Silicon Reducers Size/Question

[ein bora]

I need a 2.5 to 1.875 (63mm to 47mm) silicon reducer for my intercooler piping to turbo set up.
All I can seem to find is 1.75 or 2.0 to 2.5 reducers.
Which one should I use??

Thanks.

[DJPyro]

My experience with silicone couplers is that they don't stretch, so I'd say go with the 2.0 and clamp it tight. I think you'll have issues trying to squeeze the other one on. Use T-bolt clamps, you'll strip a worm gear clamp before you get it tight enough.

[ein bora]

My experience with silicone couplers is that they don't stretch, so I'd say go with the 2.0 and clamp it tight. I think you'll have issues trying to squeeze the other one on. Use T-bolt clamps, you'll strip a worm gear clamp before you get it tight enough.

Maybe the problem with that might be (as you can see in the picture) is that there is no lip on the turbo to stop the hose from sliding off, I wonder if it could be made tight enough to prevent that?

[vanbcguy]

I used a 2" silicone coupler with the 1.875" manifold inlet on my car without issue.  The T-bolt clamp had no trouble compressing it down that much.

Yeah definitely not a lot of meat on that turbo outlet to grab.  You could try roughening things up with a file and then clamping it good and tight.  Another option would be to weld a bead on the end of the pipe, if you have facilities to do so.  If not there's always this trick:

http://dsm.fidke.com/articles/diy-bead-intercooler-pipes-with-jb-weld.aspx