Pipe from air filter to turbo collapsing '86 HCI

[cookieguy]

Here's the problem. The large red pipe (air intake) from the air filter to the turbo, looks old and worn (Esprit Turbo HCI, 1986)

The pipe (call it what you will) has a seems to made of a material with a metal type 'spring' running through it to give it its' shape and rigidity.

In places (just after the K and N air filter and in front of the turbo itself) the metal spring inside the pipe, has broken down and the pipe itself looks like it is collapsing in on itself.

Under load when the engine is revved, the problem is made worse by the turbo drawing air through the pipe and making the pipe collapse in on itself further (imagine sucking on a paper bag)

Sorry my explanation is rather basic, but so is my mechanical brain!! LOL

Out of interest, what effect would this have on the engine/performance of the car?

Next question....how does that K and N filter come out of the car to get to the air pipe? I couldn't see a way of getting it out.

Any help greatly appreciated.

Adam

[Sparky]

Hi Adam

A common problem - the hose can lose its integrity and collapse under load. It's also just possible that the filter may be blocked, but I'll guess at the hose. It can have a massive effect on performance! It's held on at either end by a jubilee clip. I know it's available from SJ Sportscars, and it's pretty expensive at about £90. I know of no alternative. To answer your other question, the airbox held in by 4 clamps - 2 top, 2 bottom - around its lip against the engine bay wall. Feel around the edge for four 10mm bolts.

[cookieguy]

Cheers Sparky, I'm going to replace the pipe, but for the life of me, could not see any bolts/screws to undo the airbox!

Are they underneath the box? Where exactly do I need to look?

Cheers again

Adam

[Sparky]

It's a horrible arrangement! Feel along the edge of the airbox, from inside the engine bay, and you'll find 4 10mm bolts, 2 top, 2 bottom. They hold down clamps that pull the box against the side wall.

[The Veg]

Hi Adam!

I was Adam's mechanically-talented helper when we found this problem. Thanks for the tip on the filter-housing; I've made a good mental note and can't wait for the 'A-HA!' moment when we find those fasteners.

I also can't wait to see what a difference that new hose will make. I was shocked when I saw how much it was constricting! Basically, it appeared that a few turns of the wire-coil were missing at each end, more from the turbo-end. Out on the road it made the car pull off the line with all the fury of an old Toyota truck.

I'm so grateful that Adam is letting me help him get his car sorted; it's good learning experience that'll make me that much more knowledgeable when I get my own Esprit someday.

[Bibs]

You need to replace the pipe sooner rather than later too. Anything that's delaminating from it is going into the compressor and then your engine, it's not a good situation to be in!

[cookieguy]

After a far bit of ringing the stores I managed to locate a pipe HURRAH!

350 smakeroos (not including shipping)

I figure it should last another 24 years!

It arrives tomorrow and we'll do our best to get it fitted on Friday.

Any tips on getting the old one out and the new one in?

PS good spot by The Veg, as I had not seen the duff pipe with my untrained eye. I'm hoping it'll make a difference to the engine feeling 'under powered'.

[Mesprit87]

One clamp at each end, doesn't get simpler.

Just took mine off and the clamp at the turbo was completely loose!

So much for unmetered air...

Here is a view, don't rely on me to tell you if it's easy to remove with the trunk floor in place...

Luc

[molemot]

S&J have the pipe...

TURBO AIR INTAKE HOSE F907E1089F EACH £78.40

And I thought that was a lot.....but 350? 350 whats?!!

[Sparky]

I did refer to SJ in post 2. For that amount I could have flown it over, had a slap up meal at Darby's, and still made a profit!

[The Veg]

Dollars...we're in USA.

[Sparky]

Yup - I'd still be in profit.

[molemot]

Yes....you're right...it tapers, cursed thing....mine was all patches when I finally had to change it some years back, and I still wince at the price!!

[wookiecj]

You're right Budsy, the pipe is different diameters at each end and it tapers uniformly from the large diameter (air box) to the small diameter (turbo). We have tried very hard in the past to source a cheaper replacement but have always met with "you're ****ing joking! Who makes stuff like that?" and "never seen one of those before" type comments from any supplier we've contacted.

I've thought around some sort of arrangement using stepped connectors to join pipes of different diameters to achieve the same effect but there are some problems which spring to mind.

Airflow into the turbo:- for best efficiency the air should be presented to the turbo blades in a smooth flow which may not happen if it has passed through a step close to it

Pulsing:- the turbo spools up and down during it operation dependant on the engine requirements which quickly changes the air demands and must vary the pressure of the incoming air in the pipe.... hence the pipe has got to have a certain amount of flexibility in it to withstand the many thousands of changes of pressure between the inside and outside it is going to be subjected to. It could be allowed to expand but that's an unlikely scenario as the pressure inside should always be less than the pressure outside (otherwise the air would not move into the engine) but it can't be allowed to contract and choke off the airflow.

I can't put solid figures on the requirements but here is something to think about.

