12 replies to this topic

[Mini_Tom94]

I'm interested in supercharging my '92 SPi, but I'm trying to research as much as possible so I don't make bad decisions.

 

What would be the best fuel system to supercharge? Or is it a case that they all have advantages and disadvantages depending on the style of driving?

 

If I choose to supercharge it then I'll be using it as a daily driver.

[Tommyboy12]

Best or easiest?

 

Best is easily injection but not the the SPi or MPi system. You would want a standalone system that can be fully adjusted to the pro's of running a supercharger. You would save fuel and get maximum power on demand, especially if you could inject as close as possible to the port.  The SPi and MPi are too limited for proper supercharging really. The MPi system is the better of the two and can cater for around 80-90bhp maximum before it runs out of puff.

 

The easiest way is going down the suck-through carb route although you wont want high expectations for fuel economy! You can also suffer carb icing which can mean being stuck at the side of the road sometimes. You wont need to modify your carb outside of a new needle profile though.

[Mini_Tom94]

Ah I see. The best way sounds expensive but for a daily driving car I'd need the best fuel economy as possible as well as good power. Do you would be involved in a stand alone system?

[maccers]

I have done both of these in a progressive kind of way..!

 

My engine was originally an SPi that was pulled from a wrecked 95 cooper, and then ran on twin SU's when I bought it. I had the engine re-built after a gearbox failure and re-bored to 1293cc, correct pistons to provide lower compression and re-built cylinder head with larger valves. My plan was always to install a supercharger even before gearbox failure.

 

My first setup was HIF44 carb and dizzy (simon bbc), then went to mega jolt which made the engine run so much smoother, and make the most of things. This setup alone was great, and had it not been for carb icing i would have stuck with it. By the way mine is not a daily driver.

 

I installed a carb heater from SU, yes its actually a part and is a +12v collar that goes round the dashpot. I also put a heated element in the air filter. I would like to believe these helped but I dont think they done much expect thinned out the dash pot oil. I have seen some people on here use copper pipe connected to the engine cooling system wrapped around the inlet to help cure this. One guy on here has actually fabricated an alloy tank around the inlet thats plumbed into the engine cooling system - quite an impressive piece of work..!

 

My inlet snorkle did ice up summer or winter, due to the fuel evaporation it causes ice to form on the pipe from carb to supercharger. This is not carb icing... which I believe is due to moisture building up within the carb and the constant flow of cold air (summer or winter) makes the moisture freeze. Have a google on it.

 

So, next thing I looked at, to cure this and also add further tuning capability and smoother running and also fuel economy as a by-product (but its made a huge difference!) was fuel injection using Emerald ECU. Another inlet to take injectors was made up, I used two injectors, and also to accept the throttle body. It was a lot of effort, and needed a few more parts such as MPI fuel tank, adjustable fuel pressure regulator, few lengths of fuel pipe, and of course ECU kit with all the sensors,  but can say its worth it. I know power figures are rolling road specific, mine was mapped last week at 149 at flywheel. Engine has done about 900 miles since re-build so still being run in etc, tuner has mapped to 6000 rpm and reckons a few more hundred miles and oil change to 10w/60 can map to about 7000 rpm not that I will be using that...!

 

Main reason for getting the car more up to date with fuel injection was the potential carb icing thing leaving me with no power, which happened on busy A road with little run off with my two sons in the back. I can say that barring any other mechanical failure I have every confidence in the setup now, and could easily use the car as a daily driver.

 

Driving wise, its a bit of an animal. I run 10" wheels, 7.5 s discs, hi lows with standard but new rubber suspension units all round, solid subframe mounts, neg camber front and rear, this all needs to be set up correctly, but as its all new am waiting for things to settle in..! Had a few teething issues with ECU over fuelling but with time, more miles and re-mapping this has now been resolved. With further re-mapping after engine has had a few more hundred miles on it I am hoping it will have smoothed out the power curve somewhat.

 

Engine build and tuning all done at VMAX in Surrey.

 

PM me if you want some more info, costs etc although as a rough guide £1200 to £1500 for the charger and ECU etc would get you started.

[superteddyeddy]

Very good bit off info there. I am Runing a supercharger but with a weber 45 on the end. It's very hard to get Runing right and it just drinks the fuel. I been looking into the injection setup and defo going down that route this winter. Just got some questions to ask you. Any idea what type or size the injectors are that you use? Did you make your own fuel rail or buy one? Some pictures off the injectors in charger or setup would be great. Cheers ted

[Gr4h4m]

Like all of the setups going down a well trodden path is of an advantage. The injection is the most versatile in terms of tuning. But like all setups getting it right can be an art, having a known setup or someone that has done it before will save money in the long term.

The injection has given me much better fuel economy but also headaches in terms of mapping and setup. Like all things it will get there..

[superteddyeddy]

Do you no what the injectors are off or modle/make? What type ecu are you using with your setup?

[Gr4h4m]

Yep I have two bosh 440's on the sc 5 port setup

[superteddyeddy]

Ok thanks very much. Which ecu system you Runing. Lots off different types on the market.

[Gr4h4m]

The sc 5 port kit that uses the typhoon.

[maccers]

Not sure what injectors - Stuart at Vmax supplied them. Fuel rail - assume you mean how the fuel gets to the s/c? MPI tank - > braided lines under the car into adjustable fuel regulator on the bulkhead - this has a return back to the tank. From regulator, rubber fuel hose to injectors, using t-piece to split the fuel delivery, then jubilee clip on the injector.

 

Just clocked up about 3500 miles and its still running great - done some motorway work recently and apart from a bit loud in the car, it went fine.

[superteddyeddy]

Thanks very much for the info. I guess you use the standard mpi throttle body for the air in take. I best ring up vmax and see what he uses to get the bits and build me self a injection manifold. Thanks

[maccers]

The TB on mine is from a Rover 600 I seem to recall, again Stuart supplied it - he would be mapping it (and still does) so figured best to ask him. I had to modify it a bit as I got a servo. Are you local, pop and down and see him, arrange first, but he is a very approachable guy and will give you lots of good info.