What is better with CARB - suck or blow???? (I am talking about turbocharging not anything else)

Don't know about 'better', but a darn sight easier to jet with 'suck', from what I've heard.

With 'blow', you need to seal the float bowl, then have a feed to it so that it operates at the same pressure as exists in the venturi.
However, this approach does run the risk of an explosion occurring in the compressor, which could be something of a drawback...

ken

After more thinking - I am going for the draw though system (suck) as the carb is easier to set up and does not need sealing for boost. Anybody want a second hand dump valve ( can not use with this system)

Why can't you use a dumpvalve please tell me i'm stupid............

When I understand right then you are going to do this:

Carb
lowpressure
turbo
high pressure
engine

so you can do

carb
lowpressure
turbo
high presure so here you can put a dumpvalve!!!
engine

Yes you are right you need 2 chambres of highpressure to make the dampvalve work, but I still think there's a way to make it work.....

If I use dump valve on suck (carb before turbo) the gasses after turbo will have petrol mix. Dump valve would exhaust petrol mix (not good!!!!)

This is not your biggest problem you could leed it away under the car.

But a dumpvalve needs 2 high pressure chambers 1 infront of the butterfly
1 after the butterfly. Now when you close your butterfly (trottle) then your engine still sucks airso creates a vacuum. infront of the buttefly the pressure rises because the turbo still pumps air.... now you have 2 diffrent pressures so the dumpvalve opens... Hope you understand.


In your configuration you have only 1 pressurised chambre...... turbo to engine.... so a dumpvalve never works....

The biggest issue is that a dump valve isn't needed on a suck through system, It can only provide the benefits it's designed to when the carburettor or throttle is downwind of the turbo. When the throttle is closed on a blow through system the build up of pressure between the turbo and the throttle butterfly has nowhere to go except back through the turbo. This stalls the turbine and results in turbo lag when the throttle is opened again. The other benefit is that in the same circumstances it protects the throttle butterfly from potential damage caused by high pressure differences across it.

As to the suck or blow question, a blow through system has much more potential but a suck through is easier to build. The disadvantage of the suck through system, as well as the explosive potential that Ken mentioned, is that the amount of boost you can run is limited by the fact you can't use an intercooler.

Found linked to Burton site - I think somebody's got his pipework wrong!!!!!

I don't like to laugh, they have given it a go which is more than most of us, but it never ceases to amaze me how people have the confidence to launch into stuff with so little technical understanding.