I've heard 32 psi . im running 28 psi with stock headstuds and stock turbo. Also i've heard if you replace the studs one at a time you wont have any problens with the gasket loosing it (seat) . Also if i remeber corecctly doesnt arp have a lubricant for the threads . if your dont use it they ma not tourqe down to the right specs.

 

ok so from what most of you guys are saying the stock ones will hold up to around 30 psi with no worries.....then i should be fine running 26 psi right? oh and btw i will be keeping a close eye on how my engine is doing and will be constantley doing logs while running that high of boost...so knock shouldnt be an issue for me......
anyways thanks for all the info..

 

If the head is already coming off for the cams, springs and retainers then it's added insurance to just have the head studs replaced. I am doing this in anticipation of adding a bigger turbo, and even if I don't the recommendation is to use them when boosting over OEM levels.

For an extra 45 minutes of labor and $110.00 for the studs it's a no brainer.

 

Personaly, I would like to see the scientific proof & data from you guys that says from Mitsubishi's engineers that sustained boost at those levels above OEM is OK for long term reliability/driveability and will not stress out the interals of cause issues. What long term testing/proof/evidence do have to support that 26-30psi is OK and doesn't require the use of headstuds?

If you can pull a pool of 30-40 guys that have run that level without studs for say even 50,000-60,000 miles without any problems then great! I personally would like to hear many of them chime in on how reliable the 4g63 is running at that level of boost for that many miles.

If your basing your conclusion based on a handful of people or a person here or a person there that has been running at that level for just 5-10,000 miles big deal, that doesn't prove anything.

People want to see long term reliability/driveability with their cars not just a quick 5-10,000 mile jaunt before something breaks.

A $200 investment on a $33k car is cheap insurance, and anyone who is discouraging this guy from putting in head studs with the heads already off is crazy and not credible.

 

Not doing them when the head is off just makes you a jackass... the studs can be had for $100. With the head off, there is NO downside, or "risk". You need to replace the OE head bolts if you pull the head anyway as they have already been stretched!

 

i agree.....but ill only be turning the boost up while running race gas, so it wont be very often.....i only run around 21_22 psi for daily driving...and even then i hardly ever get into full boost unless im racing...

 

Stock head bolts here. Brother is on a 35R and he is also on the stock headbolts. They hold fine and I have no worry about yanking the valve cover to re-tq them after heat cycling or oil leaks. I believe DSMotorsport ran 130mph on stock headbolts for a WHILE before he busted a headgasket due to what he diagnosed as the stock bolts stretching.

 

It's cheap and easier to have it done while the head is off for the retainers and springs for another $200.00. Get the studs and have them installed and don't look back on the extra money spent.

 

Zeus, I respect your knowledge and insight on this forum and couldn't agree more with what you are saying.

 

So pretty much ill be all set to run 21psi on the stock head without worrying about anything. Do the studs when my cams go from ym garage to my engine!!

 

Sorry, to answer the original question... think of it like a tuner rotary engine. As long as you don't ping it, it will actually hold a crap load of power. One ping can take the engine down and put it on a stand. Same thing with people running serious power with their Evo OE head bolts. Can you do it? Of course! There are many examples out there. However, as with the above, one good ping and you can stretch the head bolts and POP goes the headgasket.

Which method of head stud install should you use? There in lies the debate. I whole heartedly believe they can be done successfully with the one at a time method. However, I also whole heartedly believe that 9 out of 10 Average Joe's stand a better chance of screwing up this type of install. So take that for what it is worth...

 

If you are going to be removing the head, change the head gasket, head studs, bolts, retainers everything all at the same time if your pocket can handle it.

I have 43,000 miles on my car and it still runs like new. (at least to me) I have the Greddy 25G turbo kit & HKS 264s on my car now for the past 7-9 months running 27 pounds at peak boost with stock head bolts. No issue as of now. I am upgrading to the RNR 37R kit in the next few weeks and plan on running 28-30 pounds. I installed HKS 280s so I went ahead and installed the ARP bolts. I did them one at a time with no issues. You want to take one out and than install the new one. If you do them one at a time the head never shifts so it wont move around breaking the seal.
Like everything, nothing is a for sure thing. I was lucky and did not have any issues, be careful and take your time while doing it.
As a side note I have 2 friends that are running stock everything on there heads, 1 is at 30 pounds making 570HP the other is at 32 pounds at just under 600HP.

 

One more thing, you dont run full boost all day at all times. You will only see full boost at short time frames, street racing, just getting on it when you want to, etc.
Unless your racing the car in a time attack event or something. So go for it!!!!!
Just my 2 cents.

 

perfect answer......thanks

 

Ok who here has broken or stretched a stock head bolt from boost?