98Z28MASS

iTrader: (6)

Im sure its been said but the cam isnt that big, my guess is with the patriot stage 3's that they werent milled and the compression on your engine isnt that high, and your running an ls6 intake, so that would be my guess, but 450 rwhp isnt too shabby with the ls6 and stock tb and 1 3/4 headers. Maybe step up to the 90/90 and some stepped 1 7/8th headers and you will see more power. Maybe even mill the heads for more compression if you dont want to go with a bigger cam.

NEVRLIFT

It's a six-speed. The numbers might be worse in Denver as the altiitude has a big effect on N/A engines.

67camaro

iTrader: (28)

ringram

Total power is made up of all the parts, no one part may be bad in itself, but each one is less than optimal. If you replaced them all with optimal parts. 225 heads, larger cam, intake, tb, maybe tune etc all will contribute towards your "missing" power IMO.

Ksett

I think it's your combination of heads, intake and throttle body that's killing your numbers. I've seen many low dyno numbers with the same heads you're running on 408's and 402's. It would be interesting to see what you would make by just going to an AFR or ETP head and then add the 90\90, measuring results along the way.

383ss

iTrader: (14)

it is NOT the headers. they are not hurting you.

a fast 90/90 would probably pick up 30rwhp.

those run-flats are also very heavy. they are probalby taking an additional 10rwhp to spin

ringram

I agree headers are fine at 1.3/4

Cyborg

iTrader: (8)

Is there any reason to think you might be getting weak gas? Maybe burn up what's in the tank now, and then go to a different station & try a fresh tank of sunoco 93 and see if there is more in the tune? Just a thought.

STRIPSTAR

iTrader: (4)

Hes got no PTV as is from what i gathered from the thread.

allngn_c5

iTrader: (3)

Way better then the last time. Don't be too mad. She will run. Good luck.

AINT SKEERED

iTrader: (2)

You are running through cats as well. I say if the car flies, dont sweat it unless it still does not seem fast enough.

Miles in Florida

It didn't occur to me until you brought it up, but the gas in the tank is a year and a half old . Is that a concern?

Doc

iTrader: (9)

I'm no chemistry major but I would think that year old gas couldn't help your situation. Easy swap. So the tune was done with the year old crap gas too? Maybe somebody else will chime in and say gas is gas...however tuning on gas that has been in the tank for a year? I don't run gas that is over a month old in my lawnmower let alone a sweet motor like you have. Just a thought.

TroubledWine3

iTrader: (3)

Gas is not gas. Gas breaks down after a few months if I'm not mistaken. ****, I went from the middle of October to January 1st without driving my car and it ran like ****. Thank god I had parked it with only a 1/4 tank. I filled it up with some Shell 93 and put some octane booster and it ran like a champ.

dalejr8ls1

iTrader: (1)

hope you find some hp hidden somewhere...something is holding you

JakeFusion

iTrader: (7)

I'd check the fuel injectors and fuel filter if you're running year old gas through the system. May have some muck in there.

Cyborg

iTrader: (8)

Any update here?

Slowhawk

iTrader: (12)

#'s look good to me for what you got.The intake and exhaust is choking the setup,nevermind the old gas.

The Cam is not too small.

VINCE

iTrader: (1)

I have to agree. Also I think he said he is running cats? What is your actual compression? Also, the gas does matter. If its that old that tells me the tuner had to decrease timing because the octane on the gas was low and he wanted to prevent detonation. The tuner might not have known about the old gas at the time or he would have drove the car around to burn it out and then put fresh gas in. Lets go into guess mode... Say you are at 450rwhp with bad gas. Get retuned with good gas and you should be able to pick up 10rwhp minimum just from getting the timing tables right. When I removed my cats I picked up 20rwhp. So thats 30rwhp right there. We are now up to 480rwhp. I picked up 20rwhp from the FAST 90/90. Now you are up to 510rwhp. Dont forget to get the intake port matched. The headers are not that much of a big deal, but you can pick up atleast 10rwhp peak by going with 1-7/8ths. Now you are at 520rwhp. Remember you will need retuning to get these guess #'s. Your cam is not as big as others, but you could get more power with a bigger cam. Last but not least.. Compression plays a factor. You can make even more power if you compression is too low. So things are really not that bad.... You just dont have all the supporting mods..