The engine with the bad harnesses IS the good engine, so its a love hate thing. its got way more low end torque, AND top end ponies, and its mated to a transmission that starts in 1st gear (previous models started in 2nd unless you floor it). Assuming you want a wagon, you'll find these in 1993 300TE and 1994-1995 E320 wagons. in 1994 they changed the model numbers, so they no longer indicate sedan vs coupe vs wagon, lovely. also in 1994, they did a face lift of the front end, with a flush grill, and different euro-style headlights.

 

Well this helps a lot cuz like I said the total number of models can be overwhelming. Now I know what to look for. Thanks

 

afaik, fuel injection is based on mass air flow, and coolant temperature. the boost modifies the air flow, of course. the MAF is before the turbo so its measuring the air sucked in...

the volvo turbos, the boost is limited by vacuum control to the waste gate, too much manifold pressure and it bypasses some of the boost, thats purely pneumatic/mechanical

the TD05 turbos on the later 7/940s quickly develop full boost at fairly low RPM so give you lots of low end torque. a supercharger won't do that.

I'd hop over to turbobricks, those guys know WAY more about this stuff than I ever want to. I left all of mine bog stock, as I like the longetivity aspects. more power == more repairs, exponentially.

 

Thanks, as always, for the info. I assumed it was the air flow that controlled it. You're right about a supercharger(driven by a pulley) would need to achieve high rpms to achieve full boost but the advantage is a totally flat power curve as opposed to a turbo's peaked power curve. Also, much more torque available right above idle which makes for better low speed, around town, driveability. Less requirement for low gearing. And the Merc's 4 cylinder Kompressor comes from an engine almost identical to the redblock in bore and stroke and total displacement. Seems like an easy fit that would change the whole characteristic of the car. I think Volvo went to turbos because of their truck experience and Mercedes went to superchargers because they studied the advantages and disadvantages. Maybe I should drive a Mercedes first.

 

the turbo 940s really aren't very peaky, they have just about all the boost they get at 1500 rpm, mine just pulled strong right off the line and all the way up til it ran out of steam at 5000 rpm or so.

 

Well mine does the same but the downside is it can only do that with very low gearing. And the result is at 70 mph my engine is buzzing at 3,000 rpms. And has the worst highway gas mileage of any 4 cylinder car ever made. Mercedes would never have that. It would destroy their "luxury" image. Ha!

 

actually, the mercedes inline 6's in the 124's cruise silently at high rpms, and butter smoothly. I think mine are doing 3000 at around 65MPH, 4000 or so around 90, and you can hardly hear the engine with soft acoustic music playing. The wind noise picks up a bit when you get well past 100, its still louder than the engine, and there's no vibration.

the differential is rubber shock mounted in a sub frame thats rubber shock mounted to the car chassis. the W124 was the first generation to have modern multilink IRS. the drive shaft is connected to the transmission with a pair of polymer flexdisks (oh, those should be inspected on any used car, and replaced if they are hardened or cracked...). even the serpentine belt tensioner has a damper on it to elimate vibrations. they use an internal timing chain instead of a belt.

the 3.2's generally get better gas mileage than the turbo volvo... I see around 24-26 MPG on the highway, and 16-18 around town in the benzes, while the 740 was getting low teens in town and at best 18 on a road trip. US model 3.2's got 220HP at 5500rpm, 229 lb-ft at 3750 rpm.

 

Sounds super smooth. But it's a 6. To understand the advantages of a supercharger vs a turbo consider this: the Mercedes c230 makes 192 HP@5,500 rpm vs 162 HP@4,800 rpm for a Volvo 940 Turbo. The Merc has 200 ft lbs of torque@2,500 rpm while the Volvo has 195@3,450 rpm(about the same but 950 rpm later). The Merc goes 0 to 60 in 7.5 secs while the Volvo(sedan) takes 8.8 secs. And last but not least, the Merc's gas mileage is 20-28 while the Volvo is 17-22. The engines are almost identical in displacement and the cars weigh roughly the same. The better gas mileage obviously had to come from taller gearing, yet it didn't bog the engine down, as reflected in the 0 to 60 times. So you have one that makes more HP, makes it's torque much sooner, is faster and yet, gets better gas mileage in city and highway driving. It's obvious the Merc engineers saw a supercharger as having many more advantages over a turbo. My mental theory is - if I swap my Volvo's turbo with a supercharger and change the gearing I should be able to match the Merc's numbers.

