Turbo plumbing for a simpleton

[MeanBean49]

I run a 260lph pump as 130lph couldn't supply enough flow at full chat, but mines a big 1216 motor. Smaller pump should be fine on yours. I run mine at 2psi above boost pressure. so 20psi pump would be fine.

the lower you can get away with running fuel pressure the better, the higher it is, the more likely it is to overcome the float valves and start flooding the motor as the pressure rises.

I also disagree with what was said earlier about FPR vaccum feed. I take mine from the carbs not the plenum. That way when you shut the throttle the fuel pressure drops straight away, again stopping the fuel pressure overcoming the float valves and flooding everything.

[El Gringo]

Thanks for the reply chap

I presume to get 2psi at the FPR you need to modify the spring a bit?

I'm actuely aware of how fickle the GSXR4 carbs can be so anything i can do to make life easy for them the better.

I was chatting to Ben at Valespeed about my project and his trip to Pendine the other day and he said you were the person to speak to.

[MeanBean49]

Dave Dunlop did my kit origionally,yeah i believe he cuts the springs a bit, so a lot of it is trial and error.

Ive picked up a lot of stuff from Dave and finding bits out as i go.

Ben os a top bloke, his bike is ace.

Yeah i find that the easier time you can give carbs the better they behave, now ive got mine setup nice it rides brilliantly. I also find its worth stripping carbs cleaning and re-setting float heights regularly.

My system is fairly basic, carbs still have plastic tops. Did half a mile at Pendine bouncing on the limiter at 17psi. (By accident) Never missed a beat.

[Rene EFE]

This thread is awesome, reading with much interest. Carry on 

[Paulm]

You could always mount an oil cooler on the swing arm brace or under the seat with a fan of some sort pushing air through the cooler,or even in the fairing with holes drilled to suit for air flow.

[El Gringo]

Thanks guys, it's ticking along nicely now

I'm pretty sure the standard cooler will work now, got a bigger rad coming too which should help.

There's plenty of space under the back to run a cooler like a plate hanger - i seem to remember a bike ages ago that had a rear cooler painted up as the plate, i think it was Schaeff's yellow one?

Any who, the engine end stubs for the headers are done so should be able to get them fully mocked up this weekend.

 

[El Gringo]

Spose i better update this

Headers and exhaust are away being welded this week, i don't trust myself to do them, my welding goes as far as tacking and non structural sticking together 

Also have the up pipe silicones and tubes ready to go, just waiting on a sheet of ally to start on the plenum.

Have been thinking about the oil feed and return again, from the posts above, bearing in mind its a journal bearing i was wondering if -4 is too big, the fitting on the turbo is a 4.3mm hole, if i've got it right -3 is 3.6mm ID and -4 is 6mm ish?

On the drain i think i can get a -10 fitting on there and was going to look at the 12V Facet type scavenge pumps.

My question on that is wheres best to return it to? I was going to use the oil filler as a breather which doesn't leave many options for existing inlet points. Was wondering if i could modify the timing plug on the front of the clutch cover and put it back in there, it's above the oil level and i'm hoping the pump would have enough lift to get the oil in there, it's probably 3-4" maximum between the drain outlet and the timing plug. Or.........

I've seen quite a few pics of turbos recently with the drain feeding into the sump below the oil level, i presume this would require a check valve and a pump with enough pressure to over come the oil in the sump?

Anyway, few piccies

Cheers in advance

Chris

 

[JOE]

really starting to come together chap.  Are you going back to fully faired (if possible with the pipework) or 'fighter?

[El Gringo]

Cheers boss,

Fightered but clipons rather than flats,a) the pipework and new rad wouldn't fit inside a fairing and b) it didn't come with one and i'm trying to keep the costs to a bare minimum.

Air filter has arrived, pipes should be welded early next week but the guy who does my turning is away on holiday so i'm a bit stuck on the plenum till he's back.

 

[JOE]

cool, did think there would have to be a fair bit of surgery to any fairing if it went back on.

[Scara]

On 15/06/2016 at 9:18 PM, MeanBean49 said:

I also disagree with what was said earlier about FPR vacuum feed. I take mine from the carbs not the plenum. That way when you shut the throttle the fuel pressure drops straight away, again stopping the fuel pressure overcoming the float valves and flooding everything.

I concur on this one. Had to move my connection point to carbs from the plenum location on the kit, which was causing over supply on my build, I was chasing it forever and was documented in the build thread. A Quick chat with the Guru via email across the pond  > Once the piping was rerouted the bike began to behave as it should, cold starts were a no brainer, plugs remained healthy and has never drowned out since.

With that in mind, only thing left to do was re-jet for accurate AR ratios at WOT and haven't had issues since.

I can only put forward a theory it may be specifically Mikuni carb related which differentiates between models (#34 / #36 / #38 / #40 CV etc) hence the FPR behaves according to its own feedback on a blow through system.

[El Gringo]

Thanks Scara, good info.

I'm hoping it's going to be relatively straight forward.

I've also been offered a set of machined standard pistons that give 9.5:1 compression and an ignition cover with adjustable timing pick up and oil feed for the turbo which is awesome as i was strugggling to work out how i was going to do it.

[El Gringo]

Done a bit more

Made a start on the plenum, not quite sure how it's going to fit with the silicones in place but we'll overcome that one when we get to it

Found a location for the fuel pump, it's a bit long to fit where i wanted to put it under the back of the tank so it's going on the shock mount, should be able to keep the hoses neat and run them up inside the frame uprights.

Just need to take the shock etc out to drill the mounting block for the clips.

Back to the hose sizing dilema, the Garratt website states a non restricted -4 oil feed and a -10 drain.

