BikeTuna's winter turbo build

Well all turbos are balanced due to the speeds they spin at.

 

You are right... looking into it i do need to balance the turbo... cheers for the tip off!

So I found a local company to do it for me, Owen Developments, mostly deal with cars but said they would balance it for me if i get the housing to them, and for a good price too.

But seeing as I was literally 2 bolts away from it being back together i connected the bolts for a quick test to see if the seal kit has worked and the pump is working too....




...it isnt. The seal kit seems to be restricting the turbo and it's not spinning up properly. Something clearly went wrong with the fitting of the seals. The bike is running but the turbo is literally spinning as fast as i could turn it by hand. 10 seconds later and oil is coming out the turbo again! So thats completely ballsed up - not only have i bricked my turbo but ive not even fixed the original fault... i guess rebuilding turbos is harder than i thought!

So left with the dilemma of a turbo bike without a turbo, I'm hanging in there until friday to get paid again, so I can see my options. I imagine that I'll be back on evilbay looking for a 2nd hand turbo again as I'm also on holiday for a week next week and if the missus finds me buying a £300 turbo the week before I'll have wish i did a car project as they are easier to live in*.



*My car project is waiting until the bike is finished, cannot stretch my budget far enough to do both...

 

have you asked Owen Developments if they have a similar turbo in stock, or can rebuild it rather than just balance the shaft?
you are playing the lottery buying used turbos, tbh

 

I know 2nd hand turbos will always be a lottery, but I know that having mine redone by Owen will be way out of my budget.

If I had a proper budget for this build I'd have had it finished months ago!

 

Fwiw that's the appeal of what your doing for some of us mate. Using your ingenuity, and finding ways makes for a much more involving project IMHO.

Any of us can take the "just buy a kit & bolt it on" approach to modifications, you're taking it well beyond that.

 

Fwiw @Biketuna, I think this is a really cracking project and your engineering skills makes my tinkering with mods etc look like child's play. Good on ya - shows just what can be done!

 

i have utmost respect for what is being done as well. especially on a tight budget.
and every bit of related or ancillary work you have done is absolutely awesome.
but the fundamental part of the whole project is the turbo, and it would be a shame that all of your hard work is wasted by the pursuit of budget control on this most important part of the whole thing.
consider how you would feel if a used turbo fault caused the intake impellor to break up and go through your engine intake?

i just think that its maybe a bit of a false economy not knowing the provenance of that single used part.
thats all.

having been involved in turbo car scene for over 16 years, i have seen a lot of economy builds fail on this single aspect. sorry

 

Cpszx, I completely agree! If the bike was to detonate due to a cheap component withing a week of its completion would be devastating! I also love all the comments about how ingenuity is overcoming cost,makes me feel very clever

But a £300 turbo is simply out of the question. I'm playing as safe as I can allow. Admittedly not as safe as not doing it, but where's the fun in that!?!

 

I say whip round!!

 

It's a kind thought, but I'd never accept. A true testament to the brotherhood of this forum though, you should all be very proud!

I've bought another turbo. Not the cheapest I could find, the one with the lowest mileage within my budget. It has a 3 month warranty too, so if the bike leaks oil after this is on then I know I have a build issue. Sadly it's estimated a week away for delivery so no updates for a while...

I am wondering if the turbo is backing up oil and forcing through the turbo seals as the lift pump isn't as fast as the feed from the filter. I guess the test for this would be to start the bike with the outlet hose leaking into a bucket, I'll try it when the unit arrives.

