I have the N/A car as well, but was looking at the SRT-6 injectors as a more simple means of fuel modification. The guy working on this said they could be an option provided they're a common flow rate to allow the EMS to control it easier.

I know this is way off topic but HDDP do you have any custom suspension parts made up?

I just signed up for nasa and know in the future I will want this thing to handle as well as I hope to drive.

 

based on standard injector sizing the limited should be 19 lb injectors for 58 psi fuel pressure, NA consumption, 80% duty cycle max (what OEMs limit it to in order to prevent injector lock up) ... or slightly larger...

the srt-6 at also 58 psi fuel pressure (hoping their fuel pressure is the same), FI consumption, 80% duty cycle max should mean they use 36 lb injectors or slightly larger if they do not utilize a 1:1 fuel pressure regulator to compensate for boost pressure counter acting the fuel pressure...

either way, those sizes dictate standard high impedance injectors...

 

Welcome to NASA... Now I have to be nice to you, except on the track ...

 

Message Deleted

 

Yep that's what I thought.

 

DOES THIS MAKE SENSE TO ANYONE ?

As mentioned earlier in this thread, I decided to send my injectors off for flow testing and matching to the "INJECTOR GURU" in Indianapolis... When I pulled them I noted the product numbers, both the MB part # A1120780149 and the Bosch part # 0-280-156-014 and researched the specs from Stan Weiss... His extensive list noted zero information except for the fact that these injectors were spec'd out for the MB 2.6L engine... I immediately thought it was a typo and called Bosch directly who said that they could not give me the specs on this injector because the information was proprietary to MB... That made me really happy...

Needless to say, I did an impedance reading and came-up with 15 ohms on all the injectors, then sent them to Doug for testing... Well, Doug called me today and said he has not flow tested the injectors yet but wanted to let me know that the injectors I sent him are the injectors that are spec'd out for the C240 2.6L MB engine, not the 3.2L MB engine which are Bosch part number 0-280-156-072 and he was confused... I got confused as well...

Then he told me that the 3.2L injectors have a flow rate of about 37 lbs and the 2.6L injectors have a flow rate of about 26 lbs... Then we began a discussion about this while I pulled-up Stan Weiss' injector tables on my computer... Low and behold !!!

We have not yet determined exactly why there are smaller injectors in this car, but we speculated that the Crossfire was fitted with lower flow injectors to increase fuel economy numbers.

That being said, I would like to ask both HUGO in Australia and WOODY in England if they would pull their injectors to get the Bosch part number and compare them... Perhaps we can get to the bottom of this and may find a cheap way to increase HP by installing the higher flow injectors...

 

Give RC fuel injection a call, they do flow testing of injectors and might have that info available already. they are located in Torrance.

http://www.rceng.com/

 

Thanks, I know those guys... Good group of people... I like using Doug at http://www.lindertech.com I have had great experiences with him... And you can't beat his resume'... He already has my injectors and is going to flow test them on Monday. That's what sparked his call... He opened the box and said these are not the standard injectors from the 112 engine, they are lower flow...

The point behind my previous post was that DCX has installed lower flow injectors into the Crossfire than the normal MB 112 engine... This is probably to increase fuel mileage numbers... Which obviously hurts HP... There is an 11 lb difference between our injectors and the injectors that were spec'd for the 112 engine...

 

anychance the fuel pressure regulators are different between mercedes and chrysler.?

 

I have no idea... but the injectors are built to deliver appx. 11 lbs lower fuel volume than the original spec 3.2L MB engine.

 

Boy was I way off on my guess about the OEM fuel injector size... They are only 17 lb injectors on the NA version of the car... 14.5 ohm

 

HDDP,

I'll see if I can't get part numbers for you from my SRT6 this evening. I'll let you know here.

If they used smaller injectors, I wonder if that's why these cars were spec'ed lower than the SLK 320 and SLK 32 AMG. Especially if the fuel regulator is also at a lower pressure.

If both of these things are proven true, then we should be able to up our numbers with simple injector and regulator changes. (Providing that the PCM isn't monitoring the voltage to the regulator).

Thanks for your research Derek!

