BXProject

[docchevron132]

You're not seriousley going to strap a turbo to a N/A lump surely????

[Philhod]

I'm going to modify the KKK by drilling small holes in the periphery of the intake side.

When the blades spin, they go very fast, causing a partial vacuum between the ends of the blades and the casing, producing quite a hefty drag.

We countered this on "big uns" by measuring the peripheral steam values, then drilling small holes at a sharp angle to the direction of rotation, surrounding it with a box full of steam
(or air in our case). This was then drawn in, releasing the vacuum, giving something like
40% more push.
Well that's the theory anyway

And stop calling me shirly

[docchevron132]

Either way, on an N/A lump it wont last long...

Erm, you prefer Belinda maybe??

[Philhod]

The btm end is well strong enuff and with a proper front mounted home made I/C, nice cool charges should stop swirl chamber issues at the top.

That head you gave me is sound throughout there were no cracks around where they are pressed in and I re shimmed the tappets to minimum once the head was on, so.......

Well it's not mine now, is it


OK Shirley will do

[Bx Bandit]

I'm not so qualified to talk on such matters but they had a lot of troubles putting a turbo on the BX 1.9 - head related - going bang and stuff. But the con rods and err other stuff is uprated on the 1.7 TD.

Anyways, won't that turbo draw in unfiltered air and stuff?!

[Philhod]

It will unless I do some plumbing. That's still at the drawing stage yet. shouldn't be too hard cos I'm thinking of mounting it on the inner wing driven by electrikery, so you can switch it on and off.
So it's a part time blower, to use when you feel you need a bit more .....err push.

[Bx Bandit]

and your grandson will only use it occaisionally?! Bandit tip: Bin the switch!

[gregzee]

haha well my mate has a toyota starlet gt turbo imported from japan and i need something that can beat him so need a turbo me thinks. don't think i can beat him anyway cuz he just tuned it to 205bhp. i'll av a go though hehe

[Bx Bandit]

Go for it mate! I want the full works though. Lowered susp, extra hard spheres, ultra violent head lamps and a bo shackala sounds systeem maan!

[docchevron132]

Get a valver instead.
That'll rip the Starlet a new arsehole without any mods!

Running the turbo from lectricky??

Like, through a motor and gearbox??

[Philhod]

err Yeah I'll let you know what I'm using when I've done the sumz and....technically it will be a supercharger

[docchevron132]

hmm, wouldn't it then be more efficient to use a supercharger? I mean, surely a made for spurpose supercharger will move more air than a turbo at the same speed??

[Philhod]

Not if my calculations for reducing drag are anything like correct

An anyway, that would cost munny and he aint got non

[docchevron132]

I see, so in effect you want to increase the output of the turbo by reducing the frictional drag of the rotating veins?

Interesting stuff...

I assume then that the same principal could be applied to a turbo being operated by air (ie, as turbo's are)? Therefore giving a performance gain...

Like, so I could get even more boost from the Garrett....
Thats twin vein though, I guess that would rather make a difference to how to go about reducing the drag..

[Philhod]

Err... no yes and no.

Basically your correct only its not frictional drag..
When you propel a err propeller I mean a turbine, by whatever means, the action of the blades zooming through space at a high rate of knots causes vacuum drag between the end of the blades and the casing or cylinder. It's the same principle as ground effect on a racing car or if you ever held an oxy pipe near a flat surface, rather than push it away, when you get close to the surface it actually sucks it downwards.
As the air is passing laterally from the inlet side of the blade to the exhaust, the effect is heightened at the periphery.
There is no way you can bleed this off so your only option is to inject whatever you are driving it with, through "tueres" stratigically spaced round the periphery, at an angle back from the direction of rotation, slightly off ctr towards the exhaust side of the blade C/L.

Now I know all this from building and modifying big ones, but, Details of the angle of the holes, size of holes and how many, are what the experiment is all about.
It will be a mixture of given knowledge, mathematics and guesswork, in whatever percentage you like
Seeing as it would spin faster for less given effort it should have most of it's effect at the lower end but thats a guess . Theoretically it should improve across the range.

[Vanny]

Give me a call so i can be there when it blows up

[Philhod]

O ye of little faith

[docchevron132]

Surely though there's some friction caused purely by the veins rotating through air rather than a pure vacuum?

[Philhod]

If the blades/vanes were flat yes. but the curve is designed to give the best push with minimum
impedence to the flow across from inlet to exhaust, where the airspace is at maximum

A normal air tool has flat vanes and is relatively inefficient and stalls a lot when they get worn, through air friction and need changing about once a year.
I have an old (very) Desssouter rotary file which is pencil thin but has a small turbo like rotor at the top
That never stalls and I only ever serviced it once (in a very long time).
Blade/ vane form, is probably the most important factor in turbo design, they have ones that change form (angle) with the increase in speed. Some have two angles to pick up quick at low revs but these cause more of what I am on about at high revs. the move now is to have two, not a twin system but two in tandem, one working efficiently at low revs with the second coming in further up the scale, but excluding the first one by airflow redirection. and vice versa. all very clever.
I have mailed Garret for some info on the subject because the other factor of course is, although large turbines suffer by as much as 30+%, how much real effect does it have in small ones???

[docchevron132]

Blimey, it's a minefield..

I think I follow, which could explain then why the T3 has what looks like to sets of veins, almost like an impellor inside an impellor, so I guess thats their way of getting more out at lower revs with the more typical veins giving it the grunt at higher spool speeds....

hhmm...