Turbo bandit

[wombat258]

Turbine housing too small for the engine, and you are probably overspeeding the turbo. See if you can find a larger cm2 housing for that turbo (TD04?).

[luke2152]

9 hours ago, wombat258 said:

Turbine housing too small for the engine, and you are probably overspeeding the turbo. See if you can find a larger cm2 housing for that turbo (TD04?).

Perhaps - but its designed for a 2.3 litre saab so surely made to take quite a lot of exhaust flow

[Arttu]

Like already said, direction of WG connection is pretty important. 90 degree exit is far from optimal. It may work in some cases but generally it's asking for boost creep. Connection pipe size might be on small side as well, difficult to say from photos. 38mm gate should be fine. I would try to redo the connection, make it as smooth flowing as possible and large enough.

A funny example relating to topic. I was recently tuning a drag racing Busa. We were tuning low boost areas, there was 0.5 bar spring in the gate and based on partial throttle pulls it was making pretty close to that boost. When doing the first full throttle pull the result was a bit surprising: over 500hp! As we were expecting something like 250hp we thought there was something wrong with dyno calibration. So checking calibration and new pull, still the same. Then I checked the datalog and found out that boost was creeping to 2 bars at top end. Doh! Reason was placement of the WG connection pipe, it was on back side of the collector and at 90 degree angle. Even when the wastegate was removed it still made 1.3 bar...

[wombat258]

3 hours ago, luke2152 said:

Perhaps - but its designed for a 2.3 litre saab so surely made to take quite a lot of exhaust flow

A 2.3 litre NA engine that produced 150 hp at 5500rpm . . . not really a high performance engine compared to the gixxers. Just my 2  cents.

[luke2152]

Redone the wastegate pipe for a bit more flow.

 

Edited August 13, 2017 by luke2152

[luke2152]

Tested and finally have the boost under control   Now to get electronic boost control functioning.  I'm having a fueling issue thoughj.  When the bike heats up in traffic if it has less than 10L of fuel in it it basically dies and won't start until it cools down a bit.  At the same time the fuel pump makes some unhealthy noises!  So I'm guessing it is something to do with the pump not dealing well with hot fuel (cavitating?).  I know they talked about vapour lock on carbs but never heard of it on anything fuel injected.  My fuel setup is as follows: Fuel leaves tank at rear, through a large filter and then walbro gsl392 fuel pump, large aluminium fuel rail then returns to tank via MAP referenced 4 bar regulator.  When I fill that tank up it seems to be ok and likewise when moving at a reasonable speed so as to not heat up.

Maybe I should put the pump in the tank or use a fuel cooler on the return line.

[no class]

What size is your return line ? Is it above the fuel level in the tank ? Any undo resistance can cause heat build up .  I remember having an external pump on my gsxr turbo and it got bloody hot too.... I believe walbro make an in-tank version of your 392.... better option I supose if heat is a major factor . Your fab abilities are good , so I do not see any issues with getting the tank done....just make a large enough pocket to keep from sucking air when the fuel level is lowish .

[Arttu]

New wastegate pipe looks much better. And glad to hear it works better as well!

Fuel pump noise could be cavitation. How large is hose on pump intake side? And what kind filter, fine EFI filter or coarser pre-filter? Generally pumps don't like about restriction on intake side. Too much restriction will cause cavitation. And hotter the fuel is easier it happens. 

[luke2152]

Fuel filter is 100 micron.  Fuel hose is 8mm ID with AN6 fittings.  Fuel return to tank is m14 banjo which is not above the fuel level.

I might start looking for a spare tank and start the fuel system again from the beginning!

[Gixer1460]

Injection tanks - bike or cars tend to all have a baffled sump arrangement located below the general tank bottom level. With low fuel sloshing around it could be allowing the pump to suck air whilst braking say, with no fuel the pressure decays almost instantly hence the stall. Cavitation is certainly a possibility - pumps i've played with have 12+mm inlets and some even have a separate break tank to ensure a constant reservoir of fuel served by a separate LP pump. I think either run with at least 1/2 full tank or add a sump which will help both internal or external pumps?

[luke2152]

Well I've just scared the bejesus out of myself.  Was testing my boost control settings giving it some in top gear.  And then my clutch started slipping so I got off the throttle.  And then found myself going sideways.  Wasn't my clutch slipping.  My turbo sump had broken off and the turbo was draining all over the back wheel!

If I tip bike about 10 degrees to the right I can see oil level on the sight glass so I think I shut it off in the nick of time.  Didn't get oil pressure light and the oil temperature didn't skyrocket.

Most annoying is that the sump broke at the turbo flange which I brought pre welded to the pipe because I didn't trust myself to not warp the flange!  My two ugly welds further down held up just fine.  Next time I'm welding the flange myself and grinding it flat again if need be!

