k-jet fuel distributor mounted upright. - PeachParts Mercedes-Benz Forum

rwd4evr · #1 01-07-2018, 08:12 AM

I planning on some serious intake modifications for my 450slc drift car. does any one see any reason standing up the whole fuel distributor and air meter assembly up on its end with the air meter part on top and the distributor part below would be a problem(besides plumbing)? The intake portion where the air filter would be facing forward and the output to the throttle body rearward. now that the air meter arm is no longer horizontal would the calibration be affected by it not having gravity acting on it? Would the acceleration forces contribute enough to affect the calibration? something like the pic i've photoshopped. I know it won't fit under the hood at this point.

Larry Delor · #2 01-07-2018, 03:58 PM

Gravity pulls the plate down, which forces the pin up inside of the distributor. I don't think that this will work, at idle, or wherever the plate happens to be - especially when you're stopping, or accelerating.

rwd4evr · #3 01-07-2018, 04:14 PM

Fuel pressure holds it up and air pressure differential above and below the plate, causing air flow, pulls it down. On many k-jet cars the plate actually is pulled up to flow now that i think about it.

duxthe1 · #4 01-07-2018, 08:12 PM

I'd say go for it. I doubt that there is any significant effect from gravity and if positioned properly any deflection from acceleration may add slight enrichment. I wouldn't expect much though, I'd be very surprised if it would require tuning around it. As far as plumbing I remember some older Audis (and maybe VWs) had flexible lines to the injectors held to the FD with banjo bolts. A trip to the JYD could yield some very useful parts.

rwd4evr · #5 01-07-2018, 08:41 PM

yeah i was thinking full throttle enrichment wouldnt be a bad thing. the porsche 930 turbo WUR that ill be using can probably take care of all that though, if you can see where this is going

97 SL320 · #6 01-09-2018, 08:26 PM

SAAB 900 and VW Rabbit / Golf had air up configuration, the dist was on top of the air filter. This made sense since the dist was off engine.

Accel and decel are going to affect fuel mixture even for a short period of time. What are you wanting to gain by turning the fuel dist?

For a warm up regulator I'd probably use an adjustable fuel pressure regulator with a remote cable, this way you have easy adjustability. Given the car is limited use, cold starts could be accomplished by turning the knob X turns.

rwd4evr · #7 01-10-2018, 02:38 AM

well.....I'm building a turbo setup for it using the system the porsche 930 uses. i was evasive because i wanted opinions on the air meter idea before everyone says "k-jet turbo wont work right!" the WUR which is really a "control pressure" regulator on the porsche is boost referenced and enriches on boost differently than the audi and volvo turbo which only enrich in lack of vacuum.

I want to turn it so i can have the pipe from the bottom of the air meter(now pointing back toward the windshield) turn 90 and angle down to the turbo inlet where the battery would be on some cars, passenger in front of the firewall next to the engine. then it will clear the valve cover. if the meter assembly stays level and i just elevate it i'll have to turn the pipe to horizontal with a 90, then either come up and over the valve cover and back to horizontal to the turbo inlet. Or turn 90 to horizontal then straight back through the firewall where the blower wont be anymore, turn 90 toward passenger side go a foot or so then turn 90 forward back through the firewall to the turbo inlet.You have to remember that the turbo has to pull through the air meter not pressurize it, and the tube on the bottom is almost 4".

After more research i found there is a counter weight in the air meter so it probably will mess with the calibration if its upright. crazy as it sounds the U turn through the firewall/blower area may be the best option.

Raffaelli · #8 01-10-2018, 09:39 PM

Never heard of megasquirt? You could have a million times better setup for less than $1000 bucks.

duxthe1 · #9 01-10-2018, 09:57 PM

The counter weight is a blessing, not a hindrance. It equalizes the mass on either side of the pivot allowing only airflow to deflect it. The issue you will have is the maximum amount of fuel you can deliver through the fuel distributor. Before I went EFI with my turbo wagon I could only push enough fuel through the distributor for ~6PSI, I lowered my redline and could push 9 PSI. With EFI I go to 18 PSI no problem and could push more but the fuel here is crap. If you're starting with a proverbial blank slate I'd have to recommend EFI out the gate. You would not regret it.

rwd4evr · #10 01-11-2018, 09:24 AM

Yeah I would/will probably go efi but I got the turbo wur for 200 bucks new in a sealed bag, figure I'll give it a shot. The rest of the setup will be waiting for megasquirt (and forged Pistons)at that point. The v8 fuel distributor was used on the Porsche with two circuts plugged up to 400hp plus is stock on the 6.9 and has been used on m119.960 conversions. I'm not looking to push to hard, 400 max I think should be ok I hope. Not sure stock pistons are good for more than that anyway. How did you boost enrich on your setup?

So I never thought about the fact that every time you compress the suspension in a dip or jump the car or something it's pushing the same as acceleration would if it was upright. So you think it would be ok with the acceleration forces? It's not going to be leaning it out. Is there a spring in there too that keeps the plate up with no pressure? I have a bad fuel distributor/air meter on the long block I'm going to prepare for the turbo with looser ring gaps. I'll have to disassemble it for inspection.

97 SL320 · #11 01-11-2018, 09:14 PM

I'd think you would need to have a solid suspension and a really bumpy road to equal accel and decel forces ( especially decel as they will be greater than accel. )

rwd4evr · #12 01-12-2018, 02:58 PM

Not bumps. I mean like a dip in the road that compresses suspension, like bottom of a downhill that's going right back up on a twisty road or a rapid up hill.

97 SL320 · #13 01-12-2018, 06:17 PM

I just thought about something that "duxthe1" said in relation to the counter weight.

This weight would counter any G forces since G forces would be acting equally on _both_ sides of the pivot and cancel each other out. This should take care of the dip in road issue in a normal install.

A test would be to turn the air flow meter with dist upside down and see that happens to the air flow meter disc.

rwd4evr · #14 01-12-2018, 06:57 PM

Right. That's what I was thinking. I want to build a flow test setup anyway, I gues I could build it on a swivel so I can kinda whip it around. It would be easier to test there than redo the intake once on the car.

duxthe1 · #15 01-12-2018, 08:54 PM

There is a very weak spring pulling the air flow plate back to zero. It is inconsequential compared to the force of the fuel distributor plunger with control pressure behind it.