The Mega Supercharger 4AGZE thread, using twinscrew charger

[Hen]

I've driven a 4AGZE for years making 11-16psi from superlow RPM. It's fine. Fun if you want it, fine to take off from the lights in the wet with a pig of clutch if you want that too.

Non-issue.

[jondee86]

Thinking it thru a bit further the answer becomes rather obvious

The charger can only make 18psi if it gets enough air, and the throttle plate controls the amount of air. So by definition, the throttle is in fact controlling boost. The degree of control authority will relate to the % TPS at which futher throttle opening has negligible effect on airflow. And this suggests that correctly sizing the throttlebody will have a direct bearing on driveability.

Cheers... jondee86

[Norminator]

Just use a wastegate on the inlet to bleed the boost vs. rpm down to wherever you want via the ecu. Add a speed sensor on the tailshaft if you decide want to get tricky later and have the ecu control boost per gear, but as Hen says it is really a non-issue on a 4A unless you are wanting TC for the purpose of launch control.

[jondee86]

Traction control is well down my list of things to do I have to get this project built first, and then get it running. My priority is to have an engine that responds to the throttle in a progressive and predictable manner. If there are no surprises in the torque curve, then traction (as pointed out above) is not an issue.

Being a noob to boosted engines, I need to sort out anything related to engine/boost/water injection control before I do the final layout for the intake ducting. Stuff like the bypass valve, IAT and MAP sensor placement, ISCV and placement for the water injection nozzle/s. This project has been on the back burner for a lot of years, so I only intend to do it once, and I want to make sure I get it right the first time !!!

Thanks for the input. There are bound to be more questions once I start getting stuff fabricated.

Cheers... jondee86

[trdee]

yeah linear throttle response is not an issue for supercharged engines. turbo only (and even then it isnt anywhere near as big an issue as the internet would lead you to believe)

any other questions that crop up just post in here. plenty of us around that have played with boosted 4As in all their forms

[jondee86]

Finally... some progress



Picked these up today, and tomorrow I go and make a trial fit on the engine to see if my "guesstimated" measurements will get the charger sitting in correct alignment. As you can see I slotted a lot of holes to allow for some margin of error !!

Cheers... jondee86

[knightrous]

That's a nice way of tackling the situation.
I'm currently reusing the lower factory SC mount and tensioner for mine.

[jondee86]

Yeah... I'm using the GZE lower mount and the GZE manifold. Made the job of figuring out how to mount the charger much easier, and avoided having to build a custom intake manifold. Won't be the best flowing setup, but it will do a job, and since I don't have a welder/can't weld, I like bolt-on parts. Will have to get the ducting welded or use some of that aluminum flexiduct

Should have a pic of how the charger sits tomorrow. The mounting plate bolted up and so far is looking good. Put an AE92 water pump onto the RWD rear pump housing to get all the pulleys lining up, and it looks like RWD water fittings/circuits will be OK. If it turns out there is an interference problem, I will have to sort that later. I already have a RWD hard pipe modified to miss the Knock sensor.

Cheers... jondee86

[jondee86]

Managed to get all this stuff bolted up loose to see how it looked...



Charger sits well out to the side but still has about 50mm of clearance from anything important. May have to relocate the fuel filter if it gets too close.



I'm hoping that the top radiator hose will clear the top run of the belt, and the bottom hose go under the bottom run. Worst case, I have to modify the bottom water outlet. Pulleys all line up within 1mm at this first fit stage, so I don't think I'll have to do any modifications to the mounting plate.

Now to start collecting bits for the ducting...

Cheers... jondee86

[jondee86]

Well, it's all in there now





Just need to get it driving

Cheers... jondee86

[knightrous]

For my install in the AW11, it requires the supercharger to be tucked in fairly close to the motor to prevent it hitting the firewall. However, I ended up having issues with the supercharger fouling on the intake manifold. I recently resolved this issue by switching to a small port head and intake manifold, which gives a good 20+mm of clearance.

[jondee86]

Yeah,,, not a lot of room on the AE either... there are several places where I have only about 5mm of clearance between the ducting and immovable objects. The most time consuming part of the whole job was designing and re-designing the ducting until I was able to find a layout that would work.

The idea was to try and keep the ducting free flowing, and bring the discharge into the GZE manifold in a way that would give moderately even distribution to all cylinders, and I think I have achieved that. Fitting the ducting and getting the clamps on is a real mission... just hope that it does not have to come apart too often !!! If you put the S/C discharge closer to the block you will need to be creative with your discharge manifold. But being able to support the S/C off the end plates will save a bit of room on the discharge side.

Had the engine running for ten minutes today while I adjusted the fuel map. Got it idling smooth and steady at 900 rpm and 14.3 AFR. Looks like I have some calibration problems with the MAP and temp sensors, as the readings don't look right, so I'll try and put some time into that tomorrow.

Cheers... jondee86

[trdee]

looking good! good to see someone finally following through with this

[jondee86]

Had to make a few changes as it turns out having a by-pass valve actually
does have some benefits apart from fuel economy...



That's a standard Bosch valve as used on some kind of Ford... Sierra Cosworth
IIRC. Sounded fast enough for my Corolla Spent a couple of nights reading
178 conflicting internet opinions on which end should be connected to boost,
and went with the option that made sense... boost under the valve and intake
manifold pressure on top of the diaphragm.

I've had a few small problems to work thru, and today was the first real drive
with everything running properly. Started working on tuning the fuel map with
a gentle cruise on a couple of back roads. Log shows maximums of 31.1%TPS,
112.2kPa and 5063rpm. Pedalling at this level delivers acceleration pretty close
to what I had with my N/A engine running ITB's and cams at 100%TPS

There is one question that I'd like to resolve, and that is what to do with the
IAT Enrichment Compensation table. The sensor is in the intake manifold, and
I am getting a temp of around 60degC under the above driving conditions. At
this temp the ECU is pulling 5% fuel and my AFR's run lean. Now this may be
acceptable for a N/A engine but I am not so keen on running this engine lean.

I'm thinking of just setting the compensation to zero above 35degC. Happy to
listen to any comments relevant to IAT compensation

Cheers... jondee86

[jondee86]

Awesome picture of plug sprayed with vapourised GZE piston coating...



And borescope shot showing where it came from...



That's what you get for running lean at cruise with a plug one heat range too hot.

Cheers... jondee86