Esprit's '01 Exige Over-winter refresh

[lowlancer]

Mental

[Dell'orto]

+1. Hope you're planning on cleaning the underside after every trip now

[Esprit]

Haha, no I'll probably clean it periodically... They don't get that dirty usually anyway... Just another by-product of the UK's wonderful corrosive roads!

[Esprit]

Frustratingly little was done over the weekend on SEXIGE because the bits I was hoping to turn up from Blighty on Friday only arrived this morning (Monday). Still, I've been out in the garage tonight tinkering and have taken a step forward.... and then a step backwards

The step backwards is in the area of the fuel pressure sender takeoff.

The picture below shows my proposed setup all mocked up next to the Lotus OEM piece:

Now, you'll see from comparing the two that the M14 fitting on the end (brass fitting on the Lotus OEM bit, Anodised blue fitting on the new bit) the lengths of them are different. On the OEM fitting, the brass flare nut pulls the tapered tube flare up onto a tapered seat in the fuel filter housing. Because it's shorter on the new piece, the thread bottoms out on the hex before the tapered end of the fitting gets near the tapered seat in the filter. F**K.

Now, I could turn the hex right off the fitting altogether but I think the black hex of the next fitting in the line would almost foul too.

I'm now left either looking at achieving this differently with another fitting, making up my own custom male-to-male fitting (expensive) or modifying the fuel filter itself by sticking it in a lathe and turning the end of the filter's female boss down.

The last one is certainly the easiest for me, a ten minute job in my lunchbreak tomorrow.... but it means I'll have to modify the fuel filter every time I change it out for a new one... not quite as tidy as I'd like.

Still, I don't need to get fuel flowing through it tomorrow so there's no immediate hurry so I'll investigate it a bit further. It's just annoying because it's another thing I can't tick off the list.

I then set about working out where to position the new gearbox cooler pump. After running some test lines to test bend radii, fitting choices etc, I've settled on mounting it just above the left hand lower wishbone mount on the chassis (that's the front eye of the left hand lower rear wishbone). Seen roughly in position here:

This is a really nice position for it since it keeps the pump low (good for priming), keeps the runs short, yet allows for a good flexibility when the engine moves about on its mounts. It's also going to be reasonably easy to pick up on one of the wishbone mount-to-chassis bolts with a norma clamp or similar. I can make something up out of lasercut alloy if needs be. So much tidier and more elegant than the giant Mocal pump anyway.

Either way, very little accomplished for quite a bit of time and expense... frustrating... especially with spring just around the corner

[Esprit]

Couple of days off work at the moment struck down with a midwinter virus. With 7 guys crammed into a small office and with half of them coughing their lungs up for the last month it was only a matter of time until I got it.

Been spending most of my time resting, but today started another little job on the to-do list.... the mounting of the ECU.

Now you may or may not recall that I'm bucking the accepted path of running the K on an Emerald and am trying the latest Link G4 Xtreme. This was chosen for its excellent capability for the money (it's one of the best ECUs I could find on the market at the moment, does most of what a high-end MoTeC does, at a quarter the price) and also since it's a NZ product there's more local support and tuning knowledge.

I've also begun to make up a loom adaptor box. This will allow me to connect the Exige Loom to the new ECU without cutting a single wire, the ECU installation will be 100% reversible. Any new wires run will be run into the adaptor box itself, and seamlessly integrated with the existing wiring. The shell and connector for this has been fabricated, but that's all at this stage:

The task was now to see if I could fit this into the space taken up by the original VHPD ECU behind the passenger seat, on the bulkhead:

The small black box stuck to the front of the ECU is the microwave sensor for the alarm.

I modelled up the existing ECU in SolidWorks as well as the adaptor box, LINK ECU and the LINK ECU Mount. I was then able to play around with the positioning to get the loom plug in the right position. Given that there's not a lot of leeway with the large connector on the Exige loom, this really becomes the datum position for the new assembly.

The final assembly will look something like this:

This can be seen with the silhouette of the original ECU superimposed in transparent red:

This is all mounted on a lasercut alloy bracket that'll look something like this:

This will enable me to pick up on the original mounts for the Lotus ECU in the bulkhead, no drilling or extra fixings necessary. I've still a bit more work to do on the mount plate as I'll cut a bunch more metal out of it (add lightness!) but that's the basic shape with the necessary pick-up points.

