GS(X)1100E turbo EFI

[ArttuH]

Arttu what wheels did that bike ORIGINALY have on it? They arent STOCK are they? Never looked like that over here anyway... Id be interested in finding a set like that however.

Original wheels can be seen on this picture. Current wheels are off from GSX-R1100 '91-'93.

[Sunburn]

I have replaced the fuel tap with a flange with two outlets. The return line has extension pipe inside the tank so the returning fuel exits at top of the tank.

Did you find a flange with the extension tube or did you have to modify one? Did you consider a simple check valve or would that not be as effective?

[ArttuH]

Did you find a flange with the extension tube or did you have to modify one? Did you consider a simple check valve or would that not be as effective?

The flange is home made. Actually I got it along some other engine parts that I bought. Anyways, it's very simple piece of hardware. Just a flat piece of iron with two tubes going through it. And I think that return line doesn't actually need that long extension. As long as it doesn't exit right next to outgoing line inlet it should be fine.

I'm not sure if I understand what you mean with that check valve. Where it would be installed?

[Sunburn]

I'm not sure if I understand what you mean with that check valve. Where it would be installed?

Check valve only allows flow in one direction. Intalled on the return fuel line at the point of entry of the tank. I thought this would elimnate the need for an extention tube but I am asuming the need for the extention tube is to allow the fuel to re-enter the tank without the risk of fuel backflowing.

Can the extention tube still be below the fuel line and work correctly? Am I over thinking this? LOL

[ArttuH]

There is no need for a check valve on the return line. There shouldn't be any back flow since the pump is pushing fuel always to the tank.

Basically there are two important requirements for the fuel return:
-return point should be far enough from pump intake line inlet to prevent heated fuel and gas bubbles coming from return line entering right back to the pump circuit.
-there shouldn't be any significant restriction on the return line that could disturb fuel pressure regulation.

So exit below fuel level shouldn't be any problem.

[Sunburn]

Good info, thanks

[Sunburn]

Pictures from your 1st EFI project looks like you used the GPZ pump as well. How did you figure what relay to use, or did that come from GPZ to.

[ArttuH]

Yes, I used the GPZ pump in first EFI setup. The pump was fed from a relay built in the Megasquirt box (my own circuit board version). Anyway, any general purpose automotive relay should work fine. There isn't any special requirements for the pump relay except current capacity (>10A).

[Sunburn]

The pump was fed from a relay built in the Megasquirt box (my own circuit board version). special requirements for the pump relay except current capacity (>10A).

I can see why you did it that way. There are tons of relays under 10A that are for direct fit to a board. There are not many options so far for auto style terminals. Most are 30A or more. Funny how the little things turn into big things.



Mark

[ArttuH]

I can see why you did it that way. There are tons of relays under 10A that are for direct fit to a board. There are not many options so far for auto style terminals. Most are 30A or more. Funny how the little things turn into big things.

Hmm, I meant that the relay must be able to carry at least 10A. So typical automotive 30A relay is just fine.

I fitted the relay on the board just because I wanted to save space and external wiring.

[Sunburn]

>10A <10A oops

[ArttuH]

All right, time for summary of this riding season.

After some work I managed to get the VNT and fuel tuning to pretty good state. This work was finished on a dyno of my friend. We spent a good part of a day by testing all kind different things. Though power figures were slightly disappointing it was very useful and interesting session. I got about 150hp on normal road outfit and 157hp without silencer. Both numbers were at 0.75 bar (11 psi) boost. Effect of the silencer was slightly surprising. Without it torque was improved over whole boosted rev range and the turbo also spooled up earlier. I knew that turbo engines are sensitive for post-turbo exhaust pressure but I thought that my silencer wouldn't make any restriction at these power levels.

Here are graphs with (black) and without (blue) the silencer:


Most likely the compressor of the turbo just wasn't able to produce any more flow.

And just for general interest a graph that shows effect of the VNT system. VNT vanes fully open (black) and closed (blue):


After the tuning was finished the bike was a real pleasure to ride and it saw plenty of road during the summer. Unfortunately my riding season with it ended up too early when the output shaft bearing gave up during a holiday trip, in the middle of the woods couple of hundreds miles away from home.


Since it was already quite late summer I decided to not fix the engine before winter but concentrate building another engine instead.

[rapidray]

Well! That was fun while it lasted! I would be a little disappointed with only 157 HP @ 11 psi! We see over 200 at the rear wheel with 10 psi all the time. Is the engine overly restricted? Part of it could be losing power because the turbo shaft was going I guess?! Good luck with the rebuild this winter. What is the other project??? Ray.

[ArttuH]

A small clarification: It was the transmission output shaft bearing (behind the front sprocket) that broke. The turbo is still fine.

Yes, power figure was pretty low. I think that's mainly due the compressor of the turbo. Based on information that I have found it's limit is around 175hp at significantly higher boost (it's a diesel turbo). So probably it just cant push enough flow at lower boost. Turbine side seems to be fine since I was measuring exhaust pressure on the dyno and it was staying at the same level with boost. Dyno calibration might be slightly conservative too, it's home made one and newer calibrated officially. My friend measured 94hp from his Kawa GPZ750 turbo at the same day when it went 10.6s / 125mph on quarter mile.

The another engine is a 1150 engine that I'm building for this bike. More about it a bit later. Stay tuned

[mighty13d]

Stay tuned

I just read this whole thing. I am totally subscribed now. Took bad on the bearing going but at least it's at the end of the season instead of the beginning. You have all winter to get things sorted out!