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the IAT sensor is integrated into the MAF. spraying before the MAF will destroy the MAF very quickly...

spraying after the MAF will not do much as the IAT sensor would not record the change in temp. only way to drop inlet temps is 1) port the s/c 2) get a new cooler. both wont do much if car is stock boost. if you are running more boost it will make a difference.
 

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Discussion Starter #24
Thanks subby for the info. This changes things a little!

I do have the asp pulley on my car, great mod, worth every penny I paid for it.

I assume the effects of water/meth injection would be minimal then, if the ecu can not sense the change in temperature? Also, would the ecu pull out any extra timing that a mechanic could dial in?

cheers
Luc
 

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how is the mechanic dialing in more timing? this cars ignition is all electronic, it would have to be programmed into it like doing a flash tune via the OBD port.

for normal driving intake temps are not an issue even if you do a spirited run and then back off its fine. its when you are constantly on wide open throttle things get HOT

i remember watching the OBD logger and logging the intake temp sensor in the MAF... it would spike from about low 20c degrees to 50c degrees when doing wide open throttle for sustained periods of 20sec + now normally you cant even do this on a road for that long.

after porting the s/c and putting a intercooler spray it just stays a little bit above ambient temp
 

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the IAT sensor is integrated into the MAF. spraying before the MAF will destroy the MAF very quickly...

spraying after the MAF will not do much as the IAT sensor would not record the change in temp. only way to drop inlet temps is 1) port the s/c 2) get a new cooler. both wont do much if car is stock boost. if you are running more boost it will make a difference.
This is awesome... The IAT is separate from the MAF, i thought it was not removable.

This means that if one wanted to spray water/meth post MAF, they could just buy an IAT sensor, mount it to the intake mani, and run a couple of wires from the MAF harness.
 

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before you do anything are you sure your ingition timing is actually being retarded significantly? are you running stock boost?

plug in a OBD2 scan tool and log the live data to see. if its not and you are running stock boost spraying will do nothing?

the reason people is spray is to be able to increase timing more aggressivly on aftermarket ecus. some ECUs are smart enough to back off the timing if the water injection system fails or runs low. what do you think will happen if you increase the timing and you happen to run out of water one day?...... potentialy detonate the motor

mounting a new IAT sensor would be hard... drilling a hole in the plastic manifold and sealing it correctly to stop it causing a boost leak... plus it would have to meet the spec of the existing one. also by moving it there it will actually read higher temp values. people in other cars try to remove the IAT from the manifold because it reads a lot higher ther...
 

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I agree with you regarding the need for water/met injection on a stock set-up. It's only really needed when increasing boost or on non-intercooled systems.

With regards to moving the IAT from the intake manifold, i disagree with people wanting to move it elsewhere. This is where it should be located because you want to know what the air temp is as it goes into the cylinder. measuring it too far away from the intake manifold will give you a lower reading, this will cause the ECU to advance timing, but if the actual intake air temp is higher your car can knock. But hey, the IAT said all was fine.
 

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before you do anything are you sure your ingition timing is actually being retarded significantly? are you running stock boost?

plug in a OBD2 scan tool and log the live data to see. if its not and you are running stock boost spraying will do nothing?

the reason people is spray is to be able to increase timing more aggressivly on aftermarket ecus. some ECUs are smart enough to back off the timing if the water injection system fails or runs low. what do you think will happen if you increase the timing and you happen to run out of water one day?...... potentialy detonate the motor

mounting a new IAT sensor would be hard... drilling a hole in the plastic manifold and sealing it correctly to stop it causing a boost leak... plus it would have to meet the spec of the existing one. also by moving it there it will actually read higher temp values. people in other cars try to remove the IAT from the manifold because it reads a lot higher ther...
Hi Subby. So Hi Would you recommend water methanol injection after MAF sensor and IAT sensor installed properly without leaks post methanol injectors?
 

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this is how it would look like if you did it.

note the factory IAT sensor has been taken out of the MAF and relocated after the spray.
 

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Hello!

I run a small meth setup on mine (pre facelift m111, running around 270-280hp)

all of this info is based off my personal findings:

-I use a small 85cc nozzle pre blower (yes it works and no it doesn't mess up the blower since it's only a small amount and the water doesn't puddle up in the intercooler)

-A 180cc nozzle in the elbow before the throttle body, each nozzle has it's own checkvalve to avoid dripping (the 180cc nozzle might be changed to a 80cc one later)


the nozzles I use do an amazing job at atomizing the water/meth mix, it almost instantly turns into vapour


about pre blower injection:
spraying a small amount of 50/50 methanol trough the maf is no problem as long as it has evaporated before reaching the maf, pre blower injection also does a good job at keeping the supercharger intake pipe cool!

