Setting up SC14 Supercharger

[Bazooka]

I'm planning on supercharging my IS200 with an SC14 I've had mothballed for a while now just waiting for such a project. The whole mounting and plumbing thing is not a real problem except for maybe how to work in an ABV. Now as this SC has the electromagnetic clutch on it I've been thinking of the best way to activate this. I want it to be fully automatic so no dash switches etc. What's everyone doing in the way of activating the SC? Is it as simple as a switch on the throttle triggering at a set position or something more complex such as vacuum operation?
How do the factory SC12/14's actually operate?
I'd like to keep it as drive-able as possible with boost coming on steady rather than just a kick in the back at a certain RPM.

[masterofsinanju]

As I understand it, in a factory 1ggze the SC is switched based on manifold pressure. I'll see what I can find in my 1ggze manual but it's all in Japanese. Possibly of limited use.

If you have an SC14 from an estima, I'm not sure how they were switched.

Many people either wire them for always on or from a simple cab mounted switch.

All that aside, what other mods are you panning? Does the factory ECU have enough flexibility to support the SC? Will your injectors deliver enough fuel etc etc. There are possibly better/cheaper ways to power up an IS200

[Bazooka]

I am thinking of using manifold vacuum as the trigger but just just can't get my head around a complete working system. Just wanted to know what others have come up with. It's an SC14 from the 1G, the 2TZ version has weird manifolds and harder to plumb.
Full exhaust system upgrade is the first thing on the list. Bigger injectors can be found from the 1ZZ or 2ZZ. Back in the day TTE made a SC kit for the IS200 and used a piggyback "black box" which I have found is still being copied and sold to this day. This should be good for up to 10psi boost which is more than enough for me. Unfortunately the TTE kit is no longer in production and second hand ones, if found are very expensive. I figure I can get out of it a lot cheaper going this route.

[Hen]

This is just form the top of my head, but I got a 4AGZE working nicely switched on manifold vacuum. On at 8" water and off at 10" water, with a delay on the off-switch to prevent it cycling during quick changes (eg gear shifts).

I also ditched the ABV and things still worked fine. It's a while ago now, but from memory there was a smooth transition as the SC switched on and off.

[Bazooka]

Thanks Hen, I actually just found this write up http://mr2.com/TEXT/SuperChargerInfo.html that relays what you have specified. Although it doesn't specify I assumed this to be "Hg and not "H2O as 8"H2O is very low.
A vacuum trigger at 8" sounds like the way to go and switched through a time control relay set at 5 seconds sounds easy enough. My problem now is that once boost is achieved and the manifold sees positive pressure this will switch off the vacuum trigger and I'll only have 5 seconds of boost at any point. I'm just not sure how I can control this side of things. What's got me stumped is that I don't know how I can incorporate the second figure of 10" into this setup.

Another thing I have been pondering is will I need an ABV and a BOV or just one valve to do both? I'll certainly require an ABV at idle and low RPM to draw around the SC while clutch is disengaged but also there needs to be some venting when throttle is closed during gear changes and braking. Can one valve be setup to do this or will I need to run two valves? I was just going to use a cheap BOV as the ABV.

[Hen]

Yeah, I reckon that site you link is where I got my info 15 years ago. And you're right about water and Hg. A 5 second delay is also a bit much I think. 2ish would be fine.

You shouldn't lose the SC signal once you hit boost. Boost is still less that 8" of vacuum, so that the switch will stay on. Only once you close the throttle and manifold vacuum increases beyond 10" then it will switch off (measuring vacuum seems a bit arse about, it switches on over a certain manifold pressure, and off under a certain pressure). I have only ever done it with an aftermarket ECU, but imagine that you could find a pressure switch that could control it, hopefully even with the right hysteresis. I made up a simple circuit for the delay too. It looks like I've lost the diagram on past computers, but may be able to dig out a paper copy. It was very simple.

