Project EXI

The building of a Marlin 5EXi kit car, using a Seat Leon 1.8T 20v Donor

Mon Aug 15 12:20:34 BST 2011

Wiper - Auto park

It is an IVA requirement that the windscreen wiper auto parks. For me this wasnt working. Im not sure why but the wires on 53a, motor supply were not connected. So Ive connected this up.
I havnt tested it yet, but it seems I need to run two additonal wires, from the wiper switch to the wiper motor, to get auto-park to work. Version 5.24 of the wiring diagram is available, There are two pages for wiper/wash, one for a normal double throw switch. The other is for a duralite 2 speed wiper switch.
The addition is to allow power to be fed to via the cam control, to the slow spped circuit when the motor is not in the park position.
The switch also breaks the ground connection when running in slow speed wiper. I will test out the wiring changes, and report back, prior to opening up the wiring loom and fitting in the wires permantly. Watch this space
This diagram shows how to wire up a 2 speed wiper motor with auto park

Posted by Steve | Permanent link | File under: electrical

Mon Aug 15 08:38:02 BST 2011

Wheelarch body filling


Applied body filler to the wheel arch, sanded down, refilled pin holes, sanded down again. Need to work on the join of rear clam to side panels, but the final shape is very much there. Good results as the wheel arch do not look bolted on.
Need to sand down the gelcoat around the filler,so that the gel coat will adhere, (Gelcoat has a parafin wax , which rises to the surface when curing), this needs to be removed. Then mask off the area and apply gel coat. The gel coat will look painted, but can be finished with T-cut once dry, to acheive the sheen

The next task is to complete the join on the fiber panels

Looked into the wash wipe auto park, and it seem that my moto does nothing when applying power over pin 53a and 31b. Will check to make sure that all contacts within the motor, onto the cam are making as required. Also need to check the wiper switch, as I may of left out a wire to driver pin 53a, when the wiper circuit is in the off position

Posted by Steve | Permanent link | File under: electrical, bodywork

Fri Aug 12 06:49:42 BST 2011

Fixing new FPR

Now the engine is runnign smooth with the FPR hooked up for testing. It was time to fix it permantly in place and route the fuel pipes properly
First I vacuum the entire car to remove as much of the fiberglass as I could, 40mins later the car was clean agian. The dust had got everywhere.
The best I could fit it was onto the rear bulk near the roll cage support, That way I could see the gauge and adjust the FPR should the need arise.
The bracket supplied needed a modification, so I bent it to form a 180 degree U-shape bracket, drilled a 9.1mm hole in the rear bulk head and fitted an M6 rivnut. The FPR is held in by two M4 bolts, given this was now a u bracket I had to use allen head button set screws. Fitted the in and out fuel lines, connected the vacuum hose, and job done.
With the engine clean again, it fired up, idle speed was constant, it used to rev around idling. Once it was warm, foot on the gas, straight upto 7000 rpm, with the new FPR, there was no hesitation, engine used to bog down and cough splutter, throw out black smoke, and never get passed 5000rpm.
Changing the FPR seems to off cured ALOT of fuel related issues.
A Very satisfying fix, I always thought the ECU was in control of the fuel mix, true to an extent, then you find the FPR is faulty.
Time is plug in the diagnostics again, clear any faults, and monitor the 02 Lambda sensor again and see if it happy (it used to read 80. But should not be happy at 50

With the fuel pump issue over I can now focus back onto the fiberglass wheel arches :). This time I will try and keep the engine bay cleaner, and cover it a dust sheet

Posted by Steve | Permanent link | File under: powertrain

Wed Aug 10 19:50:11 BST 2011

Fiberglass wheel arches


Applied some fiber filler to start shaping the rear wheel arches, sanded down with a flap wheel and 40 grit sandpaper, to give a structal fill. The next step is to sand down some more, and get a shape that is suitable for body filler

Thanks again to a neighbour who machined me up some 18mm hubcentric rear wheel spacers, wih an internal bore of 57.1mm these fit on the seat axle, and 73.1 to fit the inside bore of the team dynamics, without the need for spigot rings. 14mm holes on 5x100 PCD, and some 14x1.5mm 47mm long wheel bolts, and now there is plenty of clearance on the lower wishbone, and with the wheel arch extensions the tyres fit under the body
The next question is do they fit when the suspension is fully compressed. If it does then some suspension spacers may be needed.

