Hello peeps..

so what do you think is the safe or max level of boost to run with a MHG, i know its 12-13psi stock.

and im told ceramic turbos dont like going above 15psi??

and does anyone know what psi would then start affecting the pistons, being that im told they would be the weak point once you have mhg instead of the stock one.

i was thinking of 1bar, but not all the time...

the engine is stock apart from mhg,arp studs and new bearings.

_________________
1998 JDM ST205

My GT Four History:
Black 1992 JDM ST185 GT-Four, Grey 1990 UK ST185 GT-Four


My celica website

The ecu is only mapped to 12psi, so that is your safe limit.
Some ecu's have fuel cut at 17psi but are still only mapped to 12psi.

_________________
1991 Jap ST185A
ST205 Head Gasket.
Some random RV & no-name BOV
Blitz Nur-spec SS backbox
Apexi Air Filter

ST205 Front Calipers - Yes, really!

i thought the maps went higher on cars with higher fuel cut??

but in general what are the limits of stock pistons and ceramic turbos?

_________________
1998 JDM ST205

My GT Four History:
Black 1992 JDM ST185 GT-Four, Grey 1990 UK ST185 GT-Four


My celica website

So did I when I bought one, but it seems they don't.

Unless you are planning on a new ecu, I still think the safe limit is 12psi.
I think there are cars out there that have run much higher boost on stock internals and ecu, but they have all gone pop at some point.

I have read on the OC that the turbo becomes inefficient at 17psi, but I don't know a, how accurate that info is, or b, if it was referring to a steel or ceramic turbo.

_________________
1991 Jap ST185A
ST205 Head Gasket.
Some random RV & no-name BOV
Blitz Nur-spec SS backbox
Apexi Air Filter

ST205 Front Calipers - Yes, really!

yeah i have read that the ceramic turbos cant cope with more than 15psi, and thats why some people go steel, even some supra owners swap ceramics out for steel ones.

i was just interested to know what sort of boost people were running with mhg etc...but turbo etc mostly stock.

i can certainly see why people are tempted to up the boost, cause they think ive got mhg now so it can take it, but i know there are other weak points then..

_________________
1998 JDM ST205

My GT Four History:
Black 1992 JDM ST185 GT-Four, Grey 1990 UK ST185 GT-Four


My celica website

Greg - not sure there is a definitive answer on that lot?

The metal gasket and ARP stuff certainly seems to help with gasket issues on the 185, and I doubt at 1 bar on a stock turbo you have too much to worry about in that area?

"Think" 1 bar on a stock turbo is going to begin to generate a fair amount of hot air, and with the stock IC this might cause problems, especially in Hot weather...couple this with the stock ECU and reliability issues might crop up

Whilst WI is a bit of a band aid, (imho), running this will help to ensure a little more reliabilty but I would also be nervous that the timing and fuelling for the car were accurate?

Whilst a check on e.g. a dyno will help to ease worries I don't think it would be the final word in the matter due to cooling issues?

_________________
Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

good advice kris.

cheers

_________________
1998 JDM ST205

My GT Four History:
Black 1992 JDM ST185 GT-Four, Grey 1990 UK ST185 GT-Four


My celica website