Induction hoses

[Plan B]

I know this has been covered before but I'm still not entirely clear on where I should purchase replacement smooth silicone induction hoses. My Griff is a standard Serpentine with standard plenum and standard AFM and the current induction hoses are to put it mildly a bit moth eaten. I'm obviously aware of the options from ACT and Clever Trevor and I've also seen a lot of discussion about buying the raw material from Auto Performance http://www.auto-performance.co.uk/product_info.php... and in doing so saving a lot of money. I'm not a cheapskate but if I can avoid the dreaded TVR tax then I will. The AP option appears to be around half the price of the others - and they also do them in nice colours - so far so good - however after reading the various past discussions I'm still left with more questions than answers.
Relevant to going down the AP route I'd really appreciate advice on the following:
1) Plenum to AFM - I need a reducing hose 80mm at AFM to 70mm at Plenum?? Correct??
2) AFM to filter - I've just measured 73.5 mm I/D - does that sound about right? AND is this the same I/D at the filter end (I'm cursing I didn't measure this when I had the filter out last week)
3) The AFM to filter run is kinda bendy at the front and wondered if I buy a length of straight hose just how easily this will bend without kinking. (I want to keep it simple and I don't want to re-route the hose)
4) I've read that silicone hoses are more leak prone at the joints. Is this a PITA or not?

Any advice apreciated
Jim

[rigga]

Buy from ACT, perfect fit no faff.

[PH430]

Buy ACT. The others are all to short.

[carsy]

ACT.

[spend]

You can have an aluminium collar turned to fit the plenum ~ then you can have a larger dia bend to the AFM (instead of the reducer ~ reducer + bend is about the the most detrimental thing you could do for flow?)

As an example I've made collars to flare the plenum mouth upto 90mm OD then use 90-100mm bends & 4" down to to big filters, but obviously no AFM and starting with plenums that have larger butterflys over 71mm. That way you just need some ally billet to turn into a collar, a bend, bit of 4" ally pipe (run above manifolds) and 4" bendy induction to go through wing, then a bit of the ally to link to air filter (K&N 4" are a fair bit bigger). Probably £120 all in including the big air filter, but likely a waste of time going to similar extremes with an AFM...

[Pete Mac]

I bought from these fellows, I guess I just like doing it myself:

http://www.autosiliconehoses.com/silicone-2-ply-ai...

I had to buy 2 metres as the induction hose is approximately 1.2 metres in length. The hose to buy is 76mm and I also bought from them some nice stainless steel clips 70-90mm.

Total cost was £44.59 for 2 metres of hose and £2.22 for 2 clips, all plus VAT - P&P was free. I also bought a very nice stainless steel T-bar clip to replace that rusting U bolt that clamps the exhaust.

At the end of the day it's up to you how you do it. I am sure the ACT hose is great. I couldn't believe what a faff it is, changing the filter and clamping the filter chamber back, then feeding the flexible hose onto the filter chamber, past the radiator and on to the AFM. Well worth changing the filter whilst you are at it.

All best done through the nose with the grill removed, which, incidently I plan to replace with a nice piece of stainless steel grill held in place with some stainless steel button head machine screws into stainless rivnuts. TVR's answer was to use black sprayed chicken wire screwed straight into the glassfibre - very classy...!

As for the AFM to plenum, I am afraid I can't comment as mine is in good nick so didn't change.

Good luck.

Pete

[Pete Mac]

spend said:

You can have an aluminium collar turned to fit the plenum ~ then you can have a larger dia bend to the AFM (instead of the reducer ~ reducer + bend is about the the most detrimental thing you could do for flow?)

As an example I've made collars to flare the plenum mouth upto 90mm OD then use 90-100mm bends & 4" down to to big filters, but obviously no AFM and starting with plenums that have larger butterflys over 71mm. That way you just need some ally billet to turn into a collar, a bend, bit of 4" ally pipe (run above manifolds) and 4" bendy induction to go through wing, then a bit of the ally to link to air filter (K&N 4" are a fair bit bigger). Probably £120 all in including the big air filter, but likely a waste of time going to similar extremes with an AFM...