Just wondering what people were using on the drain side, and how they're mating the big ID hose to the Facet type pumps, stepped down fittings? Also what PSI rating would be suitable, i was thinking either the 4-6psi one or maybe the 7-10psi

I was thinking of using one of the big 12V mechanical geared scavenge pumps but it's pretty big to "lose" on such a small bike and seems a bit overkill if a 12V facet one will do the job. 

[marc7/11]

really enjoying this thread , some great fabrication going on ,, learning alot too.. 

[El Gringo]

Thanks guys

Got the fuel pump mounted.

Been thinking about the oil return, think i'm going for -10 hose with a scavenge pump. Was initial going to feed it back in at the timing plug as mentioned above but having measured it i think it'll stick out too far. So plan B is to add a threaded fitting here in the crankcases (where the round mount is)

Only issue i can see is that it would feed in directly above the back of the clutch basket which would fling the oil everywhere, which i'm guessing isn't ideal - so i could put the oil back in through the filler hole out of the way of the clutch and use the other point as a crankcase breather

Any thoughts?

Cheers

Chris

[El Gringo]

Hi All

Made a bit of progress but not much, plenum is away having the first round of welding done.

Quick question regarding Boost/Vacuum take off points.

FPR needs to see boost pressure and has been suggested that it will also work better if it sees vacuum as well (Don't start arguing again!)

BOV needs to see a vacuum

The boost gauge i've bought will also show vacuum if connected to a vacuum source (I know it's not strictly necessary but it's there).

I have 1 take off point on the inlet rubbers that was for the vacuum tap on the standard tap - there are also the 4 vacuum take off points on the carb tops.

My question is, can I/ should I tee all 3 things from the 1 "big" take off on the inlet rubber?

As in, the main thing that needs a vacuum is the BOV, the other 2 won't hurt if they see vacuum. Conversely the only thing that doesn't need to see boost is the BOV but the other 2 definitely do.

Are the carb top takeoffs suitable for taking a vacuum signal from?

It just means i only need to add 1 boost take off from my plenum to run to the WG actuator when i add an inline boost controller to start turning the wick up a bit

Any and all suggestion appreciated

Ta

Chris

[CossiEst]

I use 3 of the carb top take-off's for FPR, BOV and Boost gauge, one is left closed. For the wastegate actuator I use the take-off on the turbos compressor side (with controller in the line)

[MeanBean49]

I use 3 of the 4 carb take-offs. I find its best not to link any of them as i think you can get bleed off into the other cylinder thats not on tge same stroke if that makes sense.

Technically they arent vaccum points anymore. They are pressure takeoffs now your pushing air into the engine.

However on closed throttle you will also get vaccume

Fpr only needs pressure, Bov only really needs pressure and boost gauge will go either way off the same tapping.

Hope that makes sense, sounds like your getting muddled up with pressure and vaccume and what its doing

[El Gringo]

Thanks guys, 

I realise that each one will give both ways once it's under boost, just wasn't sure if it was ok to do them all off t he same point.

I can see how it could be affected by having them linked.

I guess it doesn't hurt having the FPR on vacuum as it shuts the pressure down quicker (I'm sure you mentioned that before)

Carb tops it is then!

Might have it running soon

Ta

Edited November 12, 2016 by El Gringo

[El Gringo]

Might as well stick a few more pictures up, doesn't appear to be much further ahead but i've done a few bits

Got the plenum back from the first round of welding and finished up the angles cuts at the bottom and blended it to the frame shape

And made the plates for the lower edges - still working on the end caps

Once that's done that'll be off for final welding

Got the fuel block finished and tidied up

FPR is mounted and the fuel hoses are run

Scavenge pump is mounted

And the return to the clutch cover is done

Radiator is fully mounted now too and all the hoses are joined up

Last issue are the 2 big under diaphragm ports that need to see boost pressure according to the guide on here, haven't left enough height on the plenum to add any stubs!

Anyway, we're getting there now - plan is to have all the major fuel/oil/air systems finished by Christmas

Then on to the wiring

[MeanBean49]

Looking really neat mate.

Your 2 big feeds, on mine the takeoff is in the up pipe just before it goes into plenum. Just one and the y piece to split it 2 ways.  Inside the pipe its cut at about 45 degrees and orientated pointing down the pipe towards the turbo so it gets positive flow. Sticks into the up pipe about 10mm before the degeed bit. Hope that helps and makes sense 

[El Gringo]

11 minutes ago, MeanBean49 said:

Looking really neat mate.

Your 2 big feeds, on mine the takeoff is in the up pipe just before it goes into plenum. Just one and the y piece to split it 2 ways.  Inside the pipe its cut at about 45 degrees and orientated pointing down the pipe towards the turbo so it gets positive flow. Sticks into the up pipe about 10mm before the degeed bit. Hope that helps and makes sense 

Thanks Rob,

I've got the pitot tube made but i though that went to the float bowl vents?

I've got 2 extra take offs that seem to run under the diaphragms

Can probably see it best here

Fuel in at the front, Float Bowl vent behind it and then the Big one on top - same on both sides between each pair 1&2 and 3&4

In the modifying CV carbs guide i took it that these big ones had to see boost reference from the plenum?

Edited November 14, 2016 by El Gringo

[MeanBean49]

Strange. On my carbs ive got fuel in feeds and then just the float bowl overflows that you put feed to. There are no other feeds. They dont have liquid warmer things on em or owt daft do they? 

Will have a look at my 400 carbs when i get chance. See if i can suss it out. Might just want blanking off

[El Gringo]

I got the pressuring bit from here

http://oldskoolsuzuki.info/archives/396 & http://www.turbo-bike.com/Pressurize Carburetor R1.html

It'd be properly handy if i can just blank them off!

[MeanBean49]

Sounds like they could be like the 40mm carbs that have seperate venting system. I think I would start with them blanked off and use the 2 big ones at the top