Idle concerns - Page 2 - ZR-1 Net Registry Forums

Jim Nolan · 12-07-2009

I bought a set of plugs with the intent of changing them regardless of their condition. The car had been set up by a tuner after full heads up porting. What I found was all the plugs looked as plugs should look with 500 miles on them. The disappointing part was the passenger side was gapped to .042 and the drivers side had plugs 1,3 and 7 gapped to .035 and plug 5 gapped at .030. The passenger side took some effort to break them loose but the drivers side no effort at all. This tells me two people were working it at the same time. It runs much better now.

The car was dynoed with the plugs like this. Would this have effected the dyno numbers. Based on what I read I was expecting 410-420 RWHP but came up with 397 RWHP or was I being too optimistic.

jonszr1 · 12-07-2009

by full porting do you mean heads ,inj housings and plenum/ who did the porting and assembled the motor ? i have a callaway 475 s nat thats supposed to be fully ported and the hp dymo numbers are 396 . i also have a 90 that has only the inj housings and plenum ported and the hp on that car was 409.9. so i can depend on how it was ported . more info would help on finding out if you are getting what you should be getting

Jim Nolan · 12-07-2009

May be I should rephrase this. I wasn't complaining about the engine builder or the numbers. I was just curious to know if the plug gaps as stated earlier would have affected the dyno numbers.

It was a porting of heads, injector housings and plenum. I also added headers with no cats.

12-07-2009	#11
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: Idle concerns I bought a set of plugs with the intent of changing them regardless of their condition. The car had been set up by a tuner after full heads up porting. What I found was all the plugs looked as plugs should look with 500 miles on them. The disappointing part was the passenger side was gapped to .042 and the drivers side had plugs 1,3 and 7 gapped to .035 and plug 5 gapped at .030. The passenger side took some effort to break them loose but the drivers side no effort at all. This tells me two people were working it at the same time. It runs much better now. The car was dynoed with the plugs like this. Would this have effected the dyno numbers. Based on what I read I was expecting 410-420 RWHP but came up with 397 RWHP or was I being too optimistic.

12-07-2009	#12
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,407	Re: Idle concerns by full porting do you mean heads ,inj housings and plenum/ who did the porting and assembled the motor ? i have a callaway 475 s nat thats supposed to be fully ported and the hp dymo numbers are 396 . i also have a 90 that has only the inj housings and plenum ported and the hp on that car was 409.9. so i can depend on how it was ported . more info would help on finding out if you are getting what you should be getting

12-07-2009	#13
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: Idle concerns May be I should rephrase this. I wasn't complaining about the engine builder or the numbers. I was just curious to know if the plug gaps as stated earlier would have affected the dyno numbers. It was a porting of heads, injector housings and plenum. I also added headers with no cats.