If you are going this route then you definitely should be buying from someone like Auto Silicone Hoses because they stock a wide range of hoses and clips and the prices drop through the floor.

Having said that they are not the only one around who stocks silicone hoses but they caught my eye.


Pete

[T1pper]

I used ACT, fitted nicely and they sorted exactly what I needed.

[Wildfire]

ACT, no messing around, no issues.

[Plan B]

Thanks to all for the useful feedback. I take the point ACT clearly gets the majority vote but I'm still tempted to do it from the raw material.

Pete - I assume from your comments that the hose bent around the your rad top hose and then back on itself to connect to the air filter housing OK without kinking? That might sound like a stupid question but I've not played with big bore silicone hoses before so I don't know how they behave when bent through tight angles.

Another thought - how about putting in a 90' elbow (like the one for the plenum) at the air filter end? I reckon with a bit of trimming it will fit down there and of course will have no kinks and will have the hose pointing up in the right direction to go over the top of the rad top hose to the AFM. This will entail extra cost of elbow + 2 clips + connecting tube however with the elbow in there contributing to the overall hose length there should be no need to buy that second metre of hose. Does that make sense or is that B****cks??

[Hedgehopper]

I think that you will finish up with hose joints and clips all over the place if you try to assemble your own hose. Not only have you got a very tight bend around the radiator top hose but you also have to route the hose under the bonnet rollers and back up again.



I can't imagine that 75mm hose would be very bendy and I'm sure would kink. The ACT kit isn't cheap I agree but it is a perfect fit.

By the way, if you do fit the ACT kit, coat the right-angle bend around the rad. top hose with silicone grease to help it slide into place.

[Pete Mac]

Hedgehopper said:

I think that you will finish up with hose joints and clips all over the place if you try to assemble your own hose. Not only have you got a very tight bend around the radiator top hose but you also have to route the hose under the bonnet rollers and back up again.



I can't imagine that 75mm hose would be very bendy and I'm sure would kink. The ACT kit isn't cheap I agree but it is a perfect fit.

By the way, if you do fit the ACT kit, coat the right-angle bend around the rad. top hose with silicone grease to help it slide into place.

Plan B said:

Thanks to all for the useful feedback. I take the point ACT clearly gets the majority vote but I'm still tempted to do it from the raw material.

Pete - I assume from your comments that the hose bent around the your rad top hose and then back on itself to connect to the air filter housing OK without kinking? That might sound like a stupid question but I've not played with big bore silicone hoses before so I don't know how they behave when bent through tight angles.

Another thought - how about putting in a 90' elbow (like the one for the plenum) at the air filter end? I reckon with a bit of trimming it will fit down there and of course will have no kinks and will have the hose pointing up in the right direction to go over the top of the rad top hose to the AFM. This will entail extra cost of elbow + 2 clips + connecting tube however with the elbow in there contributing to the overall hose length there should be no need to buy that second metre of hose. Does that make sense or is that B****cks??

James, just to try and answer both yours and Hedgehopper's questions, the hose that I gave the link to is very flexible, it is wire reinforced wrapped silicone hose just like the original hoses, nothing special really but it needed a bit of manoeuvring over the radiator. It doesn't kink because it is fully flexible, have a look at the photo spec. I can't imagine how the ACT hose would do it any differently although I assume it is a solid silicone pipe, with a bend in it?

The only hose clips I used were one on the AFM and one on the air filter housing - two in total. How many more would I need?

I like the idea of spreading a bit of silicone grease around, it would help.

The real pain in the @rse that I found was fitting the new filter in place and bolting down the filter housing through the nose and then clamping the air hose onto the filter housing. A few blind bolts.

I like your idea of fitting a 90 degree bend but you also have to weigh up the ACT hose as well as it isn't that expensive.

