77mm Supercharger Pulley - MSL Dyno Test

[Cyclone1]

Hi All,



As some of you may be aware there is a new 77mm Supercharger pulley (twin bearing) available from MSL and manufactured via UPD. It offers the ability to match the power / torque figures of the tried and tested 180mm crank pulley and as such, potentially offers owners a new pulley to purchase over and above the existing 83/84mm clutched SC pulley and the various crank pulleys and fixed pulleys.



So, does it work.......



In order to test the pulley we decided to use the same car (mine) and ran it in 3 states of set up;



1) Stock (OEM supercharger pulley)
2) Euro-charged 83mm supercharger pulley (X pipe fitted in place of secondary cats and resonator removed)
3) As above with 77mm Supercharger pulley




See below a picture of the 3 different pulleys, with from left to right - the new 77mm pulley, the 83mm Euro-charged pulley and the standard OEM Supercharger pulley;







The power and torque figures at the wheels were as follows (flywheel in brackets);


1) Stock - 423.7bhp / 475lb/ft (500 / 561)
2) 83mm -480.5bhp / 532.66lb/ft (567 / 629)
3) 77mm -509.3bhp / 596.80lb/ft (601 / 704)







Whilst the actual numbers may not be that important, the incremental gains are absolutely clear to see. Acid / Sarim at MSL took care to ensure that the dyno runs were set up as close as possible for each run as the runs for each of the 3 stages of tune were done on different days, however what we did do was do a test on each day to ensure the numbers obtained previously were accurate and give or take 2-5bhp, they were.



The Map



With regard to the map supplied by John@BFT@MSL then at the moment with the limited driving I have done it is spot on, there may be more refinement to come but the way the car drives it feels great. The AFR trace was spot on but IAT's as expected were slightly higher than the previous pulley, this is not surprising given that the supercharger is being worked harder, yet the numbers delivered speak for themself. Going forward with this upgrade it is almost a necessity to look at additional cooling, with a starting point being to split the cooling, other options around Killer Chillers and Ice tanks would certainly generate lower IAT's and provide quicker cooling in spirited driving. I currently have no additional cooling apart from a recently fitted Johnson CM30 IC pump, the car still pulls like a train but I am sure if I tried to sustain repeated runs then it would affect peak power and torque delivery. In normal driving though I have no complaints...



The fitting of the pulley is identical to the EC pulley, the only difference being I opted for a Gates 8PK1255 belt (smaller) to accommodate the smaller pulley dimension.



So how does it drive?







The difference between each stage is very clear. The responsiveness is the most noticeable aspect and with the 77mm pulley the response is instant, the low down torque is fantastic with part throttle enough to send the car flying down the road. It is certainly a worthwhile upgrade that takes the car to the next level of performance. The map feels fine and if anything the car drives better than previous.



So what more can I say.......



A big thanks to Acid, Sarim & John and the team at MSL. Especially for asking me to be the guinea pig, of which I was more than happy to oblige. To date and apart from the one Guy in the US running this pulley I see no other updates yet on the US Forums, so hats of to Acid for moving quickly and getting this installed with a map to deliver the results.



Acid currently has these on offer so check his thread in this section of the Forum. If you are thinking of a supercharger pulley then my advice would be to consider this one. If you have an existing EC SC pulley and are tempted.......then do it



To be fair it's a great situation for a 55k owner to have. There is now the tried and tested EC Supercharger pulley, which as we know and can see from the graph makes great gains and requires few other mods and now this 77mm pulley.



I'll post future updates to let you know how the car performs and the robustness of the pulley etc. please feel free to post any questions on here as I am sure myself or Acid will answer them.



Cheers
Jules.

 

[AMGeed]

So that was your car I spotted on the MSL/Facebook post this morning

Nice work! and something to seriously consider.

How are you finding the exhaust note after Imrans work?

 

[jimiE55]

Great threat jules, & great results, you must be chuffed!

 

[BFT]

Glad you are pleased with the results. Enjoy!

 

[Mrhanky]

Very interesting indeed.

 

[Ginger55k]

The AFR trace was spot on but IAT's as expected were slightly higher than the previous pulley, this is not surprising given that the supercharger is being worked harder, yet the numbers delivered speak for themself. Going forward with this upgrade it is almost a necessity to look at additional cooling, with a starting point being to split the cooling, other options around Killer Chillers and Ice tanks would certainly generate lower IAT's and provide quicker cooling in spirited driving. I currently have no additional cooling apart from a recently fitted Johnson CM30 IC pump, the car still pulls like a train but I am sure if I tried to sustain repeated runs then it would affect peak power and torque delivery. In normal driving though I have no complaints...

Well done to Jules Acid Sarim and John.

Whilst testing olly's front mounted tank and monitoring IAT's for my cooling thread, for those that may not know the battle is the heat, moving to the EC pulley raised my temps on average 10 degrees and that's after the split / tank fit and EC HE and pump upgrade, stock would have been much hotter and would have affected recovery times as well with the dreaded heat soak and the loss of power after repeated runs.

The new pulley will generate more heat so its important as Jules states to think about serious cooling mods.

I do remember Acid testing mine on the dyno, 4 back to back aggressive runs 4 lines on the graph each near enough matching each other, only possible because of the extra cooling systems, although the last run just about made it before the ECU took over

 

[Andrew W]

As much as I love the subject of tuning cars
I really feel my e55 has more than enough
Grunt , I really have to make a conscious effort
to rein the thing in , but I'm sure 600hp is amazing , nice to have some options though

 

[Cyclone1]

How are you finding the exhaust note after Imrans work?

The exhaust note wasn't quite as loud as I expected but the sound is superb. Even more so with the latest pulley and remap.

Jules.

