Tech-Tune

Figured I'd start a thread in order to accumulate information from members who have installed the new fixed (clutch less) pulley.

What I noticed right away is that during cruising (off boost) driving, the IAT's are on the average 10 degrees higher than before when I was running Shardul's smaller SC pulley. Meaning if I was at 12 degrees above ambient, I'm now at 22 degrees above with the 77mm pulley. This is only during cruising but totally understandable being the blower is spinning all the time now so it will generate more heat.

In order to put things in better perspective, here's a list of my cooling mods:
-split system
-PLM heat exchanger
-Bosch 010 pump (constant circulation)
-small reservoir located outside the engine bay (behind grill)

I am however enjoying the absence of the clutch engagement, as I've always felt it robbed the car of it's luxury feel. Also feels noticeably peppier than it did with the smaller SC pulley.

Hoping others chime in with their thoughts and findings. Its a new mod so the more information we share the better it is for all of us.

viren.89

So I'm assuming you car didn't get the tune yet right ?

You didn't step on it much did you ? cuz if the car isn't tuned it isn't wise to

go WOT right?

Tech-Tune

Currently on my old EC tune, so I'm not driving it hard (staying under 5lbs and for short intervals).
I'm keeping a close eye on my gauges to prevent any potential harm.

Sir-Boost-a-Lot

iTrader: (1)

You might want to consider rigging the bypass valve with a sensor like "Finny" did in his Stock to Awe thread so you can know what's happening with that at different throttle positions and speeds.

lm7

I'm hoping the tune is resolved soon so we can see results of full potential and actual #s

Toadster

i'd expect IATs to be higher, you're essentially going from a 168-172 pulley to a 180

HeissRod

More reviews:
https://mbworld.org/forums/w211-amg/...ge-thread.html

cij911

Incorrect as he stated this is at cruising...Essentially what he is showing is that having a solid unit, which runs the blades all the time, creates heat (dahhh)....It will be interesting to see if the on throttle benefits outweigh the off throttle disadvantages....I am still skeptical.

Tech-Tune

Exactly, I too am skeptical because now I'm seeing 25-30 above ambient at cruising (off boost). Those spinning lobes make significant heat even prior to creating boost.

cij911

Technically speaking, reducing the weight of the pulley system should help with response, but with the massive torque our cars produce (even off boost), I really doubt it would be evident by most...

Shifter

I agree with Toad on this one, even while cruising the 180 size spins the blower faster creating more heat than a 168 would. Remember even while cruising our pulley is engaged majority of the time.

cij911

Ughhh incorrect...do some logging and you'll understand a bit more.

Tech-Tune

Off boost the clutched pulley is not engaged, so this is not an accurate statement. ^
If I were to run the 83mm fixed pulley (which is equivalent to my smaller clutched pulley) it would still create more heat off boost than the clutched one.

Both my clutched pulley's engaged at around -2lbs of vacuum (just prior to boost).

CharlyE500

Is this will shorten the SC life which is always engaging ?

Style_Front

Who can really answer this? What if the supercharger life was 500,000 miles and it shortened it in half, only 250,000 miles? Yes it will be running more but as long as it stays within operating temps and well lubed it should run like a top for a long long time.

CharlyE500

Running more even with the right temp will still shorten the SC life. Plus, I don't really think they will last 300K in stock form. My point is, few of us has the car more than 100K miles and how long the SC will last with this pulley.

Style_Front

I doubt theres a documented expected life span on the supercharger. The answer is definately yes, it will shorten the life span, but to what degree I dont think any one can really say without fabricating a number. Time will tell.

Shifter

So are you saying at any speed while out of boost the clutch is disengaged ?

Shifter

Incorrect, our cars don't make massive torque off boost.

Shifter

This is a very general statement about when the clutch is or is not engaged and is not fully accurate either.

cij911

You really should do a bit more homework and datalogging....You'll understand a lot more on when the S/C engages and is not engaged...

As for you stating that our cars don't have a lot of torque off boost, I am not sure what your comparison is, but generally most would agree that a 5.5L v8 can generate a fair bit of torque....Add boost and you have the potential for monster truck levels (j/k)....

I really am not convinced the extra heat, or load for that matter, is worth it...

Shifter

You haven't elaborated when you say it is or isn't tho.
What I'm saying I have seen that's all.

I guess I'm comparing torque off boost like driving with a bad ic pump after the sc shuts off and the engine makes 200 lbs. give or take ofcourse.

A 5.4 liter v8 with 8.5:1 compression isn't going to be a beast off boost IMO

Tech-Tune

I monitor my car daily, trust me its accurate.

Tech-Tune

Agreed.

That's what I want to find out. The new pulley feels incredibly responsive and I'm enjoying the absence of the clutch engagement. I really hope the tune gets ironed out and the higher intake temps have minimal effect on performance.

I just uploaded a revised file so I'm gonna go put some miles on it to log the differences.

johnnyblaze

:Not directed at the OP but everyone inquiring about fixed pullies, OP sorry about OT:

A lot of you guys stayed away from a 180 crank pulley because of the heat it builds on the motor and some of you wouldnt get it because of the one in thousands of crank pulleys that broke or otherwise. Now you're slapping a fixed 77mm upper pulley(basically 180mm crank), without a tune? What the hell lol..

I'm still interested in to what the tune does for a fail safe...

The reason, well one of them, the pulley is clutched is to save the motor from its own temperature demons. It turns off the supercharger if your temperatures get too high, makes sense right?


So you've added a heat exchanger, good, that's going to make sure you recover faster and hold your IAT's down a bit longer(a couple seconds) when you're on the boost. A lot of you guys have already noticed, just having a heat exchanger in conjunction with a better pump, does not eliminate temperatures eventually reaching high levels(back to back pulls). You guys that are adding this fixed pulley need to find a more helpful modification to reduce cooling especially if you guys are daily driving your fixed pulleys. Killer Chiller, Methanol Injection and Split cooling would be your only options. Based on what I know of our cars I would safely say these are must needs now with these fixed pullies and high mileage motors.