The Mega Supercharger 4AGZE thread, using twinscrew charger

[jondee86]

also, this may be interesting for you http://www.toymods.org.au/forums/eng...or-2087-a.html

That is a bit interesting. That's the size below the Autorotor that was for sale in NZ, and got me started down the twinscrew track. I'm going to be mounting the charger a bit lower on the engine, and I have to bring the intake back over the top. I've already drawn up the Sprintex mounting plate, and will be mocking one up out of plywood or similar this week to check clearances.

Cheers... jondee86

[Q-Authority]

Actually I think 1.8mm is the standard hg thickness, while variations are often available in 1.2mm & .8mm thickness. At least that is how I remember it when I ordered my Toda 1.2mm 'stopper' hg. As for hg cylinder size I think the oem and Toda gaskets are designed with os pistons in mind, so it's one slightly oversized cylinder gasket hole fits all. Not sure about the TRD hg, but would think it allowed for os as well.

[trdee]

Pretty sure the stock HG is 1.2mm. Also I think you might be right about the "one size fits all" style for the stock head gaskets. Actually, I'm currently looking at head gaskets for my motor as it's one of the last things I need to pick up before I can start building it. Tempting to get one of the HKS 2mm head gaskets and just go spastic with the boost lol.

[Q-Authority]

Yeah, I think you're right on the hg oem thickness. It's been awhile since I checked on it, and keep getting some of the numbers from HKS and others confused. Toda actually comes in 1.0, .8, and .6mm, which confuses me even more, lol. Plus HKS only makes extra-thick gaskets to make things even more confusing.

Most of them though seem to make the bore diameters from 82 to 83mm, with most being 82.5-83mm, allowing for full oversized boring.

[jondee86]

Found this at Pick-apart today...



Came off a turbo wagon and measures 65dia at the front opening, 60dia throttle plate. The cool thing is that it has some gearing built-in to the linkage. Slows down the first opening, so could save me having to dick round making my own gearing. The roll of tape is holding the throttle partly open to give you a better idea of how the linkage works. I also get the choice of two different radius quadrants for even more fine tuning

Cheers... jondee86

[jondee86]

The GZE rail has the pulsation damper and FPR at the opposite ends to the N.A. smallport rail. But it looks as if the FPR can be swapped over to my existing smallport rail easy enough.



Actually, I'm not even certain that I need to use the GZE FPR, as I read somewhere that the smallport FPR will work OK for boosted applications. But just to be on the safe side... I'll change them over

Cheers... jondee86

[trdee]

fuel pressure reg just works off differential pressure. it can be used without issue. you won't run out of flow either, i was making 180rwkw through one

[knightrous]

also, this may be interesting for you http://www.toymods.org.au/forums/eng...or-2087-a.html

Just to bump this thread, I bought that twinscrew.
Test fitted it in my AW11 and found it fouled against the firewall and the pulley was very close to the chassis.


My plan is to modify the stock inlet to have a difference shaped plenum but still retain the same amount of volume. This will allow me to mount the supercharger 25mm close to the head.



The fuel regulator will also need relocated as it will hit the mount for the supercharger once I move it.


The angle bracket will become more of a T bracket and the studs will be removed to allow the supercharger to bolt up nearly all the way to the bolt heads.


Found that 4AGZE flywheel bolts will do the job nicely



Plan is to run my Nevo 170mm crank pulley and the 88mm pulley that came with it.
According to the supercharger calculator, this should be around 18-19psi of boost which should be a good amount more punchy then the old SC12 at 12psi.

[jondee86]

Got sidetracked for a while, but I'm back onto this project now. Have decided to go with the S5-210 Sprintex and gear it for 15psi. So I will be using the GZE 8.9:1 coated pistons in the smallport engine, Adaptronic e420c engine management and intend to add a progressive water/meth injection. Nothing too extreme there

However, there is a question to which I have been unable to find a satisfactory answer, and that is how do the guys with the 25psi (and higher) builds avoid destructive detonation ?

One site, that seems legit, says that 9:1 static compression and 15psi of boost, gives a 15:1 effective compression ratio. Raising the boost to 25psi give 19:1 effective ratio. Yet I have read of many builds running between 15 and 25 psi of boost on early bigports with not much more than a GZE ECU, uprated injectors and an adjustable FPR

What's the secret ? Are these engines detonating themselves to death, or is the threat of detonation over-rated ?

Cheers... jondee86

[trdee]

Well firstly, bigport GZEs have 8:1 comp, makes a difference. Fuel quality, intercooling, ignition timing and intake temps all play a factor as well. a well sized turbo at 25psi will be pushing out a sweet chilly breeze compared to an SC12 screaming its tits off and spewing air hotter than the fires of hell for that level of boost... also at those levels you will likely find timing at full boost can be as low as 10deg, which drops the peak cylinder pressure down even though your dynamic comp has increased.... there's more that affects detonation than just the compression ratio.

[jondee86]

Yet I have read of many builds running between 15 and 25 psi of boost on early bigports with not much more than a GZE ECU, uprated injectors and an adjustable FPR

Ahhh... should have said that these were turbo builds, often just on old N.A. bigports. I know that some of them went thru 3 or 4 engines before getting one to hold together, but ultimately they held

For my application (road car that will see the occasional car club event), reliability and drivability are priorities. So I am limiting boost to 15psi to have a decent safety margin. As you mention, factors such as using high octane fuel and giving the engine enough fuel, cutting back timing as boost goes up, keeping the charge temperature down and monitoring for knock are all important.

I guess what I am really asking is... will 15psi with the twin screw and water/meth be a safe and pretty much foolproof setup for my first boosted engine ?? I don't want to be spannering on the car every weekend

Cheers... jondee86

[knightrous]

If this is a daily car, I'd be ditching the water/meth and just go for a regular W2A.
It doesn't mess with your AFR and doesn't need to be topped up.

[jondee86]

It doesn't mess with your AFR and doesn't need to be topped up.

The car is not a daily... just a toy for fine days I don't really have the space to fit an intercooler, so that's why I was planning a progressive water/meth (or maybe just water only) with injection starting at (say) 6psi and ramping up with boost. That way I was hoping to only be misting when I was having fun... not during normal round town running.

How much does water/meth or straight water mess with the AFR ? What kind of affect does it have on the AFR ? Is it predictable, to the point where it can be compensated for in the fuel map ?

This is the kind of information I need for firming up the system design.

Cheers... jondee86

PS: I read that meth is corrosive to metal components, so for my modest requirements water only (ala Aquamist) might be the better option.

[trdee]

I haven't played with water meth myself personally but as an obvious kinda suggestion I would suggest that the most important things to keep on top of are AFR and intake temps, and to make sure you have your intake temp correction table sorted and have timing progressively pulled/fuel progressively added as the intake temps go up.

Ive seen GZEs running 14psi reliably (well, the supercharger certainly didnt like it, but the engine coped fine) but that setup had a monstrous water to air cooler which kept the intake temps under control

[fixeruperer]

good tuner helps things stay together.
15psi is nothing for a 4agz