I was thinking more along the lines of a 10 inch tall bonet scoop with NOS stickers on the side of it...... Just to keep things stealth

Looks impresive. What kind of charger is this??

Toyota SC14 (1400cc roots) from a 1G-GZ series engine.

Originally I was expecting it to be too big (it is underdriven) and give a progressive boost as the revs increased and it moved into its efficiency range. As it turns out, it gets 5 psi of boost by 1500-1800 rpm and is only producing '5 and a bit' psi by 6500 rpm...... so it seems that the SC14 still works ok at very low blower rpm. May even be possible to use it on a A12

I thought a blower was just a big air pump an it didn't matter what size engine it was on??

Any one mind explaing it a bit more to me.

i think you are right pager as they are not like turbo's that rely on exhaust flow to get them spinning i am using the same sc14 on mine and getting 10psi

Pager, A positive displacement supercharger
displaces a set amount of air per revoulution.
If it is put on a bigger displacement engine it will have to be spun faster to produce the same amount of boost. the problem with this is each supercharger has a maximum RPM. On a bigger engine you might be over reving the blower to get the desired boost.
I hope this helps, Simon.

I agree, It does look very neat. If only we had that much room to play with in the front wheel drive F10!! It looks like I will be fitting my blower directly on top of the inlet manifold else I will have to seriously modify the bulkhead!

Thanks Simon,
So i guess you carnt have a blower to "big" for a engine.

Sort of, just the extra HP a larger blower costs us to drive and room constraints,
Also diferent blower types have diferent efficiencies. rootes type down to 45%(GM-Toyota type), Screw type about 70-75% (sprintex and others). Centrifugal (turbo type compressor, belt driven)70- 80%efficient.
Efficiency is the amount of boost V`s amount of heat added to the compressed charge (higher the percentge the better)

Note: Centrafugal blowers dont make as much boost at lower rpm, so a down side there..
Horses for courses really,
Simon

To say it a different way there are two main categories of blowers:

* Centrifigal, very similar to a turbocharger. Both use a compressor wheel except the blower is engine-driven rather than exhaust-driven. These make more and more boost as they rev up. The early designs like '57 Ford and Shelby Mustang used this type. It is also a favorite of modern racers.

* Rootes/screw/etc. (positive displacement). These are much less RPM-dependent. They make boost at low RPM all the way up to their maximum design speed

The Rootes blower was designed as an air pump for industy (not for engines). It is not as efficient as a turbo meaning it takes more horsepower to run the compressor. It is mainly used to give the full-RPM boost experience.


A turbo is third category of supercharger (called a turbo-supercharger).

IMO all valid comments so far, but here is what I was getting at:

The efficiency range of the rootes blower is typically between 4000 and 12000 rpm. above 12k it is a) producing a lot of heat and b) is in danger of self destructing. below 4000 rpm, (according to the textbook) the lobes of the blower arent spinning fast enough to prevent boost pressure blowing back past them. this is simply because of the tolerances. As the blower speed increases, this problem becomes less. As the boost level increases, this problem becomes greater.

Now. with my current setup the pulley ratio is around 0.85 (105mm crank pulley, 125mm blower pulley) i.e. underdriven, so the blower is rotating slower than the engine. At 6500rpm the blower is only doing around 5500rpm..... and at 1800 rpm when I have almost full boost, the blower is only doing 1500 rpm. Therefore it is working way outside its efficiency zone for most of the rev range.

This problem is made worse if you try and put more boost through a smaller engine. if this exact setup was used on a 1200 it would be trying to push around 8psi into the inlet manifold at the same low blower speeds. So according to the book, it would be horribly inefficient, but from what I have seen out of my car, there's a chance it might work ok anyway.

anyone got a spare A12 they want to blow up?

lovely job, looks so neat and tidy
how much power does it make? I guess the increase in torque would be the big factor of improvement?
I always wondered what a garden blower-vacuum thing would do if plumbed up under a bonnet and powered through a 12VDC-240VAC inverter and then swithced on over 5000rpm, always wanted to know what would happen but never had a car crap enough to risk blowing to bits

Well how about this from J.C. Whitney
electric turbo

And all the pretty colors too!!!
(sorry about the large pic)

Quote:

IMHO a complete waste of money and a con.

OMFG that is fully sick mate!!!! do they make curling irons as well?

$345 US is pretty expensive for a portable hairdryer..... how dumb are these people?

& their customer feedback section is hilarious "now my honda can pass a camaro on the freeway" well, yeah, just so long as the camaro isnt accelerating.

bwahahaha, I was only suggesting trying it to see what happens, and yet some people have gone into full on production!
ahhh well a fool and his money hey?

Possibly being a bit cynical here, and had a bit of a think about it..... There is a 'chance' you would see a noticeable increase in power with things. They are unlikley to give you much in the way of actual boost, But they would improve your volumetric efficiency, because the engine would not have to draw the air in. so on an old dunger with a poor VE (holden red, valiant six or, dare I say it, A-series) you could see a result.