Posted by Steve | Permanent link | File under: bodywork

Wed Aug 10 19:38:46 BST 2011

Fuel pump problems - New regulator

I had sent my Fuel pump off to be tested as the current draw was getting bigger and bigger as time went on. It needed a 25A fuse to keep going, and struggled when the system had pessure.
It the end the pump checked out ok, so it had to be another part of the system that was at fault casuing the pump to stuggle and generate an extermly high pressure. The only other part in this closed system is the fuel pressure regulator. A new Audi FPR on ebay is selling for &50. An aftermarket adjustable FPR with pressure gauge (upto 140psi) is &30. A bit of a no brainer given the extra of a gauge to diagnose problems. So I ordered one to fit in my system.
The new FPR arrived today so I fitted it in after the fuel exits the fuel return rail. This just means that the entire fuel rail is now running under full pressure.
The only problem here is how to plug the hole left by donor FPR.
I removed the original, and cut of the inlet pipe on the bottom, this then allows the fuel to bypass the FPR, but use the FPR to create a good seal.
First I turned on the ignition, and saw a very small reading on the new FPR gauge, it was fully open and not creating any pressure, adjustment is easy with a small allen key, it was very quick to adjust to 36psi. With the right pressure on ignition, the fuel pump wasnt struggling, and was able to work on a 10A fuse!!
FIred up the engine, and noticed a big drop in fuel pressure, as expected as fuel is now being put through the injectors and not getting back to the pressure regulator.
A quick adjustment and the FPR is now at 36psi on the engine in idle (36 psi is 2.5 bar). So far all seems good
I couldnt run the engine too much as it is covered in fiberglass dust from the wheel arch extensions, running covered in this dust will eventually bake it onto the engine, exhaust and thats not what I want.

Posted by Steve | Permanent link | File under: powertrain, electrical

Mon Aug 8 12:22:32 BST 2011

Fiberglass rear wheel arches


I have been thinking about what to do with the rear wheel arches for quite some time now. The problem is the edge of the tyre is exposed to the outside and would run the risk of an IVA fail.
There are three options to fix this problem
1 - Reduce the wheel off set to bring the wheel close to the hub, runs the risk of wheel fouling the lower wishbone 2 - Get the Marlin made wheel arch extensions, stuck with the shape and might look bolted on"
3 - Build my own wheel arch extensions, and go for the "it was designed like that look"
I elected to go for the later, possibly cheaper, but more labour intensive.
So here we go
I was lucky enough to get the services of a local fiberglass professional :)
Removed the flat part of the rear wheel arches, and scruffed up the gel coat and flow coat to provide a good bond for the fiberglass.
Created a mold from cardboard, covered in selloptape and then applied honeywax, to act as a releasing agent
Using chop strand fiber glass , and RAL 2004 (Pure orange) coloured resion, built up the arch foundation with 3 layers of glass matt.
Set the cure off with gentle heat from a heat gun
Removed rear clam shell, and turned upside down
Sanded down the underside of the orange glass (remove the honeywax to bond the underside)
Applied 2 layers of glass with pure black resin, around underside of rear clam
Set cure off with gentle heat
Put rear clam shellback in place
Drew outer edge profile of rear wheel onto fiber extension, removed excess with diamond cutting disc
Allowed to cure overnight
Added fiber filler on top of glass extension to roughly fill to the required profile
See newer posts for the rest of the post

Posted by Steve | Permanent link | File under: bodywork

Sat Jul 30 15:45:52 BST 2011

Seat belts fixed


My seat belts arrived in the week from Marlin. I needed to get my own 7/16" UNF eyelet bolts and 2 7/16" Cap head set screws for fixing them to the chassis
The seat belts are black 3" wide, 4 point harness, with quick release turn buckle.
First job is to fit the eyelet bolts, I had to recut the thread and remove powder coating that was on the nut threads, which have been welded into the chassis, so removed the seats and re threaded the captive nuts with a cap head set screw
I could then screw int he four eyelet bolts. Using a screw driver I rotated the bolts until they were fully home and secured. Clipped on the lower seat belt straps

