The engineer should be able to give you details of what the test involves. In NSW and some other states the IM240 test is deemed to correlate well with the full ADR drive cycle. The IM240 is a 4-minute (240 seconds, hence "240") subset of the ADR drive cycle, run on a warm engine, thus eliminating cat warmup time as a factor. It mainly tests closed-loop operation and doesn't have much full-throttle acceleration.

The only wrinkle in NSW is that the test is done in a sealed lab which collects ALL emissions from your car, so any oil vapour from leaky gaskets, petrol fumes from a poorly-sealed filler etc will all count as hydrocarbon emissions. One common issue on AU's is the diff breather hose which plumbs back to the intake or fuel system canister, often breaks near the axle. So if you have to pay $3000 for the test, make sure you don't have fuel, oil or vapour leaks, a good cat, oxy sensor, plugs, leads, filters etc.

I've got a 6 psi pulley (3.15) and belt to suit if your interested. Pulleys done about 1,000kms and belt is about 100km old. I'm stepping down the to 2.7 pulley now so it uses a shorter belt due to the smaller pulley, so both have to be replaced. If I remember correctly CAPA sell the pulley for around $160ish and the belt for around $180.00 ish.

Terrific - thanks for that info - I knew some of it rang a bell !

Funny that you mention cat warmup time - I recall this was a fairly main concern - specifically for turbo setups having to ensure the cat was as close to the turbo exhaust housing.

The belts sell for 180? Gee! But yeah, i will pm you once i have the dosh for one

I rang Capa the other day "A technician will call you sometime later today"
That was Wednesday, might give them another buzz today
Sure i'd be interested in the 6psi pulley, but i do have a few questions.

The higher the rated pulley (say 9psi) means the earlier the supercharger spins up, hence eliminating negative boost?
1. So if i go from 9 to 12psi, boost will kick in earlier, because at the same engine rpm (say 2000rpm) the supercharger will be spinning 1/3rd faster, eliminating negative boost and increasing economy, power, reducing lag etc.

2. I really, really want the supercharger to produce boost much earlier, but how?

3. Is it possible to get the sc boosting up earlier (so in the higher rpm it would max out), but then maybe a clutch stops it maxing out earlier, keeping it at a predetermined speed (to save the sc from revving out)

A few things me and my friend Alex are wondering are:
4. To eliminate back pressure when in the lower rpm range (supercharger creating negatibe boost) why you cant put a one-way check valve to allow air to be sucked into the pipe between the sc and the throttlebody.

Under boost, the valve is closed, the bov or plumback does it's job, boost results.
Under negative boost, the bov does nothing, the one-way check valve opens and allows air to flow in (of course this will have an air filter)

Sounds so simple that i am sure it has been thought of.

5. A plumback on a sc? How are there any emissions coming from the sc?
It's driven off a pulley? -Thats Alex's argument, im just like "i agree, but if it needs to be done, it needs to be done, plus its quiter"

lol, life story *yawns* im gonna go flush my cooling system, change the oil and get a new windscreen fitted
Laters; and thanks so far
Matt

Yeah, blower stuff is not cheap. CAPA probably arn't the cheapest to buy from either but.

I've never had a trouble getting through to CAPA by phone, only e-mail.

1. The smaller the pulley the more boost the blower will make and the earlier it will start to boost up. So going from a 9 psi pulley to a 6 psi pulley will make you loose power and torque throughout the rev range. The smaller the pulley the higher the boost rating of it.

2. in theory what you could do is fit a small pulley to the blower so it boosts up low and early to give nice down low and torque. Then use a bleeder or some sort of waste gate contraption to vent off excess boost (i.e. the blower will still be producing it, but some of it is vented out of the system to avoid putting 15psi or whatever into an engine that can't handle it).
with the powerdyne this is not possible. Basically the powerdyne has a maximum internal RPM. With out Falcon I6 a 2.7 pulley is about the smallest you can go. You could run a 2.5 probably if you were careful with it and didn't rev the engine up as if you did the bearings in the PD would s**t themselves.
There's also a second problem in that the impeller of the PD has a maximum rpm efficency, anything after that speed and it's not doing a great job...
There's also the belt but I've heard these usually break when the bearings have gone or are on there way out.
Another option I've recently found is that in the USA there's a mob, 928 Motorsports who sell a replacement impeller, this impeller is rated to up to 60,000rpm. They claim that it is 20% more efficent that the standard impeller. So if you replace your current impeller with it, they reckon you'll make 20% more boost. They say that most of the blowers they rebuild with it, the owners go up a size in pulley and still make the same boost, which prolongs the life of the PD's bearings as they're not being spun so fast.
Aside from that I know of no other way to increase your low down, especialy with not increasing your top end.

By the way what size is the current pulley your running?


4. I reckon you'll find that although the engine is capable of taking more air, it's wouldn't actually have enough suck to it to work.


5. AFAIK - plumbacks were not made because the air actually has any emissions in it. Think about a turbo, they are no different to the blower, the air still doesn't have any emissions. They were made due to cars running MAFs. Basiccally the air would come in through the MAF -and so the ECU would know how much air had entered. The ECU would then provide the amount of fuel required for that air. But if the BOV later on in the system released that air the remaining air was going into the engine with more fuel going in than required for the correct ratio of that air, therefore the exhaust gas was very rich being bad emissions. So any car running a MAP doesn't have this problem as MAP measures only what has entered the manifold after already going past the throttle body and BOV.

twr7cx is spot -on with point 5. As far as emissions go, an atmo-vented BOV is perfectly legal on a MAP (or TMAP, MAF-less) equipped car but may not be legal with a MAF. I posted a long technical explanation of this from an engineering signatory (NSW) on AFF. But emissions are not the only hurdle to jump. An atmo-vented BOV may be too noisy to pass a drive-by noise test, so the plumb-back may be needed on noise grounds.

As far as point 4 goes, IIRC the CAPA or Raptor (or maybe 928motorsports) site explains that a centrifugal blower offers little restriction to air being sucked through it. So "negative boost" would be negligible. There should be slight positive pressure (perhaps under 1psi) by 2000 rpm anyway.

Hmm, thats cool to know, thanks

You've all been incredibly helpful, thanks for all your time its most appreciated.

I cant believe i waited so long to get into the forced induction scene, wow its a totally different thing isnt it?

Matt

I got an engineer to look into engineering a Capa kit about a year ago. At the time he said he couldn't get any documentation off Capa that the 4.0L powerdyne met ADR emmisions requirements. So i didnt go any further buying that car.

Its a myth that each emmision test is ~$3k, they can and have been done for about $1.5k. As others have said best thing is to get the list and start ringing around.

Cool thanks alot mate
Matt

That is what I was quoted from Dynomotive in Bayswater who use Archie Robertson as their VicRoads accredited engineer.

Show me / prove who will do the emissions test for cheaper ? AFAIK, it all gets done at the same testing facilities.

Emmision testing in NSW Sydney at Botany or Penrith is for free.

If it passes the emmisions test then you will recieve documentation which you forward onto your engineer then he can engineer the work.

WOW free in NSW

Just goes to show how much VIC bends us over, Hey ?

Yeah $1,500 is stupid, $3,000 is totally unrealistic!
Matt

Last edited by -GAS-MAN- on Thu Feb 14, 2008 8:23 pm, edited 1 time in total.

wait till you get to WA.. I think there is only one company in the state that actually has the equipment.