Board logo

Velocity Stacks & Gauze
scootz - 19/10/11 at 07:11 PM

Still mulling over what to do for an air-feed for the trike.

What do the masses think of running these stacks with gauze only? I normally wouldn't entertain it, but the BMW boxer-engines TB's point towards the back of the vehicle so are less likely to come into contact with grit and other crud (that's the theory anyway! ).


franky - 19/10/11 at 07:19 PM

quote:
Originally posted by scootz
Still mulling over what to do for an air-feed for the trike.

What do the masses think of running these stacks with gauze only? I normally wouldn't entertain it, but the BMW boxer-engines TB's point towards the back of the vehicle so are less likely to come into contact with grit and other crud (that's the theory anyway! ).




what i'd do it cut some foam and put it inside the stacks. Then it looks cool but still stops it sucking in crap.

Confused but excited. - 19/10/11 at 07:19 PM

But then there's the effect of vortices to consider.

Confused but excited. - 19/10/11 at 07:21 PM

quote:
Originally posted by franky
quote:
Originally posted by scootz
Still mulling over what to do for an air-feed for the trike.

What do the masses think of running these stacks with gauze only? I normally wouldn't entertain it, but the BMW boxer-engines TB's point towards the back of the vehicle so are less likely to come into contact with grit and other crud (that's the theory anyway! ).




what i'd do it cut some foam and put it inside the stacks. Then it looks cool but still stops it sucking in crap.


What stops it sucking in the foam?
Surely you would use the mesh to support the foam?

HowardB - 19/10/11 at 07:21 PM

they look good, where are they from?

Just a little bit of foam over the mesh might keep some of the sh1t out?



[Edited on 19/10/11 by HowardB]

scootz - 19/10/11 at 07:27 PM

quote:
Originally posted by Confused but excited.
But then there's the effect of vortices to consider.


Do explain...

scootz - 19/10/11 at 07:28 PM

quote:
Originally posted by HowardB
they look good, where are they from?...


Dellorto PHM trumpet + gauze 45mm Guzzi BMW Ducati | eBay

Confused but excited. - 19/10/11 at 07:40 PM

quote:
Originally posted by scootz
quote:
Originally posted by Confused but excited.
But then there's the effect of vortices to consider.


Do explain...


Was said tongue in cheek.
As you move forward you create vortices which swirl around the back of the vehicle.
Look at all the crap on the back of a van. Wheels throw it up in the air and air movement swirls it all around the back.

scootz - 19/10/11 at 07:52 PM

That makes sense!

clairetoo - 19/10/11 at 07:55 PM

All I would say on these is - NO WAY !
One thing no one seems to realize about that gauze - it cuts the area of the inlet down by as much as half , and while it will stop small children getting sucked into the engine , it will also stop a lot of air getting in as well - and that will cost you horsepower .

scootz - 19/10/11 at 08:01 PM

Cheers Claire! Decision made!

Confused but excited. - 19/10/11 at 08:16 PM

Good decision.
These things are OK to keep gravel out of a race engine, which will be re-built after one or two races but all the road dust that they let in, will wreck a road car engine in very short order, relatively speaking.

scootz - 19/10/11 at 08:18 PM

... and that's just made up Howards mind too! You're not getting any!

Confused but excited. - 19/10/11 at 08:19 PM

MikeRJ - 19/10/11 at 11:19 PM

quote:
Originally posted by HowardB
they look good, where are they from?

Just a little bit of foam over the mesh might keep some of the sh1t out?




It will keep most of the air out as well.

bi22le - 20/10/11 at 07:31 AM

I had a knightmare with this and am currently running with cut up womens tights!!!

I cleaned inside the TBs before and there seems tobe no gunk at the mo.

i did try zip ties and foam but it really choked the engine.

HowardB - 20/10/11 at 07:36 AM

quote:
Originally posted by scootz
quote:
Originally posted by HowardB
they look good, where are they from?...


Dellorto PHM trumpet + gauze 45mm Guzzi BMW Ducati | eBay


thanks for that, very sweet,... but essentially useless,.....

[Edited on 20/10/11 by HowardB]

40inches - 20/10/11 at 07:41 AM

There was a feature in PPC by Dave Walker, in that trumpets with the gauze dropped power by as much as 25% I think it was a Jag
engine he was setting up that lost 50 BHP with them fitted.

MikeRJ - 20/10/11 at 10:36 AM

quote:
Originally posted by bi22le
I had a knightmare with this and am currently running with cut up womens tights!!!


Unless you mean you are out for a jog wearing hosiery which is past it's best, then you are strangling your engine.

franky - 20/10/11 at 11:39 AM

maybe you could do a few dyno runs just to see how it does affect it. If you only loose 2-3bhp but it gives you the look you're after then maybe you could use them.

The best way would be to use the standard airbox but i bet it looks like a plastic titanic

sprouts-car - 20/10/11 at 11:51 AM

Wouldn't this be cheaper?




scootz - 20/10/11 at 06:48 PM

quote:
Originally posted by franky
The best way would be to use the standard airbox but i bet it looks like a plastic titanic


The standard HP2 airbox looks like a Dalek (and wouldn't fit into my frame anyway)!

What about those 'cone' type filters made by the likes of K&N and Pipercross going straight on the TB?



franky - 20/10/11 at 06:59 PM

quote:
Originally posted by scootz
quote:
Originally posted by franky
The best way would be to use the standard airbox but i bet it looks like a plastic titanic


The standard HP2 airbox looks like a Dalek (and wouldn't fit into my frame anyway)!

What about those 'cone' type filters made by the likes of K&N and Pipercross going straight on the TB?





I use to use them on 2 stroke bikes in my yoof

to be honest i'd look at some sort of airbox design, even if you just match the volume and size/shape near the inlet. Bike engines are so so sensitive to airbox's. I'd put 28.3p on all the BEC cars that run really well on here have standard airbox's.

scootz - 20/10/11 at 07:10 PM

28.3p ... I can tell you're confident!

40inches - 21/10/11 at 07:28 AM

How about something like this. Link