTW... :nice:
 
Thanks
The Bullitt made the 340 number. The LX only made 235rwhp/246rwtq uncorrected(no idea corrected).

They both found different ways to hit mid 12s at the track. One with power and the other with no weight and ridiculous traction(1.64 60ft times).
 
I'd go back to the basics.

FUEL-does your model have a returnless fuel pump? If not, consider checking the fuel pressure regulator. Check the fuel filter and pump too.

AIR-Check for leaks past the meter. Check for any kinks or obstructions in any and all air and vacuum lines.

COMPRESSION-as stated by others, I wonder about your CR. I would check compression on all cylinders and do a leak down.

TIMING-I also wonder about if the cams are timed right. I would also consider having another chip burned.

RPM-dumb thought, but DOHC, ported heads, X-pipe etc. are high rpm items. did they rev it enough?

For me troubleshooting works best if I break things down into categories. Take each category and completely eliminate it before going to another. Otherwise I wind up chasing my tail. And I prefer chasing someone elses tail! :)

This probably doesn't help much, but i'm trying!