Velocity stack options for ITBs

[pampadori]

I've gone thru a few different setups with my triumph ITB setup.
At first I used some UNI foam filters without a velocity stack under them. This filtered the air but didn't handle lean pops very well - the foam ended up splitting near the flange on 4 of the 6.
Next up I tried these motorcycle v-stacks with metal mesh filter cap on top. Cheap junk. The caps with the mesh kept blowing off.
Moved on to the PMO rain hats and K&N with the weber style stacks. This worked great but the mounting required me to use these things:


If you look closely, they aren't round but oval and add another restriction point before the throttle plates. I can actually feel a difference between the motorcycle stacks (no filter) and the rain hats. Top end felt sluggish with the PMO setup. Disclaimer - the PMO kit is nice and probably doesn't have this issue when used with their carb or ITB kits.

So I'm ready to try something else and would ideally like a velocity stack that has a reliable mesh filter on top. I need the throat to be 52mm or 2". Prefer height to be 3"-6" but not too picky here. I'd also prefer the set of 6 to be somewhere under the $200 it i could.
Anyone got anything similar they could recommend?

[1979-930]

Have you thought about getting a Dremel with a metal cutting bit and reshaping the inside rubber section?
There looks like enough thickness there you could cut it down, reshape it or maybe remove it completely.

[jpnovak]

Fix the lean pops and you will stop melting the foam. You should not have them.

[pampadori]

Its a fair point. I shouldn't have them. Its only present when cold so I could probably make a few changes and get rid of them easily enough.

The dremel suggestion is a good one. I'll have to go look and see if that would work or not. I recall the kit has an aluminum adapting plate that also has oval holes that might need a mill to round out.

[DeRRis]

I’ve seen these on the IB forum. I really like the look.

[msmall215]

I used the Triumph throttle boots you have pictured in your first post coupled with the PMO rainhat kit and the Closed Course Motorsports adapter plates. The dremel suggestion the way to go to bore out the boots and you can also take the dremel to the CCM adapter plate to port match everything and create a much better flow path. The other reason for dremeling the boots was to get enough lip for the boots to fit over the throttle bodies.

[pampadori]

what is the IB forum? Would love to read more about that...what do you call that? an airbox?

[DeRRis]

Impact Bumpers Forum

https://www.impactbumpers.com/forum/index.php?/topic/32160-triumph-itb-conversion/&

[DeRRis]

Originally Posted by pampadori

...what do you call that? an airbox?

SheWee trumpets

[evan9eleven]

Here is my solution, for what its worth:

915 rebuild and ITB/EFI project, here we go!

[PhillIB]

The "shewee" (that never gets old ) trumpets are mine. Sadly, they don't fit under the lid so I have had to make some different ones. Check out my thread for the details. I have used trumpets from DanSTengineering here in the UK. The adapters would be easy to make so it might give you some ideas for options in the US.

[pampadori]

@evan9eleven that is the perfect solution. Want to cut a couple more of those plates out and mail them to me?!

[theenico]

Originally Posted by evan9eleven

Here is my solution, for what its worth:

915 rebuild and ITB/EFI project, here we go!

That's pretty much exactly what I'm planning on doing. I've already sourced a pair of Triumph Tiger/Daytona 955i ITB's, silicone couplers, and hose clamps from Ebay ($167.38 spent so far).

Next I need to buy Clay's manifolds, linkage kit, and fuel rails. (I'm a teacher, so parts accumulation takes some time . )

Pipercross and ITG have blank base plates available for their filter kits that I was thinking about getting.

[evan9eleven]

Originally Posted by pampadori

@evan9eleven that is the perfect solution. Want to cut a couple more of those plates out and mail them to me?!

Originally Posted by theenico

That's pretty much exactly what I'm planning on doing. I've already sourced a pair of Triumph Tiger/Daytona 955i ITB's, silicone couplers, and hose clamps from Ebay ($167.38 spent so far).

Next I need to buy Clay's manifolds, linkage kit, and fuel rails. (I'm a teacher, so parts accumulation takes some time . )

Pipercross and ITG have blank base plates available for their filter kits that I was thinking about getting.

Thans guys. I'm happy to provide a drawing of the adapter plates if you want to have some made, but I don't think I'm going to start shipping these from Norway. PM me if you like. As I mentioned in my thread, it was important to me to keep the round bore for as much of the intake tract as possible.

[theenico]

PM sent

Thanks in advance

[Nux]

Are you looking for suiting trompets for the Triumph ITB's - or just filtration? Or both?

My Triumph ITB from Clay O:

[pampadori]

Hi Nux. I'm looking for both. I think I found a solution combining Evan's plate and welding some 2" tubes to it that protrude enough upward to where i can use my clamp-on velocity stacks inside of the PMO filter/rain hats. The weber compatible stacks aren't exactly the same diameter as the triumph ITbs either so this will allow me to get rid of them too.
I'll try to post a pic here when I finish getting them made.

[Nux]

I also had difficulties finding stacks for the Triumph ITB's . Got mine custum made from efihardware.com

[betterair]

subscribed and thank you for the ideas guys.
I am looking to upgrade or replace my piper cross filters .looking at IGT filters or individual screens/filters on each stack.
PS KMS Netherlands has a selection of stacks and trumpets.These are what is currently on my 3.6 l setup below(using the piper cross filter plate and KMS stacks and trumpets. )

[pampadori]

I tried my hand at drawing up my design in Tinkercad. Considering I've never messed with this sort of thing before, i found it pretty intuitive and easy to use. Plus, its free so win win.



The tubes are 3" long. Not sure how that will impact the "tune" of the stacks but i think longer is better right? I should be able to still close the engine lid with the rain hats on top.
I plan to use my cheapo velocity stacks on top and then rubber couplers to connect the plate to the throttle bodies.




I'm probably going to have to order a handful of these to reach the shop's minimum order qty so after i get them fitted i might have a few sets available to share. PM me if anyone would like one for cost plus shipping. I'm thinking around $175 for both sides. I'll know for sure once I place the order with the local machine shop.