Help with open loop boost control Sprint RE
 

Right now I have generic out 1 set to map switch. I'm confused on what psi I should open and close the solenoid for a specific psi. Right now I have it set to open at 10.1 psi and close at 10psi. The wastegate seems to never close after it opens. Thanks in advance.

Your open boost table should look something like this:

https://www.rx7club.com/attachments/...oost-table.png

With those settings, I am able to run 13psi from 4750rpms till redline, without any fluctuation in the boost pattern.

What psi spring are you using on your wastegate?

Is that map on a sprint or a sport, because I don't think sprint came with that option.

I'm using generic output as a map switch.

I have the stock wastegate, which I believe is a 5lb spring.

Enable the output as a generic duty map and setup the map similar to what you see above. You can't run it as a MAP switch like you're trying to do.

i control it like op, it works great if you add a ramp to it, so the solenoid can find an equilibrium. if you have just two duty cycles, i think boost would fluctuate too much. you could just separate your boost divisions from 0.1 psi a few psi. it does overshoot a little, since there is no integration going on, but not too bad

https://www.rx7club.com/attachment.p...1&d=1445255928

also, verify your solenoid operation to make sure you have the right polarity.. meaning zero in the map is closed, 100 is open or however you have it hooke up. i believe a value of zero is power applied to the solenoid

You're not doing what the OP is trying to do. He's trying to use a MAP switch. A simple ON/OFF state with no PWM. It quite simply is never going to work for him. With the Sprint, he needs to do just as I said to enable any sort of PWM control of the valve. Then, of course, he needs to do as you suggest and make sure the valve is properly plumbed.

Thanks for the input guys.

Gxl90rx7, What psi are you running with those settings?

sorry.. didnt see you had it set to map switch.. change that to generic duty output. you should experiment with the values, since it depends on your setup

Understood, Just curious about how much psi your running with that setup, so i can get a general idea of where i need to be about fot the pressure im running.

So the generic out put worked great to get my boost up but now it's surging.

by surge do you mean overshooting or compressor surge? if you do it my way boost will overshoot initially.. you can try decreasing the boost level at which the solenoid starts opening. in the map i posted, instead of starting at 7.1, maybe try moving it down to 5.7 and linearize to 10.1. the problem is this will open the wastegate earlier and probably cause more lag

or you may just have to use boost control function instead. boost control uses an PID control, so it can anticipate boost rising at fast rate and be able to compensate. and there are some settings for better spoolup.. read the help screens for "start duty" and "control start pressure"

On my text map for generic duty, the psi goes like this:

-3, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

I have zero values from -3 to 6, 50% at 7, and 8 to 12 100%.

It's surging from 6 to 8 like this.

I decided to try putting 50% for 5, 6, and 7. The surging is not as violent, but it still surges.

What pressure are you trying to run? Post a log of your MAP with the current settings.

Attached

Trying to run 10 for now.

So I made the map run 7.1 to 8.6 in .1 intervals. 7.0 to 7.8 is 0%, 7.9 is 50%, and 8.0 and up iS 100. I'm still getting about .3 boost surge.

Any one know what Frequency i should set it to? I've heard 33hz is good. please advise.

Edit:

NVM i think i found it. 31 Hz.


https://cimg2.ibsrv.net/gimg/www.rx7...cc390e171d.png

30-35hz usually. It's a variable that can be used to alter the responsiveness of the valve.