As you can see, the new setup will sit a little deeper than the original ECU. This is no problem as there's a chunk of space there (as indicated by the fact that the alarm sensor sits atop the ECU at present. I'll probably have to stick this elsewhere but there's plenty of space for this in isolation.

The new arrangement should fit neatly and very snugly (2mm to spare!) in the gap left by the old ECU... it'll look like 'twas made to be there!

Will get this cut in the next fortnight and test-mount it in place so that it's in-situ by the time the wiring needs to begin.

[Mike-e]

love the thought that goes into your build. gives me inspiration to plagiarize your ideas

[Esprit]

Plagiarise away! If I can trigger an idea in someone to do something on their own car then this build thread has served it's purpose

[KKtrips]

Where will the wires be coming out of the box?

That is going to look sooooooo trick!!

Also did you weigh the car before you pulled it apart - will all the mods/extra bracketry/pumps/oil lines/coolers/6th gear etc make much of a difference to the weight?

Seeing as Lotus is all about minimal weight..

[Esprit]

The Link Looms will come out of the RHS of the box loop around and into the RHS of the Link.

Obviously the OEM loom connects to the adaptor box at the top.

The new wiring (for additional non-Lotus sensors and gear will come out of the Left hand side of the adaptor box and will terminate inside the box itself.

I've certainly added some weight to the car with the following items:

6-speed box (about 3kg heavier)

Oil thermostat (350g)

Gearbox oil cooler + Pump (1kg)

Extra bracketry for ecu, oil thermostat etc (1kg total).

New Gauges (250g)

New wiring (500g)

Engine Assembly +1kg (heavier crankshaft, lighter flywheel, lighter backplate for air filter, heavier oil filter)

Total gain (estimated) = 6100g = 7.1kg

Weight Savings:

Lightweight battery (new battery 5kg, old one 13kg) = 8kg

New design undertrays = 1kg lighter

Removal of brake splash shields = 200g (unsprung)

Use of lighter oil hose / unions in cooler circuit = 100g

Miscellaneous savings (removal of emissions control solenoids, miscellaneous bracketry = 200g

Lighter engine mounts = 1.5kg lighter

Total Savings (estimated) = 11.0kg

Overall weight difference = 3.9kg lighter.

Of course this doesn't take into account the probably 5kg of stones/gravel/crud I've cleaned out of the chassis and body cavities.

Overall it'll be about the same weight as before. I've not really started to look at saving weight yet.

I've plans to do some further mods down the track to get some more weight out of it (autoclaved carbon roof, autoclaved carbon front cover, forged wheels, aluminium fuel tank etc which should combined shave maybe 25-30kg off the kerb weight) but I won't be going to extremes with this car.... so much with the lightening on these cars involves hacking things about... this one is about remaining original or at least easily reversible to original should I choose to do so.

The next Lotus I build will take a no-holds-barred approach to weight and power with zero consideration for originality or correctness.

[KKtrips]

but I won't be going to extremes with this car.... .

Quote of the year mayte...

Jeeze it looks good though - I love the idea of the original wiring etc being used - so so lush..

Not sure on electrical side of things but are you having to change any of the factory sensors for the Link to be able to read them?

[Esprit]

Haha yeah, I guess it's a bit of an ironic quote.

And yeah, I've tried to retain original things where possible and where not (such as the gearbox), I've made sure the improvements are pure bolt-ins with no modifications required to reverse them. In some ways this rebuild is a bit of a compromise... I'm increasing the performance as much as I dare and modifying a few things to improve the car for how I want to use it, but I'm doing everything with a nod to originality, not replacing any of the actual Lotus bits.... shame is it ends up being really expensive to do it this way and ends up not being as quick as it would have been had I just said "f**k it" and thrown a supercharged K20 Honda engine in the back of it.

As I like to think of it, this is the car that Lotus would have given me had I bought the car brand new in 2001, taken it straight next door to Lotus Sport, given them a huge fistful of dollars and told them to build me the ultimate expression of the Exige... it embodies the best of everything given the direction Lotus were heading at that time.... and to me that's my ideal spec, even if it's not empirically the best.