 

go over to turbobricks and folks have pushed b230ft engines up over 400HP and 400 ft-lbs. but much over 250 horses-n-torques, and you gotta start looking at different transmissions, differentials, etc.

now, which C230 are you talking about? that designation has been used all over the place, for 3-4 different chassis over the decades.. most of the 4 cyl ones after about 1995 have DOHC with variable valve timing, sequential injection, variable intake path length (these are all features pioneered on the M104 3.2L 6 cyl in my wagon+cabrio), so they were 150HP engines before they even stuck the compressor on it (the B230F N/A engine was 115HP). Starting about 2002, the 230 no longer reliably meant 2.3L, it could mean almost anything.

 

https://www.caranddriver.com/reviews...t-drive-review

As far as turbobricks, those cars are not built for gas mileage and/or driveability but pure speed. If I tackle this project it will be to use as a daily driver and comparable to modern cars.

 

ok, that 2002 C230 was the first year of the W203 series car (3rd generation C class), and in 2002 only, came with the M111 with those specs, thats a 4 cyl version of the 3.2L 6 cyl in my beloved late version W124 cars. the very next year, the C230 Kompressor came with a new 1.8L with slightly less power but higher efficiency.

again, the base 2.3L non-charged M111 motor was 150HP and 163 ft-lbs. Thats way more than the B230F non-charged version (114HP and 135 ft-lbs). if you want that supercharger to actually do something in the volvo, you'd best bring over the whole C230 Kompressor motor, ECM and all. likely won't be much fun mating it to the Volvo transmission.

 

Sounds like these engines unboosted are very similar to the 16 valve GLE engine. And that engine achieves it's power high in the power band as do all 4 cylinder, non boosted engines that produce over 150 hp. And btw, 150 hp from a 2.3 liter 4 banger is not possible unless you have a high compression ratio. When you add even a little boost you have to drop the compression ratio to 8 lbs or less, or you'll blow the head right off the block. Doesn't matter how many valves or cams or unequal runners. So those engines with lower compression ratios had to be close to the redblock hp(look at the old 190e). If the super charger just added to that at the high end it couldn't handle the higher gearing around town and the gearing and city gas mileage would have dropped.(Why the GLE still has a 3:73 rear end without a Turbo). Also why the first 960's had a 3:31 rear end. The added torque from the inline 6 could handle that. I think adding a supercharger to a redblock will accomplish the same. My goal, if I do it, is not performance per say. My goal is to eliminate any engineering compensation to prevent turbo lag, such as low gearing, non locking torque converters, etc. I think boost is boost. And, like you say, Turbobricks have proven that just increasing the boost on a stock turbo from 6 to 10 lbs will yield over 200 hp. The Eaton superchargers on these Mercs provide 8 lbs of boost which should yield around 190, same as the Mercs. So the Volvos can handle it and it will yield appropriate performance numbers. Remember, I want driveability and gas mileage. And And by providing more midrange torque, which will handle taller gearing I think it can be achieved. Kind a like this guy:

And here's a graph showing results with a supercharger and then a turbo on the same 4 cylinder engine. Notice the power is less but the curve is flatter. Then look at the torque, huge difference.

 

the Mercedes M104 (6 cyl) and M111 (4 cyl) have variable cam timing, and a variable length intake runner so they get good torque at low RPMs *and* more horses above about 3500-4000 RPM when that stuff kicks in. they also have true sequential fuel injection, which better optimizes fuel delivery per cylinder. technology wise, they have more in common with the Volvo 850 'white block' engines.

 

Look at the graph I just posted. Says it all. Modern engine with no changes other than the type of boost.

 

Boy, I just put my foot(and leg) in my mouth. I read that chart backwards. The turbo did post higher numbers in hp and torque. Hard to believe, but true. I guess you're right Pierce, this could be a big can of worms.