 

you might also want to consider an oil inlet restrictor, if you think its backing up too much, as you might be pushing more oil than you actually need.

check the pressure going in, compared to the turbo specs. up to 60psi is generally more than enough at high rpm, but you want it very low at low rpm. and as its a small turbo, it could easily be overwhelmed.
have you got same outlet pipe size?
is the outlet blocked or restricted?

if the turbo has a bad history of hot stops with non synthetic oil, then it could have cooked the oil into the channel causing a restriction, imagine those cholesterol filled artery pictures you see from time to time.

the seals are there to keep the air in the right place, rather than keep the oil in the right place, so if you are cramming it in at low rpm, it could overwhelm them

 

An interesting thought, the oil is fed from the oil filter sandwich plate which a local car tuner said would be the ideal supply for it and they fit them to their cars, but I have no idea of the flow rate to it or what a GT15. It could be over-feeding it... It s also coming in via a brake hose which will have a very small internal diameter, which may be upping the pressure but it's a standard pipe diameter for feed so I shouldn't think that's a problem.

I think the test of putting the oil outlet pipe straight into a bucket should tell me if its the turbo seals not holding or if the return pump isn't powerful enough for the feed, and if it is the pump I can look into either restricting the flow in to a safe minimum or uprating the pump outward.

I also need a new feed for the power to the oil pump, ive connected it to the killswitch and it works great, but now my dash lights flicker when it's running! Any suggestions on a 12v feed point for it?

 

The earliest 675's had a feed for the fuel pump that was fed via the ECU!!
This caused "some failures".
Triumph changed the wiring design, and did a recall on the affected bikes (including mine) which was basically installing a small sub-loom with a relay to take a direct feed when the ignition was switched on.
Perhaps that would be a useful point to tap a supply from.?

 

Have fitted a new (2nd hand) turbo core today...



And after rebuilding ran the first test...

Disconnected the turbo oil outlet pipe and let the oil come straight out of the turbo into a pot, and put the pipe from the return pump into the pot. The pump is working as expected, the oil is flowing through the turbo OK, the turbo is spinning up OK...

But it still spits oil from the exhaust.

Any ideas?

 

Only thing I would do is check the oil pressure with a gauge put into where the oil pressure sensor goes. See what the pressure is and then seek advice from turbo company to see if pressure is to high. From my days of having a Renault 5 turbo. I was seeing pill pressure readings at the turbo of around 50 psi cold dropping to around 40 psi once warm. On idle around 15-20 psi. So id say u want readings around that.

 

Well, what an eventful few days!

After the 2nd turbo blowing oil it led me down a track of possibly overfeeding it of oil. It turns out that the seals on the turbo drive are not there to hold the oil in but to keep the boosted air and exhaust gases out of the oil, and as such are not designed to hold oil pressure at all.

So on the route of inline pressure restrictors led me to finding that people out restrictor banjo bolts on the turbo feed to limit oil feed in high power builds, and that they are a mere £17...

But I'm not a fan of spending money as you all know, so I made one. I got a m4 bolt, cut a small groove in it to make the 1.5mm hole I needed, used a bench press to stuff it in the end of my existing banjo and cut it off. How pikey is that!!!



And you now what? It worked flawlessly! The flow rate has been reduced by over half, and with my feed draining via a bucket so I can measure the rate in from the feed and out with the pump they match up surprisingly well.

So a bit of reassembly and this happens.......



There it is, people - IT LIVES!!!!!!

The bike is officially running! It's super smooth and not too loud at all, but the exhaust note has a brutally crisp edge to it, with that crackle you get, top fuel dragster style. I love it!

I have to replace all the crush washers on the feeds as they have been on and off a few times and some are a little weepy, and I have to raise the cash for the map, and then when it's back I have to bolt the fairing on before I can call this finished, but it's pretty much there now..

As I say... a eventful few days!

 

This is such a good thread. Love the updates!

 

The flickering dash I can't get around. It's a by-product of thr oil feed pump. I've tried about 6 different power feeds for it including direct from the battery but it flickers whenever the pump is on. If anyone has a solution to this I'm all ears - maybe using a lower voltage led for thr dash bulbs?

 

hate to say "i told you so", but, erm, i told you so

glad to see you got it sorted.
onwards and upwards!!

 

Congrats, so glad you've cracked it! I reckon it will sound epic at WOT