Author Topic: Turbo M42 Questions (Read 34005 times)

bmwconnect · « **Reply #30 on:** April 23, 2010, 12:00:42 AM »

Quote from: Ryann;91293

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.

My knock sensor is a microphone and headphones. I run the motronic and I have been tuning BMW's professionally for years. Colder spark plugs, correct fuel and spark you can run on pump gas with boost and without issues.

bmwconnect · « **Reply #31 on:** April 23, 2010, 12:04:26 AM »

here is one of my 12psi runs on the lowest grade fuels in Canada. 89Octane -2degs from stock timing and no counts of knock
http://www.youtube.com/watch?v=f6pkow5hti4

Ryann · « **Reply #32 on:** April 23, 2010, 12:04:48 AM »

Actually, I know what I'm talking about. These are REAL NUMBERS, from a REAL auto manufacturer:

Saab 2.0L 16 valve non-turbo: 9:1 CR, 128HP/131lbft torque
Saab 2.0L 16 valve Garrett T3 turbo w/IC @7.5psi max: 8.5 CR, 160HP/188lbft torque

That is a difference of 32HP and 56lb/ft twist. You're claiming more than twice the HP gains at the same boost pressure? With or without intercooler? With or without engine & engine management mods? I'm on your turbo-enthusiastic side, dude. So prove it!

Ryann · « **Reply #33 on:** April 23, 2010, 12:05:54 AM »

BlueBMW: your table would be excellent, particularly if you included the performance data and overall cost of each project!
bmwconnect: props for actually having installed a setup in your car. some of the missing info in BlueBMW's table could be filled in by you.

bmwconnect · « **Reply #34 on:** April 23, 2010, 12:12:06 AM »

Quote from: Ryann;91299

Actually, I know what I'm talking about. These are REAL NUMBERS, from a REAL auto manufacturer:

Saab 2.0L 16 valve non-turbo: 9:1 CR, 128HP/131lbft torque
Saab 2.0L 16 valve Garrett T3 turbo w/IC @7.5psi max: 8.5 CR, 160HP/188lbft torque

That is a difference of 32HP and 56lb/ft twist. You're claiming more than twice the HP gains at the same boost pressure? With or without intercooler? With or without engine & engine management mods? I'm on your turbo-enthusiastic side, dude. So prove it!

Thats because the tune is very conservative. A good tune will get you 8whp per psi and 14.7 will get you little more then double the stock HP

Ryann · « **Reply #35 on:** April 23, 2010, 12:24:25 AM »

I assume by "tune" you're referring to the engine management software, which I realize is an interest of yours. To their credit, however, SAAB's conservative tune allowed for enhanced performance while preserving the 250-300K mile engine life expectancy.

bmwconnect · « **Reply #36 on:** April 23, 2010, 12:28:23 AM »

Quote from: Ryann;91301

I assume by "tune" you're referring to the engine management software, which I realize is an interest of yours. To their credit, however, SAAB's conservative tune allowed for enhanced performance while preserving the 250-300K mile engine life expectancy.

My m42 has 230,000kms on the motor and I have been boosting for 2years on it. doesn't burn a spec of oil. It's all in the tune at the end of the day.

Ryann · « **Reply #37 on:** April 23, 2010, 12:31:54 AM »

okay, so that's 142,000 miles. how many of those were put on in the last 2 years?

bmwconnect · « **Reply #38 on:** April 23, 2010, 12:37:08 AM »

Quote from: Ryann;91303

okay, so that's 142,000 miles. how many of those were put on in the last 2 years?

Around 60-50,000kms its a daily driver

I purchased the car at 120,000kms

zero motor problems but after boosting I can't keep my drive line intact for long . been threw 2 blown diffs and lots of rear end bushings

Ryann · « **Reply #39 on:** April 23, 2010, 12:51:24 AM »

18,600mi/year? that's a lot. that's like 2 years of driving for me. Destroyed drive lines, diffs, and bushings are not for me. Nor is untimely engine work.

Ryann · « **Reply #40 on:** April 23, 2010, 12:54:18 AM »

I have a dream: a bolt on turbo kit that offers moderate power gains (170hp/torque), is easy to install, and doesn't require modifications or untimely service. Oh, and costs $1500.

NisseJ�rnet · « **Reply #41 on:** April 23, 2010, 02:06:53 AM »

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!

I would say yes there is! But this is with E85 pump gas that we have pretty much everywhere here in Sweden, good for tuning

For example, a M50B25 VANOS with stock engine, not even rebuilt:

Precision SC5862 billet, 0.63 A/R.
E85 and 850cc injectors.
1 044 in the tank. (stock fuel lines etc)
ViPec ECU with VAG coils.

NA = 167 whp.
1.1 bar/16psi boost 406 whp.

BUT again, this is on E85 wich allows for higher compression ratio.

NisseJ�rnet · « **Reply #42 on:** April 23, 2010, 02:15:49 AM »

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")

Higher octane and/or lower compression will make the engine mor knock resistive = moore boost and moore hp

The low rpm torque losses are pretty small, u might not even notice it. I think the biggest "loss" with low compression is the fuel consumption at normal drivning, not a big deal.

rob_e30 · « **Reply #43 on:** April 23, 2010, 08:27:05 AM »

I'd love to see the dyno sheet as I have a hard time believing you're getting 350HP on that build. I know what it takes to get to those numbers and I've found it takes more displacement and boost unless you've made pretty radical head changes.

Are you talking RWHP or at the crank? I agree that the tune is important but I don't recall which ECU you are running.

For the record, I've built and race with BMW CCA a turbo M42 that's 1.95L and puts down about 300 RWHP in race trim with 16psi wastegate springs (with boost creep it's getting a little higher) on 110 leaded.

http://www.cardomain.com/ride/2980038

Quote from: bmwconnect;91288

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 #44 on:** April 23, 2010, 10:01:32 AM »

Quote from: rob_e30;91316

I'd love to see the dyno sheet as I have a hard time believing you're getting 350HP on that build. I know what it takes to get to those numbers and I've found it takes more displacement and boost unless you've made pretty radical head changes.

Are you talking RWHP or at the crank? I agree that the tune is important but I don't recall which ECU you are running.

For the record, I've built and race with BMW CCA a turbo M42 that's 1.95L and puts down about 300 RWHP in race trim with 16psi wastegate springs (with boost creep it's getting a little higher) on 110 leaded.

http://www.cardomain.com/ride/2980038

I will get on the dyno as soon as I can. I was talking 300 crank hp. I run the stock motronic 1.7.2 tuned by me. Vac motorsports did one with 12psi turbo stock everything and they claim they pulled 250rwhp out of it. The DASC 10psi stage 2 I think it is got 200whp so the figures for 250whp, 12psi ,turbo are probably purity close I would imagine

Nice machines also rob:)