Chassis

Varex exhaust build part 3

Built the other side of the exhaust today. Welding is ‘better’ than when I started but still pretty uneven. I can’t weld too far consistently around the curve yet. Did punch a few holes in the metal in places which results in having to ‘glob’ in filler rod to build it back up again. This part was back gassed as on the others before as it was a butt joint.

The 45º and straight pieces are sleeve fit, have welded these too so less clamps are needed. It also cuts down on potential exhaust leaks.

Once the two back boxes were hung I used some boxes and various peices of wood to hold the tips in place at the right height, this is with the car on the ground. Nothing on the Sportster is straight so this was done visually.

I used a piece of angle metal to line the tops and ends of the tips up. This helped make sure the tips were aligned  straight with the ground, with each other and spaced from the back of the car.

Welding the tips on was a bit tricky, blew a few holes in the metal especially where the gaps were bigger. The left box alignment is slighly off, but it’s not visible once mounted and the tips are in the right place visually.

Both exhaust pipes mounted, the v-bands are visible in this shot. I used a tiny bit of exhaust paste on the mating surface, shouldn’t be needed with v-bands but I’d rather not have to take them off again! Also visible the zip tie exhaust hanger, nothing like attaching your exhaust to your suspension ;o)  Kinds tempted to make some straight pipes that can be put in place of the back boxes, but that’s a whole new level of noise (did try running it with just the header and you need to wear ear protection…)

The more permanent hanger, this is a part is from pypes a US manfuacturer of exahust pipes. Had that left over from building an exhaust for the Mustang (http://www.mustang67.co.uk/exhaust-upgrade/) last year. Available at https://www.summitracing.com/

View from the otherside, wiring is hanging down. These cables need plumbing in properly and the metal shields putting back on the mufflers.

Car down on the ground from a low angle, the exahust tips are closer together than before (due to the input on the backbox being offset rather than in the middle).

The tips stick out a little further than the old ones, the wall thickness and slash cut work quite nicely.

Temporarily wired up the control box, and now for the noise test:

Closed it’s quieter than the jetex micro bullet muffers + the magnaflow boxes. Open it’s a bit of a beast, louder than before so that should be fun 😉 It’s pretty much were I wanted it to be, will see what it’s like on the road once the wiring is done.

Chassis

Varex exhaust build part 2

Step 14: Cut down the output pipes, otherwise the tips would stick out too far.

Step 15: Tip test fit, could move these back further by cutting the tip input down a little which would make the hole bigger.

Step 16: Test fit on car, it’s just push fit to at this point

Opened up the cover that’s over the mechanisum which actuates the volume flap

View from the top, position seems quite good here

View of the inside of the back box, the perforated metal is the bypass output

The other side, the hole show is the bypass, the perforated tube up to the flap works much like the straight though magnaflow back boxes I took off when it is open.

Chassis

Varex exhaust build part 1

Progress on building the new exhaust. The welds a’it purdy but they’re solid and not tea bag considering I’ve never used a TIG before and have learned how to use it with YouTube tutorials…

Step 1: Remove the old exhaust:

Step 2: Test fit some pipes, ordered the wrong bend, so either need to modify or get another one

Step 3: CAD (Card board aided design) to get the angles for the 2″ to 2.5″ transition. The height difference is 80mm, the input and output are parallel.

Step 4: Transition parts tacked together with v-bands clamps at one end. The v-band connects the backbox to the rest of the pipes, will allow for some angle adjustment later if needed.

Step 5: Back gas feed, v band clamp in place to reduce chance of warping when welding that part.

Step 6: The two height / size transitions welded up (don’t look too closely). Back gas worked well, clean weld through no sugaring / oxidisation on the backs.

Step 7: Cut down the inputs on the back boxes, they input at a slight angle so needed cutting flush for the v-band to be welded on.

Step 8: V-bands welded on – these were both back gassed

Step 9: Cut out hangers for from stainless tock and cut holes in each.

Step 10: Hangers bent 90º – welded these on, bit of a tough one to get the amps right, melted away a bit much of the original metal but I think I made it longer than it needs to be to compensate.

Step 11: Finishing up welding the first piece – this goes from the exsiting output all the way to the back box

Step 12: Pipe in place, it will be clamped were the colour changes from stainless, to stainless covered in dirt

Step 13: Back box in place on the hanger (into the existing E36 style exhaust hanger).

