Silicon Hose Collapse

[Patrini]

Hi,

Sry if the answer to this lies in a post somewhere, I have tried a few searches and could not find any info.

Just did a Front Mount Intercooler conversion on a 4AGZE and I notice that the Silicon bends used to join the alloy pipes tend to collapse quite dramatically under vacuum conditions i.e. idle etc.

Amount of silicon hose used has been kept to minimum lengths and hoses are 5 ply.

Driving the car does not suggest any performance deficit or running problems, long term I suppose the hoses may wear out quicker.

So is this normal behaviour for Silicon bends (did not occur with the original hump hoses on the Top Mount)??? Or is it just the brand I am using ?? If so which brand is recommended are there some with extra reinforcing that prevent this occurring ??

Or should I get some mandrel bends and get the majority of the piping welded ??

Also heard about internal springs to stop collapsing any idea where I can get them ??

Thks in advance for any advice.

Chrs, PAt

[Sam-Q]

and what brand is it exactly?

[Skylar]

Do single piece piping if you can. Less silicon couplers to break/tear/leak from and less hose clamps to tighten up. Ideally, you just have one straight at the cooler and another straight at turbo/tb, both preferably humped.

I've never seen one collapse though, and I'm using cheapie autobahn88 stuff. Then again, I've never tried to observe it.

Edit: I've never seen one collapse because I'm mainly looking at turbo cars. GZE is much more likely to collapse hoses since the whole inlet tract after TB is seeing vacuum.

[Todd]

yeah i have been through this exact same thing. mine collapsed everytime at idle on my gze. right angle bends with silicon are shit.
it doesnt actually affect the engine at all from what i could tell, but it would be good peace of mind to weld a 90 deg bend on and use a straight bubbled coupler as suggested by skylar.

[Patrini]

Thks for the replies guys, may go the mandrel bend route, with some hump hoses.

Sam - Hose brand is KKR.

Chrs, Pat

[Sam-Q]

that's odd, KKR joiners are quad ply and shouldn't do that at all.

[Jonny Rochester]

You could get a big wire spring to put inside the pipe to stop it collapsing.

[ke70dave]

You could get a big wire spring to put inside the pipe to stop it collapsing.

yer they have that on some radiator hoses that go around crazy bends.

prolly want to make sure said spring is stainless steel. dont want anything rusting in your intercoler pipes!

[Nikkojoe]

What I tended to do was making pipes with most of the bend done. I then put the silicone bend on it so that the pipe/bend was almost 50% in the hose (so that the hose and pipe bend were at the same point/angle etc) and clamped the hose down on the straight section of the pipe(main problem when no room for bends is that your pipe bend does not allow for full clamping).

This seemed to work well and minimised the collapsing of the hose.

[FAST EDDIE]

its because the tb is at the start of the system so the pipes will be under vac all th time the throttle is closed, not at all an issue unless they are choking it!!