This car came with small velocity stacks that integrate with twin air filter boxes. I decided to sideline that setup and try these big velocity stacks. I plan to fabricate air filters for each stack and will use debris screens in the interim. The EFI is TWM throttle bodies on a Weber manifold by Hall Pantera. The ECU is Holley Terminator X. This car is a Pantera project that I received in February last year. It is a 1972 Pre L that is setup as a GTS.
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Nice...
Very nice Steve. Where did you source the stacks?
Here's a guy that does cool screen filters for stacks.
Thanks for the link to PJ Motorsports. I had not seen that before and they have good ideas.
The stacks are from https://dansperformanceparts.com/
I had to fabricate the stacks. My TWM throttle bodies are similar to Weber 48 IDA carbs but do not accept slip in stacks, only bolt on units. I bought the set of 48 IDA slip in race stacks along with a set of cheap steel stacks for Weber 48 IDF that bolt on like the ones that came on the car. I sawed off part of the horn on the bolt on stacks allowing the race stacks to slip on. It resulted in a mostly snug fit and I secured the joint with an ample amount of Ultra Black silicone.
I came across someone that makes nice billet stacks for my application but they were nearly $1,000. I'm not certain they would actually fit. I spent about $250 on the setup you see here.
For the time being, I am using these aluminum debris screens that fit under the stacks. I notched them with a rat tail file for bolt clearance. I have some stainless equivalents on order.
I have 5" tall aluminum spun stacks on Borla throttle bodies.
They came out of one of the VW aftermarket shops.
They are from my 48ida's and had the extended skirts that extended into the carbs, like yours did. Those don't work with the throttle bodies.
As with yours, those needed to be removed,
What I did was simply machine 1/8" thick round aluminum flanges and aluminum solder them on to the stacks. Some call that aluminum welding, but it is more like soldering then welding. It is at a much lower temperature then welding is.
The flanges that I fabricated were drilled with two holes that match the mounting stud location and then at that point just bolted them on.
I was not convinced that silicone or using any kind of adhesive would be dependable, so I went the addition step.
When talking about screens, the flat screens tend to be restrictive. So you need to consider the coarseness of the fabric/mesh.
Also, even though you may find the best balance of filtering ability to air flow with a different mesh then I used, the more surface area that you can provide to them, the less restriction you will have.
This is a picture of what mine look like installed. The black bands you see are the "rubber o-rings" I used to retain the screens. The shape that you see of the screens is a result of increasing the surface area the most that was practical for me to reduce the restriction to air flow of the screens themselves.
The other thing that you need to consider is how are you going to protect the stacks from water. AT LEAST the last two are "out in the weather".
You may be thinking that, "I will never drive this car in the rain". OK, but are you going to wash it?
In my case, the increased height reduces the ability of the stacks to suck in water since they are within 3" or so of the bottom of the roof and also in my case, there is a clear Lexan shield (roof) extending over the stacks and made integral with my louvers.
You can't see the Lexan in this shot because it opens with the deck lid and the deck lid is up.
Remember, you cannot compress water and if you suck it in, you can bend the connecting rods and if you do. likely crack the cylinder walls.
I'm not posting in criticism of what you have done, just trying to give you more information for your solution and help it.
beautiful work Steve. That cylinder head color is starting to grow on me.
Thanks John. It is growing on me a little but don't be surprised if that cylinder color changes.
Now you can play beer pong wherever you go…
Oye! I have actually seen people do this to cars at shows when they see open stacks. The Devil never sleeps. Serious consideration should be given to a method of vermin elimination to ensure that they can never reproduce and spread their curriculum with personal seed. I think instant vaporization should be considered as appropriate and in order?
You have to cover the tops of the stacks for your own good to protect from that kind of a malignancy.
Back in the day I saw the Formula 1 cars with tennis balls in the stacks when parked in the pits.
Even the GT40's had a cookie tray mounted over the top of the Webers. You can decide what you think the reason was but I suggest that there was more then just one reason.
Both of these are stack drop ins and are stainless steel so if you don't like them you can use to strain the pulp out of your morning orange juice. That's what I told "wifey" what they were for anyway.
My stacks are 3.73" diameter. The seller cautioned that there are not any filters available for them. I will likely have to fabricate screens or filters.
Also, some of the screens and filters are pricey. Some are about $100 each.
Another option is a plexiglass shroud. Here they are on Ferraris.
@stevebuchanan posted:My stacks are 3.73" diameter. The seller cautioned that there are not any filters available for them. I will likely have to fabricate screens or filters.
Also, some of the screens and filters are pricey. Some are about $100 each.
Another option is a plexiglass shroud. Here they are on Ferraris.
They have no mice in Italy to climb into the stacks and nest there while you are not watching over the car. You need screens.
You can get those plexiglass covers at one of those "all you can eat restaurant buffets".
Just wait for the owner to walk to the back and take one and slip it under your coat. That's how I got mine. It was from a Chinese restaurant, not a Ferrari.
Just another Chinese racing part.
Do mine look like I bought them somewhere? The screen is easy to form. You just wind up with stuck finger tips for a week or so. Stop wimping up.
Those shapes are not very hard to make…
just make the plug like you Want it Make it nice and smooth, Get some plexiglass or Lexan (I like it better to work with) clamp the sheet into a frame…
build a table with a hole in the middle to hook up the hose of your shop vac…set the plug with little spacers on the table over the hole..
Hold the frame with the Lexan horizontally and heat it with a heatgun gently up until the sheet starts bowing evenly down..
now take the whole frame and gently put it over the plug.. Frame touching the table all the way around evenly and turn on the vacuum cleaner… puff - done..✅
just trim..
