Building your Own Inlet

cheers mate, think i will reuse the orignal heat shield and put eaxtr heat wadding behind it. i was going to base the inlet size on the orignal cus the turbo wont take up much more space any how

Yer that was done on a TR a while back, but the Turbo from the metro has not really considering how easy it is

Well the K-series VVC started out using plastic throttle bodies, but they removed those and I think they became alloy, cause the original was a bit of a disaster, they warped under heavy use. Steel seems the way to go in the long term, or if light weight is a big priority then maybe alloy, but for reliability I'd have said steel

While the Metro setup is simple it is quite archaic and you'll have to fiddle about with the carb to get the a/f ratio correct on a 1.8. Even then it's never going to produce the kind of results EFI will. Of course you have the ingnition advance to think of too and there's no facility for retardation via a knock sensor. The bulk of the work will be with the fabrication of manifolds and the related plumbing so it's probably no more work to go efi rather than carb. I avoided EFI like the plague for a long time but after I initially took the plunge I suddenly realised what I'd been missing and how damned simple it is to work on and fix!

I doubt there would be any real advantage of using throttle bodies with a turbo. Throttle bodys on an n/a engine, yes but on a turbo it seems a bit pointless so I'd avoid that route. A long runner manifold with a good sized plenum and nice big throttle body will do the job just as well and will be a heap easier to fabricate.

On SDS's site there's some ideas of how to knock one up (good tech site BTW) www.sdsefi.com/techinta.htm

A manifold like this will easily flow enough to support way more power than you are aiming for. The setup shown below is on a Nissan Silvia CA18ET which produces just short or 300bhp from a 1.8 SOHC. This intake was made by chopping down the factory one then adding a custom made plenum.



Either way it'd be nice to see someone going down a new route with a B rather than the tried and tested n/a tuning methods. I don't remember seeing a turbo'd B series before and I'm sure it's plenty strong enough to handle it. The only thing I would question is the pistons and rings, especially the latter. Most turbo motors have wider rings and a a bigger land above the top ring. I guess that could be easily sorted. Compression is the other issue but with decent intercooling you can turbo pretty high compression engines these days. I know the KA24DE in my 510 can be turbo'd and run to 10psi safely even though it's 9.5:1

Difficulty comes from there being positive pressure inside the carb when there would normally be vacuum. The only way around this is to pressurise the float chambers our even to build the entire carb into a box that is sealed and pressurised. It is possible to run a setup using a blow thru turbo and side draughts though, just not easy to set-up and callibrate. This is a setup I saw on an old KGC110 Skyline in Finland... turbo and triple side draughts!!



Here's another similar set-up but this time in a Toyota Carina...

There would be an easier way.....

My capri has been slightly modified...(2.0Pinto with turbo, Water injection, Mappable ECU etc etc)

and all its cost me is about £400 quid to do...

I used the Megasquirt ECU www.megasquirt.info and the sierra injection setup..(but i would advise you to spend the 140 quid and buy a Jenvey 2 injector Throttle body for your intake manifold...)

I have been asked about injection on a mini (a-series) recently and done some thinking about it.
Many mini 'experts' have tried to create an injection setup...but they always seem to try multi point (injecting at the ports)...
People inthe mini world
You can use Multipoint injection on your car unfortunately....not the standard type, because of its five port setup. You would have to have a very sophisticated or specialised ECU to do the job, and i don't think its available. Obviously because of the uneven way the air uses the two ports...
I would use a Megasquirt ECU and run a TBI (throttle body injection) setup, with two injector set to inject as often as possible (variable with megasquirt) This would mean that the cylinders are always getting an equal amount of fuel...(Also injecting at the throttle body provides a more powerful setup than at the ports)
This setup will work because you are supplying the fuel in a similar manner to a carb...all at one point for distribution by the airflow.

I think a standard manifold...jenvey 2 injector throttle body, and a pair of good sized injectors would be a nice setup. All run by a mega squirt. This system requires no changes to ignition. and simply uses the tacho signal from the dizzy to determine engine rpm.
The software for it is surpirsingly good and i would say the system is nearly as capable as some very expensive ECUs out there.

If you needed a hand on such a thing, I'm not far from you and i wouldnt mind helping.
I have it working in my car... and it should be fun setting up a mk3 capri using a laptop!

::: i should also add that the MS ECU has a builtin 21psi? MAP sensor and can be modified easily to run as mappable ignition. I think ill be going down the ford EDIS coil pack route with the capri.