41 replies to this topic

[Sprocket]

Hello All, Happy New Year.

I am that bloke

Cheers Mini Sprocket.

correct not two manifolds (where would you put that lot?) just the one.

I need to correct you on one bit Mini Sprocket, it does work and always did, although in a fashion because, like you say, i had no driver for the 2nd injector.

I drove the car with it on, no leaks, around the block a couple of times, just leak & 'fouling' checks, of which there were none.

I have never really pursued much, the need for an amplifier which is all it needs to run the second injector from the original ecu trigger.

I made this assembly 7 or 8 years ago! with standard parts original for the spi.

an opinion for you: - the advantage of carbs is limited to the fact that they allow the engine to draw what fuel it wants at low revs in particular, hence the ability to run wilder cams that in an injected form that 'gives' fuel whether needed or not, causing tuning difficulties as a result of cam overlaps etc.
This advantage is quickly affected by the rolling road tuning limitations of the likes of (no matter how well set up) su's, which would always be the best carb'd choice for most, for historical and originality/practicality reasons. They are not able to be adjusted for incremental rev range & load fuelling, only 'near' fuelling due to the millions of jets not being accurate for each individual engine.
Peter Baldwin (you either know him or you don't) set up my car as spi, to 95bhp with more accurate fuelling than a later setup with twin 1 & 1/2" su's, although with su's i had a slightly wilder cam and about 5bhp more.

can't post pic, it won't let me, i enjoy cars and bikes more than computers, the file is too big i think.

:nugget: Well it was only a short conversation Not all points picked up on :nugget: :nugget: Just impressed with the quality of re engineering

[Sprocket]

Oh and now just thinking of removing the throttle from its body, plugging the holes and having the plenum made up with the same throttle built into it, using a bypass idle control valve.

Its not overly complicated. I've seen a twin single point throttle/injector body set up made up but not working yet, all ready to go. They guy never new about Megasquirt which could drive the two injectors

Now after pulling my spare injection manifold apart, i am thinking of removing the whole throttle body and having a spacer made up to take its place. Then bolting the original throttle and stepper onto the plenum. simple

[Sprocket]

Rethink on the turbo set up

Going to leave the throttle where it is. Been reading some books and now thinking that the SPI injection manifold set up should be left as it is( closely resembles SU carb), maybe some mods to make it a sealed unit, drill a small hole in the top of the fuel regulator cap to make it boost sensative. At the worst is to remove the innerds and seal it off using an after market regulator on the out side of the unit. The unknown bit is the injector, how will it react to 7psi of extra fuel pressure. I'm going to have sent away for cleaning and testing at 3.5 Bar if possible.

Also with the non Cooper SPI CR being 9.4:1 same as the Turbo i believe, it would be a matter of fitting the turbo without engine mods, though the turbo pistons are more durable. Not being overly daft with the boost pressures and keeping it somewhere around the standard 7 psi should be fairly reliable with obviously the biggest intercooler you can squeeze under the bonnet.

Going to order up some exhaust manifold flanges, some tubing, bends for the manifold and get a plenum made up. I've already got the turbo IHI RHB5. Hopefully no body mods like the Mirrage kit.

[Jackman]

After thinking about this and deciding that if i cant sort out my fueling issues then this will be the next idea as it sounds very intresting.

What things will i need, i know i need this but what else.

SPI injector setup.
SPI fuel tank.
Megasquirt setup.
Ignition components.

Is there anything else?

[The Matt]

I think minicb is selling an injection manifold setup on ebay (I clicked a link in the for sale section before and someone had one anyway)

[Jackman]

I think minicb is selling an injection manifold setup on ebay (I clicked a link in the for sale section before and someone had one anyway)

So he is, shame im not in the position to start it yet.

[ed4ran]

now thinking that the SPI injection manifold set up should be left as it is

I love it when things get easier!! ok at least simpler

I wouldnt mind testing some if this stuff when i get some time,
got a spare engine in the back and a cheapo turbo with some life in it
and eventually SPI stuff (but will have to wait for my brother to change), and already got MegaSquirt, just needs putting together! and exhaust manifold doing

[Sprocket]

Further inspection and thought.

Would need to remove the diaphragm from the fuel reg and blank it off. Fitting an external fuel regulator working on manifold pressure. Again very easy to do.

The throttle is only 41mm, but there may be room to bore this to 44mm and fit a HIF44 throttle disc, but not much more, there just isnt enough metal. As for the manifold and spacer, they in succession, step up to 46mm at the manifold. There is a ridge that could be removed from the port ends of the manifoldand a little port shaping would not go amiss.

[ed4ran]

Sounds more and more do-able, makes me want to get my spare engine and set up a rig in the garage as a running engine to make the manifolds and get it all tested

[Pandora]

Yeh like thats going to happen lol you do know the garage is going to be pulled down you muppet

[Sprocket]

You would need to fit a normal crank sensor, as Ed already has. Don't think any one has decoded the Rover SPI crank sensor pattern for the Megasquirt ECU

There may be an option to use the standard crank sensor position on the fly wheel for use with magasqirt without any complicated decoding, as I have become aware

Oh and I have fitted a bigger injector to the standard engine and seems to run OK. I suspect though that the injector needs cleaning as the spray pattern is not very good This should increase the BHP potential a little before it max's out

Turbo SPI still seems in theory to be very simple indeed. I still can believe it :saywhat: Litteraly bolt on a turbo fit a bigger injector and install a Megasquirt ECU :cool:

[Matt_Brum]

Hi Mini Sproket,

I was wondering if you could advise me on a couple of points;

My SPI mini dizzy has cracked (dont ask!) and was wondering if i can use the existing crank sensor and MAP sensor etc etc to provide the relevant inputs to a megasquirt unit to power a MPI coil pack i have to provide the spark??

Any info would be greatly appreciated.

Thanks,

Matt