that all comes down to your sas table settings the feed for the sas valve is always pressurized under boost whether or not the valve opens and for how long is determined by the user defined settings.

by running no bov you are inducing compressor surge and completely negating the effects of the sas system. You are also fooling yourself into thinking sas is creating positive pressure pre throttle body when infact the result would be the same regardless of whether or not sas is functioning correctly. Think of blowing into a straw with your finger blocking the other end, of course there is going to be positive pressure. But in doing so you are completely stopping the compressor wheel and creating opposing loads on the turbine thrust bearings with als dumping air and fuel into the exhaust manifold and the throttle body effectively blocking the air flow coming from the compressor housing.

 

Would the size of the BPV matter? ie stock vs Tial

 

maik:

my timing pegs negative


I plumbed the SAS valve directly from the intake manifold vac. Not sure of the results. I will do some more testing on my way to work.

Im searching for a piece of the puzzle thats for sure.

JB, andrew.. anyone whos done this any suggestions?

I dont think the explosions are happening in the manifold, but more after that.

 

Good call. I see that a lot of big wigs talk about no BPV/bov etc etc. It led me to try it for sure. I have a greddy type s that I recirc. I remember seeing spikes of pressure that were moving the needle rapidly when I had the type s with single spring mod. I attributed the failure to hold pressure due to that. Maybe I will go back to that and start over.

 

just run a stock ix bov unless you are running 25+ psi of boost if not I have heard nothing but good things about the synapse.

What kind of fuel are you running? your timing is very aggressive. I would not step the ignition retard pocket like that either there is no need to run it that far in to engine load especially at those rpm's. Just fill in a rectangular portion from 0 load to the edge of your load be low value. similar to the geek mapped guys.

 

Im running 93 oct, my timing shown in the log is at 14-15 psi of boost.

the greddy functions exactly like stock, except it basically adds the gus mod if you dont use the boost ref port on bottom, or you can take a single spring out of the top. I plan to run around 28-30 psi. That is what I have been running in the past. ive followed the synapse thread, and there is an abundance of users who have trouble tuning the valve to work properly.

I had a 2 second delay on fuel pulse for the sas settings. I zeroed that, and air injection delay out. Tomorrow I will setup my bpv to work normal. and go from there.

 

If you zero the fuel delay im not certain but it may disable it. I set air delay and fuel delay both to 0.1s as that was the recommended setting

 

I think its the zero that drives funny. You ever get any transition from off to on throttle hesitation? Im gonna tune my sd setup tonight so i can Autocross sunday

 

evocentrik is correct you cannot run zero, the minimum value is 0.1

 

i ll get a screenshot...but it looks like the samples off geekmapped

mine looks like this
http://www.geekmapped.com/forums/att...&d=1234387260&

 

Sounds like we need a airflow meter on the uicp. There might be flow but no pressure.. or shaft speed logging

 

Ok so the load under table seems to do exactly what i thought. I need to find out how to log activity on pin 5

What controls ignition timing on an evo ix. The exhaust cam?

 

Are you really running -20* - when you log what is the lowest timing? I only ask as the address for max retard on every rom Ive tried was wrong and it didnt do anything, max retard has always been -10*


hesitation from off to on throttle, yeah that happens when you set the air injection time too long. I think it holds the SAS valve open even once you are back on throttle and you effectively have an enormous boost leak feeding back in the the exhaust manifold until it closes. What are the settings? For starters try the values from merlins tuning guide, between about 0.6 and 2.6s

 

posted a log earlier

 

Ah ok I see you can actually get -20 happening. Lucky you. No one can or has worked out the correct address for max timing retard for 90550001 so I am stuck at stock -10 which isnt so exciting.

Even with no neg timing I can get some crackles happening but I suspect it makes no difference to the spool state of the turbo.