HELP! Engine power loss

[timsev]

So i've been having some issues with my engine lately. About a year ago, i dyno'ed my car when it was pretty much stock(JimC chip) and it was at 195.2 rwhp. Since then, i have added a Cosmos intake and M50 manifold. When i dyno'ed it this week, i hit 190 rwhp. I think something may be clogged though after the engine because my air/fuel seems to be fine. If my air/fuel is fine, wouldn't it mean that there is restriction somewhere in the engine and my fuel system is working fine? Maybe somewhere in the exhaust system? My shop is convinced on telling me that my car just makes that much power and there is nothing i can do about it So I am going to figure this one out on my own. Please help! :(

[habbie]

doa compression test to rule out the motor being bad and a leakdown test.

[timsev]

anything else?

[96technoM3]

Are these corrected numbers? If these numbers were done on a different days or with different dyno's you results may vary. When I had just an intake and exhaust I dynoed at two different places different days and pulled around 213whp and 218wtq one day, and 204 whp and 225wtq. Does you car feel low on power to you, or are you just going on your numbers?

I assume with the baseline number being the 190's this on a mustang dyno? I'm not a dyno expert by any means, but if this was on a mustang dyno (which I think is a loaded dyno) then it is possible that it is not calibrated correctly.

[timsev]

no, it was done on a dynapack. both times it was the exact same dyno. it's just that i can't figure out why i would have a power loss. I don't have any vaccum leaks. the car runs fine. The car pulls fine too. These numbers are way too low though to just be coincidence. It's like there's a clog somewhere that I can't pick up.

Oh yeah, when i was installing my manifold, I noticed a lot of nasty buildup on top of the valves. Could this be the problem?

[aeryk7]

Were the temperatures diffenrent when dynoed?

[timsev]

the first dyno was at about 60F and the second was around 45F.

[yod88]

have you looked at the results other people had with these parts?
maybe the parts themselves are restrictive.. there are some parts that will actually produce less power because it will be "choking" the motor...
as suggested above, do a compression test to make sure the motor isnt having problems that would cause less power..

[timsev]

the parts i have installed are less restrictive. people with the exact same setup almost always see numbers around 220 rwhp and up. the 30 rwhp that i am losing is a huge deal.

[hillzz22]

With the less restrictive manifold and CAI I would have definitely expected your numbers to go up. Something doesn't add up....I would definitely check through some of the easy things such as fuel filter, spark plugs, O2 sensor, HFM, etc. to see if any of these might be causing a problem. Take your car down to Autozone or a place like that and have them read your DME codes (for free) to see if anything is being thrown, that might help you get a better idea of what might be wrong.

-Aaron

[timsev]

that's the thing. i replaced my spark plugs, fuel filter, O2 sensor, HFM, fuel injectors, compression/leak down test, and no codes are showing. I also, cleaned my air filter, and changed oil too. What the hell could be wrong? HELP!

[hillzz22]

wow, beats me. All I can say at this point is good luck!

[Bernanke]

check vanos solenoid / chain tensioners / possible O2 sensor. all those will rob power. also if you are running real K&N filter that will degrade performance over time. also remember the more mods you do the more fuel you need so over time you may be too far ahead for your software and your ECU will actually start pulling timing in order to ensure your engine doesnt knock. so you might want to updated software as well.

[canyonm3]

sounds like a vanos issue... but that ought to show an error code

[timsev]

yeah, i had my vanos replaced about 1.5 years ago, there's also no knocking. what are these chain tensioners you speak of?