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R32,

do you realise how much air you have to by- pass,and it is around all the throttle bodies.
That whys it is easier to do it on a single throttle bodie.

From what I rememeber when we used to use it on the Cossies you had to port the
idle control valve to flow more air then it could un-modified.To enable it to flow the
required air to allow the anti-lag to work.

Steve will be able to correct me on this.

Mark
 

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I understand its much easier with a single throttle body.

And no, I don't know how much air is required. The pipes behind the throttle bodies are 2x1/2" ish. I've used one for the vaccum and blocked the other one off. So im left with one 1/2" ish pipe that could be used. Would that not be enough?
 

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Abbey M/S said:
R32,

do you realise how much air you have to by- pass,and it is around all the throttle bodies.
That whys it is easier to do it on a single throttle bodie.

From what I rememeber when we used to use it on the Cossies you had to port the
idle control valve to flow more air then it could un-modified.To enable it to flow the
required air to allow the anti-lag to work.

Steve will be able to correct me on this.

Mark
Yup, like Mark said for ALS to work PROPERLY you really do need a LOT of airflow, a lot more than any std idle control system could flow.
Dont forget, your trying to make the engine still see BOOST, and thats a shitload of air, esp if you want it to sustain any decent amount of pressure.
Even trying to keep the car at zero vac' needs a fair bit of air bypass, probably a good bit more than the std idle setup could give!
Also another thing to bear in mind is we not talking a 2litre engine running a 400-500bhp rated turbo here, we talking a RB26 and much bigger turbos, so much more airflow needed for a good effect.

Thats why 99% of roadgoing ALS systems ive seen do bugger all but make a few pops n bangs.

On a 6throttle GTR i could see the only sensible-ish way would be using some form of throttle kicker to electronicly hold the throttles open a bit when the ALS is on.
On a single throttle it makes life a lot easier to make a suitable bypass (im on single throttle now, if was on 6 still i wouldnt even think about it).

Marks right about the modified idle setup on Cossies.
There was a few ways to do it...

With the valve itself you could either mod the std idle valve to enlarge the opening which worked "ok" (what i mean by OK is it WAS effective performance wise, not just some crappy pops and bangs) on milder setups, or could go the whole hog like i did for a really vicous setup and use a dirty great Mountune ALS valve which was about 45mm diameter and had a lift of about 30mm too.

With the body the valve sat on, you could either mount it on the std ISCV location on the throttle body and enlarge the ports that bypass the throttle (they have a lot of meat on them, can make them well over an inch wide so thats very effective), or you could use a remote mount which of course you could make the pipes etc as big as you fancied (and then can keep the std ISCV on the TB too).

Heres some pics that might help explain...

Std ISCV

Right, youl have to look closely but not just above the rubber o-ring theres a indentation, thats the side of a plunger inside the ISCV that lifts to let air thru (it enters from the hole at the bottom), as you can see thats bloody small, but you can enlarge that hole to go almost all round the ISCV which makes it far more effective.
The limitations are obviously you cant enlarge the entry hole, and you cant make the exit hole any higher, just wider.

Proper ALS Valve

This valve as you can probably see is just literally one huge valve (in its "up" position) that moves up and down on a spindle. Its opened and shut by an electro magnet.
Its pretty obvious from the pics how huge it is compared to the std one, even when the std one is modded.

As i mentioned earlier, if we talking RBs and big turbos youl need even more airflow than YBs running relativley small turbos to have the same effect...

:)
 

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Yup, thas used on some rallycars ALS setups, throttle kickers they call them.

Youd have to obv have a play with it to work out the right amount of throttle opening tho but thats a minor detail id of thought.

I dont know much about throttle kickers myself, be interesting to know prices and so on.
 

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A 12v solenoid like on for central locking would do I reckon. 1 on each end and your quids in. I've got some really strongs one too, time to play about methinks :smokin:
 
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