 

[Andrew W]

The stock figures look really healthy ,are these
Numbers common on a stock 55k engine ??

 

[Cyclone1]

The stock figures look really healthy ,are these
Numbers common on a stock 55k engine ??

Most make pretty much close to stock figures and some more. 500bhp as standard isn't unheard of.

Jules

 

[ricky s]

Great write up here Jules, always good to read the details of these type of fitments.
Did you fit a BWK..? just wondering if it was necessary. More so as my own BWK, has been a pain, currently on a third set of bearings, and have considered removing it.
Did I also read somewhere the bearing design on the pulley itself has been altered from the previous smaller SC pulley? or was I daydreaming!

 

[Cyclone1]

Hi Ricky, no I didn't fit the belt wrap kit. I checked the dimensions of the new pulley and simply calculated the correct belt size. It's a fairly tight fit so I would suspect slippage will be minimal.

The new supercharger pulley has a twin bearing assembly. Without doing the background digging I guess this is down to not being able to get the correct single sized bearing to fit. The twin bearing set up will not affect what the pulley is designed to do and from the graphs it doesn't. It'll be worth removing the pulley periodically to check condition as theoretically the twin bearing set up may not be as efficient as the single bearing set up, but as I don't know the loading forces / friction it's put under then it's hard to comment further. I think for this application there will be no noticeable difference in either performance (we know that already), or longevity down to the twin bearing design. This does not factor in the quality of the build of this pulley, of which we can only monitor in time, which is no different to the early generations of 83mm/84mm pulleys.

Jules

 

[Cyclone1]

Thinking out aloud Ricky, then third set of bearings means there is some misalignment or the belt used is too tight putting the bearings under undue pressure...could be wrong though as I don't have a BWK.

Jules

 

[ricky s]

Thinking out aloud Ricky, then third set of bearings means there is some misalignment or the belt used is too tight putting the bearings under undue pressure...could be wrong though as I don't have a BWK.

Jules

Appreciate your thinking here Jules, but I am not thinking belt alignment issue, had that checked twice, and still running the same original belt, would have thought the belt would have imploded by now, but it still looks in good condition. The Belt came with the kit from Shardul, (brought 2 spare belts at the original purchase as well, which are still in my office), so assuming its all correct for the fitment, am assuming all should be OK.
This said you have me thinking that perhaps to get the BWK off and fit a smaller belt, as you suggest, but I am running the original smaller SC pulley and the Kleemann crank pulley (168mm), thinking perhaps that crank pulley will stress the SC pulley connection to the belt a little more than your own set up, or have you upgraded your own crank pulley..? what do you think, of my theory, and in my position, what suggestions would you advise here. Appreciate your comments, weather its good or bad mate.

 

[BFT]

Aside here when I fitted by Weistec supercharger I was shredding belts for fun. Check all your auxiliary pulleys for any play at all. Minor play will do it. I had a aux pulley all over the place. Replaced and job done.

 

[ricky s]

Thx for your comments John, but I am not shredding belts mate, still running on my original belt, but what I currently am doing, as per my post with Jules, is getting through bearings on my BWK, on the third set now, which are currently sound, but think my SC pulley bearing is on the way, which the original one, I had replaced due to rivets on the clutch plate breaking up, so the replacement has been on the car for best part of 1.5years, but think it's whining a little now.
Thinking its a mods thing, but still cheeses me off to re attend to it, but that's cars and modding I suppose.
So interested to hear how Jules is doing with the smaller SC pulley, with no BWK, may encourage me to remove my BWK, and see how it goes.

 

[BFT]

Sorry I misread that mate. It's easter Monday and I've been on the pop for a while...

Understand completely. If it's an EC sc pulley though sure there are no issues there. Just speak to acid or Paul who will help. Both very helpful chaps.

 

[simon1966]

Appreciate your thinking here Jules, but I am not thinking belt alignment issue, had that checked twice, and still running the same original belt, would have thought the belt would have imploded by now, but it still looks in good condition. The Belt came with the kit from Shardul, (brought 2 spare belts at the original purchase as well, which are still in my office), so assuming its all correct for the fitment, am assuming all should be OK.
This said you have me thinking that perhaps to get the BWK off and fit a smaller belt, as you suggest, but I am running the original smaller SC pulley and the Kleemann crank pulley (168mm), thinking perhaps that crank pulley will stress the SC pulley connection to the belt a little more than your own set up, or have you upgraded your own crank pulley..? what do you think, of my theory, and in my position, what suggestions would you advise here. Appreciate your comments, weather its good or bad mate.

Ricky - did you ever run your current Kleemann 168mm crank and EC 84mm s/c pulley set-up without the BWK? It may be worth just removing the BWK and fitting a stock length belt and see how it runs as you may not experience slippage anyway. I'm currently running a shorter Gates belt, but as you know I don't have a larger crank pulley so the shorter belt is recommended. I would think your set-up would work with a stock length belt.

The BWK looks nice but maybe it is just adding too much load on the bearings

 

[simon1966]

Jules

Thanks for posting such informative information, it's exactly what we need on here

Keep us posted as my key concern is cooling. Like Tony (Ginger) has stated, we all know cooling is pretty much the main issue. I've always thought that any mods in addition to what I'm already running will require cooling upgrades which is what is putting me off! Not that I don't want to improve the cooling, but it's factoring in approx an additional £1K on top of any pulley costs whether that be crank or s/c. Recovery times are one thing, but I rarely do constant repeated runs, my main concern would actually be safety of the engine

 

[simon1966]

Acid & Sarim!!!

We need another MBClub meet at MSL!!
Get you're a*rses in gear and get one sorted out. There's been some interesting developments since our last meet and it would be good to get everyone together again