I relocated the stock iat sensor into the intake manifold but that responds way to slow, it only picks up the colder airtemps during a long pull. (and the sensor failed very quickly) so I went back to the stock sensor location in the MAF

using meth injection is tricky on the car without extra added timing: spray to much and you lose power (10-20hp loss easy and you won't even feel it) this is because water/meth + gasoline burns slower then just regular gasoline

intake air temperature: I try to keep them at ambient, temps below ambient are possible tho!

Carefull engine power measurements need to be taken to get it setup correctly or you lose power.

I have my system set up so it adds a bunch of torque down low and keeps the air cooler in high rpm's under boost so no power is lost on very hot summer days,
this gives winter performance on hot summer days!

my setup uses an analog pump controller hooked up to a facelift m111 boost sensor


For water/meth reservoir I use the windshield washer tank (it's a perfect size for it)


I don't recommend water/meth injection on a single pulleyed car or installing it blind without measurements, nozzles also need to be picked very carefully and setting this up correctly without a special tune takes a lot of time and measuring

here you see a pre-blower nozzle located in the supercharger intake pipe, the pipe has insulation around it to shield it from exhaust heat (check valve out of view)



and a nozzle + check valve on the elbow just before the throttle body

 

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Hello!

I run a small meth setup on mine (pre facelift m111, running around 270-280hp)

all of this info is based off my personal findings:

-I use a small 85cc nozzle pre blower (yes it works and no it doesn't mess up the blower since it's only a small amount and the water doesn't puddle up in the intercooler)

-A 180cc nozzle in the elbow before the throttle body, each nozzle has it's own checkvalve to avoid dripping (the 180cc nozzle might be changed to a 80cc one later)


the nozzles I use do an amazing job at atomizing the water/meth mix, it almost instantly turns into vapour


about pre blower injection:
spraying a small amount of 50/50 methanol trough the maf is no problem as long as it has evaporated before reaching the maf, pre blower injection also does a good job at keeping the supercharger intake pipe cool!

I relocated the stock iat sensor into the intake manifold but that responds way to slow, it only picks up the colder airtemps during a long pull. (and the sensor failed very quickly) so I went back to the stock sensor location in the MAF

using meth injection is tricky on the car without extra added timing: spray to much and you lose power (10-20hp loss easy and you won't even feel it) this is because water/meth + gasoline burns slower then just regular gasoline

intake air temperature: I try to keep them at ambient, temps below ambient are possible tho!

Carefull engine power measurements need to be taken to get it setup correctly or you lose power.

I have my system set up so it adds a bunch of torque down low and keeps the air cooler in high rpm's under boost so no power is lost on very hot summer days,
this gives winter performance on hot summer days!

my setup uses an analog pump controller hooked up to a facelift m111 boost sensor


For water/meth reservoir I use the windshield washer tank (it's a perfect size for it)


I don't recommend water/meth injection on a single pulleyed car or installing it blind without measurements, nozzles also need to be picked very carefully and setting this up correctly without a special tune takes a lot of time and measuring

here you see a pre-blower nozzle located in the supercharger intake pipe, the pipe has insulation around it to shield it from exhaust heat (check valve out of view)



and a nozzle + check valve on the elbow just before the throttle body

Thanks for the info. I've got a W/M kit and haven't fitted it yet (I bought the kit nearly three years!). I'm wondering now should I bother fitting it? But I think I have found the correct standalone IAT sensor that could be mounted closer to the Throttle Body and after the nozzle.
 

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This IAT sensor info may be of interest to some on here. Found this searching the net and cross referencing the part number. Also available as an aftermarket part from many, eg: Febi 37142, Hella 6PT 009 109-291 etc.

