Yoof's Turbo

[scully]

Adapter Plate Design
When designing the adapter plate there were several key considerations to think about:
-   Differential positioning remained the same for 085 and 02J installations, this gives the inboard CV joints sensible articulation, and does not necessitate the need to alter suspension geometry
-   Gearbox installation angle to be the same in the Polo as per Golf

The above caveats dictate the angle of the engine.

I still don't really get it. Why does the above dictate the angle of the engine? When you have the position of the gearbox correct, can't you just rotate the engine say 360 degrees around the gearbox? Why can't you keep the engine in the original angle, and needs it to be rotated to 40 degrees?

[Yoof]

No, unfortunately these annoying driveshafty things seem to get in the way...

[scully]

Yeah, there quite important to.
But is it because of the 26 mm delta in Y direction? So the drive shaft mounts are 26 mm's higher than with the 085 box, and that means you get contact with whatever is located back there? To require this clearance, you need to rotate the engine 28 degrees?

*edit*
I've been looking a bit on the net, and Roettele also offers this conversion, but the engine doesn't seem to be rotated. Can you tell me what the difference is between the Roettele conversion, and yours?

[Yoof]

Yes, it's earlier in the thread. They take two casing halves from the 02 series, bolt them together, and then weld sections from an 085 transmission in.

Means you have to buy 3 gearboxes from the off, and leaves you with a custom gearbox housing, not the direction I wanted to take.

Look at this picture, it will help explain:



Distance between gearbox input centreline and diff centreline is fixed for both boxes (obviously), and I need the input shaft to align as per the original box, the diff centreline is the un-constrained variable, which isn't far away from a stock box (allows sensible driveshaft angle and articulation).

Unfortunately, I can't sit the engine in a stock position with this box, as the rear mount on the block would be in the driveshaft centreline.

Thus canting the engine over (not enough room to cant it rearwards btw)

[scully]

Allright, that makes sense, it is clear to me now. Thanks for the explanation.

[Yoof]

Fabrication - Part 1

So, I haven't been working on my Polo that much over the summer, but now with winter time, I'm in the garage a few nights a week. Deadline is to have it running and MOT on the road by Easter next year, and use it as my wedding transport June 2015.

On with some fabrication, it all fairly self explanatory, cardboard cut-out, transfer to steel, weld in steel... a few points I had to consider:

-   Retain subframe mounting points
-   Not spaceframing the front end (although with hindsight this may have been easier)
-   Fitting everything in with a reasonable static clearance (20mm+)
-   Driveshafts
-   Everything else, shifter mech, starter motor, clutch actuation, speedo cable, reverse light switch etc.

The engine will be fairly stiffly mounted at 4 points, A and B mount on both longitudinals, these support the powertrain roughly in its desired installation angle, then C & D mounts to resist torque, Polo as standard doesn't use a front gearbox mount, but due to how I will mount the C mount, it's necessary for this.

So, after I'd cut a fairly sizable hole, and made a Polo even more wobbly than usual, I got to welding bits in. For the next stage of welding I'll mount the subframe back up so the chassis is as per previous geometry. On to the pics...



After cutting a big hole, I had a think about supports, my intentions was to mask as much as possible under the original chassis legs, it's neater and doesn't raise as many eyebrows come MOT time.

So, this was the plan:



Which obviously required lots of cardboard templates, measuring, cutting, and making of mess:





And my least favorite part of fabrication, getting old seam sealer, paint etc off the chassis, deep joy.



First on the list was to weld the two lengths of CDS together and insert them in the chassis, several tack/mock ups prior to this to ensure it was right:



Hole saw used on the chassis that had tube passing through it, gave a nice tight fit, these have plates welded over the top to spread load.



Before I welded the plates in I stitched the chassis leg where possible.



And then next was to weld plates in around these tubes, tube poking through the upper chassis leg will be the last one to be completed.





A quick tidy up of previous stitch welding on the chassis was done too:



And then moved onto the NSF subframe mounting point, the access tubes are for the fixings, will try to find some plastic caps for them so they don't get full of crud.



I ran out of gas at this point, so progress has halted up to here:



All for now- please feel free to abuse my welding... it's not like riding a bike, I've still burnt myself several times, still I've remembered what Spanish underseal smells like when it's burning.

Cheers

Pete

[mark_crox]

That is pretty cool!

[Karlos the jackyl]

Good progress by the way, this is a very good upgrade in every way compared to the original 085. The only minor downside is the additional weight  and a little slower to shift in comparison to a rod 085. But nothing to really complain about

[Yoof]

Good progress by the way, this is a very good upgrade in every way compared to the original 085. The only minor downside is the additional weight  and a little slower to shift in comparison to a rod 085. But nothing to really complain about

Cheers- I'd not noticed much difference in shift speed between the 02J and 085, Mk4 20v to various Polos, not that I'd notice anyway!

Additional weight will be interesting, even if it's +30kg, it's worth it!

[breadman]

Great work Pete.
I certainly wouldn't worry about the weight increase. The gearbox side of the Polo's is lighter anyway especially in RHD cars so it can only help even things up.
Yeah, maybe it won't look cosmetically as good with the engine canted over but other than that I can only see this as a massive improvement on the standard setup if you have a serious piece of kit like this car is.
Keep us posted Pete, BTW - the welding looks pretty good. I've seen far, far worse MOT repairs by garages that are supposed to know what they are doing.

Cheers Rich.

[Karlos the jackyl]

Just dug out some info

Gearbox only Weights

085 = 34KG
02J = 43KG

Both with CV cups and oil

Only 9kg difference .

[Yoof]

34kg seems heavy for an 085?

Taking 02J back out at the weekend so I'll weigh both, should also add flywheel, clutch, starter weights in too I guess.

That said... I've probably added 15kg in welding wire and 3mm plate 

[Yoof]

So, a weekend spent with the welder & grinder, and the NSF chassis leg is almost done, about 20hrs to get to this point, I didn't take pics along the way, but essentially the chassis leg was boxed in internally, with two CDS tubes welded in, and then boxed on the external side.

Engine mounts will hang off one of the CDS tubes, that's next weeks job :thumbup:















Cheers

Pete

[MaxGT]

Very nice work pete!

[Yoof]

Thanks Max, few more recent pics:

Little more done recently, B-mount is now done, and mocking the A-mount up currently. Time consuming part is dropping the subframe and engine/box out constantly. Hopefully I can get it sat on it's own mounts this weekend, and then measure up for driveshafts.

RobT and Gurds have been useful sources of knowledge regarding gear shift/clutch cables so thanks chaps! More pieces of the puzzle coming together.







Cheers

Pete