It may be OK without an ABV. Will the throttle be pre- or post-SC?
If it's pre-SC then there is no need to worry about throttle closing. It just causes vacuum at the SC inlet and thereafter manifold.
If it's post-SC, which is not recommended for positive displacement SCs, you can just run a biggish blowoff valve. I've done that for a few years and it just sounds silly.

And at idle, even with the SC clutch disengaged, the motor will suck air through the SC, spinning it slowly. All this might make it inefficient/sluggish off boost, but that has never bothered me much.

[shrike]

2AZFE injectors are larger again then the 1ZZ or 2ZZ and are newer, they should fit without hassle

[Bazooka]

Maybe I have been thinking of vacuum in the wrong way. I may have to put a gauge on the car first and see what it is actually doing to get an understanding of what I need. Obviously at this stage the figures we have been throwing around are only a starting point and may have to be adjusted to the specific setup. I was thinking of an adjustable vacuum switch, one I found is adjustable from 6-22" so in the ball park. This triggering a time delay relay, again adjustable from 0-999 seconds should give me all the adjust-ability i need.
The TB is post SC so I think an ABV will be required, especially for drive-ability. This should also be able to be adjusted to allow boost to come on steady and not just a big whack of boost at a single point. The whole concept is to make it feel as smooth as possible and even be able to drive around town off boost and keep the fuel economy. We also have to factor into the equation the fact that the wife also drives this vehicle. So in consideration she will most definitely be upset if she has to wrestle with a hard to control, boost spiking beast.
I did come across this diagram of a setup on a Honda (excuse the french) which pretty much lays out what I have been thinking my setup should be.

http://i180.photobucket.com/albums/x...erconcepts.jpg

Only thing he's missing is an intercooler which I myself am still toying with.

[Bazooka]

2AZFE injectors are larger again then the 1ZZ or 2ZZ and are newer, they should fit without hassle

Only going off what I have read from the UK guys and their TTE kits. Many only use the 1ZZ injectors and the 2ZZ (314cc) are good for over 250bhp. That's more than enough for what I chasing. Haven't looked at the 2AZ, what do they flow? Are they the newer 12 hole injector?

[shrike]

Only going off what I have read from the UK guys and their TTE kits. Many only use the 1ZZ injectors and the 2ZZ (314cc) are good for over 250bhp. That's more than enough for what I chasing. Haven't looked at the 2AZ, what do they flow? Are they the newer 12 hole injector?

07 up they are 370cc the supercharged version are 440cc and yes they are the newer 12 hole injector from my understanding

They are also super cheap and easy to get at wreckers think I was looking at $50 last time I got a quote with the injector loom as well (pretty sure the plugs are the same however)

[Bazooka]

Thanks shrike but as I said the 2ZZ injectors flow more than enough and no point in overfueling. These are good for 250HP at 80% duty cycle so right in the range I need.

[AE25]

bozooka. having the throttle after the SC changes everything completely. An ABV becomes mandatory. A BOV could be used but as Hen says, the noise from it is stupid. The most widely used ABV are either a poppet (wastegate) valve or butterfly valve operated from manifold vacuum. Without it, a toyota roots charger will have a short life from overheating and having 20psi against a closed throttle causes all sorts of drama.. slipping belts, burst piping etc.

Also throttle after SC, an intercooler can be the usual for a turbo system. But throttle before SC, the intercooler and plumbing volume has an affect on lag and run-on after the throttle is closed. The more volume of the system between sc and engine, the longer it takes before the engine decelerates. ie a plenum, big or long piping and large intercooler have an annoying negative affect. you'll notice on 4agze, 1ggze that the plenum are small because they're a throttle before SC system.

[porkrot]

Hey guys im currently installing a 1ggze into a hilux and was thinking about adding an intercooler and upping the boost alittle but from what AE25 says this may have a negative affect ? Should i be looking at running a BPV and moving my TB to after the SC so i can use an inter cooler ? Ideas and advice appreciated.