999rs' Red Headed Step Child

....aaaaand this where I “tucked the front” on fitting the sub-tank:



The bulge in the belly of the sub-tank is clashing with the vertical TB bell-mouth, so the tank is sitting way high at the front: shit!



Lord gimme strength...

Some beer-fuelled inspiration had me wrapping a couple of layers of carbon fibre around a cardboard shipping tube:


To make a tube section:


And performed a tummy tuck on the sub-tank:


This is resting on the frame rails, it should sit 10-15mm higher once mounted:


Hmmmm, can't have it all hanging from the filler neck/cap arrangement; smaller volume or not that was going to end in tears.

I umm’d and aah’d for a bit, weighing up various configurations but eventually beer came to the rescue: using some mounting nuts cast into the sub-tank I made an alloy prototype for a rear mounting “strap” then used that as a mold/template to make a kevlar/carbon version:


2 x layers of kevlar + 3 x layers of cf was fairly stiff, with just a bit of flex, so no need for vibration mounts.

Low profile Ti bolts sit nicely under the recess fabricated into the RS carbon seat:

 

Haha, if you think this is dumb (and you'll get no argument from me) you should see the ideas I reject

Not totally sure yet, but the mounting points make for a solid triangle supporting the "tank" (unlike many with only single points front and rear). Your point is also why I did the cut 'n shut job at the rear square end of the sub-tank, that is now pretty much wedged into the narrow portion of the cover where you knees lock into so provides a fair amount of support. If you want something a bit more sturdy just add another layer of carbon, and it would still weigh next to nothing.

 

Speaking of weight, with a nervous breath (did I really want to see this?), I chucked it on the scales:



1.47kg, no pump but including filler. Ooooooh, that’s not too bad….

….but what does a steel 749R tank weigh?



5.3kg minus pump and filler cap (completely bare) but it does have a bit of filler/bondo added for some dents and the tank pad indent so it evens out.

In those immortal words; "That'll do pig, that'll do".

 

'Zorsts! Who doesn't like a good 'zorst?

The problem is: what exhaust do you install on an RS engined “not-so-Special”?
I mean a slip-on isn't going to cut it but any decent full system requires a government grant to purchase these days. Prices for any 57mm system are just nuts, let alone genuine 63.5mm RS exhausts which are just Tesla $$$...and you need the subframe to suit.
Ok, ripping off the band-aid, this is the only remotely suitable option I could afford, and I think it's fairly obvious why I'm not super excited about it :


It was originally fitted to this 1098 engined 999 concept built by Giordano Loi:


It mightn't look flash but it has 60mm primaries with a 65mm tail pipe, so very much in the RS size range....and the seller was very kind in helping me out on the price.

....but I suspect it is in a class all it's own when it comes to sound:




If you ever find yourself in Perth at a trackday, just look for the bloke sponsored by "Zeus - God of Thunder", that'll be me.

I thought it would be a simple case of chopping up some el-cheapo 999 exhaust flanges to adapt the 3 stud 1098 flanges to 999 4 stud:


Oh naive and foolish (mid-50's) boy! A few seconds on the 'net would have shown me Testa and Testa Evo heads have the exhaust flange positioned quite differently. The front header wasn't too hard to sort but the rear, with the shock, linkage and subframe mounts in close proximity, plus transition from oval port to round tube was a real ball-ache. It also explained why the system had employed a skinny 50mm dia OEM header stub to negotiate the above obstacles, before expanding out to 60mm.

Basically the rear header clashed with the subframe mount/frame, and any simple mods would only have it clashing with something else so I had a crack at fab'ing a replacement from 60mm tube, shown here against the remains of the 50mm stub:


It's not pretty but nothing else is either and it'll get the thing up and running, and it's light, weighing just 4.5kg all in.

But eventually it's fitted and I'm thoroughly confused by the result:


Hmmmm, pinch the shorter tail off the 749R, minus the shroud = a bit better:


I'm not convinced, but a headache shared is a headache halved...

 

A couple more pics:




Yes, it makes my head hurt too.

 

Aaaah, the ol' "if you don't have anything nice to say, don't say anything treatment"....who knew you lot were so polite!

The above is an interesting exercise, super light, but was almost a kind of insurance policy, the affordable options for these things are so thin on the ground it was literally a case of beggars can't be choosers.

