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I would like a 90 degree 75-65mm silicone reducer.
I can only find 63mm to fit the 65mm Throttle Body. Not having used silicon before I assume the 63mm would not go over the 65mm as well as the lip on the TB which is bigger again.

Any suggestions?

Silicone generally stretches over. 2mm should not be a problem. Just use good hose clamps to hold it on.
I'm sure I have 2 inch silicone connected to my SE intercooler pipes. From memory the intercooler pipes are a strange diameter, 2 and 1/8 inches.
So that is just over 3mm of stretch.

this is what i used as it has a nice tight radius

Luke wrote:Silicone generally stretches over. 2mm should not be a problem. Just use good hose clamps to hold it on.
I'm sure I have 2 inch silicone connected to my SE intercooler pipes. From memory the intercooler pipes are a strange diameter, 2 and 1/8 inches.
So that is just over 3mm of stretch.

I wasn't sure how much it stretches, so it's pliable like the standard rad rubber hose?

MX5NB, thanks, but I have found plenty of 63mm. the issue is the TB is 65mm plus the diameter of the cast ridge/bead

you want it tight you can stretch silicon a heap i think my TB is 78-79 OD

MX5NBpsi wrote:you want it tight you can stretch silicon a heap i think my TB is 78-79 OD

Cheers mate, sounds like the 63mm will do it

A typical bead on the edge of a pipe built to accept a silicone tube/clamp is going to be 3-5mm larger than the ID of the hose across the bead. You aren't holding 20 or 30 psi of boost pressure in on a loose connection.

Dann

NitroDann wrote:A typical bead on the edge of a pipe built to accept a silicone tube/clamp is going to be 3-5mm larger than the ID of the hose across the bead.

Understand

NitroDann wrote:You aren't holding 20 or 30 psi of boost pressure in on a loose connection. Dann

Not sure if this is a question or not Dann?? I'm just hooking up some tube to the TB on a non turbo locost/clubman track car. So no pressure (at this stage)

Silicone on passenger cars is used alnost exclusively as a pressure carrying component. As a result a tight fit is engineered into the design.

Dann

NitroDann wrote:Silicone on passenger cars is used alnost exclusively as a pressure carrying component. As a result a tight fit is engineered into the design.

Dann

Cheers Dann, I guess a 63mm ID silicone over the 65mm TB is a tight fit. Thanks again

The best way to stretch it, is to put it in a pan of water and bring it to boil. Easy

I've got a 2.5inch (63mm) elbow on my throttle, went on without a problem, didn't even need to stretch much.

The Zork wrote:The best way to stretch it, is to put it in a pan of water and bring it to boil. Easy

C'mon, this is an MX5, you SHOULD be using a hairdryer for this!
(I use my "industrrial hairdryer", a hot air gun)

The Zork wrote:The best way to stretch it, is to put it in a pan of water and bring it to boil. Easy

hks_kansei wrote:I've got a 2.5inch (63mm) elbow on my throttle, went on without a problem, didn't even need to stretch much.

Thanks Guys, great help