Trumpet filter

[BMK]

Hi all,

I currently have foam filters pulled over the trumpets and wondering if anyone had an idea of a supplier of a filter. I also have tea strainers that I swap on but have not used foam with them, just the wire strainer - they are ideal on track days stopping small stones going down the throats. The trumpets are held on with 3/14 stainless bolts.

But any alternatives would be ideal.
Thanks
Bernie

[Dwight]

Bernie, I am searching for better filters for my GT 40 setup. There are several threads on the GT 40 about this.

Do a search on weber filters or trumpets

http://www.gt40s.com/forum/

Dwight

I'm still looking. I may build my own. But I hate to hide my injection system.

[OZCOBRA]

Originally Posted by Dwight

As good as these look they do restrict the flow on a bell top trumpet as it stops the flow over the edge and changes the flow pattern through the mouth....an air box surrounding away from the bell top with some form of panel or pod filter would be an ideal!!

[Dwight]

I've seen boxes with a flat filter on the top and others with a tradition filter with a plate on the top, like the carb filters.
One with plexglass so you could see the injection system. A little bit of both worlds.

Still looking.
Dwight

[BMK]

dWight

Is the Gt40 in the photo your vehicle or do you know where the mesh filter tops are available? They would be ideal as my concern is stopping the stones/gravel going down...

Thanks
Bernie

[bobcowan]

Originally Posted by BMK

Hi all,

I currently have foam filters pulled over the trumpets and wondering if anyone had an idea of a supplier of a filter. I also have tea strainers that I swap on but have not used foam with them, just the wire strainer - they are ideal on track days stopping small stones going down the throats. The trumpets are held on with 3/14 stainless bolts.

But any alternatives would be ideal.
Thanks
Bernie

The tea strainers cost me 100hp on the dyno. Most of the restriction comes from the rubber lip, but some does come from the foam. On the track, I use open stacks.

A few years ago, I got the bright idea to replace the foam with gauze filter element from K&N. The engine ate 3 of them. The rest went into the trash.

[Dwight]

Bernie
yes that is my GT 40. I'll with check and see if I can find out were Allan bought them.


Dwight

[BMK]

Thanks Dwight much appreciated

bernie

[Dwight]

Allan said they came with the set up but he has seen them in the Pegasus Racing catalogs.

Dwight

[BMK]

This is the current setup on the GT40

[BMK]

[Pumpkin]

Hi,
I run webers (ida48) and have obtained my screen filters from Pierce Manifolds in Gilroy CA.
Glenn

[Rick Parker]

The largest share of the volume of air into the stacks comes not from directly above but from the side. The OEM stacks with the non rounded edge shears the air as it is drawn into the stack. The others with a more rounded edge promote better flow. In my opinion the placement of any individual screens (such as the sanwiched foam OEM type) or the more recent production "Stainless Mesh" type which have a rubber band around the perimeter and secure themselves around the edge of the individual stack will cause a disruption of air flow at the outer edge and a resulting reduction in performance. This may only become really appearant at WOT because up to that point anything can be compensated for by further depression of the throttle, but will be felt to a minor degree throughout the operating range. Admittedly a big part of the mystic of the Webers is their no holds barred appearance, but the box type filters, such as those from TWM and others will most likely provide a better overall package because there is more filtering area and a larger "filtered plenum" from which the individual stacks pull the air. You dont see individual filters on the injector stacks on F1 cars, there is a reason.

[BMK]

Thanks for your help and advice.

Bernie

[Gaz64]

Originally Posted by Rick Parker

The largest share of the volume of air into the stacks comes not from directly above but from the side. The OEM stacks with the non rounded edge shears the air as it is drawn into the stack. The others with a more rounded edge promote better flow. In my opinion the placement of any individual screens (such as the sanwiched foam OEM type) or the more recent production "Stainless Mesh" type which have a rubber band around the perimeter and secure themselves around the edge of the individual stack will cause a disruption of air flow at the outer edge and a resulting reduction in performance. This may only become really appearant at WOT because up to that point anything can be compensated for by further depression of the throttle, but will be felt to a minor degree throughout the operating range. Admittedly a big part of the mystic of the Webers is their no holds barred appearance, but the box type filters, such as those from TWM and others will most likely provide a better overall package because there is more filtering area and a larger "filtered plenum" from which the individual stacks pull the air. You dont see individual filters on the injector stacks on F1 cars, there is a reason.

A plenum box (like K&N for sprintcars) offers multiple times the filter area per cylinder with a volume of filtered air for each cylinder to draw from unrestricted.

No single airfilter can deliver enough airflow that IS clean.

Some only filter down to .009.

That's still going to sandblast your motor.

[Alan P.]

Bill's Filters are some of the best available.
We've used them on our GT40R's with both Webers and fuel injection and have no complaints.

http://www.bills-b-racing.com/

[CHANMADD]

I always thought that the area under the rear window was a plenum.
Why not get some nice filter in the intake vents above the rear wheels?
Then it will catch any stones coming in and a plate of lexan or the like cut out fit around the trumpets with a little foam seal around each trumpet and to the engine cover...??

[PoppyMod]

Originally Posted by BMK

dWight

Is the Gt40 in the photo your vehicle or do you know where the mesh filter tops are available? They would be ideal as my concern is stopping the stones/gravel going down...

Thanks
Bernie

Hi,
Google "Bill Hirsch". I'm running his filters on my Webers. He'll do custom colors, as well.