As for the sensors, I'm pretty sure I can calibrate the Link to read all the factory sensors, nothing in the documentation suggests that it'll be a problem. Given that I've heard that the Emerald ECUs which are practically plug-and-play use very similar architecture to the Link G3, I'm thinking it won't be a problem. Extra sensors will be added (knock, Wideband O2, extra temp / pressure sensors etc) and these have all been specced so as to work with the Link.

[KKtrips]

Awesome man - one more question then I'll shut-up

Knock sensors - is there a specific place to put them so it does not pick up another engine harmonic and determines that to be knocking?

FYI - All the knock sensors I have seen have all been midway along the block and just about half way up the block from the sump flange to the head flange..

[Esprit]

Hahah love the sig...

Well ideally, knock sensors should go as close to the cylinder wall as possible as this will be the most direct path from the detonation to the sensor. Ideally further up the block the better (nearer the combustion chamber). I'm going to be picking up on an existing block tapping about halfway down the block near cylinder #1, which isn't entirely optimal, but more than good enough. It's also away from other things (exhaust and ignition) which could hurt longevity and accuracy so short of welding a boss on the block or tapping the engine casting (not really a go on the RoverK since it's paper thin anyway), so it's about as good as I'm gonna get.

[Esprit]

Well this weekend's been a little disrupted, but I've still found a bit of time to get into the garage and do some more work on the car.

First little job was to source some clamps to allow me to mount the gearbox cooler pump. These have had to be ordered from Oz and will hopefully be here during next week. This is preventing me from finishing the routing on this.

The bit I CAN finish though, is the oil return line from the cooler to the gearbox. An hour in the garage making up the line today and I've got it installed. Central in the picture you can see it running from the cooler near the firewall up to the top of the gearbox. There's just enough of a loop there to allow for engine movement without the line rubbing on anything.

The other job I'm starting is thinking about air filtration.... this is a bit of a long story.

The airbox can be seen below. It's a carbon-fibre box that sits over the trumpets and bolts to the trumpet backplate. The flexible trunking then runs over to the left hand side-duct on the car.

In the mouth of the trunking, is an air filter, commonly referred to as a "witch's tit", since it's a flat-conical shaped cone filter resembling a cross between a witch's hat and some prominent female chestular topography. Some Exiges have two of these (one at the trunking mouth, the other at the junction between the trunking and the airbox.... although this is more about quietening down induction noise rather than filtration. Mine had just the one.

The filter can be seen in place at the end of the trunking here:

Given the small area of this filter, and its position right in the duct, it's fairly restrictive and becomes damaged / clogged easily by road debris. The general accepted solution is to run a sausage-style filter inside the airbox itself where the area is large and the air velocity is low.

ITG make Lotus specific filters, but they're very much not cheap. They come with their own filter back-plates, which clamp to the filter (sandwiching the airbox, instead of bolting to it).

Clive (Mr Bean from SELOC/Exiges.com) posted up an interesting mod he did on his ITG filter whereby he was able to adapt his ITG filter to run on the OEM backplate. He also had a spare filter I bought off him as I intended to do the same modification.

This is where things get tricky. There are two ITG Lotus kits. One is the original Lotus Sport kit (LKP100700). This was originally developed for the Lotus Sport 190 kit. Then later on, ITG also did a "LC74" version of their "Megaflow" filter which was more specifically for the Exige. I thought these two were the same, but they're not quite.

The one that Clive used and the one I got was an LKP100700, and when it arrived, I had my doubts. It's more of a wedge-shaped filter than the photos suggest, especially at the ends and I felt that the filter runs a little too close to the #1 and #4 trumpet and could disrupt the airflow somewhat.

I bit the bullet and also ordered a JC74 kit. This means I ended up with two filter assemblies, but this allows me to examine the differences. The photos below show both side by side. The LKP100700 is the slightly shallower, more tapered filter with the silver backplate and the JC74 is the more domed filter with the red backplate:

As you can see, the JC74 has a lot more clearance around the end trumpets. It also does away with the 1/4-turn dzus fasteners of the LKP in favour of M6 screws and rivnuts. This made the choice easy since the JC74-s clearly the better filter for the application of the two. The difference comes about due to the Sport 190 Elise's shallower airbox I think.

