High comp & boost

[yoshimitsuspeed]

Hey guys, been a while hehe.
Ok this isn't for a DSM but I need input on the setup I am building.

Toyota MR2 supercharged converted to turbo. It is now going 20 valve blacktop which is 11:1 comp ratio.
Once I get it in I'll run with the WG disconnected till I'm confidant it's all dialed in.
I want to run 6-8 psi.
Now I live at 7k feet which is about 4 PSI lower than sea level so I don't think 6 psi will be too tough. If I could hit 8-10 up here and 6-8 down in Denver that would be pretty sweet.

Ok so anyway airflow sucks in the back of the car so I will be running a pretty massive water to air IC setup.
I am using the stock GZE (supercharged) ECU so it's set up for boost.
It has a knock sensor.
I have a wideband, just got a pyrometer and will buy some sort of knock alert before I run boost.
I think I'll start with a FP T28 I have and if it's too laggy put the T25 back in.
It's a Dizzy system so I can easily tweak timing.
Hmm that's all I can think of now.
What do you guys think?

 

[5150DSM]

I don't know what the pump gas is in Colorado but you are getting close to the edge for basic 91-92 octane. Air to water should help but I would still be leery of running 8psi. That being said, superchargers generally have lower thermal efficiency than turbochargers so if you were running anywhere near 6-8psi on the blower then you will probably be good with the turbo. Just watch you AFR's, EGT's and knock count closely while you tune and maybe shoot for RBT(Rich best torque) as opposed to MBT(Mean best torque) to give yourself a cushion. If you tune it right you should have awesome off-boost response and go ripshit in boost. Have fun and good luck.

 

[chanley talon]

What i would do is retard the timing a couple degrees. If your having trouble with knock get you a water/methanol kit.

 

[yoshimitsuspeed]

I don't know what the pump gas is in Colorado but you are getting close to the edge for basic 91-92 octane. Air to water should help but I would still be leery of running 8psi. That being said, superchargers generally have lower thermal efficiency than turbochargers so if you were running anywhere near 6-8psi on the blower then you will probably be good with the turbo. Just watch you AFR's, EGT's and knock count closely while you tune and maybe shoot for RBT(Rich best torque) as opposed to MBT(Mean best torque) to give yourself a cushion. If you tune it right you should have awesome off-boost response and go ripshit in boost. Have fun and good luck.

The origonal SC motor was 8.1:1 comp ratio and the SC made 8 psi.
Once I converted it to turbo I hit 10-12.
The ECU has a major design flaw where around 10 PSI it goes crazy lean under 3500 rpm otherwise I know I could have thrown a lot more boost at it.
I figure I will be walking a pretty tight line but seems to me I should be able to do it reasonably safely with the right monitoring.


Oh here's a DSM question.
Is there a direct bolt in WG actuator that has a lighter spring for my T25 and T28?
If not is there a good writeup on modding one?