Type4 2056 SDS

[Bill K.]

Walter, I found the Golf G60 injectors as 0 280 150 906 or 905. These are rated at 38.6 HP/ for 43.5 psi, 80% duty, .52 BSFC. The 100% duty flow at 3 bar (43.5 psi) is 263.8 cc/min (25.1 lb/hr). Very similar to the 24# Blue Top Bosch/Ford units. What pressure do you run on your 2056?Jake recommends the 24#'ers for this combo also.

Ray, These values are based on the rated fuel pressure of 43.5 psi at 80% duty. This site has a nice table of fuel injector values: http://users.erols.com/srweiss/tableifc.htm#BOSCH There is also values for 95% duty and other BSFC ratios. There is also a handy calculator for converting rated flow rates to different pressures here (not that you would need it , but I do): http://users.erols.com/srweiss/calcpchg.htm

[raygreenwood]

Nice site! I would tend to select an injector whose max flow range in lbs/hr ....happens either about 3 psi lower than what I need or at a max tested cycle about 10% lower. Ray

[Bill K.]

Ray, are you making the same point as Walter? That the rated flow of "modern" injectors are based on AFR of 14.5 and ACVW like 13 or so (10% more fuel). Or, are you talking about 90% duty cycle?

[raygreenwood]

Good question. Actually the same point I beleive.

I am making the point...that the pressure these injectors list (say...43.5) psi...is usually the mazimum safe usable pressure that the injectors can handle and still reseat or reseal the pintel. You want to make sure your pressure regulator is such that it does not give pressure much higher than that.

And....if the rated flow in lbs/hr...at that maximum pressure is at 85% duty cycle (which is generally held to be the "real" and "reliable" maximum)......then at 85% duty cycle @ 43.5 psi....that injector is maxed out. No room to move.

If you size your injector along those lines....and the chart says it is "perefct" for your engine.....AND you have not thought about the injectors ability to supply that extra .3 to .5% AFR....you have no place to go.

There are several other reasons you may want to a few percents more available from a given injector.
Many aftermarket systems say they have complete pulse width control. Thats fine...but the gist is that almost all injectors are unreliable both resealing and frequency wise above 85%. Thats why they use that 85% #.
They can be even more unreliable...potentially...when the pressure running through them is close to the maximum rating.

This is why I always question teh injector rating sites. Is that 43.5 psi....a downgraded "safe" #? By that I mean....does that injector statistically run most reliably at 43.5 psi....yet it can actually go to 50 for short periods in a pinch? If so...thats a great thing to know. It can give you room to tune if you know how to work pressure. Ray

[Wally]

The 24# seem like a good choise Bill!

They are supposed to be run a 3 bar or 45 psi. I had the fuel pressure a bit higher, but don't mind that

[Bill K.]

Thanks guys. 24# Bosch 0280150947 modified for barb inlets will be used. The intake runner seating boss for the injector clamps will be modifed to take the shorter injectors.

Now, I'm on to the fuel system. I plan on removing my gas tank to clean and de-rust it. The tank filter sock will be removed. From the tank, the stock d-jet filter and fuel pump will be used as a feeder pump. New german 7mm FI hose will be used with FI clamps. The stock 412 chassis fuel lines will also be used. With SDS, the cold start injector is not needed and will be removed.

In the rear, what is recommended for filter, main fuel pump, and fuel pressure regulator? Again, this is for a 115+ HP 2056 daily driver with plenum based intake and SDS ECU.

[Wally]

In the rear, what is recommended for filter, main fuel pump, and fuel pressure regulator? Again, this is for a 115+ HP 2056 daily driver with plenum based intake and SDS ECU.

Those are not so critical, just get good quality parts. I use a regulator with a fuel pressure gauge within. Very usefull when dialing in the fuel pressure. For fuel pump I used a good used porsche 944 pump. 928 or 911 pumps will do just as well. Plenty supply and pressure from those

[raygreenwood]

Are you using fixed or variable fuel pressure?
Since you are feeding from a D-jet pump....which is relatively high pressure, you need to be careful what filter you put between the D-jet feeder pump and the main pump in the back. The filter has to be designed to be on the pressure side of the loop. Just look for a filter from any car that had the filter on the presure side of the pump.
I will see what I can find. Ray

[Bill K.]

Walter, are you using a dual pump setup with CIS main pump?

Ray, since SDS has MAP and TPS input for enrichment control, I'm leaning toward fixed FPR for ease of tuning. Agree?

Plan for fuel system layout is:
Tank -> D-Jet Filter -> D-Jet Pump (feeder) -> Chassis Lines -> large High Pressure Filter (accumulator) -> CIS Pump (main) -> Injectors -> fixed FPR -> Chassis Lines -> Tank

[Wally]

No, just one 911 Bosch pump from a motronic engine I believe it was.

[Bill K.]

...The injectors and runners will need some modifications, so I'll test them out on the 1.7L before going to the new 2.0L.

The injectors need the plastic housing removed from the inlet to expose the metal barb. This was done with a small cut-off wheel. The pintle end needs a larger O-ring installed to seal on the stock intake runner. 034133557E works well. The pintle cap was removed to install the fat o-ring by carefully prying with screw driver while holding the injector in vise. The injector spacer washer is retained so the pintle cap doesn't bottom out in the bore of the intake housing, ensuring a solid o-ring seal. I screwed up the first pintle cap removing it, but replacements are available (Mr. Injector on ebay).



Compared to a d-jet injector (green top) with a new stock lower o-ring, the modified 24# injector (blue top) has more clamp down clearance, so the injector clamp boss of the intake housing does not need to be decked. It's a bolt-on conversion


When fully clamped, the modified 24# injectors (4-hole/brown) are recessed about 3mm compared to the d-jet injectors (1-hole/black).



Similar results with a 1.7L intake runner.

[Bill K.]

Bosch 0 280 122 001 throttle position sensor (TPS) fits the d-shaft of a type4 throttle body and has variable resistance feedback compatible with SDS. An aluminm stand-off and the base of a stock type4 TPS was used to make an adapter for the new TPS.

Gutted type4 TPS with mounting studs added and aluminum stand-off


Stand-off slip fit on boss of type4 TPS


Type4 TPS plate with locating boss still intact for locating on throttle body


New TPS located with some play beyond full open/close and with Type4 TPS plate located in middle of slots (SDS adjusts to actual location)


2L bus throttle body modified to add lip seals (020311108A) for throttle shaft.


Bottom of throttle body also modified to have counterbore to locate TPS plate


Throttle shaft from '74 412 with radial return spring modified to accept larger bus throttle plate (shown with 1.7/1.8L plate on top for reference)


2L throttle body with longer 412 throttle shaft


Final assembly 2L TB with TPS and adapter


TPS adapter also works with 1.7L TB/shaft without radial return spring

[MarioVelotta]

What are the chances you measured the od of those seals I winder if they would work in a type 1 throttle body?

[Bill K.]

The seals don't fit a type 4 throttle body without modification. A .560/.561 diameter by .160 deep counterbore was milled into the TB. The seal is a light press fit.

[MarioVelotta]

Nice, thanks Bill!