Howdy,

Had pulley installed on Saturday ...

Firstly there is very little work that needs to be done from the bottom of the car. The pulley and all the hard work is done from the top, but car needs to be raised to get at the mounting holdings for the front fan ... think this needs to come out even if you try and take pulley out from bottom.

The removal and install is pretty basic. The toughest part was getting the existing pulley off - yes after the bolt was removed. NOTE: Do not attempt this at all without having the specialised pulley holder tool. This is necesary to keep the pulley stable while undoing the considerably tight and large bolt.

Pics will follow shortly of alll the bits and some of it installed. The water pump pulley was a tight fit and only seated properly once the bolts were all tightened up. Its much smaller as the pics show. We did not try and squeeze on the stock belt but put the new belt from the kit on. When on quite easy with the tensioner providing plenty of tension.

In all took 1hr30min ... work done by an MB tech - at his house. No names but great guy and great job. The chap also did a SL55 - in 30mins !!! Did not need to do any underneath work to free the fan housing.

Tech also told me that these MB pulley's rubber inserts do perish and tear over time ... so on older cars I would check for these.

Anyhow enjoy the pics - they are pretty obvious I think....

 

Excuse my ignorance but which is the old and which the new?

 

Looks like the set on the left is the old, right is the new.

 

erm... the bigger crank pulley is the new one (on the right of comparison picture) ... the smaller water pulley is the new one.

The pictures are all with the new kit installed / part installed.

Also there is a difficulty on the install getting the accessory belt on since the bigger pulley wheel obscures the this tensioner bolt which is on lower right part of the crank pulley - so this is a 2 man job one depressing the tensioner from below the car and the other putting belt in place.

 

OK readouts as follows

......................Pre ASP.........Post ASP
Ambient temp.....~12C........~12C
MIN IAT...............21C..........21C
MAX IAT..............38C..........55C
MIN PSI...............2.3...........2.8
MAX PSI.............25.2..........28.2
Full throttle PSI...24.8..........27.8
Water temps.......~90C........~90C

IAT recovery is pretty good although have not held full throttle for more than 1 gear in a row ... i.e. wet roads so no full throttle in first possible ... even full 2nd gear run was difficult. But F/T in 2nd saw the above peaks in IAT's. The Pre ASP saw rises in IAT's but much more slowly ... post ATP saw them rise much more quickly. I have never had a heat soak issue with this car with stock setup and have had no shut down as yet and with ~12C ambients even with ATP I should be no where close. With ambients >30C things could get interesting ito heatsoak.

I would really like to know how the IAT's peak in a drag from 0-150mph ... I would like to see if they plateau, or if they simply keep rising.

Fuel was V-Power Shell 98 RON. 102 RON BP was available but at ~$5/ litre it was a no go.

The butt-dyno ?
Car sounds different. It sounds like more air is flowing and more going on - but it is really subtle. Wife says she hears no difference !!!

Response is more immediate and car feels like its producing good power. The power seems also to extend deeper into rev range rather than tapering off at around 5k in stock form. Since road was wet it really is difficult to gauge the real difference. But its changed the character of the car - feels lighter on its feet now.

Avg MPG of the day was 14.4 ...

My friends SL55 said his car feels like a different car ... but could not really say how...

BTW these were straight pulley swaps and no ECU re-mapping.

 

Thats the problem with larger crank swap, after about 10 seconds or so of wot the iats rise fast which means hp goes down, evo cooling upgrade?? yes. but lets face it were running 12 sec 1/4s and st races last about 10-15 seconds so all in all a safe bet for full performance in these circumstances.

 

Looks great... Glad to see they are now sending the right belt with the kit.

Last month I went though hell because the belt the were sending was to small for some cars. One member on here told them they need to change to the Dayco belt but they never did.

When I call them and told them I could not get the belt on and asked why didn't they switch to the new belt that the member told them about? He said he never got the belt #, So I gracefully gave it to him and its nice to see they listened.