Inserted the haness bar into the new higher brackets, feed through the top straps and secured the bar in place with 7/16" unf cap head set screws.
Fitted the seats back in place, and feed the straps through all seat openings
It was that easy and a simple job to do

I have removed the high pressure fuel pump and sent this off for some testing, it seemed to off needed and higher current than expected. Hopefully hear in the week, if there is a problem with it

Looked into extending the rear wheel arch width, by about 20-30mm, by adding some additional glass fiber to the arch edges. Found a friend of a friend who can offer some expertise in this area. Will start this job next saturday all being well.

Posted by Steve | Permanent link | File under: structual, powertrain, interior

Fri Jul 22 07:41:39 BST 2011

Rear lights


Fitted the last of the rear lights to the bodywork
Bolted the reverse and fog lamp to the rear, using one of the bolts that hold the hinge bar on. Then screwed the lamp housing to the support plate.
For the number plate light, i made a 60mm x 17mm hole in the body, so the light points down, to illuminate the number plate when it is fitted.
Thought about how to fit the high level brake light, I think I will secure this on top of the rear clam aluminium panel, I can then permanently fix the wire for this into the the brake ligh wiring on the rear.

Posted by Steve | Permanent link | File under: electrical

Wed Jul 20 12:41:04 BST 2011

Suspect HP Fuel pump is faulty

Ive been in discussion with Marlin and it seem that the high pressure fuel pump is faulty. Other builders report that they can run both fuel pumps from a 15A. My HP fuel pumps is commanding 22A by itself. So this is excessive and does indicate that a fuel pump failure is imminent.
Marlin have agreed to swap out the fuel pump
My seat belt harness is currently at the powder coaters, so when that is done, I should receive my seat belt package

Posted by Steve | Permanent link | File under: powertrain, electrical

Sun Jul 17 16:41:34 BST 2011

Fuel pump fuse

Today I took the time to investigate why the fuel pump fuse kept blowing. I had a 25A fuse in the main board, but it kept blowing. Obviously there was a wiring problem or the fuse rating was very low.
From this line (Brown 11) I have the front fuel pump, rear high pressue fuel pump and power for some of the engine components, like lambda, injectors. This was obviously too much for the circuit to handle.
The highest device on this circuit was going to be the high pressure fuel pump. So I removed the wiring for this and connected directly to the battery with an inline fuse. It blew a 20A fuse immediatly, but did not blow a 25A fuse. So i needed to provide a relief relay for the high pressure fuel pump.
What this means is using the original feed line for the fuel pump to activate a relay so his will switch in another supply line.
Given the high rating of this line I elected to use 4mm cable (I only had red left) so I marked the ground return by slipping some heatshrink over the ends.
Connected some crimp eyelets to connect to the fuel pump, and some a larger eyelet to connect directly to the battery ground. The battery fuse plate had spare blade fuse holders to used one of these and solder the power end onto the battery fuse plate.
Stuck a 30A 12V switch relay, to the rear bulk head, with cable tie base, and connected the relay switch live (original brown 11 fuel pump supply) to the relay. Now when power is applied to brown 11, the realy can switch and provide a separate power supply for the high pressure fuel pump.
I also reduced the fuse panel fuel pump fuse down to 15A, but maybe a 10A fuse will be enough for the circuit, will experiment and see what I can get away with

During the week I also managed to finish the gear gaiter, using the orignal donor leather gear gaiter, I cut a small square panel, stuck carpet onto it, shaped it to fit over the gear stick, and fixed the gear gaiter to it, with M5 nuts and bolts. The plate is held in with M8 bolts that secure the gear tick mount to the car. Looks good and does the job really well.

Posted by Steve | Permanent link | File under: powertrain, electrical
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