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Discussion Starter #1
Hi,

I was looking around youtube and noticed people getting good results with water/meth injection in various SC cars.

Some looked like they were getting 10+ degrees reduction in inlet air temp when using 100% methanol.

I started looking at the various kits available and some look really good (pricey, but good).

As the SC runs hot in the R170, a bit of water/meth injection might do it some good.I have the ASP pulley, which runs the SC even hotter then the standard pulley.

Has anyone tried this before? What results did you get? What kit did you try?

Cheers
Luc
 

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looked at them too but...

1) spraying before the s/c into its intake will strip the teflon coating off the rotors and cause them to flake and crap going into the intake. go online and see some pics not pretty

2) our cars use a MAF sensor so spraying at any point BEFORE the MAF sensor will shorten its life significantly and possibly destroy it.

only place to spray is right after the MAF sensor next to the throttle body
 

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you may initial see slightly higher boost reading initialy as the water will help seal the gap b/w the rotors.. but after a while using it the teflon will be stripped off and the gap b/w the rotors will be INCREASED so you will loose boost

edit: spraying is fine for aftermarket s/c's and they have a tougher and harder coating. the teflon coating used in OEM applications wasnt designed for that use and will come off
 

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Luc, you might want to edit your profile to show what model car and location you are in.

Reason, there are some replies that may/may not be appropriate for your particular car. ie: the SLK32 doesn't have a MAF.

As far as the rotor coating: I took my supercharger out to clean the intercooler & intake manifolds and can tell you that the teflon coating comes off without water/methanol also, as mine was stripped clean and there was gold color residue in the intercooler. I don't run a methanol kit...
 

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... only place to spray is right after the MAF sensor next to the throttle body
That's where i would want to spray... tap the intake tube and spray into the TB. Since the car isn't going to get a tune with the water/meth, you won't see a huge gain until outside temps get into the 90's and up.
 

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wow.... do you know what rpms your unit spins at with your pulley combo? excessive heat in the unit may cause the coating to come off?
 

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Discussion Starter #7
Hi,

I have a 2003 slk230 rhd model. I do not know if the rotors in my supercharger have a teflon costing. I believe they put in the smaller m45 in my car which is on full time. If the costing comes off easily, I would suspect there would be a filter or something to prevent it from getting into the engine and causing damage?

Can you post some links of people that have had these problems with meth/water injection. I did a search on youtube and google and could not find any, where the coating came off due to the water/meth injection. I did find some links and videos of before and after shots where the meth/water injection cleans the parts that it comes into contact with.

I would also advance the timing with water/meth injection as there is more power to be had by doing that.

Cheers
Luc
 

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alan the rotors were stripped clean? this is why i havent tried the howerton kit as i was afraid of the long term effects but if the coating comes off anyway whats there to lose except high heat temps!

subby heres some info i found on the xfire forum. same engine as buggin and mine and we both run the same c3 pulley
"The MAX RPM our SC can spin is 20K but that will distroy it quickly.
MAX safe SC RPM is 15.5K to have any chance of a long life.

Let's calculate SC RPM.

Crank / SC = (Ratio) * Engine RPM = SC RPM

155 / 74 = (2.10) * 5.8K = 12,180 SC RPM (Factory)

178 / 74 = (2.41) * 6K = 14,460 SC RPM

181 / 74 = (2.45) * 6K = 14,700 SC RPM

185 / 74 = (2.50) * 6K = 15,000 SC RPM

Code 3 pulley = 65mm (so I've read)

155 / 65 = (2.38) * 6K = 14,280 SC RPM

178 / 65 = (2.74) * 6K = 16,440 SC RPM

red would be what we are running so about 2100 over oem max rpm's
 

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from what i've seen its not even a teflon coating its a high temp epoxy coating on the rotors - i cant speak for the charger on the SLK32 though.

if its spun at factory specs it should be fine but the reasons for it to fail are;

Small fragments of dirt and debris may have found their way past the filtration process and cause pitting and delamination of the rotor coating. Other causes of delamination include water injection, excessive rpm, heat cycling and general wear and tear.

more likely reason is high RPM and the heat as a result of that. for a roots blower like on the SLK230 they generate heaps of heat when spun harder, but the SLK32 is a different type of blower it actually does the compression of air inside the s/c itself.

lots of heat = causes stuff to expand = rotors touch = start to scrape and material flakes off... the tolerances are so tight!

the M45 from the newer SLK230 is already spun quite high rpm (still within recommened safe specs) from factory and there isnt much room to move. its close to its limit already

i spin my eaton M62 at 14,500rpm but it is ported... safe factory redline is 14,000rpm. ive done this for few mths now and no dramas
 

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oh just checked one of the rotors in the SLK32 is indeed teflon coated...

i think they spin close to 20,000rpm stock? 3.3 times crank speed (max rpm 6,200) = 20,460rpm stock form.

