compound charged complications lol

[Chops]

Hey all, ive been plotting out the idea for my compound charged hi comp 5e build while i machine away at the block, and have come to a problem i cant get my head round.

the plan is to do everything i can to reinforce the engine and use a huge turbo like a td05 or bigger and a toyota sc12 supercharger, the latter being chosen as its pretty small, was used on the similar displacement 1.6 A series engines and uses the same magnetic clutch pully our a/c pumps use . when set up, i wanted to be able to turn the superchargers clutch on and off using the ac button on the dash for fuel economy when trundling around, and have it automatically switch off and freewheel when the turbo gets going to sap less power when not in use.

to set up the transition, i was going to find out from peeps on here at what rpm the chosen turbo gets up to a bar of boost, then work out what pully ratio the supercharger would need to be at that same boost pressure at the same rpm, so the transition would be as seamless as possible, but then i realised the problem with this. Surely, if the turbo is being fed the higher flow exhaust gasses from the supercharger running, it'le spool up much faster lol, which messes my plans up a bit. can anyone here help me work out how to sort this problem out, its been pissing me off for a while now.

[richardc9052]

You can't work it out that easy..

But I can get all the details off John who already has exactly what you want to build. I know he uses an RX60 ball bearing turbo but I'm not sure what rpm it spools at with the added supercharger.

I do know that the ecu opens the diverter valve when the intake pressure hits a certain point which is 12psi. It's not set via rpm

[richardc9052]

Also his on his setup the supercharger blows through the turbo with the diverter valve on the turbo inlet so it's not choked by the supercharger. He plans on running 2 bar and I think the supercharger with his custom pulley will hit 12.7psi

[Chops]

Oh i see! does he run a custom ecu to have that feature? that doesnt look like the sc12 i mentioned, i cant see whether its clutched either. im wondering whether the ecu could deal with a supercharger suddenly being turned off or on, i wouldn't want it to lean out or overfuel with all the effort made. id like to have a chat with that John chap, ive seen the red starlet on here before but never seen anyone take credit for it, just peeps saying they've seen it on basefook or whatever.

[richardc9052]

Yeah I know him so I could try and arrange a phone call at some stage..

Why wouldn't the ecu manage? Most maps are done on vacuum- boost/rpm so if there's no boost it still runs perfect.. It would be like driving without a turbo on the standard ecu.. It runs perfectly.

The sc he has is electronically clutched and it's off a mercedes

He uses an Fcon Gold ecu with coil on plug ignition

[Chops]

ah! dont suppose my mines ecu could run it with a little fpr intervention and whatnot? though i suppose with such a custom build needing a custom map to run it all seems kinda inevitable. if the dudes happy to get a few questions via email from me sometime that'd be great! id rather have his answers written down so i can refer to them again if needed, I'm a forgetful bugger at the best of times lol.

i would rather run the diverter valve off the turbo like a wastegate, just turn the supercharger off and bypass it once whatever boost i set it to is achieved. i prefer to be able to adjust it physically over messing with ecu software/

Edited July 21, 2014 by Chops