My goal is whatever I can support with up to 20% methanol. So to test, arguably I need to go beyond. If I keep making power and reach 90% duty cycle, then I may have more on the table unless I adjust the actuator

 

That day I was spiking 28psi @ 4500rpm.


After I rebuild my laptop, I'll get some logs of different situations. I'm going to disconnect the WGA from the pressure source and see what boost is like from 5k and up.

I have noticed on my logs, when spiking 30-32psi that I am maxing out 2-byte load at 380. It stops at 379.xx and doesn't ever go over that. Anyone else seen that before?

 

If you can log pressure loss for the IX intercooler during your boost runs that would be great! And temps?

 

mixmastermatt, I've not seen it because that would be about 2.8 bar boost on the standard setup. I think you'll need to rescale your GM MAF with the MAFTPro or rescale the MAF readings in the ECU to get the airflow readings down a bit, and then redo every map that references load (ie fuel map richer at the same load, ignition map more retarded etc).

 

I'm at a point now where the taper is the same from 6500- whatever duty cycle I run - 0 or 90%. I think on the stock acutator the exhaust manifold pressure at the top end running the boost levels I want is far more important than the air feed to the actuator diaphragm. By tightening the actuator I will be able to get the top end up a bit, but it will not be controlled by the boost controller up or down, so will vary a little from gear to gear and probably depending on atmospheric pressure as well.

I would think a stronger actuator would give better control at this point?

 

you guy are confusing yourself on how the WG and the Actuator flapper work. if the longer flapper close it boost even faster and hold boost even better. to an extend of course cause you don't want to over boost. That's why if you have a MBC or EBC. Poke a whole in the going towards the wastegate. That bleed more air into the air instead shooting it straight to the WG and not a loud it to open the flapper and bleed air by passing the turbo hotside blade. So some of you are saying it's not holding boost because of the flapper/actuator/WG side is restrictive Which doesn't make a fk sense.

 

I'm not sure I follow, but what I think is happening is that it boost creeps when the preload on the actuator is too high because the actuator rod on full extension does not allow the wastegate to open enough to divert sufficient exhaust flow from the turbine wheel to stop the turbine and therefore the compressor speeding up. I now know my O2 housing wastegate exit does flow enough to not creep excessively if the actuator preload is not excessive.

At the top end it doesn't matter what I do with the EBC solenoid duty cycle - 0% or 90%, the top end boost profile is the same - in other words I can't raise or lower the top end boost with my controller but only by adjusting the preload. So the wastegate at the top end is only under the control of the exhaust manifold pressure pushing it open, but by increasing the preload I can restrict how much it opens.

This is why I think a stronger actuator would be better because it will open with sufficient boost pressure on the diaphragm to allow control, but not be blown open as easily by the exhaust manifold pressure at high RPM, which as long as it is supported with adequate octane and the temperatures don't go out of control may allow more power.

Which bit have I got wrong?

In looking for an actuator, they are $350 in the UK from Forge, and they are made in the UK. Seems pricey for a simple actuator, don't see anything for a IX on Ebay - the acutator is I gather a little different. Suggestions?

 

Phone Antony from Indigo and ask if he can get you a 18psi actuater from the evogreen?

 

https://www.evolutionm.net/forums/sh...d.php?t=271641

 

Also, stock IC is good for 2bar!

If you peak to 1.95bar and can hold 1.7bar, I would call it a day! I think what you have achieved is almost the limitation of the IX turbo.

For good measure, stronger actuater and port turbine housing!

I would dial in 1.95bar at 4500rpm and see if it helps hold boost better higher up.

 

stock turbo holding 1.7 bar ? umhhh.

 

JCS -- You are 100% correct.

 

It seems OK holding 1.7 to 6000, but I've not managed so far to make it hold that beyond that point and I think it is an exercise in futility this side of a Green. I should get the 2 byte airflow logging going again as that would be quite useful I think to see how much air I get for each boost increment from say 1.5 to 1.7 bar at 6000. I will phone Anthony.

I don't think I need to port the O2 housing as my problem of excessive creep is only caused by excessive actuator preload.

 

I've adjusted the actuator so it just has moderate preload, and the result with the AVC-R on 68% duty and target of 1.8 (it does increase to 90% duty at the top), and the AVC-R are shown (units of boost kPa). The creep with the AVC-R off is to 230 kPa, and then I was quite pleased with how it would hold - almost as well as the bad creeping situation before.

So now I can log some airflow data at various top end boost levels without adjusting the acutator. I think if I see more airflow from extra boost then as long as there is enough octane I should be able to get more power. So I hope to see where the efficient points are to make sure I'm not chasing top end boost in vain.

 

At 6000 RPM, the load is only 4 behind the MAP in kPa whether I run 250 to 270kPa, so for 2 degrees difference in timing I think it will probably be better to have the higher boost level.

At 7000 RPM, the load is 12 behind the MAP in kPa at 1.4 bar, but 16 behind for 1.5 bar. So for adding 10kPa I'm only gaining 6 load and losing 1 degree of timing. I think here I'll let it taper to 1.4 bar here, regardless of octane. I'm also going to keep it nearer to 11.4 rather than 11.2 AFR up here with the lower boost.

It does feel nice on 93 octane running 25 PSI to 6000, tapering to 20 at 7000. The extra boost at 6000 RPM does feel worthwhile.

If I run 26.5 PSI at 4500 RPM on this octane, then the timing has to be trimmed excessively, whereas it will run about 7 degrees at 25 PSI without any knock at 11.6:1 AFR.

I attach the original and final timing maps. I can run a few boost levels with the final map, so if I get to the dyno or do acceleration testing I can just flick the AVC-R between the low and high settings to find the optimum boost curve on 93.