GN1s or S2s

[rking]

I am already planning for my future build. I have a set of aluminum S2s with valve covers, but is there an advantage to going to the GN1s. I see that not too many guys are running the S2s, WHY . TIA

 

[Buicksx2]

I got a buddy who runs S2's on the street and doesnt have a problem, course he's got no air but he's ok with that. The trade off is well worth it in his opinion.

HTH

 

[rking]

Here in Missouri it can get real hot in the summer. I have to have the AC. How hard is it to get the AC to work. I forgot to mention that I already have the intake to go with it too. How much work is required to get a stock intake to work with the GN1s, port wise, and what are the cost of GN1s, and who has them. I want a 9s in a heavy TR that can see limited street duty. I know the S2s flow a TON of air, but wouldnt that be ideal for 9s. TIA

 

[rking]

I already have a S2 intake too. All I need is to have the injector bungs machined in. Is there any advantages or disadvantages to running this intake. TIA

 

[KendallF]

Originally posted by njturbo
You can run 9's with GN1R or S2 Heads. S2 Heads for ac you will need to run ATR heater box to keep the ac. There are also some misc brakets you may have to have made or contact precsion and speak to Patrick. Dan's car went 9.80's with s2 heads with ac. As far as GN1'S Champion racing in Florida sells them. Or make a post in wanted parts. They are pricy, $1800-2600. As far as intake the GN1'S work well with stock ported intake from what i hae been told a stock ported intake will get you into the low 10's. If you are running S2 Heads a cas or BG intake would probally be your best fit (pricy)

Let me clarify/correct a couple of things. The GN1s are a much easier bolt on. The major reason for this is that you can use stock style headers, intakes, and valvetrain. If you have an off-center motor, it can use a stock intake. If you have an on-center motor, you'll need to find a BGC on-center intake or pony up for sheet metal. There have been at least 2 cars well in the 8s with the GN1s; neither could be considered a street car. There are several cars in the very low 9s or 8.90s with GN1s that I consider street cars; Cal Hartline and Gary Harmon come to mind first.

The S2 heads are a better head for a full-out race effort and can be made streetable with some care. The only readily available intakes are 4 bbl intakes which many people convert to port EFI. Of course, sheet metal is an option here. The only single turbo headers available are the ATRs; they fit with a notched A/C box but make plug access on the passenger side a challenge. Greg Kring and my block-ventilating buddy Dave Fiscus are in the low 9s with very streetable cars with this combo.

Running stock style accessories is possible with either head; you may have spacing issues with an on-center motor, depending on the casting.

 

[Mac in SD]

Well...my S2-headed motor is running. I'm still breaking it in relatively easy, but it seems pretty stinkin' responsive on the street... to me, anyway.

The heater box mods were pretty easy IMO. A roto-zip and a fiberglass patch kit from Home Depot...no big deal. I didn't feel like dealing with the header flange-to-back of AC bracket issue, so I ditched the AC. (Pretty moderate temps here in San Diego, and it's not my daily driver.) Also, I had been gong on 3 years since I bought my block due to house-rebuilding (!), so I was getting impatient. I may reinstall the AC in the future.

I just don't see what's so difficult about using S2 heads. Sure, you need to spend a few bucks on headers and intake mods, but S2 heads can be gotten pretty cheap, and a good GN1 setup isn't exactly cheap, either. Personally, I like the different look, too.

Do a search. I don't recall seeing any posts from people who switched back from S2's, or are crying the blues wishing they hadn't. Lots of posts from people who have no personal experience with them telling you "it'll never work."

 

[rking]

If I run TT will I be able to still make all the factory accessories work, or is a TT for only all out race cars. Who makes a good set of headers for a single turbo, and for a TT. TIA

 

[TurboCrazy]

ATR...