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.

That's a lot of air... and in this instant it is probably wise to fit the recommended part and just steel yourself against the cost. It seems like a lot of money but, as you can see below, it's the one for the job!

No prizes for guessing that the old one is at the top of the picture....

Edited September 3, 2010 by wookie

[espriturbo]

Wow, this is something that I am going to have to get over the next couple of weeks as my intake pipe is missing, so in the interim have secured a cone K&N filter directly onto the turbo.

I have made enquiries with Paul Matty and was shocked to hear the price of £90.00 for a piece of corregated pipe.

Now I've seen the picture above, I am now completely reassured that I certainly am not paying someone £90.00 for that!!! regardless if it is the standard fitment or not.

I can just imagine the air bumping down the pipe over all those coils - doesn't seem too good for smooth air flow.

For half the price I can get it in any colour and in smooth, unrestricted, silicone/stainless steel pipe and at the right stepped diameter too, which is also resistant to heat and oil.

[Sparky]

OK if you have a Skyline, I suppose.

[richardvg]

y

i have used a standard turbo pipe.On the turbo side you will see the addition of rubber outhose - this is to ensure that one does not squash the pipe and crumple it.

makes life easier and works perfectly.

richard

[cookieguy]

Indeed it was $350!

I still cannot sit down comfortably yet, as it was rather a severe shafting!!

Fitted to the car a couple of days ago and realized it was worth every last bean! Car now runs 'as new'

100% improvement on acceleration,power etc . Now sounds fabulous.

Now...don't get me started on the brand new headlight motor I've just bought.......................................

cheers to Big Ben for helping me fit the aforementioned item.

[fsrowsell]

Adam, do you have a picture of the installed pipe?

[The Veg]

I've got a picture (I'll post it later) of what came out of Adam's car- it was a real bodge! Thank you DPO! The new pipe doesn't taper gradually as in Wookie's picture but rather all at once a few inches downstream from the intake-end. It was also made of very tough, stiff black rubber with a coil-wire inside the rubber, and it only wanted to bend at angles rather than curves. Maybe this will loosen up after it's been hot a few times. We did the job with the boot-floor in place; piece of the proverbial cake when you've got two people: one to stuff it in from the side of the engine bay, and one to fish it out from under the relay-box and pull it up to the turbo.

All during the job I was imagining some sort of lifetime (or at least a very, very long time) replacement item that could be moulded to exactly the right shape and would be smooth inside for better airflow.

[wookiecj]

I can just imagine the air bumping down the pipe over all those coils - doesn't seem too good for smooth air flow.

How can you tell from the picture that the inside of the new pipe is not smooth?

You appear to be assuming that the pipe is formed by filling in the gaps between the reinforcing coils with material rather than placing the reinforcing coil on the outside of the (smooth walled) pipe.......

[The Veg]

OK here's what came out of Adam's car:

At left is the bit that was attached to the assembly under the airbox (MAF?). Looks to be like the new one, except that it's old and has been cut off and the red hose was attached to it by a jubilee clip. The other end of the red hose was clipped to the turbo. You can see toward the top of the picture a bit of the coil hanging out of the collapsed end of the hose. We also found a hole about the size of a fingernail near one end. We found the 'Aeroduct' name on this red hose, and a quick-n-dirty web search makes me think that this is the stuff that is sold as race car brake-duct hose. Or it could possibly be some sort of aviation-related product... Anyway, the red hose was collapsing under load at both ends and had a hole in it...definitely not good for proper running.

Also of interest was another bit of bad equipment we found. The item in the middle of the picture is the oil dipstick, which is an aftermarket temperature-sensing type. It had wires coming from the handle which went nowhere. More importantly, it did not appear to have ANY level-markings, correct for the car or otherwise. I wonder if this was installed by the same %#@*&!!! DPO as the red hose.

We took a short run around the block and when Adam hit the throttle I felt my stomach being pulled back toward my spine in a very good kind of way, and I don't think he even opened it up all the way since we were in urban traffic. I can't wait to drive it again!

[Mesprit87]

Sounds like well invested money even if it's a lot.

Mine is already sagging a bit at the turbo, good I've heard from you so I can find a solution before I need aircraft ducting to fix it! (Definitely aircraft related, that red rubber is all over the place)

As for the "MAF" you were close but Bosch calls it a sensor plate, does the same as the MAF but mechanically measures the flow.

Thanks for the pix

Luc

[The Veg]

As for the "MAF" you were close but Bosch calls it a sensor plate, does the same as the MAF but mechanically measures the flow.

Ah thanks Luc; that's sort of what I figured when I saw the springy plate after we pulled the airbox. Rather crude really when you consider that I once had a BMW motorbike that was a few years older than this car but had a similar Bosch system that did use a hot-wire sensor. The smaller size and weight of such a thing would be nice in the cramped Esprit engine-room.

[The Veg]

I'm with you Scott; I just like to theorise out loud sometimes.