Hi guys, this is a quick thread on how I made some cheap ITB bellmouths; hopefully of some interest!
Basically I didn't want to spend £200+ on something I'd have to modify (I need some very short - 25mm - bellmouths due to space constraints) so I went looking for alternatives and found some mention of using stainless egg cups for the basic form - here's my approach.
I chopped the top off the egg cups with a hacksaw and tidied them up on the lathe. I used a piece of ally tubing which was a tight fit inside my TB's as a gauge so I opened them out to the right size.
I then cut some short lengths of stainless tube to bring them up to the right height and welded the two pieces together using the ally tube to keep them aligned.
After that I cut some base plates out and again used the tube to keep the alignment whilst I welded them together - this lets me bolt them into the air box.
And voila! Six bellmouths for about £30.
Because of lack of clearance to get to the bolts due to the low height and restrictive airbox I had to drill access holes - not ideal but also not avoidable :/
These obviously aren't going to flow as well as bought ones, but I'd hope are better than nothing
Anyways, that's the way I did it - the lathe helped speed things up but I'd say is not essential, and I'm sure with some cunning something like these could be made without welding. The egg cups can handle a range of intake diameters as the top part is tapered; mine are 51mm diameter.
Edit: And hopefully one final picture will explain the harsh space constraints!
Basically I didn't want to spend £200+ on something I'd have to modify (I need some very short - 25mm - bellmouths due to space constraints) so I went looking for alternatives and found some mention of using stainless egg cups for the basic form - here's my approach.
I chopped the top off the egg cups with a hacksaw and tidied them up on the lathe. I used a piece of ally tubing which was a tight fit inside my TB's as a gauge so I opened them out to the right size.
I then cut some short lengths of stainless tube to bring them up to the right height and welded the two pieces together using the ally tube to keep them aligned.
After that I cut some base plates out and again used the tube to keep the alignment whilst I welded them together - this lets me bolt them into the air box.
And voila! Six bellmouths for about £30.
Because of lack of clearance to get to the bolts due to the low height and restrictive airbox I had to drill access holes - not ideal but also not avoidable :/
These obviously aren't going to flow as well as bought ones, but I'd hope are better than nothing
Anyways, that's the way I did it - the lathe helped speed things up but I'd say is not essential, and I'm sure with some cunning something like these could be made without welding. The egg cups can handle a range of intake diameters as the top part is tapered; mine are 51mm diameter.
Edit: And hopefully one final picture will explain the harsh space constraints!
