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Use of ribbed hoses and its adverse effects on the intake air flow - Page 3 - Induction/Turbo/Chargecooler/Manifold/Exhaust - The Lotus Forums #ForTheOwners Jump to content


Use of ribbed hoses and its adverse effects on the intake air flow


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7 minutes ago, Chillidoggy said:

It could be a placebo effect thing.

No, It does actually make a difference , I did some flow comparisons when I did my latest adaptation.  There was a marked improvement in flow volume at the same velocity when using the same O/D pipe , one ribbed one smooth..   I used that information and combined it with the minimum amount of bends, also making them as smooth as possible..   As a result we saw a lower MAT compared with previous set up under matched testing..     This is all on my Esprit which is very different , but the principals behind it are the same..    I will also say that it is only one part , so the results when isolated show improvements in flow , but its full potential and benefits may only be fully realised when used with other tuning mods..    Saying all that , during my tuning process we did identify this area as one of the  primary chokes in the induction system .. so it should give some benefits straight out of the box .   A lot will depend on your air filter and post filter delivery system.      

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Jaques,

I did not measure it, but there is a noticeable difference in the throttle response. This mod increases Volumetric Efficiency

I can feel an immediate burst of torque when I step on it. I like it very much.

Before...  it was not so obvious.

Regards

John

 

Edited by MrDangerUS
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My K N filter arrives today, I can't wait to see if these mods work. I haven't driven it since I re-routed my elephant hose. What about the hose from the air cleaner to the turbo? Have you modified that to smooth bore  also?

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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On 11/06/2018 at 12:10, 89esprit said:

. What about the hose from the air cleaner to the turbo? Have you modified that to smooth bore  also?

I Have and it again does make a difference .. However mine is in a different position and straight,  so I can not do an exact comparison  to what you all will be doing.   I have given a heads up to Barry on parts and a technique to use ,  we will await his comments on  installation and how it performs.    There is no reason why it should not give very similar flow improvements as mine did..    

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Word about filters:

33-2011 has the largest flow area, 12% more flow section than the stock.
IMPORTANT: Don't forget to transfer the rubber edge seal to your new filter. The rubbery edge around the mesh is 3.6-3.8mm thick and inadequate to seal off the perimeter of the air box and hold the filter in the right place.

 

Re: an elephant trunk

I'm going to change it later this Summer. I'd love to use a single contiguous AL tube 3.25-3.5" diameter, like Mike Rodrigues did on his 87 Hyper-Esprit.

Without taking out the rear wall, single tube insertion may be bit difficult, thus I may use two sections and a couple of silicone couplers. 

 

P1000115.JPG

Edited by MrDangerUS
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That's quite a setup he's running there! What turbo is that and how much power is he getting out of it?

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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Not sure how the airboxes changed over the years, but I had issues with the bulb seal and the K&N filter on my '85  not sealing totally at the corners of the airbox, allowing grit into the intake and hastening a rebuild.

Check to make sure you have a good seal on the engine side, I ended up adding soft foam on a perimeter plate for a better seal.

AirboxModification3small.jpg

AirboxModification1small.jpg

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18 hours ago, 89esprit said:

That's quite a setup he's running there! What turbo is that and how much power is he getting out of it?

GTX3071R with a twin scroll exhaust housing .  North of 400HP line,  ZF 5 sp tranny, Motec ECU. Recently he doubled the size of the charge cooler.

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14 hours ago, snowrx said:

Not sure how the airboxes changed over the years, but I had issues with the bulb seal and the K&N filter on my '85  not sealing totally at the corners of the airbox, allowing grit into the intake and hastening a rebuild.

Check to make sure you have a good seal on the engine side, I ended up adding soft foam on a perimeter plate for a better seal.

AirboxModification3small.jpg

AirboxModification1small.jpg

Excellent observation/advice, thank you. I have the same problem.

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4 hours ago, MrDangerUS said:

Excellent observation/advice, thank you. I have the same problem.

My '77 Elites and my Esprit all have that same gasket. Great advice, I'll be putting my K and N in later today, I'll double check the fitment.

 

What did he do to the transmission to take all that extra power?

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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4 hours ago, 89esprit said:

What did he do to the transmission to take all that extra power?