The spec's of the sensor below (if correct) correspond with Subby's contribution in this thread, thanks again Subby :thumbsup: : https://www.benzworld.org/forums/r170-slk-class/2637041-going-fit-water-meth-injection-kit.html

Mercedes A 651 153 0028.
I.A.T. sensor

Here's the spec's:

Temp/Voltage:
20C/68F = 2.7v
40C/104F = 1.8v
60C/140F = 1.1v

Resistance:
68F = 5800-6300 Ω
86F = 3700-4110 Ω
104F = 2500-2700 Ω
122F = 1700-1850 Ω
140F = 1100-1350 Ω
158F = 800-920 Ω
176F = 550-700 Ω
 

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Thanks for this info John, I ordered 1 of those sensors and I'm planning to try to install 1 in the intake manifold! (and hopefully it lasts longer then the 1 I sourced from a chinese MAF)

since I can't find a decent tuner for my setup (well they all download their files pre-tuned from a database, I don't blame them)

I have been very busy in the last months into researching these Bosch ME2.1 ECU's and learned how to tune them (very happy and thankful that I've met the right people who were willing to share some knowledge)

I also managed to install and ecu tune 350cc injectors @3 bar (relative pressure) with almost perfect AFR's

My latest methanol (and most succesfull yet) setup consists of:
-180cc nozzle pre supercharger (still no problems with rotor coating coming off, no intercooler puddles and no maf problems)
-80cc nozzle just before the intake manifold
(I swapped the nozzles around since my last post)

After a lot of testing I have found that this nozzle combo @300PSI is just perfect for this engine and provides the finest possible mist and amount (any more will bog the engine)

The tuning:
I managed to add 2 degrees (around 3K rpm) and up to 6 degrees (5k rpm and up) of timing advance on top of the existing pulley tune, the fuel also has been altered to provide a steady 13AFR low rpm up to 3k and 12.5AFR all the way to redline on meth spray and the results are just fantastic!
(I think I have written 100 tunes on my ECU in the last 30 days )


Results:
peak numbers are not so impressive, the most impressive is that the engine gained more then 20nm on some spots and overall 10+nm across the entire rev range compared to regular 98 octane without adjusted fuel trims

3 results merged: (note: these results are taken after a full ECU reset each time so no adjusted fuel trims)

1 = Water/methanol with tune, 2 = regular 98 octane fuel, 3 = Methanol injection without special tune (same amount injected as the with the meth tune)

2603605


The feel:
The engine feels a lot smoother under WOT, the added torque is very noticable!

ignition system:
2 step colder spark plugs: Bosch FR5KI332S with a 0.7mm gap, stock coils

to be continued! still need to make a failsafe in case the meth tank runs out
 

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Just brilliant Ndrmini. 284 BHP! I'm guessing the driveabilty of car has really improved including great 'in-gear' acceleration?

Hell, I would be very happy with 'just' another 25 BHP. I had to work a bit to out pace a 2018 Golf GTD the other day on the motorway...

Keep up the good work. (y)
 

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excellent work!!!
 

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have you tweeked the map for the bypass valve to get it to ramp boost up earlier?
 

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Just brilliant Ndrmini. 284 BHP! I'm guessing the driveabilty of car has really improved including great 'in-gear' acceleration?

Hell, I would be very happy with 'just' another 25 BHP. I had to work a bit to out pace a 2018 Golf GTD the other day on the motorway...

Keep up the good work. (y)
Thanks John,

the car is a blast to drive! especially during WOT, donuts without clutchkicks are no problem! and it still drives/cruises very normal during partial throttle, the methanol only engages on boost and the window washer tank lasts surprisingly long
(it endures 2 full tanks of gas easy)

vw gtd's are no problem for it, same for these 2.3l ecoboost mustangs (those are very popular here)

I do notice the ecu having problems keeping up with the fast revs sometimes, it's not able to add the needed timing fast enough

for example:
2nd gear sometimes pulls only slightly stronger then 3rd
(or there is a X degrees/second limit) the facelift SIM4LE has less problems with fast revs

this might explain why the auto boxes are so good on this platform, the engine revs up and almost stays in the same rev range while the torque convertor does all transfer work while the ecu only has to take care of a limited amount of rpm variation

still looking into this

@Subby_ I havent played with the boost maps yet but those maps might be the answer for the above problem




Sent from my SM-G930F using Tapatalk
 

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i know stock the slk doesnt close the bypass valve early to be very smooth to drive and not "aggressive". once you alter that map by a small percentage factor (scale it evenly) it will really wake up the car.

mid range is very very strong... again it wont change peak power as the bypass does fully shut at WOT just low to mid. i cant take off from WOT off the line it will just spin the wheels and yes thats with good rubber. mid range acceleration from a roll is very very good fun! torque pushes you well and truly back in your seat!

you have to be very very careful in the wet with it being this aggressive as the car will step out :)
 

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Thanks @Subby_, the wet is indeed very dangerous, having an lsd makes it even more risky, way less forgiving then an open diff, especially in a corner

will give that map a go this weekend and report back, cheers!

Sent from my SM-G930F using Tapatalk
 
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