The other issue not addressed yet is the parasitic loss in power due to driving the S/C... The faster you try and spin it I would think this climbs exponentially. So you need to make substantially more power from an incrementally larger pulley ... I heard somewhere that the SLR's S/C at peak engine power needs ~100hp to drive it....

Still v interested in the SLR setup if anyone has the info...

No need to reinvent the wheel right?

 

Most excellent point.

 

i lost about 1.0-1.2psi when i went to headers and 3" exhaust...

i have a 175MM Evosport..

 

Someone else posted this info...I can't remember who.

stock==========154mm=10psi(number depends on gear and rpm)
Rentech/kleeman=168mm=12.8psi=+42rwhp
Various========172mm=13.6psi=+54rwhp
VRP===========175mm=14.2psi=+63rwhp
Various========178mm=14.8psi=+72rwhp
Evosport=======180mm=15.2psi=+78rwhp

 

here is my before and after dyno on a stock car and then 180,H/E and tune

 

Does any one make a 170mm pulley ?

 

One other thing is power delivery ... bigger pullies will feel
more powerfull low down as this is still in the S/C efficiency range and parasitic losses are relatively small... Car feels more powerfull, and it is at this rpm but perhaps the trade offs at higher rpms combine and make things too counterproductive....

We got
bigger rotational masses
higher iat's
higher parasitic losses
less S/C efficiency (do we know the efficiency boundaries?)
and given generally poor intercooler performance, this will now be even worse.

On the good side we got more boost.

 

here, most of the guys since couple of months are installing 210mm pulleys on a stock car.

their tuning is 210mm pulley + smaller waterpump pulley + the tensior one + software tuning. they are gaining 100hp on the engine.

so if how HooleyBoy calculates the S/C speed. it will be 210/76 * 6500 = 17960.

so whats the maximum speed of the s/c ? u will think its 18000 ?


naah, wrong again.

why ?

because one guys installed a 240mm pulley on his car. and it is damn fast.

again the calculation is 240/76 * 6500 = 20526.


and again you think its the biggest.

nop

coz another guy installed 280mm pulley.

and again we calculate it.

280/76 * 6500 = 23947.

so whats the mximum speed of the S/C.

i dont know.

because the last guys drove his car and it was very fast. the engine reaches couple of times the redline ( tuf tuf tuf ) between changing gears.

but it was too lean. he needed bigger injectors, @ least 1200cc.

E/CLS/SL/S 55 are 750cc. SLR is 1000cc.

so the S/C can handle the big pulley.

im will install the 210mm pulley by next week.

with my other mods, i think it can give me about 100hp more which will be cool. ^_^

 

a 280mm? What size is his water pulley? I may need to call bs here. The 180 already adds a load of lag. A 280 would be a dino.

 

It was 280mm and the waterpump pulley was very small. About 35mm.

The car was sooo lean. It was f**ked up after 30 minutes of hard driving.

It was 280mm believe it.

 

lean and heat don't go well together. Hope he didn't detonate

 

Who's making these pulley's?

 

probably custom.. like ASP. Just welding a bigger ring on stock piece. I doubt the pulley is a single piece.

 

280mm thats almost 1' ... can you imagine pressure on the crank bolt.

Man that poor motor.....

Also just because people fit them (dont ask me how they squeeze it in there) and the car makes power for a short while does not mean it "works"... surely for it to "work" (i.e. be viable) it needs to be reliable too...???

 

280 that must be very high boost can the stock intercooler even flow that sort of boost. it will have a hard time and cooling the air will be a *****.
I think the e55's biggest down fall is the size of its intercooler

 

soo true. but the welding is hot plastic\rubber and freezed fast while sqeezing the outer ring on it.

diffecult process but good one.

 

i say for the sake of safe side.

i woill install bigger than 210mm.

thats the biggest i will go for. and i will post the dyno results before (with my current setup) and after.

 

sorry - gotta call BS on the 280mm pulley. that is 11 inches in diameter.

i don't think there is a way of even getting that to fit. pulley pictured is the stock 156 or 158 whatever it is....

 

Why doesn't anyone use methanol injection to cool the inlet charge and add octane? It seems like it would do the trick. If we did that, it seems like we could run larger crank pulleys to increase boost up to the limits of the supercharger itself (barring dimensional constraints).

I am from the Corvette world and for high boost applications (SC or TT) we use a methanol pump that is activated off of a Hobbs pressure switch (manifold pressure) to spray methanol into the intake. On my Corvette at 18 PSI it cools the inlet air charge from ~180 F to ~85F and that is after the compressed air has run through a massive air-to-air intercooler. The amount of methanol delivered is adjustable using a small control box (basically a rheostat) and you can use either a 1 nozzle or two nozzle set up. We spray upstream of the temperature sensor so the computer gets an accurate reading of the true intake air temperature. Some people use their windshield washer fluid reservior for the methanol and some use a custom made tank. Either works well, it is just a matter of whether you want to maintain the ability to clean your windshield with the washer fluid. In the MB World, I think most would opt for the extra tank. The dual nozzle kits that we typically buy from AlkyControl are in the $650 range and I imagine a custom tank would be in the $300 - $500 range just to give an idea of price point. As a fail safe, we set our tunes such that when if the methanol is not delivered for any reason, the computer sees the high intake air temperature and pulls ignition timing and adds fuel. Just driving around normally, you will use very little methanol depending on your activation and delivery settings. The methanol would only really be consumed when you really put your foot in it, so worrying about filling the tank up all the time is not really an issue. On my Vette I only have to refill the methanol reservoir every two to three tanks of fuel. You can just keep a five gallon container of methanol in your garage. You can buy methanol at just about any speed shop and it generally costs about $5 - $6 per gallon.

Comments?

 

I was wondering the same thing! Methanol really cools things down and its never been mentioned here. I have seen gains of 40whp on a dyno with methanol.

 

vrus & vadim explored this with an Aquamist setup ... so far I have not found anyone to get it to work on the cars. I think the interaction with the ecu is the trickiest... man I cant tell you how I struggled just to get my car to work with a different diff ratio...

I think these 55k cars in 3-4 yrs time when people have had enuf of the electronics will just rip it all out, plug in a stand alone and go mad......

The motor base is there to do this .... but someone has to be first.

Maybe someone can chime in and tell me if you ripped out the ECU for a stand alone how much of the rest of the cars function would you lose? E.g. ABS, etc etc

 

great post, sorry to be off topic here but what wheels are those on your CLS?? they look hot..

 

Issue with water/meth becomes the nozzle palcement in our cars. It could be sprayed into the supercharger (keep in mind water does not compress well ) or it could be sprayed after which would be really tough to do since the IAT sensor is right after the intercooler and right before the Y pipe split to the surge tanks. You can do a dual setup into each one of the surge tanks but then the IAT sensor will not see the temp drops

 

HRE 891 R

Front: 20 x 9
Pirelli PZero Nero 255 30 20

Rear: 20 x 11
Pirelli PZero Nero 305 25 20

Brushed Aluminum Centers
Chrome Lips
Silver / Black HRE Center Caps

Some pictures are here: https://mbworld.org/forums/cls55-amg...ntech-5-a.html in my intro thread.

 

The methanol evaporates rather quickly and that evaporation is what generates a lot of the cooling effect. Liquid compressibility is not an issue in this case. Consider that you inject liquid (atomized) fuel into your engine's cylinders constantly and it undergoes tremendous compression without issue (considering proper metering and tune).