Pipe from air filter to turbo collapsing '86 HCI

[Sparky]

I've fitted that item to my and other Esprits, and it's a decent bit of kit.

[jonwat]

Wookie said

It's a2.2litre engine, hence approximately 2 litres of air/fuel mixture sucked in at every revolution.

This probably equates to the contents of two large bottles of cola.

At 3000 rpm and you are looking at the contents of 6000 bottles of cola being sucked into the engine every minute.

If it was a 2 litre naturally aspirated engine then it would consume a quarter of a litre of air every revolution (one induction stroke per revolution) when the throttle was fully open & if there were no restrictions in the inlet tracts (which there are). You also need to factor in the boost the turbo is supplying.

If the Lotus hose is too expensive then why not fabricate something of your own using hose restrictors and hose from Demon Tweeks???

[jonwat]

Sorry, my mistake, Buddsy is correct : two induction strokes per crank revolution = 1 litre of air.

[wookiecj]

two induction strokes per crank revolution = 1 litre of air.

or whatever....

Yup, hands up to that one... doing numbers on the fly was never my strong point. Still, as an illustrative point, it's a lot of air, even before you start to add the effect of the turbo.

[jonwat]

The V12 Merlin engine in the Spitfire had the exhausts angled backward to give an extra 70 pounds of thrust (or roughly 70 horsepower) at 300 mph.

[wookiecj]

Mmmm, I wonder how that would stand up to the MOT emissions test?

[eddie111S]

A job I have long been considering to do. My air duct is tired but not completely collapsing. So I've just looked on SJs for a price. It's now £113.48 so with the 20% vat that makes it £136.18!!!!!!!!!!!!!!!!!!!! Taking the peee I feel, if I'm being polite

What warrants this price?

[Bibs]

The fact it's the only place you can get it from? SJ's certainly aren't looking to make friends... If it's a part from the factory, I can get it for you and offer you FFM 10% off?

[richardvg]

The problem with induction is that we all tend to use the consatina typ piping whereas an unrestricted flow should be sought.Take for instance the existing piping and think about the flow of water through it.Now take a smooth pipe and bend it slightly and assume water runs through it.....naturally the water runs through the latter faster.Air will have the same characteristics and therefore instead of just buying what is available ,look for the alternatives ,bearing in mind that you want to get the maximum amount of air through that little flat space into the turbo.

[The Veg]

I was thinking along such lines recently when I replaced my ageing 'elephant-trunk' intake pipe with a mandrel-bent piece of aluminium tubing, connected with reinforced silicone fittings. There are a couple of posts about it in another thread somewhere around here.

[molemot]

I can't see that it matters about flow rate through the induction piping...the turbo is sucking like a demon and as long as you can get the waste gate functioning and limiting the boost to the upper figure, what might possibly be restricted by the pipework will make no difference. A normally aspirated engine would be a different beast....there, any restriction in the pipework would result in lesser performance...but with a turbo, as long as it gives you maximum boost, you won't get any more oomph from it, no matter how smooth the inside of the pipes are....

[MrDangerUS]

ouch! $350?

I replaced mine with 3" smooth bore alloy piping and silicone connectors/reducers for under a $100.

Flows much better than corrugated canvas "dryer vent" hose, looks better and will outlast the car!

PS. Any pressure drop at the turbo inlet adversely affects its efficiency and increases the outlet air temperature. Therefore, you want to minimise restrictions in front of the turbo! The last thing ever I would use is corrugated hose.

In addition, on Bosch CIS injected cars, the duct between the fuel head and the turbo inlet MUST be air-tight. Otherwise the AFR won't be right and car will run v.poorly, if at all. One more argument in favour of replacing "soft" tube with alloy piping.

Edited April 11, 2012 by MrDangerUS

[The Veg]

John, I did the same thing last year and it's holding up beautifully.

[Chillidoggy]

Moved

[andy b]

I replaced mine I am only great full a car that is over thirty years old i was able to obtain the correct part after one phone call i did have to shorten the turbo end as my car is 1982 and has a metal fitting on the turbo to hose.

Also i think lotus went to a lot of trouble to sort the turbo pushing air through carbs to get it right so i prefer not to mess with things i now little about.