Theoretically, yes. But to spin the supercharger faster, you need to reduce the diameter of the SC pulley. Looking at the M271 supercharger, the pulley is already very small in diameter, and the clearance between the nose of the supercharger and the pulley is very tight. Thus, there is no room to significantly reduce the diameter of the SC pulley. This is the reason that everyone has decided to work on overdriving from the crankshaft, and underdriving the accessories by the same amount.

It's not an easy solution, as the M271 supercharger is already operating within a gnat's eyeball of it's max design pressure. Even overdriving it by 20% won't increase the output pressure more than a couple of %.

Basically, in order to see big gains on the M271, you're going to have to replace the SC with a bigger unit.

 

I believe KLEENMAN, RennTech, CARLSSON use the pinned OE pulley or solid pulley. Correct ?

{ caveat: I'm not being a smart-@ss, just trying to educate myself, before I make a decision on the UDPS. }

Brad,
the above 3 mentioned problems, are really the only reason, why I have waited so long on getting the evosport UDPS for my M112 V6 3.2L (non-supercharged). There have been other local MB tuners that point to these 3 items precisely, and have generally said that the whole pulley idea is a "mechanical engineering" mistake. Can you say that your design-from-scratch product will not cause these problems (aside from poor/improper installation) ? I know nothing is guaranteed. But has the design actually taken these 3 problems into long-term consideration ? I just need a warm fuzzy, and not fall for just good marketing / sales strategies.
I want to keep my C320 running for a VERY VERY long time, and any potential damage to the crankshaft is what worries me most.

Finally, what mctwin2kman, references below:
What steps has the evosport UDPS design taken to avoid:
- causes of crank seal oil leaks
- loss / damage of keyway
- pulley disintegration
- installation mishap prevention procedures

Thanks, and I sincerely hope, I don't come off as an agitator. I just really need to know the facts of long-term reliability of the UDPS before I spend the $$$. Long post, I know, but I need peace of mind.

Carlos

Saprissa@aol.com

 

ok i'm a newbie. didn't know that. i only recently got into hardcore modding the bmw. uuc seemed to be a popular choice and it looked decent.

 

wow good post. i was thinking about that, BIGGER S/C muahahahahahaha
how bout a seperate MOTOR to spin up the S/C :v lol

 

That is true, but remember, the SC speed is directly proportional to the engine speed. The new pulley changes the constant of proportionality... Simply put, while the SC is near its limits, a smaller pulley will increase the speed at all RPMs which will give you more boost at slower speeds where most will use it. When the SC hits its limit it at the higher RPMs, you dont hang out there too long.

As I was typing this response I realized you might mean that there isnt much room to make a bunch more boost Like the M111 engine... My bad, but my post still stands that we can get a descent amount of boost at low RPMs where its more fun!

Also, saying that the evosport crank pulley is lighter, I find that a major selling point. Less rotational mass means better engine response.

 

[QUOTE=Capt Nemo o2]MUST HAVE A S/C PULLEY NOW!!!! give it here!!? evo plz!? :p

 

Well you're in luck! With regards to the UDPS kit, you only need concern yourself with item #1 as there is no change to the crank or crank pulley. The UDPS kit only underdrives the accessories (alternator, water pump, pwr steering). Let me first state that just about every problem we've ever seen with the pulleys has been due to improper installation. While we do provide installation instructions with the kit (with nice pictures too!), we HIGHLY recommend you having them professionally installed. Most of the pulleys, especially the power steering in this case, require special tools to remove/install. I must say, however, as someone mentined earlier, that we have seen improper installation by shops as well. With regards to reliability, this is where the R&D dollars go. When you can state that you have several cars with over 60,000 miles with a pulley kit w/o failure should mean something (I personally have a car that's had pullies installed since 2001 w/o a single failure or problem). When a pulley kit is copied, you MAY be able to replicate the power gains, but you CANNOT necessarily replicate the reliability or quality. Our pullies are aircraft quality T60/T61 billet aluminum that are then hard anodized for not only appearance but to mitigate premature wear.

