vrus

Does anyone know what our factory fuel injectors are rated at (cc/min) ??

Thanks in advance.

Vetluver

Looked high and low and my guess is 480. I have found specs for Bosch injectors for V8/12 MB and the small V8s have 380 and the V12s have 480. Don't hold me to it though, that info seems to be hard to find without a shop manual.

vrus

Hey Rob,

Thanks for the info.. I will try to confirm with a second source.

I need to confirm this info so I can figure out the correct jetting for the Water/Meth injection system I am installing.

Marcus Frost

Victor,

I can't help you, but if you can't find what you are looking for take out an injector and send it to RC Engineering... they can flow test it and tell you it's rating.

-m

vrus

Reviving this topic because I still cant get a concrete answer and I dont feel like taking an injector out to get it professionally flow tested..

No one has access to this info??? Surely one of the tuners out there knows this???

Anyone? Bueller? Anyone?

E55AMG99

40 lbs per hour or good for about 650HP

vrus

So I can take this as fact and run with it??

Just want to be sure because I have to figure out the proper nozzle size to support a 15% water to fuel mixture for the methanol injection system. If I am off it will run too lean.

Thanks!

E55AMG99

The info came from Vadim at Evosport. Give them a call to verify.

Are you going with Snow Performance? They have some very extensive systems and parts available. I thnk Summit Racing has them. How much power do you think it will add by itself? 30, 40, 50HP? Why not use a greater ratio of meth, like 50%? Are you going to add more boost? How? Sorry for all the questions but I'm very excited to see how well this works! I can't understand why very few people are using it today. I had it on every turbo engine I built back in the 80's.

Good luck with the project!
Greg

houston

from this thread

vrus

I have been working with the owner of Aquamist (Richard) to build a custom kit for me that I will help to promote to the Mercedes community if it does what I think it will. It is an all-out kit with all the possible bells & whistles and safety mechanisms.

I will post pictures soon of all the components.. to get an idea check this thread: https://mbworld.org/forums/showthrea...ater+injection

Its been in the works for a LONG time but custom stuff takes time and we are almost at the end of our timeline and ready to complete the install.

I am going to be running a 51% meth to 49% water ratio to start. In order to get proper combustion I need a MAXIMUM of 15% WATER/METH combination to FUEL ratio. In other words, my meth/water jets flow 300cc/min.. I need to make sure that my 8 injectors will flow at least 250cc/min each. (8*250=2000... 2000 * 15% = 300).

I will be doing very thorough testing on the dyno.. I will be testing different Meth/Water ratios which will help either richen or lean the mixture.. I will also be testing pre-supercharger and post-supercharger. It will take some time to get the perfect setup but this will all be done on a dyno so I will have data to backup my claims.

My goal has been to hit the 700hp mark. I know it can be done and I wont stop until I get there (unless I sell my car)...

E55AMG99

Awesome! I can't wait to see the results. Thanks for keeping the rest of us informed!

BlownV8

How are you going to measure the air/fuel ratio when you are using methanol injection? I have always been told, when dynoing my car, that the dyno's air/fuel gauge will not properly read if you use methanol/water injection.

E55AMG99

That's a good question. Methanol produces more hydrogen in the exhaust which will fool the O2 sensor. Then again, most ECUs go to open loop mode under full throttle which takes the sensor out of play.

Evolution Marine

I built a Turbo Porsche back in the 80's and ran it on Propane and 100% Methanol Admixture and I had a variable Menthanol pump set up that I could change the amount of Methanol that was injected into the motor. The motor ran strong with out the Menthanol Admixture, but with the Menthanol Admixture the Motor ran noticeably stronger. The only word I could come up with to describe the Motor on 100% Methanol admixture was "Brilliant". It revved faster, pulled harder and seemed to want to do all this with ease. When on 100% Menthanol admixture you would litterally have the feeling of being thrown down the road when at WOT. You would make driving decisions based on this performance and would be constantly amazed at what this performance envelope would allow you to do.
vrus - You get this combination dialed in and you to will be amazed! - - Bob

vrus

hmm.. so, based on formula, cc/min = lbs/hr x 10.5 then:

40lbs/hr x 10.5 = 420cc/min..

To find the max HP you can achieve with injector size on Gasoline:

HP = ([INJECTOR SIZE (LB/HR) X DUTY CYCLE] / BSFC) X (# OF INJECTORS)

BSFC for gasoline turbo/supercharged cars is 0.55 - 0.60.

HP = 40 x 1 (100%) / 0.55 x 8
HP = 581

Based on my calculation 40lbs/hr injectors are only good for 581hp on a supercharged/turbocharged car.

Something isn't right here...

vrus

I was hoping to have a wideband O2 in order to do this testing.. I hope this is possible??

I dont want to run 100% methanol because it is unstable and very flammable. Keeping a maximum of 51% allows me to run a mixture which is diluted enough that it will be safe in case of a crash or puncture of meth/water tank.

Also, if you have a leak in the injection system and pure methanol should fall onto an open header or something else in the engine compartment which is hot, it will cause a fire which is undetectable because Methanol burns clean and you cant see the flame.. Too dangerous in my opinion regardless of how much extra power you will get.

E55AMG99

If you are right about that fuel consumption figure, look out pistons! I think Vadim is using .5 for BSFC. I remember that .55 was great when we started using EFI and turbos back in the early 80s. About .52 for NA EFI motors of the same era. Has technology improved so that engines are that much more precise and efficient? Maybe. I haven't been on the dyno in a few years.

vrus

Even then, we are talking 640hp at 100% duty cycle which is never used because injectors become alot less efficient when they are running over 85% duty cycle from what I have come to know.

You might be right about the fuel consumption number.. I am not positive.. I just know the formula and have always used .55 - .6 as the BSFC #.

E55AMG99

640, right. I think I was rounding! .55 is certainly a safe number to use. Regardless, if 700 is your goal, they will need to be swapped. Perfect time to get a set of blueprinted and flow matched 50# injectors.

BTW, the wideband O2 sensor will allow you to read a broader scale, right? Will the ECU be able to understand this condition and compensate? I recall some early GM units that would interpret extreme readings as out of bounds and go into open loop.

E55AMG99

Oh, yeah...I don't think the MB ECU is compatible with the wideband. I think they still use the old planar "switch" technolgy. Aren't the widebands constant? Will they work as a direct replacement? So many questions to be tested and answered.

Man, you sure are adventuresome. This sounds like a TON of work but 10X more fun! I am more than a little envious!

vrus

The wideband units I have been looking at are standalone boxes and sensors that you install into your exhaust system. From within the car they give you a reading on A/F.. I am not sure about whether or not water/meth injection will throw this off or not.. I guess I will have to double check that.

I do like to tinker and wrench when I can... It is going to be alot of work, but, that's what makes this hobby so much fun.. figuring out what works and what doesn't.

E55AMG99

I see. Well, pure methanol has an S/R of about 6.5:1 and gas is 14.7:1 but maximum power is achieved a point or so lower for each. The WBO2 sensor needs to read at least down to 9:1 (assuming max power of meth is 4:1 and gas 12:1 with a 15/85% mix) which gives about a 1.5 AFR headroom....Right, or am I still sleeping?

Too much math! Find a WBO2 data logger that you can program with the above information.