Opinions on the new GN1 Intake - I'm comin' back after 3 years!!

G

GinoRin

Member
Joined
May 23, 2001
Hey guys,
Some of you know I'm at home bored out of my mind because I just had ACL Surgery, so now I'm brainstorming. I did a search but can't find much info on the new GN1 Champion intake. My GN has been off the road for 3 years now, but since I can't use my clutch leg for 9 more months, I have more ambition than ever to get the GN back on the beat while the GTO sits in the garage or gets sold. My new build for spring should be pretty stout, everything is new. I'm shooting for 11.00s in street trim and 10.30's-10.50s at 30 psi. Combo listed below. I'm trying to figure out a few things about the new GN1 intake as I have ported GN1 heads:

1. What size are the ports on the new untouched intake? I currently have my heads matched to the FelPro 1200. Can I get the ports to match?

2. Has the coilpack/windshield wiper problem been resolved?

3. Will this unported intake outflow my fully ported stocker with EGR welded and smoothed? I was also using a precision plenum that will be eliminated with this new intake.

4. What have the performance gains been with the new intake on a 11/10 sec car?

5. Any other pros/cons I should know about?

Any help is appreciated, I might wanna pull the trigger on this like today :)


New Combo: 87 GN full weight hardtop car. Fully built 109 billet cap block with RJC Girdle, Cryo'd stock crank .010/.010, cryo'd stock rods resized with ARPs, JE +.020 pistons, 8:1 compression. JW wheel and BHJ balancer. Ported and smoothed GN1s with 1.65 scorpions, ported stock intake (for now) with 70mm TB/ Plenum. 60# injectors, Tnetics T70BB .63 P trim turbo (might switch to a PTE dual BB), Vigilante 3200 lockup. ATR headers and 3" DP with big Tnetics external gate, dual atr 3" SS exhaust. Normal other stuff, walbro, hotwire, blablabla.. ohh yea and not really related but a full set of 2007 Corvette Z06 brakes- 14" 6-piston front and 13.25" 4-piston rear to stop this pig, and a ton of suspension work setup for pro-touring (this is a street car). I also plan on a Razor alky system and maybe a big stuff 3... we'll see how the funds look. Should be a fun car to rip up the streets :)
 
Ive got one but have yet to run it. Its race ported but does not have the ports raised as high as they could be. By the looks of the port design id guess that it would outflow a stock ported intake if the port alignment was right on even un-ported. There is a lot of meat in the ports to be removed if you have race ported GN1's. The runner is not sloped on the outside like the stocker creating more of a straight shot to the intake port on the head without the neck down. IMO the intake side of most combos is not what needs attention. Its the exhaust side choking off most of us. The 3 bolt configuration is to blame for this. Exhaust pressures are too high between the turbo and engine. A 4 bolt swap and gtq trim on the combo in your sig would be a tremendous gain in hp. Way more than putting the GN1 intake on your engine. I wont have feedback on the intake till next spring.
 
If you buy the GN1 intake, make sure you get it unported/not touched. The CNC porting program that Tom uses does not match up to heads that are ported to the Fel-Pro 1200 gasket. You line up one side then the other side is off. Multiple people that I spoke with have this problem.

Champion does make a raised runner race ported intake.

Billy T.
gnxtc2@aol.com
 
The intakes are all the same casting. The port matching program denotes which motor it will go on, ON or Off center. Unported they work pretty awesome. My stage 2 motor went 9.22 at 149 with 25 psi. This was using an unported GN1 intake , just port matched with some minor work were the port match met the runner. But it was unported otherwise. 5 more psi and a PTC convertor and it would been in the 8s with a decent margin.
 
Just throwing this out there, I had the stocker flowed.

Stock #1 cylinder WITH EGR = 194cfm

Ported #1 cylinder NO EGR = 282cfm

This is a 45% increase in flow regardless if the bench is dead on accurate in cfm.

I would be curious to see any flow rates from the unported and ported GN1 intake.
 
I have one also on the new engine. I have yet to install the new engine in the car. I would also like to hear from those that are running it.
 
I ordered one up from Mike Licht a couple weks ago, should be here soon.... I'll get some pics after I have it port matched and coated :cool:
 
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