GS(X)1100E turbo EFI

[ArttuH]

Update time!

After getting the engine in the frame there was plenty of bolting on accessory bits, routing hoses, connecting wires and so on. Generally huge amount of small things that take plenty of time in the end. One funny surprise was that new engine sits in slightly different position in the frame. And naturally I had fitted most of new parts very tightly with the old engine I almost went nuts when I realized that one of the injector connectors just wont fit since it interferences with the frame. Fortunately slight re-shaping of the fuel rail fixed the problem.

Oil distribution was quite interesting topic too. I decided to add external oil feed to the head since original oil passages are now restricted by HD studs. And turbo needs oil supply too. So at first all the oil coming from the filter is captured by this distribution block.


The block has a 3mm hole to bleed part of the oil directly to the crank and transmission. Rest of the oil goes to the head and turbo. And since the turbo requires some pressure additional restrictors were needed to prevent oil escaping too easily in the head. So I added 2.5mm restrictor plugs on bolts of the oil rails.


Seems to work pretty well though a bit less restriction would be good since the oil pressure goes slightly too high at top rpm. Actually the ball bearing turbo shouldn't need much pressure for lubrication but cooling of the bearings is designed for typical car oil pressure (30-60 psi). Therefore I think it's good idea to get a bit more pressure for it than standard <7 psi in these engines.

One additional surprise was that the sprocket covers aren't interchangeable between the 1100 and 1150 engines. And I had just a 1100 cover. Fortunately one helpful Suzuki-enthusiast from England delivered quickly this nice piece of milled aluminium that fixed the problem.

[ArttuH]

I also upgraded the processor of the ECU to MS2-version. It took few hours to go through all the new settings and determining some sensible starting values for them. By this far I'm pretty happy with the upgrade. Not a huge leap from the MS1 but almost everything is improved more or less.

Now the bike is almost complete. I'm going to add some kind shield for the air filter to prevent road dirt blasting directly on it. Otherwise all the bits are on their places.



By this far I have done just few quick test rides and tuning is still way off. But everything seems to work like expected and the engine responds really nicely at low rpms. Tickover is pretty noisy due to rattling lock-up arms but that smooths nicely when you get moving.

[gmansyz]

Restriction

I don't know about restricting oil for any good. The turbo was designed to be pressure fed with up and maybe more than 100 psi. Is there a restrictor in the housing? And oil to the head I feel should not be restricted either. It was always lacking to begine with. I would just hate to have the head ruined by not enough oil. I think that at high rpm, the GS only makes 10 psi? My reasoning for removing the restrictors. Just my thought.
Laters
G

[ArttuH]

Just for clarification, I didn't add any extra restriction for the turbo. The idea was to increase pressure for the turbo from stock 5-10 psi to about 30-60 psi. Just to guarantee sufficient oil flow through the turbo. There is a very small restrictor hole in the turbo centre housing, about 0.04". But it's integral part of casting so I can't alter it.

I'm not too concerned about oil starvation on the head. Since the pump is constant volume type all these restrictors shouldn't affect much to total oil flow. Only drawback is that pump takes now more power since it's working at higher pressure. But it should be capable for that since the same pump is used on 750 with high pressure oil system. So the engine should get the same amount of oil than in stock configuration, minus small amount that the turbo takes. And since I'm using 750 gears there should be enough flow to cover the difference.

Only question is if the balance between the crank and the head is good. And if I'm loading the pump too much. I guess that I will open up the restrictors a bit at some point because now 60 psi pressure gauge pegs at 6000 rpm. That's slightly too much, I think.

[ArttuH]

Tuning starts to be in decent state and the bike has been in regular use without major hiccups. Though I have been fighting with surprisingly high amount of small random problems like oil leaks, fuel leaks, charging problems and so on. Fortunately all of these have been easy to fix. Typical shake-down process, I guess.

I have done quite a lot work with boost control. At first I noticed that integral wastegate of the turbo is apparently too small. The gate starts to open at 0.5-0.6 bar (8-9 psi) and initially boost stayed at that level. But the boost creeps up as the revs go higher and on higher gears it even reached over boost fuel cut at 1.2 bar (18 psi). So I took the turbine housing on the work desk ported the wastegate hole as large as the valve allowed. This helped quite well. Boost still creeps but stays below 1 bar (15 psi). Good enough.


Then I have tried to get the boost controlled by ECU with pneumatic solenoid valve. Unfortunately it hasn't been easy to find good settings for the Megasquirt to get the boost rising quickly and stay steadily at the target. It either rises slowly or overshoots and fluctuates. Might be because I'm using rather old firmware that is rated as "stable". Later versions that are still under testing phase should have significantly improved boost control functionality. So probably I should upgrade.

[ArttuH]

Any ways, I got the boost control working well enough for some dyno testing.

