my 1st supra. 89 turbo targa top 170K

[#1StunnaVic]

waddup everyone. just got my first supra and i know these questions have probably been asked b4 but i didn't see the answers to them when i searched around. maybe i didnt look hard enough..... sorry for being repetative and asking the same questions that have already been asked but i was just wonder after doing MHG and ARP head bolts and bearings what is a safe amount of boost to run on a 7mgte with stock pistons and connecting rods.
also i heard alot about clevite bearings and king bearings. i was just wondering which ones are better for the supras. once again sorry for being repetative.

thanx Vic

 

[suprahero]

Crank it up until it blows up or hits fuel cut. I don't know what's safe, but my wife's car we run thirteen psi, and that's about 300 rwhp on an automatic. You'll have to judge for yourself what is safe. No one knows what shape your engine is in so it's kind of like an unanswerable question. Good luck, Jay

 

[#1StunnaVic]

thanks jay, do you have any idea about the bearings?

 

[kntmikado]

If you're going to ask questions like "how much boost is safe" then you need to forget that head bolts exist. Instead, you'd be much better off running ARP head studs. They distribute the pressure more evenly and they're easier to work with, IMO. Adjuster runs his torqued to 103 lb/ft. No way you'll have a problem with the HG at 100 lb/ft unless you set off some kind of fertilizer bomb in there. Sure they're a touch more expensive, but totally worth it.

Anyway, if you're planning to just crank on the boost, then you'd better also make sure your turbo and your drivetrain are up to the challenge. Trust me on this one. In the dictionary, "Supra" means "above" and these cars have always proven to be "above" average in terms of mechanical trouble unless the owner is attentive.

BTW - I remember reading somewhere on here or SF that the stock rods are good up to ~500HP.

 

[#1StunnaVic]

how about pistons?

 

[Idealsupra]

at 170k miles.... probably 10psi lol

i wouldnt run more then 14psi on a stock ct anyways.

the question is EXTREMELY broad.

 

[2543arvin]

its not the pistons and rods that will prevent you from running more boost at this point, you will hit fuel cut before the pistons and rods will go on ya. fuel cut is around 12 or 13 psi, so you might wanna upgrade your fuel system first before you will even be able to turn the boost up to the levels that im assuming that you want. But IMO i would make sure you have a strong platform built before you just start cranking up the boost on a supra with 170k miles.

 

[Clip]

i dunno about overtorquing by another 20-30 ft/lb but if adjuster is safely running it then i'd have to go with him. still, id think that the tolerances of the threads on the block wouldn't cooperate with that.

 

[#1StunnaVic]

good that answered my question. now i plan on doin my MHG. i was just wondering if it was absolutely nessicary to machine the block as well as the head. i was hoping i could just do the head and get a MHG with ARP head studs and it would be fine. as long as the block is nice and level it should be fine right? i been reading a bunch of postings on it it everyone seems to be sayin you must machine the block but i seen guy just do the heads b4 and the MHG sealed just fine. any insight on this?
once again does anyone have any idea if king bearings are better than clevite?

 

[billspreston01]

do some searching and you'll find a ton of info on how to prep the head and block for a mhg.

I'd say make sure everything is in good condition before turning up the boost. All the little rubber hoses and such like to become hard and crack on an 18 year old car.

 

[2543arvin]

the mhg will not seal properly unless you machine the head and the block,...is this guy that you know running his car under lots of boost?(which is the route that youre planning on taking) Im assuming hes not,and if he is it is only a matter of time before he posts a thread saying that he shouldve decked the block while he had the chance. Dont go the cheap route with your supra if you plan on it being reliable in the long run.