The only problem is that the construction of the JC74 means that Clive's modification to use the stock backplate won't work, which means the custom alloy backplate I made up might have to be rejected. The reason for not using the ITG-supplied backplate is that the filter fasteners supposedly end up in a really inaccessible position... which I'll have to try sometime this week with a test fitting.

Either way there's going to have to be some small modification made somewhere to make everything fit as it should... will require a little more thought, but I'm sure that I'll be able to find a workable solution.... I always do.

[Esprit]

Well a very fruitful Tuesday night working on the car. Went back into work after the gym and measured a bunch of stuff up.

Turns out the Metric/DIN M14x1.5 adaptors you can buy off the shelf run a 30 degree female taper. From measuring the flare fitting on the Lotus OEM fuel filter outlet it looked very much like 45 degrees, which backs up my research.

This meant that even if the fuel fitting had been long enough the incompatible tapers would have resulted in a lousy seal.

So 15 minutes on SolidWorks and 45 minutes on the lathe downstairs and I turned myself up an adaptor:

This has the right tapers on each end to mate the Goodridge fitting and the Exige fuel filter taper on the other.... it pinches up nice and tight suggesting the tapers are spot on... the proof will be when I raise fuel pressure, but for now I think we'll call that one done

Here's the fuel pressure sensor setup all fitted (apologies for the blurry pic).... Job doneski!

[treggo]

How do you find your daily 206 gti6? They look like a nice alternative to something like a type r? I read earlier in the thread that you took it to a trackday, how did that go? Sorry for all the questions but wanna hear about some first hand experience before even thinking about going french!

[Esprit]

Assuming you mean 306 GTi6.

Well I reckon it's the performance equivalent of a Civic Type R.... the Integra R is probably a touch quicker on track.... but there's very little in it.

I've had it on track a few times and for a "boring" car, and a reliable daily driver it's actually really good.... not the fastest thing out there (although can surprise a few things if driven right) but plenty of fun to be had in it with that lively rear end!

Around town it's very docile with its high gearing and on the open road it's very comfortable and far more refined than a Jap hot hatch.

The #1 bonus is that they're a very anonymous car... other road users won't look at you like a boyracer and I still really like the look of them (they look much fresher than most '90s hatches).... best of all is that they're completely unknown amongst the boyracer set, which means they're also completely unknown by the criminal fraternity.... I can leave the GTi6 parked out on the street overnight and be reasonably sure it'll be there in the morning.... with a Honda R, there's a 50/50 chance it won't be there when I wake up.

[treggo]

Cheers, yeah you are quite right I did mean 306. Good to hear that its good on track, I'm not looking to blow minds, just have a few giggles. Have you had any reliability woes?

[mikuni]

Cheers, yeah you are quite right I did mean 306. Good to hear that its good on track, I'm not looking to blow minds, just have a few giggles. Have you had any reliability woes?

Not GTi6 related, but some info on 306 purchasing here.

http://www.eurosport.org.nz/forum/viewt ... &hilit=306

[Esprit]

Cheers, yeah you are quite right I did mean 306. Good to hear that its good on track, I'm not looking to blow minds, just have a few giggles. Have you had any reliability woes?

Yeah it's a lot of fun... as evidenced by this photo here:

The GTR wasn't getting that far away from me in this shot, although it was streaming with rain and he was on worn semis.

Buy a good one and they're pretty reliable... they don't tolerate being neglected though and many of them have been run into the ground.... so drive a few and get to know the feeling between a good one and a bad one.

Mine when bought was a low-mileage minter (minus some vandalism damage on the roof) and has been eminently reliable since. I've had a couple of small electrical niggles, one of which was just a loose contact, the other was fixed by stripping down the indicator stalk and cleaning it. The only other thing to complain about is a couple of boot struts that are a bit weak and need replacing.

Always happy to give my opinion on a car if you're looking at getting one... if you're around Auckland you're welcome to come by and take mine for a spin to see if you like it.