 

[no class]

You are one lucky bastid !  Thread the flange and Braided hose to the sump..... it needs flex for  expansion / contraction.... may save your life 

[Gixer1460]

High frequency vibration sucks !

[Tombola]

Wow lucky man!!

Was the pipe through the flange? Or just welded one side? 

[luke2152]

The pipe was just fusion welded to the flange on the inside.  Have given it a decent weld today on both inside and outside and then got a jack under the sump and can lift the front wheel off the deck.  So its pretty strong.  But for peace of mind I'm going to look at making another one that actually attaches under the engine sump and has flexi hose to turbo.

 

[Arttu]

On 8/13/2017 at 9:50 PM, luke2152 said:

Fuel filter is 100 micron.  Fuel hose is 8mm ID with AN6 fittings.  Fuel return to tank is m14 banjo which is not above the fuel level.

I might start looking for a spare tank and start the fuel system again from the beginning!

100 micron sounds ok for pre filter. I guess you have another finer filter on pressure side of the pump?

8mm hose is probably ok for intake side but I would use larger if possible. Also check carefully if there are any tight turns or fittings with smaller ID. I'm using 10mm hose with my Walbro GSL392. About a half meter hose with a filter and quick connect coupling. Seems to work fine.

Fuel return shouldn't cause that kind problems. If there is too much restriction it will result higher and somewhat unstable fuel pressure but no pump cavitation.

[luke2152]

Well I've completely revised the fuel system.  When I opened the filter up it was full of black flaky stuff which clearly wasn't good.  Anyway I've made an in tank setup.  Got another tank off a b6 which is definitely clean inside and put a flange on the bottom.  Have the Walbro mounted inside now and is inside a 75mm pipe with a few holes drilled to hopefully eliminate fuel surge.  Its a big pump and was a bugger to get it to fit.  Took me a whole week of lunchtimes to make it all happen.  I've put  tank sealer in there too - just in case - because petrol has a way of finding pinholes in mediocre welds.  And gave it my best metallic black rattle can paint job while I had it all off.  Have a filter sock on pump inlet and a 10 micron filter before the injectors.

Edited August 27, 2017 by luke2152

[luke2152]

And after all that the fuel pump is still screaming.  Maybe its buggered.  It does it about 80% of the time and then sometimes shuts up for no obvious reason.  And it really is loud.  Louder than the bike at idle.  Still seems to be working though.

[Gixer1460]

If it's now submerged it can't be fuel starvation so I'd suggest either debris ingestion and / or bearing failure. So QED - pump is wankered! I had a brand spankers new Bosch die after about an hour total running - PITA!

[luke2152]

Well its not debris ingestion because its always been filtered but may well have damaged itself when starved before - or it could just be bad luck.

[Mike750]

Very cool build congrates. Great info to for things to look out for on a boosted project good work.

[luke2152]

I'm wondering if the fuel return right next to the filter sock in the tank is a bad idea.  Thinking the fuel might be aerated when it returns and doing no good releasing it next to the pump inlet.  Regardless I think the pump is completely toast now.  Took it out for a go today and it ran lean a couple of times so I stayed off boost completely and it would periodically just go super lean (18:1 AFR) and I'd have to stop for a few minutes, then restart and it would be ok for a few more minutes.  Barely made it home.  New pump time and I think I'll run a hose for the return inside the tank to keep it well away from the filter sock.  Bike is being such a bloody tease when its so close to being awesome!

[Gixer1460]

Return position won't help as you surmise - if you can extend the pipe towards the top of the tank - de-aerates it better.

[luke2152]

Right I've been lazy over the winter trying to save a bit of £ and there's far too much salt on the roads to make me want to ride anyway.  I'm thoroughly annoyed with my multiple attempts to get the fuel system right and thinking of hitting the restart button (and make fuel system OEM as I can).  I was thinking of fitting a bandit 1250 tank and pump.  I'm not sure it will fit but looks like it would need minimum modification to do so.  Then decap my injectors to bring flow rate in around 800cc/min.  Bandit 1250 pump has one outlet and no return so I presume it has internal FPR @ 3 bar or so.  Obviously will need to redo my mapping etc.

Will a stock bandit pump actually move enough fuel for turbo application.  The injectors will deliver loads of fuel but the pump needs to get it there.  That said I suspect most pumps will deliver higher than intended flow rate much easier than higher than intended pressure.

[Gixer1460]

What power are you shooting for? For info 800cc is good for around 500hp. I don't think Suzuki will have fitted a pump capable of supporting much more than 200hp - if they want just one pump across their product range, maybe far lower, as bigger is extra elec. power drain! For info, pressure is easier to produce / increase - flow isn't. Flow increase requires bigger holes, pressure just needs restriction! Increasing the pressure sometimes works against OEM injectors - they suffer with opening against the pressure.