Boost controller issues

[portenio78]

I have boost by gear issues that I can not figure out. Also I have a very narrow window of adjustability for duty cycle to psi. WG spring is 15psi. Everything worked out great setting up my tables using fixed duty cycle. I have the Mac valve that everyone seems to use for alot of different managements. Max boost at100% normally closed, 5psi activation, and soleniod frequency set to 32HZ. Doing 4th gear pulls, starting at 7% duty cycle netted me 18psi. 8% got me 20psi, 9% got me 22psi, 10% got me 24psi.....and so on to 14% getting me 34psi. I thought this was great because this is the range I wanted to be in(18-34psi). I have read up on most peoples setups being about the same, but their increments of duty cycle are usually by every 5% instead of 1% like mine?

At the track I like to use my own notes and select my control method to gear based duty cycle. 1-4th gear seem to boost about the same no matter what I put in the table. For example: using anything between 7-14% gives me about 23psi in 1st, 28psi in 2nd, 33psi for 3rd and 4th? I can get the soleniod to click with key on car off through setting to make sure its working. Data logs are also showing it cycle through my selections of duty cycles per gear. Its working...just not working LoL.

I race alot at my little red-neck local track, which is a quarter mile track, but they only prep it to the 1000ft marker. When I hit this spot in 4th gear, it blows the tires off due to prep and it always being at 33psi. I would like to bring the power way down in 4th to like 25psi...but the controller/soleniod just wont give me that adjustment. Do you have any ideas I could try to figure out my problem here?

[Hondata]

Do you have the diode installed? We've found that often it is best not to have the diode installed.

Second, there are 1800 different MAC valve combinations - are you sure you have the right one?

[cloviskilla]

subscribed. ive had same problem. radioshack has the diode for a $1.00

[surfingsk8r]

if you want a larger window of adjustment change the frequency of the solenoid and also there are better ways to control power then reducing boost levels for example use the nitrous controlls to pull timing at a desired time or you can set up secondary maps with a minimum speed of x to trigger the switch set x to the mph your at when your switch to 4th gear.

[portenio78]

I do not have the diode installed, and I will find out the exact Mac valve I have. I was told to run it at 32 HZ, so that is where I set everything. Yes, sometimes when I want to tone down power, we just take timing out of certain gears. But still though, with a 15# spring, I should not be getting 18psi on just 7% duty cycle right? Maybe I will play with the frequency some. Having 34psi in 3rd with 14% duty, then setting 4th gear to like 5% duty still gets me 34psi....crazy stuf LoL.

[portenio78]

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[Spunkster]

Try a different frequency (higher)

[cloviskilla]

Try a different frequency (higher)

so if im using a fixed duty cycle all the time do i need to check the variable frequency box and adjust the frequency? i read the help on boost parameters and i dont understand.

[portenio78]

Try a different frequency (higher)

so if im using a fixed duty cycle all the time do i need to check the variable frequency box and adjust the frequency? i read the help on boost parameters and i dont understand.

You have to set the frequency, all this does is tell the ecu at what "range" that particular soleniod likes to operate. Like in my case, I'm going to have to find a fequency that gives me the best boost control. For example, if you set the frequency to 50hz, then you might see 20psi on 30% duty cycle. Changing the frequency to maybe 70hz...you might see the same 20psi, but at 50% duty cycle.