EFI Systems

[Hcarraro]

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[al lkosmal]

Originally Posted by jpnovak

I like Al developed a system based on MFI. In my case it was adapters to put EFI injectors in the MFI ports. This works well on early engines where you just use the entire MFI TB/stack/linkage setup. It is still cost effective compared to some aftermarket ITB setups.

It is not hard to add the MFI ports to 2.7, 3.0 and 3.2 heads as part of regular machine work but as the engine gets bigger and the rpm range increases the Inside diameter and flow restrictions become a real issue.

Jamie,
I do think that your MFI/EFI adapter design is simple and elegant. Nice solution for those wanting to retain the cool, early MFI bits and looks, while incorporating modern engine management.

regards,
al

[SexOnTheBeach]

Originally Posted by chris_seven

It would be good if you could share the data that leads to this conclusion and if the low butterfly and the high butterfly systems perform in the same manner.

Well I'm actually using a low butterfly Rothsport system with a Gt3
Cup plenum at the top of it, coupled with a 3.8 993tt engine, it produces 875hp with one hell of a throttle response, have had it working for a few years now without a hitch, and besides if it is good for Cosworth in their Singer engines, it is definitly good for me!

[Canada Kev]

Originally Posted by SexOnTheBeach

Well I'm actually using a low butterfly Rothsport system with a Gt3 Cup plenum at the top of it, coupled with a 3.8 993tt engine, it produces 875hp with one hell of a throttle response, have had it working for a few years now without a hitch, and besides if it is good for Cosworth in their Singer engines, it is definitly good for me!

Maybe 375 HP...?

[blockhed]

3.8 993tt is the big ticket items you're looking at here

[Tippy]

Originally Posted by Canada Kev

Maybe 375 HP...?

His engine stock at 3.6L's produced 400?

[blockhed]

Yes so 3.8 plus some bigger snails and etc they'll make 800+

[clutch-monkey]

Originally Posted by Canada Kev

Maybe 375 HP...?

why would it make less than stock haha
sounds like a weapon of a setup, would like to see pics all the same

[J0hnny]

Originally Posted by chris_seven

Manifolds 100mm long and EV16 Injectors.

We are designing the balancing devices and all of the lever links during the next few days.

That looks pretty...

Any consideration to design an airbox and some way to feed cold air to it?

[chris_seven]

The spacing is the same as Webers/Zenith Cars so an Air Filter Box from these carbs will fit directly and with an SCRS Type Intake could work in the short term.

We have decided to ditch the fuel rail and try to make it look a bit older in style using hose.

I have sourced an Polypropylene Braided hose that looks similar to the Tecalan Hose used on some of the RSRs and we have drawn up fitting to seal the injector and a manifold block to connect the fuel lines. This will sit in the same position as the MFI pump and also connect the pressure regulator.

We will try to re-manufacture the MFI Filter Housing as a 'plenum' and pump fuel to this and then by-pass back to the tank.

[jpnovak]

Nicely done.

[preston_brown]

This low butterfly, tall carbon fiber stack system is installed on my 3.9L 964 RSR. Need to re-dyno things after a recent rebuild of the motor with a cam change, but on the first trip made approx 385 HP.

It's straight through, equal length. The throttle bodies are unknown. Perhaps Porsche Motorsport.

[clutch-monkey]

seen similar with this RSR type track car locally, 3.5L.

[preston_brown]

Originally Posted by clutch-monkey

seen similar with this RSR type track car locally, 3.5L.

Sweet. What's going on with the air filter/intake on that thing?

[clutch-monkey]

custom made carbon airbox, makes the powerband much nicer he said (much better mid range than previous apparently)

[preston_brown]

My system is rod actuated, yes.

I agree with your comment about rain hats / covers on a daily driver, remember this is a pure race car.

Here is a pic of the linkage. Please ignore the wonky return spring; this is a pic of the car when I got it and quite a few things were put together incorrectly.

[3literpwr]

Actually, the system appears to be cable driven. I assume this is the case from the gearbox to the rod block shown. Good looking setup by the way.

[3literpwr]

This is the data we need to determine if the slight port angle on Weber style manifolds will have an impact on total power / flow. Alas, I do not have this data.

[chris_seven]

I think that despite David Vizard's flowbench crusade that many simple flow measurements are not the complete picture.

I an accept that in flow terms a straight port and runner may give the highest flow.

I would have thought that a single cylinder of a 3.0 litre engine that produces 300BHP at 7500 rpm would manage with an air flow of about 80CFM at WOT.

This correlates quite well to the calculated 70CFM air needed to burn the fuel required to develop 300 BHP assuming a BSCF of 0.5lbs/hr/hp that we would use to size the injector.

It would be very interesting to know the flow capability of the inlet system complete with the valve at the maximum opening.

[preston_brown]

Originally Posted by 3literpwr

Actually, the system appears to be cable driven. I assume this is the case from the gearbox to the rod block shown. Good looking setup by the way.

Yes, my apologies. It is a cable to the engine itself.