I would go with the 181mm. It's safe and will provide the needed power.

The 185mm isn't too much larger, but it does create more heat.

 

So the 178 and 181 will work with the stock ECU, etc.
We know the 178 is proven reliable. What about the 181?
Also, anybody know the HP difference between them?

Edit/Update - I found a post stating that the 178mm adds ~20hp and the 185 adds ~32hp. I estimate that the 181 would add ~25hp over stock. Sound correct?

 

181 ordered , next comes new tires .

 

with the 185 is is absolutlely required to get a bigger HE? or just recomended? would i be able to run the car with the 185 and have it reliable with just the pulley and needswings intake? thanks

 

Nothing is required, but it is highly recommended. If you don't drive the car hard, then the stock HE will be fine. It will only be a problem once your foot gets heavy.

 

I'm almost ready to buy. One more question. What if any special tools will be needed to insatll othe than what would be found in a common tool box?

 

You will need an E 10torex socket to use on the belt adjuster pully to remove the belt off the pulley system. You also will need an impact wrench (either electric or air) to remove the bolt off the crankcase pully. Some have tried to do this manually with great difficulty. I tried and gave up and purchased an impact wrench. Get one with at least 600 ftlbs of torque. My first impact wrench was rated at 250 ftblbs torque and could not loosen the bolt. The 650 ftlb torque wrench I then purchased was just barley able to lossen that bolt. Any way; that was my experience.Other than that the job was not difficult.

Yeah I meant a torque wrench.

 

The impact gun, a Trq. wrench (200ft lbs), and basic etorx sockets is all you should need.

There are only a few pulleys left guys!

 

Hope you have a re-stock option with the manufacturer, if you run out!
Depending on what the new landscaping wall will cost, I may have enough
bonus+tax refund money to buy one in March or April.

Coyote

 

I already have an upgraded pulley kit (evosport) with the 178mm crank. Can i just buy the larger size 185mm pulley or will I need to replace the water pump and idler as well?

If so, how much for just the 185mm or 181mm pulley by itself?

 

We don't yet!

There are only 2 181mm pulleys left!

 

The 185mm will require a new water pump pulley....the 181 will be close.

PM me for more info...I'll make you a deal on either pulley.

 

I didn't have access to a compressor or an impact wrench - I tried to use an electric impact but it wouldn't fit in the engine bay. I also didn't have a 1/2" torque wrench capable of 160 ft lb - so used the old arm muscle torque setting.

Tools I used:

3/8" drive ratchet and extension
3/8" drive E10 socket - Belt tensioner, clamp
3/8" drive #10 socket - Water pump pulley
3/8" drive #13 socket - Idler pulley bolt
3/8" drive 1/4 inch allen - For LET pulley's outer hub

1/2" drive breaker bar and extension
1/2" drive #27 socket - Crank Bolt

Half of my floorjack handle (extra leverage for removing/installing crank bolt)

A big flat blade screwdriver - for pinning flywheel to remove/install crank bolt

Blue Thread Lock - cuz I like the stuff

 

Jerry do you recomend using thread lock? I have seen mixed reviews with the strech bolt and also the bolt from factory allready having some lock tight on it.

 

No, I try to follow the Mercedes WIS documents and they made no mention of thread lock. Also, at damn near 200ft lbs, that bolt better not move.

 

Funny! My neighbor (Mercedes Mechanic) told me that the dealer usually does not use a torque wrench when doing the OE SLK32 harmonic balancer replacements. He told me they call it 'GuttenTicht' - It's 'German' for Good'n Tight. (no, it isn't really German...but I thought it was pretty funny...)

SQ

 

Almost no techs anywhere use a torque wrench unless it's for something important like head bolts. I've worked on around 1000+ Mercs, Bimmers, Lambos, Ferrari's, etc in the last 3 1/2 years and have never once picked up a torque wrench(I am my own torque wrench LOL). I don't do internal engine repairs(at work)...........just suspension, electrical, body and the occasional water pump and oil pan when broken.

 

I've torqued heads and intakes like you mentioned, but have never really torqued anything else either...

I guess I was a little surprised to know that a Mercedes dealer didn't require and watch over the techs when a torque wrench was recommended.

They have replaced thousands of pulleys and I'm sure very few have been loose.

Sounds like You've got a nice gig!

SQ

 

Do you think they'd be willing to do the pulley swap and other mods for an okie? More specifically, an Oklahoma Univerity Alumni? Just kidding. Can you PM me the contact info if they're cool with it??

 

I'm looking at purchasing one of your 185mm pulley kits, but had a few questions regarding the balancer/pulley of these assemblies:

Is the pulley neutral balanced prior to being attached to the harmonic balancer, or is the assembly neutral balanced after being mated with the harmonic balancer? The pictures I've seen of just the pulley weren’t clear enough to show if the pulley was balanced.

The factory balancer/pulley is one piece and is thus a balanced assembly; but previously I’ve discovered unbalanced supercharger pulleys on my engines that were bolted to the front of the harmonic balancers ultimately contributing to the failure of the front main bearings. Similarly in the past I’ve installed crankshaft under drive accessory pulleys and ended up with an engine shake and a balancer hub oil leak.

I’ve heard that the red line of the supercharger is just less than 21,000 rpm. How much faster do your pulleys respectively spin the blower?


Thanks for your help
Henry