Author Topic: Turbo M42 Questions (Read 34020 times)

bmwconnect · « **Reply #15 on:** April 22, 2010, 12:29:28 PM »

Quote from: Romrog318is;91253

this..

the most i have seen out of a boosted M42 was 333 HP

Stock internals? whp or crank?

Romrog318is · « **Reply #16 on:** April 22, 2010, 06:01:01 PM »

^^ WHP and i cant remember it was a WHILE ago when i read it... lol

BlueBMW · « **Reply #17 on:** April 22, 2010, 06:28:38 PM »

I'm trying to scrounge up the cash to see if I can pick up this motor and stuff. If nothing else it might be fun to tinker with. I still have the E34 i can daily if necessary... (although city mpg is atrocious!)

NisseJ�rnet · « **Reply #18 on:** April 22, 2010, 06:42:06 PM »

Quote from: bmwconnect;91254

Stock internals? whp or crank?

whp, if were talkning about the same car it has M52 rods and pistons.
http://i188.photobucket.com/albums/z37/Bmwrille/318is%20Turbo/mappning014.jpg
http://i188.photobucket.com/albums/z37/Bmwrille/318is%20Turbo/IMG.jpg

There is another guy here in sweden pushing his 2000cc M42 to over 615hp on E85 pump gas

http://i90.photobucket.com/albums/k267/Bonje_80/318is%20turbo/DSC00274.jpg

Ryann · « **Reply #19 on:** April 22, 2010, 08:51:42 PM »

There is no such thing as 350hp from a turbocharged M42 with stock internals. Nor is there such a thing as an engine that has a 10:1CR being fed 15psi of boost and pump gas without knocking. C'mon guys, prove me wrong!

BlueBMW · « **Reply #20 on:** April 22, 2010, 09:45:47 PM »

Is the purpose of reducing compression ratio to allow higher boost pressure without having to change fuel grades etc? (trying to learn more about this thing they call "boozt")

Ryann · « **Reply #21 on:** April 22, 2010, 10:08:35 PM »

Yes. That is why I'm calling BS on some of these ridiculous claims. As I was saying before it'd be cool to devise a low pressure setup that utilized all of the stock components including the stock CR (pistons). Maybe like 5-7 psi for an output of 160-170hp using premium fuel and possibly using the SAAB APC system or some other form of knock protection. This would be a realistic and awesome performance boost!

Romrog318is · « **Reply #22 on:** April 22, 2010, 10:15:18 PM »

umm i never claimed it was stock internals... that was someone else... and that car that made 333 was on a dyno jet so its prolly closer to 260 WHP

hell i have a friend with a 350 WHP M10

Ryann · « **Reply #23 on:** April 22, 2010, 10:46:53 PM »

Romrog318is: my response should have read 350hp as I was referring to another gentleman's claims, my mistake. Maybe you can dissolve these illusions by sharing with us some specs. on the setup you read about i.e. CR, boost pressure, engine management, etc.

I'm not trying to be a naysaying shit head here. I think a lot of us are interested in the subject of turbocharging our cars, and I think it would help if someone put up a solid build thread accompanied by factual performance info. I also think a lot of us are without endless supplies of cash for things like custom forged pistons and race-level engine management systems, which is why I think it'd be cool to devise a setup that is do-able and provides a realistic and reliable performance boost.

bmwconnect · « **Reply #24 on:** April 22, 2010, 11:12:09 PM »

Quote from: Ryann;91276

There is no such thing as 350hp from a turbocharged M42 with stock internals. Nor is there such a thing as an engine that has a 10:1CR being fed 15psi of boost and pump gas without knocking. C'mon guys, prove me wrong!

You are wrong!! Im running 15psi all day long on stock internals and 91octane with 18degs BTDC spark

head bolts are torqued to 80Lbs as it was lifting at 18psi and squirting coolant out the water jackets on my last summer setup

many of the DASC tunes included a 10-12psi pulley and were intended for 91octane

There is atleast two m42 stock internal 12psi turbo setups in my area and they are holding up no problems

the m42 internals are factory strong and can handle alot of punishment.

The pistons and HG are the weak point

bmwconnect · « **Reply #25 on:** April 22, 2010, 11:42:01 PM »

Quote from: BlueBMW;91278

Is the purpose of reducing compression ratio to allow higher boost pressure without having to change fuel grades etc? (trying to learn more about this thing they call "boozt")

its got nothing to do with fuel grades . lowering the compression will increase your displacement and allow you to pack more oxygen into each cylinder for a bigger bang and over all HP will increase

bmwconnect · « **Reply #26 on:** April 22, 2010, 11:46:12 PM »

Quote from: Ryann;91280

Yes. That is why I'm calling BS on some of these ridiculous claims. As I was saying before it'd be cool to devise a low pressure setup that utilized all of the stock components including the stock CR (pistons). Maybe like 5-7 psi for an output of 160-170hp using premium fuel and possibly using the SAAB APC system or some other form of knock protection. This would be a realistic and awesome performance boost!

clearly you have alot to learn and you don't have a clue what your talking about. 5-7psi is over 200crank hp on these motors

BlueBMW · « **Reply #27 on:** April 22, 2010, 11:47:00 PM »

What are the negative effects of lowering compression?

But I agree, I think all of us are very interested in clean, reliable, budget friendly turbocharging solutions for our cars. Personally, I am interested in something that will give my daily driver that extra spunk for a little added fun factor. Hopefully without requiring me to upgrade my 14" weaves just yet! And without disintigrating my small case diff instantly! All without spending a fortune of course!

It would be nice to compile a database of sorts of methods to achieve certain gains:

For example:

That's a table of BS I just made up knowing very little about any of this stuff

Forgot to add estimated HP and estimated cost. But you guys get the point. Something like that with maybe details under each build type maybe including part numbers, recommended sources etc. Might be asking for a lot but who knows!

Ryann · « **Reply #28 on:** April 22, 2010, 11:47:56 PM »

Are you running a knock sensor/boost control setup? If you were it'd be dumping your charge far short of 15 psi because it would be hearing knock that your ears aren't hearing. At 10:1 we risk engine knock under a load while running regular pump fuel alone, BEFORE adding boost. This is a fact, and is why M42 equipped cars require premium fuel. You're running 15psi "all day long".. but not without premature engine failure. And we want to see the 300hp+ dyno sheet.

bmwconnect · « **Reply #29 on:** April 22, 2010, 11:50:03 PM »

Quote from: BlueBMW;91292

What are the negative effects of lowering compression?

Increased turbo lag and power losses down low