ACT smooth induction pipes being squashed

[Barreti]

Hi chaps,

I've had the ACT Silicone induction pipes on my 4.3 pre-cat for a couple of years now and not really given much thought to the fact the pipe is being squashed by the edge of the bonnet right down where the bonnet wheel slide channel is on the nearside.
With all the talk of induction on here at the minute though I wonder if this is going to be causing a problem.

Or does it just deform rather than squash shut so I've got nothing to worry about?

[The AJP Griff]

I wouldn't have thought it would do more than just deform,as long as it's installed in the right place.The induction hose type makes little difference to horsepower either,it's the bend that is the real restriction.I cant believe it will cause a further restriction if your running any type of afm,based on the experiments i've seen on the dyno.

[2Munkys]

Yup, the bonnet leading edge does compress the tube at that point thereby reducing the throat (or at least on mine it did). I cut out a couple of inches of the hose then rolled and welded a thin sheet of stainless into a tube to fit between the open ends. Needing any more than that and you may need to relieve some of the bonnet leading edge.

[Hoover.]

running mine slightly squashed to........

personally I don't it makes that much difference, unless its severly squashed/flattened.

[laz11]

Hoover. said:

running mine slightly squashed to........

personally I don't it makes that much difference, unless its severly squashed/flattened.

Me too...by my M5 baiting antics earlier today can't imagine it's a problem!

[Barreti]

Mmmm, seems I'm not the only one then.

I did wonder about cutting the pipework just before where the bonnet fouls it. Can't quite get my head around what you've done though Bruce. Is it so you've got a bit less profile so the bonnet doesn't touch it, or is it to change the shape of the pipework to get it out of the way?

Sorry if I'm being a) thick b) anal about this given what Mike said, but the squashed pipework is getting on my nerves 'because I know its there' if you see what I mean.

[The AJP Griff]

Barreti said:

Mmmm, seems I'm not the only one then.

I did wonder about cutting the pipework just before where the bonnet fouls it. Can't quite get my head around what you've done though Bruce. Is it so you've got a bit less profile so the bonnet doesn't touch it, or is it to change the shape of the pipework to get it out of the way?

Sorry if I'm being a) thick b) anal about this given what Mike said, but the squashed pipework is getting on my nerves 'because I know its there' if you see what I mean.

Lots of griffs bonnets crush and chaff the induction pipe a bit,even with the std hose,so i would call it normal,for sure.There must be a fair bit of variation in bonnets etc,as the two i've had,have behaved very differently in terms of space for the rollers when lifting and replacing the bonnet.My first griff was easy to lift the bonnet and not touch the paintwork with the rollers,and the rollers stayed in their grooves easily when lowering to close.The second Griff was exactly the opposite on both points,which was difficult to believe at first!!

Edited by The AJP Griff on Monday 21st April 21:02

[Bluebottle]

Mine used to do this as well, until i noticed two small holes on the inner wing about 2 inches vertically aparty and about a foot away from the AFM. I posted a cable tie thru the holes and around the induction tube, and it holds the tube low enough to longer foul the bonnet runner.

[2Munkys]

Barreti said:

I did wonder about cutting the pipework just before where the bonnet fouls it. Can't quite get my head around what you've done though Bruce. Is it so you've got a bit less profile so the bonnet doesn't touch it, or is it to change the shape of the pipework to get it out of the way?

Hi Ian

Can't remember the ID of the silicone hose, it's about 80mm. The wall itself is something like 5mm so giving an OD of about 90mm. I reduced the OD to about 82mm at the point of deformation by making a short length of metal tube. I cut the hose and fitted the insert.

I'm sure the kink just upstream of this is also not ideal.

[2Munkys]

Like this Ian:-