There's only so much you can do to prevent installation blunders. Other than instructions, we do provide support to shops if they need it. This is no different than some other automotive parts you may buy for your car. Although most non-DIY parts do NOT include instructions. Still, as I mentioned earlier, we HIGHLY recommend you seek a pro to do the install. With regards to the crank and loss/damage of the keyway, again this is where R&D comes in. I can't tell you how many iterations of pulleys we went through during testing. The dampening mechanism is critical in this case as is the machining process and material used (ie, you don't want to use a harder material than that of the crankshaft). If you ever get a chance to see our M113 damper, it really is a work of art and something we're very proud of. The M271 should follow suit.

 

I agree. I love the extra power, but the crank pulley was a whole lot scarier to mess with than the supercharger. Plus, youre running the accessories overspeed...I don't like that one bit. I'd prefer a reduced S/C pulley. We'd even be able to scare up another 2 psi that way...the crank pulleys are limited by a stud on the block coming into contact with the belt if they go any larger.

Pressing and pullying pulleys is no big deal- there's dozens of places around town that could do it. Just bring in the nose cone, or the whole SC and get it done. MB sabotaged that option by moving the SC forward so the nose pulley has to surround the nose cone to stay in line with the other pulleys.

 

Okay, so its pretty much agreed that we would all like to see a S/C pulley over a crank pulley. Cheaper, safer, proven and reliable. Now who is going to get out to Seattle to let them have a look at our stock setup???

 

so when is evosport coming out with their replacement supercharger kit for +100hp???

 

2 questions :

1- Is there a due date for the EVOSport pulley set for the M271
2- Has anyone (history question) applied something similar to the concept of a CVT (continously variable transmission) to a supercharger pulley.

We do this with turbos (if you are crazy enough to do so).... and that's mostly what my previous experience is in.

Sometimes you have an engine with an undersized turbo system which gives you quick spool. Sometimes this means that at redline your peak boost is 10-12 psi (which is the case with the turbos on my ex-car ...3000GT vr4).

This does not meant that your turbos and fuel system have the ability to boost up to 21psi in the lower rpms and be able to have enough fuel to support that hp. What you get is not much in temrs of peak power but you have an overly inflated midrange and wide powerband. Good for launching nad 0-60s. You'll still get killed on top end highway runs but it makes the car feel much much much more aggressive at lower speeds

(i just thought of another question).

So has anyone historically tried to produce a CVT type solution to alter the S/C gearing throughout the rpm band?

Q3: Since MB already has an electronically controlled bypass valve on my car (C200 kompressor) and since it has been said (by those who are knowledgable of this car) that the bypass valve prevents my car from reaching 11psi at higher rpms limiting it's crank hp to 14x rather than 189-192 for the C230, then why can't we produce a similar solution utelizing a 15psi or so crank pulley (which the s/c can not support towards redline) and using the bypass valve to reduce boost as you approach redline taking into account the extra heat resultant from the added gearing ... again i guess the solution would come down to a higher geared s/c with a clutched system so that you can clutch in and out the s/c at higher rpms to lower it's effective gearing...

i guess the clutch would wear out .

There is only 1 solution ....

twincharger : )

 

i have a question: Does our car have a Clutch Delay Valve like in some BMWs?

 

bump

 

I have never heard of this in Eaton root-type blowers. Probably not very feasible. What we CAN do is just get headers and a free flowing exhaust which will lower boost and increase flow. If the psi is the problem this would lower psi and allow us to go more aggressive with the pulley while still gaining horsepower (CFM) in the process and keeping or slightly raising the psi over stock specifications. Now if the supercharger is blowing max CFM already then we are screwed - but this is not the case as Mercedes isn't so stupid that they would put a component stressed to its maximum limits on a stock automobile. After 14psi or so most Eaton blowers lose their efficiency but this is simply solved by increasing flow and lowering the psi while increasing CFM. Very simple fluid dynamics.