At first I tried to find knock limit for ignition timing by listening the engine with "electronic stethoscope". But I wasn't able to notice any knocking even though I disabled water injection and increased ignition advance by ten degrees from my guesstimated safe values. So I ended up to increase advance by five degrees from initial values and that gave about 15hp power gain.

Slightly surprisingly the engine produced couple of ponies more power without water injection but on the other hand intake air temperature rose about 40 °C (104 °F) higher. With these numbers I'm happy to continue using water injection as safeguard. Maybe I should try slightly smaller water jet, it could result better balance between power and air temps.

After all this tuning I got 212hp with 1 bar (15 psi) boost. Not very dramatic numbers but nice improvement from old engine. And calibration of that dyno is still unclear since it is home made unit. In practise this power seems to be enough since the bike wants to wheelie heavily on three first gears. So I guess that next improvement will be a longer swing arm Here is the dyno graph, blue curves are the old engine with 0.8 bar (12 psi) boost, for comparison.


I also tried slightly higher boost and got some 230 hp with 1.2 bar (18 psi) but then we noticed a slight leak between the head and cylinder block. Fortunately the leak was minimal and occurred only under full boost. Later on I re-torqued the head nuts and noticed that they were loosened quite much for some reason. So I hope that the gasket is now fine after re-torquing. At least there aren't any signs of leak.

Here is a crappy video from one dyno pull: http://www.youtube.com/watch?v=xLI_jAyCCek

[gmansyz]

Too MUCH boost? Creeping

Hello Arttu
May I ask a really stupid question? Are you sure that the wastegate valve is completely open???? Maybe it is not and that is causing the boost creep? Perhaps the actuator doesn't have enough travel? Then shorten the lever arm on the valve. Maybe, open the wastegate hole and make a larger flapper plate? Or perhaps the flow from the valve is getting blocked by the flow coming out the turbines exhaust?
Did you "O"-ring the sleeve tops? This helps to keep those gasses in.
I would also suggest some porting of the head and a proper valve job and throating of the seat. Maybe some small drop-in cams too.
Okay, laters
Greg

[ArttuH]

Hello Greg.

Yes, I checked that the wastegate opens completely. I discussed about this with guy that sold the turbo for me. He has installed several of these turbos on bike engines and according him it's typical that boost creeps up. Now I opened up the wastegate hole as far as the flapper valve allows and that helped quite well. I may install a larger valve during next winter, if I have too much spare time

No, I didn't o-ring the block. Just plain multi-layer steel gasket. I hope it will hold now with properly torqued head nuts. Before re-torquing the nuts were so loose that I'm not wondering why it leaked under boost. I'm just wondering why the nuts were loosened since steel gaskets shouldn't compress much.

Actually the head is mildly ported and the seats are throated. That gave about 10% increase to flow bench figures. I think this power is pretty much enough for me, for some time

[gmansyz]

Boosting

Hello Arttu
Okay. I imagine that when the turbo was used in it's original application, the stock exhaust had enough back pressure to control the boost. When it is removed, I see the problems. Is your blow off valve large enough? I think make the wastegate valve larger when you can. Maybe it will be allright then? Just make sure the weld is very good as the heat will let it pop off otherwise. Get's rather toasty there.
I am surprised about the loosening too. Maybe the gasket does need to squash over time more than once thought. Perhaps the base gasket is fiber too?
Porting always helps. Especially on the older sidedraft heads. Big valves and cams too.
Hope you are having fun with it.
Laters
Greg

[rapidray]

Trust me on this, you NEED to oring the cylinders &, when you do, make sure you use STAINLESS wire or piano wire! I use piano wire on all of mine & have no problems. If you use copper wire for the cylinder orings it will crush & eventually leak. You also need to use a copper head & base gasket. Ray.

[ArttuH]

Hello Arttu
I am surprised about the loosening too. Maybe the gasket does need to squash over time more than once thought. Perhaps the base gasket is fiber too?

The base gasket is steel. One possibility is copper washers under the nuts.

[ArttuH]

Trust me on this, you NEED to oring the cylinders &, when you do, make sure you use STAINLESS wire or piano wire! I use piano wire on all of mine & have no problems. If you use copper wire for the cylinder orings it will crush & eventually leak. You also need to use a copper head & base gasket. Ray.

Yes, if the gasket doesn't hold now I have to consider o-rings and copper gasket. I have just heard so many stories how difficult it is to get a copper gasket oil tight

So let's see how it will do. At least I haven't noticed any signs of leaking after re-torque. But I guess that I have to make new dyno run to verify if it holds properly under full boost.

[rapidray]

I have NO problems getting copper gaskets to be leak free. Ray.

[blowerbike]

I have NO problems getting copper gaskets to be leak free. Ray.

how am i supposed to keep my leathers shiny mr. no leaks

[gmansyz]

Leaky Free?

Heya Ray, how about sharing with the rest of us on how to keep the leaks at bay and our leathers nice and shiny?
G