DigitalCorvettes.com

vette96 · 11-06-2009, 01:42 PM

Hello,

i have installed my new ported injector housing and plenum but im so disappointed, the car run little worse than before.

when i toke every thing apart, i noticed there is a lot of oil inside the plenum.... the old one had some oil in also.

i run it on the dyno and i got only 369 rwhp. with a rich prom.

what is rubing my power.... i dont know. i should be making around 400.

what do you think guys.

-=Jeff=- · 11-06-2009, 02:36 PM

Quote:

Originally Posted by vette96

Hello,

i have installed my new ported injector housing and plenum but im so disappointed, the car run little worse than before.

when i toke every thing apart, i noticed there is a lot of oil inside the plenum.... the old one had some oil in also.

i run it on the dyno and i got only 369 rwhp. with a rich prom.

what is rubing my power.... i dont know. i should be making around 400.

what do you think guys.

little worse how? oil in the plenum is not surprising.. my guess without having too much other info from you is a vacuum leak

Jeffvette · 11-06-2009, 02:56 PM

Are you running headers?

blkvette94 · 11-06-2009, 02:59 PM

Quote:

Originally Posted by Jeffvette

Are you running headers?

why would that matter?

Jeffvette · 11-06-2009, 03:04 PM

Quote:

Originally Posted by blkvette94

why would that matter?

jonszr1 · 11-06-2009, 08:03 PM

if he is running stk exhaust and manifolds its going to cost him about 30-35 rwhp verses headers and a good exhaust. it doesnt do too much good to port thing and then leave a cork in the system

fkumro · 11-06-2009, 08:08 PM

Quote:

Originally Posted by vette96

i run it on the dyno and i got only 369 rwhp. with a rich prom.

I don't know very much about ZR1's but why not lean it out if it's running rich. That will net you some power...

I know if I ported my ls6 manifold and throttle body I would need a tune to make use of the modifications.

vette96 · 11-07-2009, 03:08 AM

well, yes i am runnig headers. and 4,10.

and the chip is programed for my modes but it need some work.

i did a simple test by spraying carb cleaner on the intake to see if it is leaking or not, and it turn out it is not.

all my hoses are fine. the injector housing and the plenum were removed and reinstalled and same thing. i changed all the gaskets and installed it carefuly again, with all the precations but same.

some one told me it might be the oil ring. but my answer is if it is the oil ring then way the car was running strong before the modes.

i run the car with my friend who has a 95 with same of my modes and we run side by side all the time. and when i did the injector houasing and the plenum he pulled away from me one car spot apprx. rolling from 50 mph he pulled every gear.

Dominic · 11-07-2009, 07:21 AM

When I first did my P&P, the first pull on the dyno produced about 370hp with a Marc Randolph chip. With subsequent runs and my changes to fuel and spark tables, I was able to get that to about 387rwhp on the dyno I was using. Moral of the story is that you can't take full advantage of mechanical changes you make to the motor without properly tuning for them.
Now I follow that up with trips to the track to fine tune the calibration looking to maximize trap speed.

rhipsher · 11-07-2009, 07:46 AM

After I ported mine I notice a difference especially in the higher RPM's. I'm running stock exhaust manifolds and a Borla exhaust system Haibak chip and am also running rich. Dom is right though. I know I'm not getting the max benefit without headers and a good tune. But I also had to open up my finalic spacers and plenum gaskets also to match the porting. I've had to take the plenum off twice to replace an alternator and a starter and my plenum and IH housings don't have any oil in them. Clean as a whistle.
But the difference in acceleration I noticed was undeniable even without headers and a good tune.