HOW TO - Control boost using ECUFLash and 3 port GM boost solenoid
Just did a confirmation of Mr Evo IX's AEM (tru-boost, but its the same as the seperately purchased solenoid) and yes, the stocker was about 32 ohm, tru boost was about 12-14 ohm. I tried resistors in series (on on each side of the leads to the solenoid) which totalled about 32 ohm and it just wasn't enough power to move the solenoid. Spring pressure every try.
So, if you are using the AEM solenoid you are leaving the ability to send a bit more power to it, but that doesn't necessarily mean that you will be over-amping anything in your ECU. After putting in the JDM MAP I'm kind of surprised how high my spike was and how much duty cycle I need to keep the stock turbo pumping!
So, if you are using the AEM solenoid you are leaving the ability to send a bit more power to it, but that doesn't necessarily mean that you will be over-amping anything in your ECU. After putting in the JDM MAP I'm kind of surprised how high my spike was and how much duty cycle I need to keep the stock turbo pumping!
Also, I had some issue getting the right boost curve. Eventually settling on an almost flat 72% duty cycle till the turbo starts to taper and then I let the direct boost control do it's job (adding more duty). I may try to work in 100% during spoolup again, but I never could get control of the spike using that method.
Last edited by Mr. Evo IX; Apr 15, 2008 at 08:57 AM.
I'm using a single resistor just like what is used with the GM 3port . 10ohm 1 watt. I tried 2 as well and got nothing, 1 worked perfectly.
Also, I had some issue getting the right boost curve. Eventually settling on an almost flat 72% duty cycle till the turbo starts to taper and then I let the direct boost control do it's job (adding more duty). I may try to work in 100% during spoolup again, but I never could get control of the spike using that method.
Also, I had some issue getting the right boost curve. Eventually settling on an almost flat 72% duty cycle till the turbo starts to taper and then I let the direct boost control do it's job (adding more duty). I may try to work in 100% during spoolup again, but I never could get control of the spike using that method.
Yup, I think its interesting that the HFS-5 install guide (by dudical I think) recommends the MAC valve that is the same as the AEM Solenoid, but recommends a 3W 10 ohm resistor. If mine wasn't permanantly encased in jbweld I would probably check how hot it was getting.
For reference, here are my tables and a log... (scaled 2.4psi on the Baseline boost table, 3rd and part of 4th, NLTS and short shifted)
I'm having trouble logging WGDC correction% in evoscan, it seems to flatline 16% no matter what whenever I'm at boost. I definitely get an interesting curve in 4th through... I think the correction may be down in the upper RPMs of 3rd and causing that, but I like that much better than a spike. I may move to keeping only the upper 2 cells of BEC zeroed and run 2% or so in the third.
bump
I ordered the GM 3 port , Ive read this whole thread 2-3 times . But some of it over me .
Could someone tell me if I used this map listed above would that get me "close" and if change is needed I should change the '''Max Wastegate duty..." to get -/+ psi @ that RPM . I would like to hit 24psi @peak and hold it longer than my mbc can (MBC is droping to 17-18@ 7.2k)
I ordered the GM 3 port , Ive read this whole thread 2-3 times . But some of it over me .
Could someone tell me if I used this map listed above would that get me "close" and if change is needed I should change the '''Max Wastegate duty..." to get -/+ psi @ that RPM . I would like to hit 24psi @peak and hold it longer than my mbc can (MBC is droping to 17-18@ 7.2k)
^Every set-up is different, so turn off error correction (put all zeros in the err correction table), if you really like those numbers you quoted - plug those numbers, reduce them by 20 (in max wastegate duty table) do a pull. Then adjust accordingly (increase or decrease) and do another pull. And again till you're satisfied with boost.
Then log your load plug it in the boost desired engine load and enable error correction.
Done.
Then log your load plug it in the boost desired engine load and enable error correction.
Done.
Last edited by mplspilot; Apr 18, 2008 at 02:26 PM.
^Every set-up is different, so turn off error correction (put all zeros in the err correction table), if you really like those numbers you quoted - plug those numbers, reduce them by 20 (in max wastegate duty table) do a pull. Then adjust accordingly (increase or decrease) and do another pull. And again till you're satisfied with boost.
Then log your load plug it in the boost desired engine load and enable error correction.
Done.
Then log your load plug it in the boost desired engine load and enable error correction.
Done.
So i am not the most experienced tuner but one thing i did mainly as a safety precaution is zeroed out the UPPER correction only that way if I DID overboost at least there was some correction to lower the WGDC. Might be a nice suggestion for new tuners in case they make somewhat drastic changes.
Can someone please post target loads for a peak of ~27psi to X psi @ redline (91 octane + meth) ? Also, at what point is the stock turbo just pushing hot air (pv=nrt) or out of its efficiency? Thanks
No I have not done the JDM Map sensor swap. How does the MAP swap account for altitude changes (e.g. I live at the beach and take a trip up into the mountains) -- do I over-stress the turbo? Thanks Tephra!
Resurrecting this thread...Im about to install mine soon. I am a little confused on which ports get used for what cause some of the OP diagrams are missing. Is there specific ports the WG line and boost pressure line have to go too and the port that has the little filter on it is the one that would usually go to the intake hole thingy...? 
Someone enlighten me please. Thanks much. 
Someone enlighten me please. Thanks much.
ok basically it looks like
AI = Air intake, WG = wastegate
to work out which way, blow into the metal (turbo compressor) thingy and the air will come out of one of the plastic thingies, that goes to the AI.
Code:
to WG ------|------|
| GM |----- to turbo compressor
to AI ------|------|
to work out which way, blow into the metal (turbo compressor) thingy and the air will come out of one of the plastic thingies, that goes to the AI.
