Page 1 of 3

boost control issue

Posted: Thu May 24, 2007 3:06 pm
by b20luda
so i sent my ecu to hondata boost control works good for the most part, but i get a nasty spike, when cruising at like 2500 rpm and going to full throttle acceration i get a consistant 12psi (i have boost cut set at 15psi) Heres the issue when in higher RPMs like 4k or so... or in first gear, nailing the throttle will results in a spike and it hits boost cut, anything i can do to prevent this spike in boost pressure?? never had this problem with my AVCR

Posted: Thu May 24, 2007 3:57 pm
by Hondata
Calibration? Datalog? How have you got the wastegate plumbed in?

Posted: Fri May 25, 2007 8:03 am
by b20luda
using GM solenoid, plumbed into charge pipe just after intercooler, setting normally open, fixed duty at 20%

lines from solenoid are about 2 feet long each, i dont have a datalog but will get one if needed

Posted: Tue Jun 05, 2007 3:32 pm
by CivicVTi
One more question about boost control. I want to wire an external switch to D4 to run lo/hi boost. In order to activate the high boost setting, do I have to feed the D4 +12v or ground it? Thanks

Posted: Wed Jun 06, 2007 10:45 am
by Spunkster
D4 must be grounded.

You should try using the manifold as your vac/boost source.

Posted: Fri Jun 08, 2007 10:30 am
by Lococoin
Spunkster wrote:D4 must be grounded.

You should try using the manifold as your vac/boost source.
What is the reason for this? I tried the manifold and it seems to creep a bit less when running right off the turbo.

Posted: Tue Jun 12, 2007 7:27 am
by thudreem
I'm having the same problem. I went from a manifold source to the intercooler piping right after the intercooler. Mounted the GM solenoid right behind the headlight. I tuned it Sat night, was a cooler night and had a little creep. Went to the track on Sunday, temperature was a lot hotter and my intake temp were 40 degrees higher and I was hitting boost cut like crazy. I tried fixed duty cycle, gear based etc. I finally disconnected the GM boost solenoid and went with a $5 manual boost controller using the same boost source (IC Piping) and the car built boost faster and held 18 psi all the way to redline (9800 rpm's)

Hondata, what do you recommend we do here??
Is the S300 ever going to have closed loop boost control with options where you can select the boost solenoid that we are using?

Posted: Tue Jun 12, 2007 9:33 am
by Spunkster
Post your calibration and datalog

Posted: Tue Jun 12, 2007 9:42 am
by thudreem
Spunkster wrote:Post your calibration and datalog
OK, I will when I get home!!

Posted: Wed Jun 13, 2007 6:53 am
by thudreem
Here is my program and a datalog where I hit boost cut with the GM boost solenoid. AS you can see I had my target boost from 2nd - 5th gear at 16 lbs, I was still hitting 20lbs boost cut. Let me know if you have any questions.

Posted: Wed Jun 13, 2007 12:43 pm
by Spunkster
Look at your AIT compensation for boost control. You are adding 2% duty cycle above 120 degrees and since your pressure at 17% duty cycle is 20psi that is why you are over boosting.

Posted: Wed Jun 13, 2007 1:23 pm
by thudreem
OK, I will change that and see if it helps.
one more question: say I want to run 10lbs in 1st, 23 lbs in 2nd, and 30lbs in 3rd, 4th, and 5th gear.
Lets say when I was testing in the fixed duty cycle and the car ran 10psi at 12% duty cycle, 23psi at 25% duty cycle, and 30lbs happens to be at 33% duty cycle.

If I enter the corresponding PSI and duty cycle % in the parameters section and then enter in the gear based 10lbs 1st, 23 lbs in 2nd..and so on the car should hit those targets on the nose correct?

Posted: Wed Jun 13, 2007 3:51 pm
by Spunkster
As long as you put the settings in correctly yes

Posted: Fri Jun 15, 2007 10:17 am
by thudreem
Spunkster wrote:As long as you put the settings in correctly yes
OK, does the ECU use interpolation for boost levels that are not in the table?

Posted: Fri Jun 15, 2007 10:36 am
by Spunkster
yes