Stock head stud limitations

I have been doing some research in preparation for my next upgrade, sometime next month. I am planning on taking the car to SBR for the following upgrades:

EVO III 16g
550cc injectors
190lph Walboro FP

I realize that in the end you tune for no timing retard at maximum boost on the 2g. It seems that people with similar mods are running around 20psi. At this point I am concerned with the factory head studs and the head gasket. I have read conflicting information and am looking for some clairification.

Do the head studs stretch because of hi airflow (ie boost) or because of detonation? Some say that the limitation of the head studs is approx. 25psi on an 16g. Others say the only thing that contributes to the stretch is detonation. Who is correct?

My concern is that I will end up blowing the HG after the turbo installation.

I was considering having SBR replace the HG and install ARP head studs during the install of the above mentioned parts and would like your opinion on the price/labor times I was quoted.

Total price w/tax for cost of parts and installation of:

EVO III 16g
190lph FP
550cc injectors
Mitsu metal EVO HG
4 DSM turbo bolts
ARP head studs
1h dyno tuning with WBO2

= $2648.94

Labor times are as follows:

5 hours to install turbo and injectors
2 hours to install FP
6 hours to install HG and head studs

Doesn't this seem high? Isn't removal of the turbo part of the labor to replace the HG and studs?

Thats 13 hours of labor at $75/hour = $975 in labor (Fuck, I wish I was comfortable doing this myself :uhoh: )

Bottom line: :biggrin:

Should I have them replace the HG and head studs while I am having the turbo installed, or just wait to see what happens after the installation.

Thanks!

I never remove the turbo when doing a HG, so I would say no, thats not inluded. 5 hours for a turbo seems a bit high though. I dont think it took that long the first time I ever did, and I was a newb/ricer back then. 3-4 hours would make more sense. But its thier call.

More power results from more cylinder pressure. But as power goes up the pressure goes up in a predictable linear fashion. Anytime there is knock, or even just excessive timing, pressure rises exponentially.

The stock head bolts are torque-to-yield, also known as "stretchy bolts." They are ALREADY stretched when installed! So it doesnt take much to lift the head. ARPs will not stretch until a much much higher pressure. Personally I would just do it now while youre in there. OTherwise when you lift the head the car will be down hard, will probably get trailered to the shop, etc. Might as well call it preventative maintenance if you've got hte money (Even if it hurts to part with it). Its something that you will always have, they are reusable after all. The labor is a killer, but sometimes its worth it for peace of mind. I said F it and just went for it, and eventually just learned to do this stuff. But the downside is the risk of screwing something up and making things even more costly than it would have been to just have sbr do it. ;)