M112 Celsior

The 1UZFE EGR Delete Kit is available for sale here.
No Boost

I think you are expecting too much out of the supercharger, it takes time to build boost. The engine needs 2 litres of air every revolution, so at 6000 rpm it needs 12,000 litres of air per minute. The supercharger compresses that air from a catch up position as it is not engaged until the vacuum disappears ie WOT and the valve closes. Max pressure depends on the speed the supercharger turns and the amount of air the engine consumes. I'm surprised you are seeing any significant boost in park. Under load at WOT, the engine 'feels' normal until it starts to boost then it becomes a freight train and gets down to business. We are running manual transmissions, we see little boost until third gear as the engine accelerates so quickly the supercharger has no time to build boost.

As for running rich, I'm not sure what size injectors you are running. The engine only needs extra fuel under boost. If the injectors are too big, the computer can not reduce the opening time enough to give a proper idle. If you are using a stock computer, it just follows a preset table programmed for a 250cc injector. Black UZZ31 ran his supercharger on stock injectors and had enough fuel at the top end (low boost under 5 psi I think). We run 315cc injectors, stock computers, and see a 80% duty cycle under boost.

As for the belt tensioner, use the shortest belt possible, there will be some torque 'stretch' which will max out the tensioner if the belt is too long.
 
Expecting 8 psi and getting 5 is just a disappointment.
Here are my calculations.

Max air flow for 1uz @ 90% VE:
((6000*244)/3456)*0.9 = 381.25 CFM​
Max CFM * PR
381.25*1.54 = 587.13 CFM

The M112 makes 587 CFM @ 10,500 RPM

At 6000 RPM the M112 is doing 10,312 RPM
So I'd have 575 CFM
575/381 = 1.50 PR

So I should have 7.5 PSI with the assumption this engine is @ 90% VE. If we actually do the math for VE this engine is rediculous: (250*792001.6)/(14.7*10*244*5600) = 98.5%

I have the supra 315cc. Since I installed a check valve to prevent vacuum from messing up my rising rate, my afr sits about 12:1 @ 6K RPM. It used to drop to about 10:1 @ 6K rpm and idle around 15:1 :eek:.


 


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