He replaced it with ZF 5 DS25  transmission  by the German ZF Friedrichshafen AG engineering company with custom made bellhousing. Don't mistake ZF5DS25 for the Ford ZF5 transmission.  Mike has the same configuration as BMW M1with some shafts modifications.  Maserati Bora had 02 version of the same tranny.

See this     http://www.rbttrans.com/

and

http://www.rbttrans.com/graphics/5_speed_installation_new.pdf

http://www.rbttrans.com/gear_ratios.html

Edited by MrDangerUS
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Well I got the KN filter in and had the opportunity to take it for a 60-70 mile spin. That snarl/flutter coming from the passenger side is amazing. Throttle seems a bit quicker but I'm still not getting more than 1/2 bar of boost. In fact according to the gauge it didn't even get that high this trip.

One thing I noticed when I re-routed the elephant trunk, there was a vacuum hose punched thru the trunking that the PO had taped in place. I traced it back to the Barometric pressure sensor. I'm sure the way he had it rigged up was wrong, but the fsm didn't really show where it was originally terminated. 

I just secured it so it wouldn't get plugged up. Any ideas as to where it's supposed to go? And could that be affecting my boost problem?

 

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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The barometric sensor doesn't have a vacuum hose to it, in fact it doesn't have any hose to it at all, only an electrical connection.

The MAP sensor does have a vacuum line to it, though. And they look the same.

Margate Exotics.

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Thanks, I'll recheck... what could that hose been for then? Stuffed right into the elephant trunk... and loosely. Very interesting. 

 

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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I rechecked the mystery hose. It appears to be nothing more than a vent tube coming from the charcoal canister venting to the elephant trunk.

From what I've read in the fsm, it appears that the ecu controls how much boost goes to the engine. Apparently .65 bar is normal with an occasional burst under wide open throttle it will allow a boost of 1 bar. Only for a short time however, a few seconds. If that's the case there isn't much I can do.

Seems odd that I've never seen it go that high. The fsm doesn't explain how to adjust the waste gate. The actuator seems awful stiff, and I applied air pressure to it it took almost 20 psi to get it to move is this normal? It seems to have to overcome a very stiff spring in the chamber.

Maybe I'm overthinking this..Just trying to figure it out.

 

'89 Esprit, '77 Elite 503, '72 MGB, '95 XJ12, '10 Mini Cooper, '67 Imperial, '78 New Yorker, '76 Town & Country '73 Cessna 150

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  • Gold FFM

You need to hook the car upto a laptop running freescan or Espritmon.

its important that when the throttle pedal is pressed it shows 100% throttle to the ecu - or the magic won’t happen 👍 

Only here once

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My thoughts - 20 psi on the waste gate is way too much.  I think I read somewhere there may be an overboost function which can be triggered by the throttle, @Bibs?

Also, I don't think the charcoal canister should purge into the elephant's trunk, I think it should feed into the inlet manifold, probably at the front of the engine.

Margate Exotics.

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Quote

If you rev the engine to over 5000 RPM momentarily, but the vehicle speed is zero (i.e. the car is in neutral and/or the clutch is in), then for the next 15 seconds or so,  the ECM will essentially skip over the lines of code that tell it to open the wastegate at its regular setting. This means that on an SE or S4, which normally allows about 0.84bar, you  will be allowed to go to a full 1.0bar. The S4s already goes to 1.0bar,  as does the gauge, so I don't know how far beyond that it will allow you  to go. Let's just say the needle was pegged!

Lotus manuals state that on the SE and S4 max boost is 0.65bar. At coolant temperatures between 75 and 115 degrees Celsius, and at throttle angles greater than 75%, the boost control solenoid valve is activated which allows up to 0.84 bar of boost. Under wide open throttle (100% - WOT) conditions, a short duration of additional boost up to 1.0bar *may* occur.

If boost in excess of 1.01bar is detected for more than 3 seconds, the fuel pump and ignition are shut off as a protective measure. This overboost trick will allow you to get 1.0bar for about 15 seconds, thus skipping the 0.65 and 0.84bar limits temporarily.

On the S4s, 1.0bar is normal max boost and doing the trick gives even higher boost although I have yet to find the specs as to what is the overboost maximum.

 

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

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