The porting is over - ZR-1 Net Registry Forums

Jim Nolan · 07-10-2009

I picked up my '92 today from South Georgia Corvette today and I am satisified with the results. The before and after dynos show a definate improvement. The one thing that I was most pleased with was the dyno results. With the full porting, headers and the dyno tuning it pulled 394.5 hp and 354.9 torque, at peak. The most impressive part was the fact the peak occured at 5,500 rpm and never fell off up to 7,000. The horsepower on the other hand kept climbing up through 6,500 rpm before it leveled off. The big plus was once they peaked they never dropped off.

My pre-mod dyno numbers showed a peak about 5,300 and dropped off torque from 349.4 at 5,300 to 286.7 at 6,500 and horsepower from 357.8 at 5,300 to 319.1 at 6,500 rpm.

The temp that was 91.

LGAFF · 07-10-2009

Sweet numbers.....was that ported heads also?

Congrats!

Jim Nolan · 07-10-2009

That was the heads also. I originally sent the injector housings and plenum to Locobob last year for porting and Haibeck for the e-prom, it was good but not enough.......I guess I just got addicted. The part that suprised me most was Arron at SGC said he had to take more out of the injector housings to match the heads.................and with the Dana 3.91 gears I actually used 6th gear on the drive home. It's going to take a while to get used to the headers, noise. I told him if i had a few more grand to throw his way I would have went for the stroker.

Locobob · 07-10-2009

Jim, the intake port work I did for you was designed for use with the stock 33mm primary head ports. I funnel down the primarys in the bottom half of the injector housings to make a gradual transition to the factory head port diameter - you don't want to suddenly go from 36mm to 33mm. Also were I to enlarge the bottom of the injector housing ports to 36mm without having the heads I would run the risk of screwing up the port alignment between the injector housings and heads. The parts must be done together to get proper results. Hope this explains the situation.

Jim Nolan · 07-10-2009

I never intended to slam you, being a little ignorant of the whole process after you ported I didn't think there was much left to port. I was impressed with what you did and my performance definately increased, but I wanted more and was suprised there was more to give to match the modified heads.

Locobob · 07-10-2009

No problem Jim

I guess the larger point I'm trying to get across here is that there is no such thing as one size fits all port-work. When I do a port job for someone I try to tailor it to the motors current state of tune. I can and have done more aggressive stuff, guess I need to spend more time communicating with folks in regards to expectations and future plans.

xlr8nflorida · 07-12-2009

Quote:

Originally Posted by Jim Nolan

I picked up my '92 today from South Georgia Corvette today and I am satisified with the results. The before and after dynos show a definate improvement. The one thing that I was most pleased with was the dyno results. With the full porting, headers and the dyno tuning it pulled 394.5 hp and 354.9 torque, at peak. The most impressive part was the fact the peak occured at 5,500 rpm and never fell off up to 7,000. The horsepower on the other hand kept climbing up through 6,500 rpm before it leveled off. The big plus was once they peaked they never dropped off.

My pre-mod dyno numbers showed a peak about 5,300 and dropped off torque from 349.4 at 5,300 to 286.7 at 6,500 and horsepower from 357.8 at 5,300 to 319.1 at 6,500 rpm.

The temp that was 91.

Are these typical numbers for cars that have had the heads done? I thought the dyno number looks about right for cars without heads ported?

What Hp do you get from the heads ported? I thought it was an extra 25-35.

LGAFF · 07-12-2009

Maybe he meant the heads were ported at the intake surface....port matched. My 92 is running 391rwhp with ported intake/port matching.

Aurora40 · 07-12-2009

Quote:

Originally Posted by xlr8nflorida

Are these typical numbers for cars that have had the heads done? I thought the dyno number looks about right for cars without heads ported?

What Hp do you get from the heads ported? I thought it was an extra 25-35.

It may depend a lot on what kind of dyno they used. I know my car on a Dynojet made about 15whp more than on a SuperFlow. If he was on something similar, that would mean he was making around 410whp, which sounds about right for a dual-mass full ported 350ci.

I assume SGC knows what they are doing, and that it's just a matter of different dynos.

Jim Nolan · 07-12-2009

Looking at the sheets it was a Dynojet.

I didn't ask it so fess up,..Who owns the twin turbo ZR1 SGC is putting together. The paint on the motor is beautiful and Aaron said it should dyno at about 900hp.

I don't care about the hi-jacking I like the info, but I have to admit some of the dynnamics is over my head.

07-10-2009	#1
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	The porting is over I picked up my '92 today from South Georgia Corvette today and I am satisified with the results. The before and after dynos show a definate improvement. The one thing that I was most pleased with was the dyno results. With the full porting, headers and the dyno tuning it pulled 394.5 hp and 354.9 torque, at peak. The most impressive part was the fact the peak occured at 5,500 rpm and never fell off up to 7,000. The horsepower on the other hand kept climbing up through 6,500 rpm before it leveled off. The big plus was once they peaked they never dropped off. My pre-mod dyno numbers showed a peak about 5,300 and dropped off torque from 349.4 at 5,300 to 286.7 at 6,500 and horsepower from 357.8 at 5,300 to 319.1 at 6,500 rpm. The temp that was 91.

07-10-2009	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: The porting is over Sweet numbers.....was that ported heads also? Congrats! __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

07-10-2009	#3
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: The porting is over That was the heads also. I originally sent the injector housings and plenum to Locobob last year for porting and Haibeck for the e-prom, it was good but not enough.......I guess I just got addicted. The part that suprised me most was Arron at SGC said he had to take more out of the injector housings to match the heads.................and with the Dana 3.91 gears I actually used 6th gear on the drive home. It's going to take a while to get used to the headers, noise. I told him if i had a few more grand to throw his way I would have went for the stroker. Last edited by Jim Nolan; 07-10-2009 at 10:05 PM.

07-10-2009	#4
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: The porting is over Jim, the intake port work I did for you was designed for use with the stock 33mm primary head ports. I funnel down the primarys in the bottom half of the injector housings to make a gradual transition to the factory head port diameter - you don't want to suddenly go from 36mm to 33mm. Also were I to enlarge the bottom of the injector housing ports to 36mm without having the heads I would run the risk of screwing up the port alignment between the injector housings and heads. The parts must be done together to get proper results. Hope this explains the situation. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

07-10-2009	#5
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: The porting is over I never intended to slam you, being a little ignorant of the whole process after you ported I didn't think there was much left to port. I was impressed with what you did and my performance definately increased, but I wanted more and was suprised there was more to give to match the modified heads.

07-10-2009	#6
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: The porting is over No problem Jim I guess the larger point I'm trying to get across here is that there is no such thing as one size fits all port-work. When I do a port job for someone I try to tailor it to the motors current state of tune. I can and have done more aggressive stuff, guess I need to spend more time communicating with folks in regards to expectations and future plans. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

07-12-2009	#8
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: The porting is over Maybe he meant the heads were ported at the intake surface....port matched. My 92 is running 391rwhp with ported intake/port matching. __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

07-12-2009	#10
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: The porting is over Looking at the sheets it was a Dynojet. I didn't ask it so fess up,..Who owns the twin turbo ZR1 SGC is putting together. The paint on the motor is beautiful and Aaron said it should dyno at about 900hp. I don't care about the hi-jacking I like the info, but I have to admit some of the dynnamics is over my head.