Step 14: May need to move the head shield a bit as the back boxes are closer to the centre of the car due to the offset inlet.

The bullet mufflers are now no longer part of the exhaust system, in theory the closed setting should be quieter than before and open should be the same or louder!

Chassis

Some new exhaust bits

Planning an update to the exhaust, starting early in the morning or coming back late is a bit of an issue. Dispite the sound passing SVA it’s a tad disruptive. Also on long trips at 50mph you get quite a bit of resonance.

This setup using Varex X-Force back boxes gives the best of both. Open it up and it’s a straight through perforated style muffler same as the magnaflow boxes on there now and when closed the sound is reduced to stock or lower levels.

Pipes by Jetex same as the current exhaust – great quality and lots of choice.

V band clamps from eBay, will have to see how the quality lasts on the clamps.

 

Example of this type of system on a Ford 289 small block V8 (Original marked in Video had two tiny bullet mufflers and it literally made your ears ring after 10mins of driving, was also a two pipe system. New varex setup also added an x pipe)

 

Now I just need to find time to build the new one! Doing a bit of planning in Autodesk Fusion 360 – which is aviable for free if you’re a hobbist, well worth a look if you’re into playing with CAD.

This shows some jetex parts to bridge the height differene between the exhaust run and back box height:

Chassis

Clutch assembled

Turned a suitable bushing on the lathe for the clutch to pivot around on to the pedal:

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Assemebled and in place, the 3d printed part feels very solid. First time I bolted up the pipe to the front the banjo joint didn’t seal up enough – lots of fluid everywhere… added an extra washer and it’s all good now:

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The clutch is now quite similar to how it was originally, but without lots of movement of the master cylinder.  It’s now much nicer to drive again.

Engine service has made a big difference, it’s a lot smoother and quieter again now. Setting the valve clearances as reduced the M20 rattle by quite a lot.

I can also recommend the ATE pads, they bite much better than the jurid ones that were on there.

It was also a good opportunity to re-glue a lot of carpet in the footwell where the spray mount glue had failed over the years.

A few minor things need doing before the MOT – one ball joints rubber cover is rotting away and the upper control arms need some extra large washers adding on the inside – there’s a bit of movement on the drivers side.

I had help today – nothing like being upside down with your feet in the air in the foot well with a cat wandering over you:

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Chassis

Clutch bracket mk3

3rd design set for the clutch bracket. As we ran out of ColorFabb HT filament it gave me a few more days to consider the design so I’ve revised some angles:

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clutch-bracket-v9-2clutch-bracket-v9-3

Mid print:

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All 3 versions, note the middle one didnt finish printing:

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Extra support structures

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Clearance for the fluid fill. You can see the layers don’t look very smooth – that’s by design as it makes the print stronger by having thicker layers. For a display piece we’d print with much finer layers that which would look a lot smoother. As this is a functional piece you can’t see it doesn’t matter.

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Watch the print!

 

 

 

Chassis

More 3D test prints

Ran out of ColorFabb HT with a bit to go on the print unfortunately, however this is a great strength test piece. It’s very strong already with 2/3 of the triangulation structure missing. This part will work in the car, no need to remake in metal.

I may make a few more design tweaks before starting another print. More material is due at the end of the week.

Mike on mad about kit cars brought up a point about pedal / master cylinder angle. The standard placement moves the piston in at an angle which can cause failure – I’m going to check this on the car make sure the master cylinder won’t get damaged.

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Chassis

3D clutch bracket version 2

V2 clutch bracket with room for pipe and holes to bolt to the top of the scuttle.

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If this were printable as usable part then I’ve done an extra version with more structure and cleaned up edges – there would probably need to be more material to the front mount point as well:

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Updated: going to try a 3D printed one using ColorFabb HT

http://colorfabb.com/co-polyesters

Added a load of extra structure to strengthen the part were it’s bolted.

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The print is sliced like this giving the most strength in the direction the force of pushing the clutch would go through the part.:

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The yellow lines are the movement of the print head, the black cylinder is the print head, it’s shown with the top 1/4 left to go, the corrigated stuff is support material – without it gravity can take effect and the runs of plastic can sag. It’s set to print with 100% fill so that it’s as strong as it can be. The prototype had less fill which saves both print time and plastic but is not as strong.

10 hours into the print:

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