4 replies to this topic

[Sunset Chaser]

Hi guys,

I'm working on a supercharger project, but it's not on a mini. However, I'm hoping I might be able to get some advice here as plenty have been converted so I'm talking to people who actually know what they are talking about.

I'm a bit confussed, the car I'm supercharging is a Hillman Imp and the few that have had them done, have them set up so air is drawn in to the charger and then the air is forced in to the carbs (or throttle bodies) and then in to the head. However, if what I's seeing is right, you guys run it the other way round, ie, air in to carb, then the air/fuel mix in to the charger and on in to the head. Is this right? and if this is what you do, which would be the better way to run it? I've seen some crazy power MK1 escorts coming out of holland that are turbo charged using carbs and they run the carb in front of the turbo, sucking in the air/fuel to the turbo and in to the engine. Seems quite dangerous as the turbo gets white hot, but they swear it gives more power. I assume the superchargers don't generate the same heat and fuel will act as a coolant anyhow (probably why carb'd chargers suffer icing).

The only problem I see with having the carb before the charger on an Imp is the belt is right at the back of the car (engine in the back) so the carb fits at the other end of the charger and that means the carb would sit facing in to the car and picking up hot air, unless I put a u bend in the inlet from carb to charger.

[Ethel]

It's often referred to as Suck through (carb first) or blow through ('charger first).

Suck through systems are less complicated as the carb just behaves like it is on a bigger engine.

Blow through is usually more efficient because the fuel is injected just before the engine where it can provide a little cooling & displace less air if it remains liquid long enough. The downside is the carb has to operate under varying pressure - carbs meter fuel according to air velocity and can't "see" boost without some extra trickery.

It's also simpler to fit an inter cooler to a blow through system

[1275coopers]

"It's also simpler to fit an inter cooler to a blow through system"
[/quote]

Can you explain how an intercooler can be fitted to a suck through system please? i always thought it wouldnt work because fuel would end up in the intercooler?

thanks.

Edited by 1275coopers, 17 August 2010 - 11:44 AM.

[Ethel]

It would. Water to air coolers have been used on suck through systems. They can be much smaller because water absorbs more heat allowing them to be fitted directly between the blower and engine. Of course you need a radiator somewhere to dump the heat into the atmosphere.

[Sunset Chaser]

It would. Water to air coolers have been used on suck through systems. They can be much smaller because water absorbs more heat allowing them to be fitted directly between the blower and engine. Of course you need a radiator somewhere to dump the heat into the atmosphere.

Thanks for the great explanation! I now need to check dimentions of superchargers to see how best to fit it and also find out how I go about modifying my crank pulley to take a grooved belt compared to the current v belt.