Nobody really talks about them a lot for X's.
EVO 8, Its a mandatory first mod.

Currently I'm at 340whp with factory head studs, 400whp is the max ill ever push her.

At what power level are they recommended? Should I had them installed already?

Please let me know the best route.

Thanks!

 

I am very curious about the same topic...

 

subd

 

why required on an VIII? i have a IX. boosting 25+psi. 125k on engine. stock head bolts. is the VIII and IX different?

 

Up

 

I think ppl are still scared from the dsm days at least fr what I read. Iv seen people push 500+ plus on a 8/9 and still facotry studs. As long as the tune is good you shouldn't get any headlift. At 400 you will be completely fine.

 

There is no use for studs unless you pull the head for something. Or making ridiculous power as mentioned above.

This is in reply to the comment about VIIIs, that is. In case someone comes across this in a search.

 

Head studs are usually changed out because 1 people already have it apart and are building up the head and two the oem "studs" are actually more of a bolt and require a specialty tool to be used.

 

specialty tool? i've always just used a torque wrench. or are talking about on the X? do they need something special? that would suck. unless you are referring to measuring them before reuse? we all know to NEVER reuse head bolts, so no worries there. i've never found any that were to spec after one use. also, i've always found studs to be cheaper than a set of OEM bolts anyway. that's just a bonus.
actually: i've reused head bolts on a stock honda engine that was remaining 100% stock. just never on a performance engine.

 

How were you able to confirm that?

 

due to plastic deformation, the bolt will actually be longer. we just measured them. all TTY bolts i've seen are recommended to not be reused anyway, so we wouldn't have anyway, other than the stock Hondas i mentioned.

 

Yeah, I get that. I too, would advise against reusing TTY head fasteners.

But measuring TTY deformation isn't as easy as you make it seem. A stud/bolt is compromised when permanently stretched as little as +.001", and it's impossible to compare amounts of length that precise unless you knew the exact freestanding length of that exact bolt/stud prior to use. In a nutshell, it's impossible to confirm permanent deformation/stretch of factory installed head fasteners, and that's why it's advised against reusing them (at least the TTY ones).

 

perhaps, but we defitely noticed a difference on the bolts we checked (we weren't planning to reuse, just curious). maybe just coincidence. i can't remember details as it was loooooong ago.

 

The best route? Change them. The ARP studs are better and I have never heard of a head lifting , regardless of power, after they have been swapped out. I have heard of Evo X track cars, not at high power, (but running high rpm for longer periods), having problems with stock bolts. It's a pretty inexpensive mod and will give you piece of mind.

 

I keep hearing how Xs have fuel starvation issues, now heads lifting. Man, glad I have a IX.