 

My thoughts exactly... Now that I have a source inside Bosch I can get the specs on all their parts providing I have the Bosch part numbers... It looks like the pressure regulator and pump are more than adequate 58 psi (per Woody) in the fuel rail... That's more than any car I've ever seen... That being said, If you can give me the part numbers of your fuel injector (both the bosch number which will be 0 280 156 ??? and on the other side will be the Mercedes part number that starts with "A" ... I can get the flow rates of your injectors as well... Also, measure the length of the plastic injector housing from end to end excluding the metal tubes... It seems they have different length injectors and mine are 48mm... yours should be the same length...

As far as robbing us of our HP... That quite could be the possibility... If your injectors prove to be higher flow than mine and they are the same size 48mm I will purchase a set of SRT injectors and install them in the car to see what happens... MY guess is the ECU will handle the extra fuel flow but will probably still do everything it can to maintain an AFR of 14.7:1 which is really what's killing our HP...

PS: the head honcho's at DC are either really clueless about this car or are the best liars in the world...

 

Hi HDDP,

I check in on the forum every once in a while - things seem the same, you, Woody and a couple others doing all the posting on race and performance.

I have been doing quite a bit of reading on fuel injection etc and invested a few GB pounds is some bits as I prepare to fuel inject a 1975 Toyota Landcruiser (straight 6 4.2l, max revs about 3,800 rpm!). Anyway one purchase was a wideband O2 sensor with display, heater control and voltage output. Seemed a useful purchase seeing as I will have to create all the fuel maps from scratch.

Back to Crossfires - do they run narrow or wide band O2 sensors, my thinking is if they run wide band it might be possible to fit an aftermarket unit like mine (www.vems.us) and then send the output into the ECU - after altering is slightly to create a AF closer to 13.5 or so. For that matter I think the VEMS unit might be able to simulate the narrowband output.

One complication with the 112 engine is whatever the sensor there will be two of them! (edit - not counting anything after the cats).

Anyway - all on the limit of my knowledge...back to my 135 bhp 4.2...I do have an Eaton 112 Supercharger from a Jag for it...wonder what the XF would make with that attached...

 

Unfortunately we have narrow band 02 sensors, but I'm in the process of purchasing a dual wideband system. Woody and I are doing some experimentation with a "voltage regulator" and should have some info on its functionality soon...

 

Like I said, same people doing "development".

Woody, if you want to borrow my wideband sensor let me know. I haven't installed it yet and when I do it will be in a off-road toy so it's not in use much.

Documentation is poor and I haven't hooked it up to a laptop yet but my understanding is the output can be set to simulate a narrow band sensor, perhaps even with an altered AF target, ie lambda 1 is 13.5:1 not 14.7:1.

Connection is very easy, screw the sensor in and connect a 12V supply. An adaptor to rig the WBO output to the stock sensor connection should be easy. Heater and pump control are built in.

 

Woody is actually the development genius... I just happen to have a car that is completely gutted that makes a perfect testing platform...

 

Strange how as big as the net is you always end up seeing the same information thats usually years old. I was looking for some specs on non Crossfire injectors and though I would also scroll down to see the empty Crossfire entry - ITS BEEN FILLED IN!!!

Done a quick calc on a spreadsheet I downloaded a while ago and it suggests the sizes are a bit marginal - anyway just plugged rough numbers in and I don't really know how the injector setup on the XF runs.

Malcolm

 

Hi malcb,

Sorry for not responding , I must have missed this post in the thread. Thanks for the offer of the WB kit we are doing some messing with the 02's at the moment so it may come in handy at some point - your not that far from me either. What's the toy?

 

Toy is a Toy - Toyota Land Cruiser old one 1975, straight 6 4.2L.

Been collecting bits and pieces on ebay / scrap yards to convert fuel injection, megasquirt, jag (bosch) injectors, BMW throttle valve, even an Eaton supercharger from a Jag (M112), but thats for later.

Not sure how useful the WBO might be. The output can be set to match a narrow band or wide band but I haven't cracked setting lambda to an alternative point that 14:1 - must be possible. For a short run I would check the output matches or is similar to the other bank so I had some trust in the sensor and see if it's possible to send the single output into the ecu as both lhs and rhs. Best option would be not drill the exhaust and weld on an M18 nut but that not easy.

Send me a PM and I will email a copy of the Megatune version used to configure and data log the WBO output.

Malcolm