[Christophert21]

hey. bought a gtst a few weeks ago from japan
it melted a piston after a fortnight, getting it built up and remapped again.
basically i want to know what sort of power i can expect

it was rolling roaded at 347bhp before it melted a piston but the rolling road operator rang me the next day to say the rolling road was out of calibration and to bring it back down. never got back down before the engine went

basically here is the spec
97 gtst
new forged 86mm gtr pistons
gtst rods
new standard head gasket
hks gt3037 turbo
hks external wastegate
trust fmic
bigger fuel pump
740cc injectors
hks induction kit
kakimoto exhaust and decat
hks f-con v pro (no air flow meter)
hks evc 4

what power should i expect and what boost?

thanks

 

[ChrisC]

If you are really gonna use a std head gskt again, you would be limited to 1.2 bar. Perhaps less to be safe. Why not fit something like a 1.6mm metal gasket as the rest of your mods could cope with higher boost. Makes sense while the engine is in bits

 

[Christophert21]

oh. should have got a steel headgasket then! doh!

but i thought i read somewhere that the standard head gasket was ok to about 600 bhp?

 

[ChrisC]

Maybe as long as you stay under 1.2 bar

To run more boost you are gonna need a metal head gasket

Its daft imo to fit a std gskt back on

 

[needforspeed]

Originally posted by andy42uk:

It's NOT the power.....or the boost...
IF you run 1.2 bar+ you will be on borrowed time, the compression ratio is too high to sustain this and it will give.
It IS NOT an outright strength issue, the std head gasket could take the pressure if you lowered the C/r some other way....
IMHO,
Andy.

 

[BIG.SMOKE]

^^^^ andy knows his ****

 

[Poirot]

no need for steel headgasket but forged pistons would have been nice

 

[BIG.SMOKE]

^^ this guys know his **** aswell

 

[Christophert21]

they are forged

 

[Poirot]

lol brad

"new forged 86mm gtr pistons"

type?, compression?

 

[Christophert21]

wossner. i'm not sure on compression off hand, but they are lower compression than gtst pistons

 

[Poirot]

cool, i am more used to higher compression engines from my previous turbo cars and we ran a lot more boost and cylinder pressure than you think you would get away with, first thing for you is to get a map unless you have a mechanical reason for rebuild?

how are you going to run it in?

 

[Christophert21]

i was just going to drive it easy for about 500 miles. change gear at sensible revs and no full load throttle? don't really have a clue but thats my guess?

 

[Poirot]

everyone has a preferred method and the easy break in is one that works, some say this works better
http://www.mototuneusa.com/break_in_secrets.htm

 

[Bruce-m]

I always ran my engines in by not going over 4000rpm for at least 800miles normally 1000miles, the mileage was clocked up by different types of driving i.e round town, motorway, A and B roads etc then i'd drop the oil and put some nice decent oil in and now use full rpm but only on std boost for another 100-200miles after which i'd dial in the extra boost and re-map at the same time.

chris yourdef be able to run 1.2bar as for how much more only your mapper will know if you can run more depending how much DET you get as the boost rises.

 

[Eagleye]

Definitely go to this guys site about running engines in. I have run 2 engines in on the Dyno this way and we have seen an improvement in the overall running of the engine and performance...
http://www.mototuneusa.com/break_in_secrets.htm

 

[broph99]

Nice list of parts, sounds like it will be well done up.

 

[Christophert21]

ordered a new hks steel headgasket this morning

 

[Christophert21]

429.7bhp at the hubs on the rollers. thanks to TDP