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S4s,S4,SE UPDATES & IMPROVEMENTS

54K views 269 replies 36 participants last post by  Erik L 
#1 · (Edited)
S4s UPDATES & IMPROVEMENTS

OK, many of you probably took a wager how soon I start modifying my new car.
Yep, here we go...
Improvements and upgrades, of course, why not... I'm not going Ape-ballistic like on my 88"ET, though.
Who won the bet? LOL.

FYI:

Rear hatch support Struts-hold open

On Amazon, price $20 -$40 on Prime/pair
Search for: LIFT-O-MAT or Sachs Stabilus, Liftgate Lift Support (4F-484474) by Stabilus®. Body Connection: Plastic Socket with Ball Stud. Shaft Connection: Plastic Socket with Ball Stud. Compressed Length: 11.811". Extended Length: 19.685". Travel Length: 7.874". Capacity: 79 Lbs. UPC: 194879010212. More details on - Stabilus® 4F-484474 - Liftgate Lift Support

Also acceptable are BOXI 6938, Gas Charged Universal Lift Supports Struts Shocks Springs Dampers. Extended Length 19.70 inches, Compressed Length 11.75 inches, 75 lbs Force,10mm Ball Sockets.
If you have additional weigh, like glass hatch and/or wing you need 95 lbs force, look for Boxi 4279.

Front Bonnet hold open strut is shorter:
free Length 18.25"-18.75", compressed 11.5", 45-50 lbs
Sachs 083666 (45 lb), or perhaps Boxi BX54657 (55 lb)


.
 
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#3 ·
#8 ·
Sounded like a plan, thought i would give it a whirl, but......Amazon wont ship those to Canada! others no problem, those no :scratchhead:As you can see we pay a LOT more for things up here :crazyeyes

[ame]https://www.amazon.ca/BOXI-Tailgate-Supports-2002-2006-0K2FB-62620B/dp/B016IP2NG4/ref=sr_1_138?s=automotive&ie=UTF8&qid=1516136337&sr=1-138&keywords=BOXI[/ame]
 
#4 · (Edited)
Have you looked under your chargecooler, Lately? Well, I did!
And... I found a surprise waiting!

One of the vacuum/boost lines came off the plastic Tee. I noticed, that once upon a time, someone replaced a short section of the line between one way valve and the manifold Tee with silicone hose!
Silicone has a bad habit of swelling and getting mushy (what-t-a technical lingo!), and eventually disintegrates in a presence of oil or vapors.

Quick fix: replace any silicone vac. line with rubber and add mini tie wraps or metal clips to prevent slipping off under boost.


Whilst the charge cooler is off, a nice thick layer of Thermo-Tec insulation should be attached to the bottom to minimize thermal absorption of the engine heat by the CC.
 

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#6 ·
#2 Very important = MAP sensor line. Cracks in rubber elbow common, leads to real running problems, idles ok, but does not run well under any load.

#1 very important, increases fuel pressure with boost! Line from intake manifold internal pressure rail to fuel pressure regulator is very important, as is the one way check valve between that and the crank case breather. Valve must be the correct direction to prevent boost loss at fuel pressure regulator!
 
#10 ·
They are somewhat visible, but if you just loosen the chargecooler mounting bolts, grounding strap, and the intake silicone hoses, you can easily swing the chargecooler out of the way without draining the coolant.


An intake manifold leak at that location (the rail for the MAP sensor, IAC valve, and crankcase breather) definitely sounds like valve clatter.

 
#15 · (Edited)
What is the best spot to connect BOV signal line?
I assume, that the upper rail should be used for this purpose?
.
 
#16 · (Edited)
Porting Inlets

Whilst poking around the charge cooler, it may be prudent to port inlets of the CC and the diffuser.
According to Garry Kemp, this could improve the air flow as much as 10-12 cfm.
 

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#18 ·

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#20 ·
Have never done that, but what if you get caught away from home base?

You carry life preservers, does it mean you intend to scuttle your boat?
 
#21 · (Edited)
#24 · (Edited)
Thermostatic sandwich plate

Works very well on my 88' car

Oil stat?

I'm going to add stat plate to my 'Mad Max'.

Note: Connections on the Mocal plate are in opposite way. To get the same flow direction trough coolers, the in/out hose positions have to be swapped.


Font Auto part Audio equipment Wire Circle
 
#63 · (Edited)
MOCAL Thermostatic sandwich plate

Works very well on my 88' car

Oil stat?

I'm going to add this to my 'Mad Max' S4s.

P.S. Connections on the Mocal plate should be switched to get the same flow through the filter.
OE Hose end fitting hex size is 30mm
OE Plate fitting hex size is 28mm, two large open end wrenches will do the job.
Don't touch the filter until you're done with slacking the hoses. The original OE adapter plate is held in place only by the filter.
MOCAL stat sandwich plate is 40mm shorter than OE plate, hence the hex on the fittings may foul the oil pump housing. I have added 40mm extensions. Hex on the fittings supplied with MOCAL stat are... 30mm.
"Dry assemble" all components ( before the final install with Loctite 243), to check for fit and verify that oil hoses are long enough to reach the stat plate fittings. If not - add extensions.

