Dual VE table to help spool an asymmetrical turbo system?

allen22 · Post by **allen22** » Sun Sep 03, 2006 1:37 pm

Hello,
I was thinking about the dual VE table feature and got to wondering. I'm considering running one small turbo off of one bank of my V6 engine. Saab has done this on production cars, it's weird but has it's purposes.
Anyway, could I run the bank that is feeding the turbo rather rich on low RPM/high load to help drive EGT's up causing the turbo to spool much faster? This would be similar to WRC cars and their antilag feature. Seems like a neat approach and would possibly allow me to run a slightly larger turbo with less lag.

Fred

pumaking · Post by **pumaking** » Sun Sep 03, 2006 10:46 pm

I dont see why not, thats what the purpose of the dual table, to control each bank with its seperate VE table. You might need 2 widebands to double check that the other set doesnt affect it.

on a quick note allen I finally was able to get my richness issue fixed and now I can drive it. Did several highway runs last night and WOT man I'm in love with Megasquirt and turbo. Only problem im having is cold start.

Clifton · Post by **Clifton** » Mon Sep 04, 2006 2:42 am

How rich do you think you can run it? If it's overly rich you reduce power which reduces exhaust volume and adds lag.

Tommy · Post by **Tommy** » Mon Sep 04, 2006 3:57 am

I would think you'd need to tune the two sides independently. They would hve different VE maps.

Tommy

allen22 · Post by **allen22** » Mon Sep 04, 2006 6:14 am

You know what, I just realized that running it rich isn't the best way to get the turbo to spool, infact it might not even work that well. The trick is to retard the timing which raises the EGT's. Drag racers do that to actually build boost while sitting still at the line waiting to launch. That's probably what the WRC rally cars do too actually.

Is there any way to do that with MegaSquirt yet? I don't think so as you'd probably need true coil on plug ignition.

Fred

allen22 · Post by **allen22** » Mon Sep 04, 2006 6:18 am

pumaking wrote:
on a quick note allen I finally was able to get my richness issue fixed and now I can drive it. Did several highway runs last night and WOT man I'm in love with Megasquirt and turbo. Only problem im having is cold start.

Congrats man, that must be exciting. Refresh my memory on what your setup is, it's been a while since we last talked.

Fred

pumaking · Post by **pumaking** » Mon Sep 04, 2006 3:08 pm

well for Megasquirt I know their was a feature for anti-lag which made you boost while idling and other crap so pretty much you were always boosting. I dont know if Megasquirt II has that feature.

As for my setup it was a 1990 Nissan 240sx with a CA18DET on the FORD EDIS-4 ignition setup. Turns out my problem was the embedded code 2.35 wasnt allowing me to do real time tuning, so we put in 2.36 and everything works like a charm and addicting to drive.

You may remember my write up on the Nico forum in the CA section. and I sold you your 36-1 wheel.

allen22 · Post by **allen22** » Mon Sep 04, 2006 5:25 pm

pumaking wrote: As for my setup it was a 1990 Nissan 240sx with a CA18DET on the FORD EDIS-4 ignition setup. Turns out my problem was the embedded code 2.35 wasnt allowing me to do real time tuning, so we put in 2.36 and everything works like a charm and addicting to drive.

You may remember my write up on the Nico forum in the CA section. and I sold you your 36-1 wheel.

Ah yes, I remember now, great write up by the way, very informative. I hope to write one that good for my site soon. The wheel is working out great too.

Fred