hi so I always wondered why not supercharge for low down torque and then somehow at a certain rpm it cuts out and the turbo by then has spooled up. I think nissan made a similar system for the nissan march superturbo MA09ERT but i want to know what controls the engagement of the supercharger is it rpm based through a ecu? or is it psi controlled some how?

would this be easy enough to adapt to an a12? if so what is needed to control these? im guessing you could use either a amr 500 or sc12 supercharger or sc14???


Thanks!

some superchargers, including the SC12/14, are switchable, like turning your air con on or off, so you can control that however you like, by pressure switch would be easy enough

there is a few setups around like it, it's not a bad idea, allowing a bigger turbo for high boost at high rpm, it's also possible to do with two turbos

main hurdle is the large amounts of space and pipework required to plumb everything in, but its a good project idea

would the car be for a particular purpose that would suit doing this?

You can acheive the same thing using nitrous...link the nitrous switch to your throttle so it activates when you put your foot down, but also wire the switch in series with an RPM activated cut out switch, set at maybe 3000 rpm... That way the nitrous comes in straight away to give you the boost to get to where the turbo comes in then swithes itself off automatically.

Not done this myself, but read about it in the big yellow A series(Austin version, not Nissan)book from david vizard...

looking at the 'wizards of NOS' website this is much easier to install than multiple turbo's/superchargers.... although you have to keep refilling the NO tank....

hi thanks for the reply the car will just be used for road used and spirited driving on mountain roads etc. i was thinking of two turbos but for some reasons it seems a supercharger will still give better low down power? and if i can control it with a presure switch thats sound good so you can keep the turbo in the efficiency range if im not wrong.

Thanks i am actually really considering this project in a months time. if anyone has any other ideas or issues with a setup like this please post.

The setup you're talking about would have the pressure switch on the inlet side of the super charger. When it hits the threshold, say 5psi, the super charger cuts out. You'd need a normally on hobs pressure switch set up for the pressure you want.

two turbos is pretty awesome, used to make boost when the engine was labouring and ran up to 15psi, which is pretty high for a stock internal a-series

A mate was fizzing to do it to the CA18det in his esky van. We discussed it at great lengths. It's not hard, BUT it's very difficult to get a smooth transition between the super, and the turbo. The very simple design I thought would work very well would still give a drop in performance at the changeover point.
Also, if the turbo blows into the super (Even with a bypass butterfly) the charger will recompress the turbo boost, and amplify it by the Boost ratio. Then when the blower cuts out, the pressure at the manifold will drop.

to be honest, i think it's a shiet idea trying to combine the two when all you need to do is properly size your turbo

to come to think of it it seems to be more difficult than i thought because after the s/c is disengaged assuming its plumbed in series with the turbo charger the turbo will need a bypass valve to allow another air source?

and if you were to leave the s/c and turbo running together the difference in efficiency would cause a increase in intake temperatures i think.

Any one know of a bypass valve that could be used after the s/c is disengaged?



or maybe this whole idea isnt really worth it whats a good size turbo that pulls from 2000rpm up? the less laggy the better imo.

Thanks!

There are a few cars around that are s/c and turboed. watched a couple on youtube, they seem to go quite fine