NOTE: MOCAL stat sandwich plate oil flow is IN REVERSE. Thus, you have to switch OE hoses position when connecting to the stat plate.
 

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#25 · (Edited)
Bleeding the clutch slave

Installing a stainless speed-bleeder makes bleeding a one person event. PN# SB3824.
This hack applies to all Esprits.

Whilst you're "in this area", secure shifter cables to the bracket with a zip tie.
I don't trust plastic holders/clamps.

On our cars, one of the more frequent failure modes is chafing.
Check your stainless clutch hose routing. Often, this line rubs against the edge of the engine mount and fails.

Another observation:
There is a critical interference on the left side. It involves the power steering high pressure hydraulic hose and the edge of the pass-trough hole in the chassis. Plastic U-shaped moulding has been installed over the offending edge.
 

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#85 ·
Installing a stainless speed-bleeder makes bleeding a one person event. PN# SB3824.
This hack applies to all Esprits.
.
Re: posting #25

Even with the speed bleeder, the SC did not bleed properly.
Fix: remove two mounting bolts and flip the slave 180 degrees, bleeder at the top. Bleeds easy and effectively, now.
 
#26 · (Edited)
Cylinder 3 &4 cooling improvement

Seizures on earlier cars, and other piston failures, are almost always associated with cylinders 3 & 4 (especially 4).
Apparently, there is a design issue with the cyl head coolant flow.

Let's look at the whole system.
Coolant flows from the pump trough the front of the block, and goes out to the thermostat and radiator from the front of the head. Coolant circulation around the back of the engine, cylinders 3 & 4, is minimal when cabin heater is off.
Heater takeoff is located at the rear of the head, which is the same for all 910 engines. If heater switch is "ON", coolant flows through the block and exits trough rear of the head, which provides adequate cooling around cyl 3 & 4.
However, with the heater switch in "OFF" position, there is no flow trough the matrix and coolant flow is stagnant around the rear of the block/head. Temperatures can rise leading to possible piston seizure.
You are especially at risk if your heater valve is not working properly.
On 1989+ cars equipped with a water cooled turbo, some flow is maintained trough the 1/2" hose, which connects turbo CHRA to the overflow header tank. However, such flow may not be sufficient enough.

The obvious solution would be to create flow independently of the heater valve position or condition.
One could fit a 5/8" barbed "tee" at the horizontal spigot below the thermostat (heater matrix return hose) and route an additional 5/8"or 1/2"ID hose along rear bulkhead and right eng. compartment partition wall to another 5/8" tee fitted into the hose connecting rear head spigot with the heater matrix inlet.
Ideally, it would be more efficient to tap into the large aluminum pipe (the shepherd's hook) going to the radiator, but it requires welding.
 

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#27 ·
The obvious solution would be to create flow independently of the heater valve position or condition.
Or, do what I have always done:


Run the car with the heater temp control 'cracked' open. Leave the pointer at the 5PM position instead of straight down.

This won't create any noticeable heat in the cabin, but it WILL allow some flow through the heater matrix. (Which prevents clogging from building up in there, as some owners have reported.)


Now, wasn't that easier, MrD? :grin2: :wink2:
 
#29 ·
Yes, it circulates coolant with the A/C operating. But the heat doesn't affect cabin temps.

Remember, the Esprit's face-level vents will NOT provide heated air. If the control is set to INTERIOR you can get some heat, but the A/C in my car easily overcomes it.
 
#30 · (Edited)
Adjusting the water pump v-belt is "mission impossible". Allen hex head bolt behind the P/S pump pulley is not readily accessible. Pulley has to be removed to engage the bolt.
For future convenience, the offending part should be replaced with a small head (12mm) hex bolt, which can be turned with modified flat ring or open end spanner.
 

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#31 ·
^^^ Wow, on older cars the vacuum pump (which is what you move to adjust water pump V-belt) has a hex bolt from the factory. :cool:

But, you need to make a 'Special Lotus Tool' (piece of hex wrench, cut so that you can loosen with a GearWrench) to loosen it. :D
 
#32 · (Edited)
The above hack described in post #30 also works on the vacuum pump.

Here is a comment from one of the "other" forums member.

Having spent (too) many hours covered in grease working on various lotus cars, it's easy to get isolated and think that they are awkward to work on, those bolts that are difficult to reach or bits that can only be removed after others (which you don't want to remove) have been removed. The Esprit heater matrix springs to mind.

Today, I worked on the daily driver, and it reminded me just how awkward a family saloon can be.

Lotus, the company have an ethos which involves not putting unnecessary parts into the car, so, it means in a way that there are less parts than there could otherwise be. Mainstream cars, well what's an extra 30-300kg? Lotus didn't have access to complex computer aided modelling for engineering components, so if a pipe went from points A to B, the first question was whether a straight line was possible, if not how far do we need to bend it to get round the obstruction because complexity means higher tooling costs. Mainstream manufacturers have this technology much sooner and used it to the fullest extent, if you can save 10p on a part, it makes sense to do that when you're selling 100,000s of the cars, the initial tool cost almost disappears.
 
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