Then @matapaca offered up that incomplete 63mm Corse-ish system. Hmmm, it got a bloke thinking! It was in pretty poor shape, with a lot of surface corrosion (4 years sitting on a shelf after UK salt-laden roads) and a newer horizontal leg bodged up with a flexible concertinaed section incorporated.

The section comprising the merge collector from both cylinders into the tail pipe was completely MIA.

Don't get me wrong, these are not complaints. Great seller, who gave an accurate description and good pic's (linked expired unfortunately) so I knew exactly what I was getting myself into. And he was awesome in chasing up cheap shipping.

Positives? It was still a Corse-size system, with a nice RS-style muffler, manifolds, and nicely made muffler splitter (let’s not talk about the horizontal leg), and all the above negatives meant I could actually afford it.

”Nicely made”? In some ways it was “kinda-Corse” given the dimensions and style…but in others nothing like it at all: someone had gone to a huge amount of trouble to handcraft the “tube” from 1.0mm stainless sheet, then fab the bends from that pie cut tube…it wasn’t/isn’t pretty but you have to admire the effort that’s gone into it.

But onto the job. Del Boy's Harpic Power Plus 10X (handy yootoob vid) isn't available down here but it's the HCl that does the trick in cleaning up stainless surface corrosion, so a quick douse and rub 'n tug on the wire wheel and these are most of the bits I intended to use (not shown are other half of the header stub joints and horizontal header bend):


A simple threaded block for the muffler strap to tighten against gave me a central mounting point me to use the 749R subframe rather than any expensive RS malarkey.

The problem with that is the thickness of the subframe and the simple strap I'd used to mount the tail wouldn't let the tail snug down quite as I liked: the RS exhaust shroud wraps around the muffler so looks crap if not central. Which is when I realised why Ducati had gone to the complicated solution of those fussy lil' clips to mount an RS tail on the 749R kit bikes, they gain you the 10mm you need. So I shamelessly copied @mrfurry with his billet versions....only to a much lower standard:


Versus my original agricultural method:


It's a lot of faffing around for a lousy 10mm:




Time to join the dots with some 63.5mm (2.5") 1.2mm WT 304SS tube. Now I have no TIG/MIG and no idea how to use them if I did, just a busted arse self taught numpty with a cheap 20 year old stick welder. So my plan was to cut/fab it all up, tack it together and then hand it over to a pro to do some nice "aesthetically pleasing" TIG work. This is what I put together using some prefabricated pie-cut TIG bends cut to suit:




So I broke it down and handed it over to the pro'....

...only to be massively disappointed in what he handed back. Aaaaah fuck! What the hell do I do now? I couldn't see any option other than try and dress the ugly welds to invisibility, except once you start the steel becomes paper thin...and any touch up welding creates holes....which need more welding. Welding is all about creating a molten puddle, what happens when it cools? It shrinks, distorting the hell out of the tube. Yup what was previously just ugly was now pretty much kangaroo-Edward (roo-ted).

 

I was pretty angry at even being put in that position, so I explored a few alternatives, from using a different guy, to learning new techniques myself. But after watching this vid I was just angry enough to go "Fuck you!" (I'm not sure who I was saying it too, but the universe understands, lol) and have a crack with what I knew and what I had: stick welding 1.2mm WT tube:


Long story short (er) I'm soon knee deep in offcuts again and making (slow) progress:




I gave the tank cover a squirt of paint while I had the gear out for another job and "upholstered" the seat, but eventually we found ourselves here:





It's not horrendous, but I wasn't happy with the two similar short radius pie-cut bends jarring against each other:


I thought I'd need the tighter radius bends for the limited space, hence the pie-cut TIG'd units, and they were pretty cheap for what was a big ask/experiment for a plonker with only basic skills (or lack thereof) and equipment. But we had "proof of concept" now, so I forked out for a mandrel bend to get a more concentric look for the two bends marked above, and I used some of the offcut to soften the last bend heading into the muffler splitter:


(apologies for the shite photography....or are 21" rears a thing now?)

Spring hooks/springs to go and a few little bits and bobs to tidy up but it's pretty much sorted. It's very utilitarian, nothing beautiful, but it does look better than the other "insurance policy" I think. Then again, this weighs nearly 3kg's more so I'll have an interesting decision to make if it's no better on the dyno. I'll have to fit the other 'un for at least one track day though, just to enjoy the reaction.