11 replies to this topic

[blister]

is it possible to turbo a mini with twin carb hs2 ? (998)

[Ollie180]

dont see why not? would just need a modded chamber


would it really benifit from it tho?

[minivanman]

You could, but you couldnt use the twin carbs. Turbo carbs are sealed - it isnt a standard HIF they use.

[JetBLICK]

Do you not need a specific carb for forced induction? I remember looking into doing a turbo a long time ago and i'm sure you need a specific type of HIFF? i do remember reading something about a weber that was suited to forced induction too, which they used on the janspeed turbo conversion. If you just wanted something different then maybe you should look into finding one?

As i say tho, it was a while ago, so i ent too sure. That said tho... i'm not sure what you'd gain from using twin hs2's with forced induction? isn't part of the point of forced induction that it overcomes most of the problems with poor flowing N/A set ups

[Wil_h]

You can convery SUs for turbo use, but as there is a readymade carb available that will work and fit and is cheap, why bother?

[blister]

how do i go about converting them>?<

[998_Tom]

From what i understand there are 2 ways of doing a carby/turbo setup. One way is a blow through setup and the other is draw through.
Blow through setup:

Turbo----------------Carby---------------Manifold/Head

Draw through setup:

Carby----------------Turbo---------------Manifold/Head

Basically for a blow through system you need a sealed carby to deal with the pressure from the turbo.
In a draw through system you dont need a sealed carby but im not sure how you would run an intercooler for this setup, if you could at all.
And to help reliability you should have a carbon shaft in the turbo on the draw through system.

[Wil_h]

I think we should concentrat on blowthrough, it is the better system and suck through can use any carb.

The sealing of the carb is a minor issue, the worry that people have is that the butterfly shaft seals will leak under pressure. But I got to thinking about this, I can explain if you like, but leaking butterfly shafts is not a real problem.

The main problem is upping the pressure of the floatbowl as the boost rises and making sure that it is higher than the boost presure by around 3 or 4 psi.

The Metro carb does this by having a restrictor ring in the plenum, causing the a slightly lower pressure in the carb mouth compared to the floatbowl (which is pressurised from the plenum).

You need to pressurise your float bowls from a signal from near the turbo (before the air has lost some pressure through the intercooler and piping) or you need to come up with a restriictor ring.

[miRon]

looks very nice..

[blister]

well here i am now i just bought twin carbs and now have decided to go another way with my engine (turbo) if anyone is interested here you go

http://cgi.ebay.co.u...em=330172950062

[ferrox_666]

yo blister the manifold on that ebay link is poor, i read it in a Vizard book. the problem with draw through is that its very easy for the fuel to come out of suspension, an intercooler cannot be used because all the fuel will condense in it!! Everybody needs to read Forced Induction Performance Tuning by Graham Bell. Aparently you can put the whole carb in the plenum which stops seal issues but not in a mini i guess.. draw through is old technology but useful for positive displacement superchargers because it closes up the gaps between the rotors making them more efficient.

Ollie 180 how the *&$% did you get the muffler thing out the end of your exhaust? i just got mine through the post and its tight as buggery! ?!?!