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mind you in stock form its not spinning 13,000rpm. its not 1:1 like a roots blower. there is internal gearing inside the SLK32's supercharger... its close to 20,000rpm internally.

pic is from a E55 AMG supercharger - same type as SLK32 but just larger capacity. note the internal gearing... roots blowers dont have this
 

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also have a look here 2300 AX Supercharger | Lysholm it may not be the same model as the SLK32 but if you look at their range the max safe continous RPM is around 13,000rpm (taking into account external gearing) in which the stock form is OK. so by putting on any pulley its going to go way over its manafactures safe range.
 

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... I would also advance the timing with water/meth injection as there is more power to be had by doing that.

Cheers
Luc
You should only tune for water/meth if you have a mechanism to determine water/meth level and pull timing when it runs out. If not, you'll suffer serious knock. Basic kits may not have this feature...
 

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also have a look here 2300 AX Supercharger | Lysholm it may not be the same model as the SLK32 but if you look at their range the max safe continous RPM is around 13,000rpm (taking into account external gearing) in which the stock form is OK. so by putting on any pulley its going to go way over its manafactures safe range.
Twin screws are the way to go... much more efficient than the roots SC that come with our cars. looking at the dimensions of both SC units, an adapter can probably be made to fit a TS in our cars (if the correct length snout can be ordered). That would be a huge improvement in performance.
 

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thing is it would be a lot of work... the snout would have to be custom made plus our inlet manifold was designed in such a way to help low end torque.

roots blowers push air into the inlet manifold where it sits there to build boost (very inefficient). roots blowers are pretty much air pumps. the twin screw blower produces boost right at its outlet.

the power gain vs the massive costs wouldnt stack up though.. youd be suprised how quick a SLK230 can go with work done. ive got a track day this week and will take some in car footage and you can watch how fast the speedo flys...
 

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Discussion Starter #16
Yep, I agree. I would only buy a kit that has a low level indicator light, to remind me to refill when needed. Would carry a gallon of water/meth in a spare bottle, in case needed.

I am starting to think that the coating on the rotors is just a temp coating, there to protect the rotors when new and designed to come off after a certain number of kms. It is definitely not a Teflon
coating.

So far I can not find any evidence that water/meth injection is harmful to an engine. Most people that use water/meth injection do it on either a supercharged engine or turbo charged engine, because it gives noticeable increases in performance.
 

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I have an Aquamist 1S system that i've used on different cars. It's a very basic system that i turn on based on boost. I typically ran it off my windshield washer reservoir, some cars (like bmw and i think mbz) have an indicator for when the washer fluid gets low. "Winter" washer fluids can contain up to 40% methanol. Just make sure to read the label. Cheap way to keep IAT down on force induced cars.
 

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the eaton units use a epoxy coating on the rotors as i found out.. the SLK32s high end s/c use teflon.

still your call to do it... its been done to some degree before with limited sucess on a c230 spraying into the s/c. you will just end up getting the element in the MAF wet and that will play havoc with drivablity

Mercedes C230 Kompressor - Page 7 - Drifting forum - Driftworks

Worked way way better than the first try, was seeing more boost as I guess the water was closing up the tollerances in the charger, infact you could watch the gauge rise with a fairly steady rpm as it happened. Also was stronger overall so mustve had a decent cooling effect too.
BUT it was no good, either the ECU wasnt liking the extra airflow/boost, or the blowthru MAF was getting wet, but now and again it hit what felt like a boost cut.
Happened far less with less water, but the good effects were less too.
 

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I'm not a fan of running water/meth pre-MAF or pre-compressor. This just increases the opportunity for the water particles to bind to surfaces and eventually pool somewhere along the intake path.

Injecting post-MAF and directly into the intake manifold makes the most sense to me. This is how i've always deployed it...
 

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Discussion Starter #20
I agree sikdogg, I would not spray it into the supercharger as to many things can go wrong. I would find somewhere to tap into post-intercooler.

I am not sure if the slk230 has an intake air temperature (IAT) sensor?

Everything I have read suggest mounting just before it as the IAT sensor will advance timing if it senses a drop in temp :) which is what we want.
 
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