ok, im sorry if this has been answered before but ive searched and havent found a concrete answer. all ive been able to do to find some sort of answer, is to try and look at other people's mods in their sigs to see their setups.

i want to know how much boost i can run with a 3mm headgasket and ARP headstuds. everything else will be left stock. i know the internals are already forged, but i dont plan on porting and polishing anything! i was going to run around 10psi with no headgasket, but a friend of mine who works at a shop, told me hed install the headgasket and ARP studs for me for $250. i think thats a steal. so id buy the parts and he'd put them in, and all together itd only be $500, so i think its definitely worth it. he's also going to install my whole turbo kit for $500 at his shop and then tune it afterwards for around $200. my question is, would it be fine to run around 18-20lbs with the HG and head studs? i have a GT30R turbo and it'll spool rather qucikly but wont make quite as much power up top as some bigger turbos. im looking for about 450rwhp and id like a conservative tune, so itll take me more psi to reach that number. any help would be appreciated

 

I dd mine around 17psi. Iv had it upto 22psi and soon to see 26psi.

ps...check this thread also.
https://www.s2ki.com/forums/index.php?showtopic=493484

 

My setup, daily driven, 3mm HG, has a maximum boost pressure of 18-19 pounds. I also have a GT30R, albeit one with custom housings (significantly smaller than yours most likely). With an open exhaust, you should have no trouble reaching the mid 400 rwhp range with that turbo.

Keep in mind that manifold pressure does not blow up motors. It's the small tuning window that results from very high boost pressures. The 3mm gasket dramatically widens that tuning window.

Ultimately though, let your tuner decide what is safe and where to stop...

 

20psi is probably the line where engine durability drops. That said, my engine is tuned up to 19.5psi but I run at 18psi so I have a little saftey margin for overboosting, etc.

 

I'm not even sure I'd go that far...

The maximum safe manifold pressure depends on a lot of factors, some of which are:

- Incoming air temperature, a function of ambient conditions and compressor efficiency
- Engine compression
- Fuel quality, better fuel = less prone to knocking
- Type of fuel, higher octane = less prone to knocking


There are too many factors to make a broad generalization of the maximum safe boost level for FI S2000s.

 

What type of manifold do you plan to run? A tubular will help you get to 450 at only 14 or 15 pounds or so.

 

[QUOTE=afwfjustin,May 30 2007, 02:55 PM] What type of manifold do you plan to run?

 

speaking of exhausts, i have an Invidia Dual version 2. i dont know if i should switch to say...a J's racing 70mm single or if the dual would be alright. or maybe i should keep the invidia and get the piping switched to 3 inches opposed to 2.5 or whatever it is

 

I think you'll get to your goal nicely at 15 pounds or so. Make sure you're running a 3" single with only one bend or two

 

I believe the John's car at Inline (pretty much the guinea pig) runs somewhere around 21psi on an HG...so less than that would be good. He drives it to and from work all the time so, unless something has changed recently, he should have quite a few miles on it.