Whichever option you use, I assume you will need to use a wide electric tie to clamp the hose close to the body around the bonnet hinge. There should be a little bracket or two to help you.

In my view the whole thing needs re-designing but until I come up with a great idea I settled for replacing like with like. At the end of the day not much in it but you sound like me, you want to give it a go with the raw material and I don't think you will find it very hard using either product. Good luck. Pete

[Plan B]

Thanks again for the advice guys. Made a decision and finally gone down the ACT route. Induction hoses, silicone coolant hoses all in go-faster purple and s/s coolant pipes. Mission creep or what? .......

[spend]

Pete Mac said:

In my view the whole thing needs re-designing...

That's basically where I started 8 years ago.. resulting in going back to pre-cat / chim style by drilling big hole in inner wing & dumping that silly air filter arrangement.

It's only 10 mins to go through with a big starrett hole saw, even at the odd angle you require. Bit of ally sheet to finish off afterwards. Then found we could easily fit 4" dia induction, no fouling bonnet / runners / rad ~ just a modicum of careful spacing at the very front of the inlet manifold (in front of the lambda even).

[Pete Mac]

Plan B said:

silicone coolant hoses all in go-faster purple and s/s coolant pipes. Mission creep or what? .......

And I've just replaced all my coolant hoses with ACT black silicone and s/s coolant pipes - they are great. I've kept the old ones, which were actually not too bad as part of my spare kit. A tip; use silicone grease inside the hoses, it will make it 10 times easier. Pete

PS: The reason I'm a bit verbose on these threads is because I am still in Kazakhstan. Back to UK tuesday and you won't hear too much from me for 4 weeks, whilst I get my head under the bonnet again.

[PeteGriff]

rigga said:

Buy from ACT, perfect fit no faff.

DITTO - great fit, great quality - Job Done. Also Tim at ACT is so helpful, so give him a call and have a chat first.

[cureton]

I am also going down the route to replace the exsisting afm to filter bit with a hose from a local manufacturer simply because my Griff is a left hand drive(Germany)and the ACT hose does not fit (just the 90° bend does). Anyway, ordered but not yet delivered, let's see.

So far I've also wrapped the exsiting hose with some silver heat isolation but was never impressed by the looks. So asking myself is it really necessary or are we all following a myth? Can understand in slow traffic the hose may heat up quite a bit but in normal drive there's a lot of air passing through the hose. Backed by people saying that plenum feels rather cold after a decent drive. Any experience?

[Pete Mac]

cureton said:

So asking myself is it really necessary or are we all following a myth? Can understand in slow traffic the hose may heat up quite a bit but in normal drive there's a lot of air passing through the hose.

I've also wondered the same thing to the point that I have not bothered to wrap the hose as I can't believe it makes that much difference in day to day driving. Pete

[spend]

cureton said:

I am also going down the route to replace the exsisting afm to filter bit with a hose from a local manufacturer simply because my Griff is a left hand drive(Germany)and the ACT hose does not fit (just the 90° bend does). Anyway, ordered but not yet delivered, let's see.

So far I've also wrapped the exsiting hose with some silver heat isolation but was never impressed by the looks. So asking myself is it really necessary or are we all following a myth? Can understand in slow traffic the hose may heat up quite a bit but in normal drive there's a lot of air passing through the hose. Backed by people saying that plenum feels rather cold after a decent drive. Any experience?

Yes the induction insulation for the drag race / traffic light / rolling road junkies, in free air with the engine breathing the inlet pretty much cools itself and you could argue that insulation might even prevent cooling of engine via conduction from head/block to the points at which you have insulated (getting into marginal degs difference at that stage). Probably one of the dangers of using RR data to validate mods without full analysis, in some ways simple accelerometers could give more meaningful data on the road IYSWIM.

[SILICONEKID346HP]

Just remembered this ,straight from fleabay . One of the griff owners fitted this .