 

thanks for the write up and pics.... the ASP pulley is without question larger than the renntech pulley I have.....

 

sorry for my ignoarnace too, but what exactly does the pulley help in. and also does it help a lot?

 

Larger S/C crank pulley spins the S/C faster providing more boost to the motor. I reckon around ~3 psi or ~0.2 bar , but I need to check the Scangauge again as the slow refresh is a bit of a pain. Regular boost assuming atmos of 14.4 psi (1 bar) is 24.8 psi (1.71 bar). So S/C provides 0.71 bar boost in stock form - with bigger crank pulley this goes up to around 0.92 bar.

There are a few negatives to this process though. The S/C uses more engine power to drive it at this faster speed so this reduces the overall gain (this is where turbo's are by far a more efficient setup). In this circular relationship temps increase quickly ... more so than on turbo's as there are more parasitic losses with a S/C. Lastly the intercooler setup is pretty marginal in stock form and with more boost its being stretched pretty hard, so IAT's rise faster and erode more power ... so at the end of the day the bigger pulley provides PLENTY of instantaneous short bursts of power but dont think it provides allot of additional power over a long blast. On a track race I think I would prefer to have a stock car at this stage but I would like to test this pulley on a blast 0-150mph and see what IAT's do at different ambient temps. My guess is it will all get pretty marginal as we approach 30C. It would be good to see them plateau at some point - but this needs testing.

On an aside the heat exchanger at the bottom of the car is smaller than I thought and I think a fatter unit mbe up to 1" could be fitted. The airflow from this could also be directed under the car rather than fanning into the engine bay. How about fitting a second OEM unit behind or below the OEM unit with its own pump ?

The best solution would be to improve engine efficiency by improving breathing.... i.e. increasing inlet and exhaust airflow speed -> exhaust side is pretty restricted so better headers are a good next mod.

Overall its better to have boost actually drop off with headers as this helps IAT's and reduces the parasitic losses on the engine from the compressor (it has to work less hard now to spin as fast) and creates less heat since pressure is manifold is now less (or is it ?). The engine is still flowing the same amount of air as before but just doing it more efficiently (i.e. at lower temps and with less energy lost).

BTW: are there any dataloggers out there that chart A/ fuel ratios ? Or can this only be analysed with a probe in the exhaust ().

 

Drove the beast last night - dry roads - at least most of them were ... ambients around 13C and had some fun ... but had a bit of a weird result and my friend in his SL55 felt the same thing after his pulley install...

If you cruising at any speed (but not on boost) and you give the car some gas - lets say 1/4 to 1/3 throttle is accelerates immediately but about a second later it kicks in harder ... what could be causing this ?

ECU pulling timing / adjusting ?
Belt slipping / clutch slipping ?
Lag?

I am able to repeat the effect over and over again... the thing is if I am at half throttle and floor it there is immediate power and this effect is gone ...

Some more thoughts on performance ... well car pulls much harder for sure. When this thing grips it flies... The power is also definitely much deeper into the rev range.

The sound is also more "burbly" when you on the power you can actually hear the air being pushed around. Seems stupid - but thats what it sounds like ...

EDIT: Anyone manage to fit the stock belt with an ASP pulley ?

 

Could it be just the S/C clutch engaging at start of gassing it, and then it remains engaged because you already have positive manifold pressure?

You may be noticing it more now that your running higher boost. I notice it now when just crusing around and then partially hitting the gas, engine sounds like it's reving up, then the surge kicks in. (in S-Mode), Less noticable in C-Mode because the car revs up and downshifts and then engages. By that time, the S/C is already spooled up. Just a guess though.

 

You could be right - if it was belt then perhaps there would be some inconsistency in the manner in which it was delayed ... the delay is very predictable and can be repeated easiliy.

Your take on this makes sense - I just did not notice it before in stock trim.

