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MATT95M3
12-31-2005, 03:28 PM
I just replaced the engine in my 95M3 with a stock factory remanufactured engine, and im considering a turbo installation as well. I was told by the folks that built the engine that these motors aren't made to handle that much pressure, I disagreed and that was it, he had nothing to back it up. My question, how much boost will the stock internals withstand? It seems most of the kits out there range in boost pressure from 6-9psi. My assumption is that the engine will readily handle 9psi, but will it take more?
Experienced opinions?

thilton59
12-31-2005, 07:18 PM
I think you could peak higher, 12-13, but hold around 8-10 and be fine. I know of a motor which has forged internals, but the stock block and head, and it holds 30 psi.

Pinecone
01-01-2006, 05:01 AM
Assume what you want, but that is how things go boom.

These engines are high compression to start with, which means they do not take well to high boost. If you wanted to make a high boost engine, you want compression ratios down in teh 8 to 1 range, not the 10+ to 1 range of stock engines.

Go to your nearest book store, look in automotive and pick up any of the boooks they have on turbo charging or supercharging, and start learning rather than assuming for a position of ignorance. And we are all ignorant in some areas.

PHROZENM3
01-03-2006, 09:23 AM
MOST supercharger kits run between 6 - 10 psi. That is to keep the engine from going BOOM! Most companies will void any warranty when you raise the boost above the companies recommended specs.

Pinecone
01-04-2006, 05:54 PM
In consultation with my engine builder my '85 Dodge Daytona Turbo Z motor was built to an 8.5 to 1 compression ratio to run 14 psi boost with an intercooler. The max they recommended for a street car due to longevity.

rrsperry
01-05-2006, 05:44 AM
There are tons (relative term) of people running 11psi of boost on stock internals. All of them have some form of inter / aftercooling, and possibly water injecton as well. That is with the best tuning from Nick G or Stickley. Without cooling, 6.5 or so is the max. If youwant to reliably run more than 11 psi, you need to build the bottom end.

There are plenty of places to ask, ICS (International Cars of Stamford Ct.) Nick at http://techniquetuning.com/, the guys at http://activeautowerke.com/, or VF Enginerring, or Dinan...

Mr Paddle.Shift
01-05-2006, 08:15 AM
9psi will be fine. I have even seen it done on a M54B30 with stock internals and I don't see what not on a S50. You might want to visit Bimmerforums for more info: http://forums.bimmerforums.com/forum/forumdisplay.php?f=150. There are more people who discuss about this.





I just replaced the engine in my 95M3 with a stock factory remanufactured engine, and im considering a turbo installation as well. I was told by the folks that built the engine that these motors aren't made to handle that much pressure, I disagreed and that was it, he had nothing to back it up. My question, how much boost will the stock internals withstand? It seems most of the kits out there range in boost pressure from 6-9psi. My assumption is that the engine will readily handle 9psi, but will it take more?
Experienced opinions?

PHROZENM3
01-06-2006, 06:17 AM
PM if you have further questions. I work for Active Autowerke and I would be happy to help you with this question.



I just replaced the engine in my 95M3 with a stock factory remanufactured engine, and im considering a turbo installation as well. I was told by the folks that built the engine that these motors aren't made to handle that much pressure, I disagreed and that was it, he had nothing to back it up. My question, how much boost will the stock internals withstand? It seems most of the kits out there range in boost pressure from 6-9psi. My assumption is that the engine will readily handle 9psi, but will it take more?
Experienced opinions?

wongmoxy
01-06-2006, 09:45 AM
Like someone else said high compression cars should not be turbocharged. If you over rev just by a little youll be bending a valve. Also the engine will wear and tear a lot. My opinion is getting a lower compression and then you can boost safely and with confidence.