 

Can you hear the squeak of the supercharger engaging? I'm pretty sure that this is what is happening. I haven't installed my pulley yet but I know excatly what you mean. I can replicate this same scenario on my car now - once you find the yolk of the throttle right where the S/C engages you can actually time your throttle input so you can feel a significant kick when it does. As BlackCard said, now that you're running more boost it might just be more noticeable.

 

With higher kompressor speed that is to be expected. The problem with ASP pulley is that it pushes it beyong acceptable range for most owners. In exchange for an extra pound of boost, every day driveability suffers.

 

I called the local crowd here in the UK - DMS automotive - about a ECU remap and they said my ASP pulley was a "gilrs" pulley ... theirs apparently is 2.5" bigger than stock in diameter !!!!! I reckon the ASP is about 1" bigger mbe 1.25" max.

Its amazing how much abuse these motrs can take...

How much power will I gain with a decent remap post ASP ??

BTW : I dont hear any squeal from the S/C engaging ....

 

Steve - you're describing my experience to a tee. I installed the ASP but also had an ECU upgrade. The exact same description of response that you have is how I described it to a friend. And I have noticed that C mode transmission is much smoother and somehow feels more progressive with ASP.
There is more power - especially part throttle - and there's sometimes a kind of a "gap" not exactly a hesitation but a non-linear power delivery. I wonder if the ECU is learning here....last night and recently it has been wet and poor conditions for WOT runs at speed. So I have been carful...but this ASP thing is more complex than it appears.

....the jury is still deliberating

On "Driveability" - I am not in anyway dissappointed with the way it drives...its not a bad thing just different. The E55 is different to begin with so this is just more learning and a new experience to understand. In fact its quite fun to relearn the car's responses.

 

How much did you feel the ECU remap helped ??? IF any ?

On MPG was the car better on MPG after or before remap ? (gives rough indication of richness rather than economy).

I get around 14.4 avg now with spirited driving with traffic - on freeway cruising goes up to 17.5 ish... so car is around 3-4mpg worse since ASP.

 

Hard to tell I did it first - on its own it improved the throttle response and a little power (too little :-)
I need a dyno !!!

Does anyone know of a good one here in Northern Mass ???


I have been watching this for the same reason (and looking at the tail pipes ) - I have always had great variations in MPG - around town the system takes too long to average the results - but broadly speaking I see 14+ on short runs - 20+ on highway...so I think its not that rich - perhaps a little.

..which is expected right as boost is up - see my question about gallons below, as these numbers look low to me if the imperial gallon is used.

HELP - I NEED a dyno to check all this !!

-----------Here's a question for the experts on the forum------------

Since the English gallon is larger (25% more) than the USA gallon - should the UK folks see 25% larger MPG figures (presuming that the "gallon" used in their instrument panel display is an imperial gallon)

 

I don't get it, shouldn't the pulley lean it out already from all the extra air? I know the cars run rich out of the box but why are you having richness issues after the pulley?

 

Yes, Imperial Gallon is 4.54L, US gallon is 3.785L so 4.54/3.785 = 1.20 or it is 20% larger.

Just multiply your results by 0.8 to convert to US measures.

Yes, ECU remap is essential, this is why no-tuner - please ASP is not a tuner - sells pulleys by themselves. Stock MB DME can adopt, but not by much.

 

http://en.wikipedia.org/wiki/Gallon

 

Think I will be going with a Wetterauer ecu mapping ... mostly because they sell a full motor/tranny/drivetrain warranty with their mods for up to 3 yrs / 100,000km for ~$500, but also because they are one of the most repsected in Germany as well as being TUEV certified.

Their Sportversion II gets power up to 600hp and 700ftlb...

 

When cruising, the car is in closed-loop mode, which means the A/F ratio is being controlled by the O2 sensors, so there should not be a change in richness due to the pulley. The larger pulley will only affect WOT A/F ratios, where mapping to a fuel table(s) occurs. Changes in mileage post-pulley-change will be primarily due to the right foot.

 

Does Wetterauer work on US ecu's?