Suggestions and Tips for Controlling Boost

[TopMountGSR]

Hi, we have a vitara setup with a 30r on it. It has side exit 3\" open dump and its a pita to control boost with it. To my knowledge its the highest hp stock head/cam vitara setup. The car would be soo much faster at the track if it would just go up and hit the target boost and stay till redline, but it doesn't, it could creep 5+psi easy from your target. This really sucks because if your engine's limitations are say 30 psi and you want to maintain 28psi in 3rd and 4th you spend most of your time in the rpm range down on power at 22-23 then just peak out at your target of 28psi for a few hundred rpms. We are losing a bunch of time down the track. The boost controller in ectune needs a wastegate duty map like AEM and a duty cycle gear correction. If I could pull some duty in the upper rpms that would help this tremendously. Or maybe just assign a duty cycle to a gear with a rpm and gear compensation table. Also I've noticed say in your gear target map you have 23psi in 3rd, and 23psi in 4th.. Because of the added load in 4th it will build quite a bit more boost in 4th vs 3rd.. I'm not sure if I can use close loop boost control because for some odd reason something has changed and now instead of 65% = 30psi, its now 9% = 30psi / 6% = wg boost. I'm sure if we had exhaust and a filter on this setup it wouldn't creep as bad but this is a drag only welded diff tin can. I understand there probably is no fixing this creep but if I could just manage it a bit more. Any tips or suggestions? Thank you, sorry for the long post.

[patrick_yi_82]

Hi, I'm not sure this will help.. I used the graph template calvin suggested Graph1: Rpm/TPS Graph2: Ebc active/Boost/boostcut active Graph3: Ebc duty/Ebc Base duty Graph4: Ebc Target/Ebc Current and adjusted my settings accordingly. If my boost creeped, I would lower EBC activation point 1 or 2 psi (or more)

[xenocron]

The boost controller in ectune needs a wastegate duty map like AEM and a duty cycle gear correction. If I could pull some duty in the upper rpms that would help this tremendously.

It has this already, you set up your Gear settings, and then your duty cycle corrections for RPM and/or IAT

[Maddog20]

The Closed-loop Boost Control feature works great also. There's a sticky on how to set it up in the software forum. I used the recommended settings and fine tuned them from there.. but it made big difference OT: what WBO2 was used to tune this car? I wanted to see the A/F ratio during a quarter-mile run for comparison. If you dont mind

[TopMountGSR]

Hi, I'm not sure this will help.. I used the graph template calvin suggested Graph1: Rpm/TPS Graph2: Ebc active/Boost/boostcut active Graph3: Ebc duty/Ebc Base duty Graph4: Ebc Target/Ebc Current and adjusted my settings accordingly. If my boost creeped, I would lower EBC activation point 1 or 2 psi (or more)

Thank you for the tip, we will try to set up some graphs like this. Currently the "EBC Activation" = -431 mbar, fast spool = 0% and "Wastegate Activation" = -431 mbar Every time I would try to raise the EBC Activation to say 1000 mbar, it would slow the spool down tremendously, so I ended up leaving all these settings alone. I will try setting these correctly.

The boost controller in ectune needs a wastegate duty map like AEM and a duty cycle gear correction. If I could pull some duty in the upper rpms that would help this tremendously.

It has this already, you set up your Gear settings, and then your duty cycle corrections for RPM and/or IAT

Thank you, the RPM correction will help us a ton.

The Closed-loop Boost Control feature works great also. There's a sticky on how to set it up in the software forum. I used the recommended settings and fine tuned them from there.. but it made big difference OT: what WBO2 was used to tune this car? I wanted to see the A/F ratio during a quarter-mile run for comparison. If you dont mind

We use NGK Powerdex WBO2s, that log was actually of a 1/4 mile run. You can see the airfuels, boost, rpm, duty, gear ect.. We will try to mess with the close loop but I'm not sure its going to work with the duty cycles were they are at.. 6% = wg pressure 9% = 34 psi boost cut. Thats an awful fine line to walk, it used to not be like this. We are going to try to mess with the car tom. on the street with some 110 and 24.5s to try to get it dialed in boost wise. Then take it to the drag strip, shoot for 10s and if its still in one piece back to a street event at night. Thanks everyone for their time. dk

[patrick_yi_82]

I got the EBC activation point wrong. EBC activation is the point where eCtune will start using EBC. Waste gate activation is the point where eCtune will start opening the waste gate. So, EBC activation should be low as possible for fast spool up. And set wastegate activation accordingly, so boost spike will be minimized (lower it)

[Bugermass]

You may want to look elsewhere for your creep issues.. Boost creep can occur from too retard timing, too much fuel, a saturated wastegate, or a wastegate thats no in a optimal position. Also too much flow out the turbine VS a restrictive wastegate/dumptube setup. The reason your pressure will change with the same EBC duty is usually because theres somthing causeing a difference in pressure at the wastegate popet valve.. check your AFRs in say 3rd gear vs 4th gear, with greater load you may be going richer causing more pressure trying to push the wastegate open and throwing off your balance.. Also too retarded timing on top end could be causing this as well.. Log where the boost really starts to creep, then from that point up add like 3 deg of timing and see if your boost stabilises or the creep is reduced. Just some stuff to try..

[TopMountGSR]

Thanks everyone for their input. Honestly how it ended up I used all of your alls suggestions. Now it holds 28psi rock solid in 3rd and 4th. Without the use of closed loop. I used the rpm comp map mostly. I ended up really low wg activation, I learned fast spool is sweet and very effective. I also ramped timing more aggressively after the fuel fell off from peak tq all the way to red line. It feels great, I love how hard the boost comes on now and holds rock solid to redline. Its going to the track tom. We will see if its times get any better. Thanks again everyone, dk

[TopMountGSR]

Chris, I always tune in 3rd mostly and remove 2% in 4th and 3% in 5th. Its helped me level the air fuels better in different gears. I think it was you that you spent a great deal of time setting up compensations on a bone stock car and use those values as a base for all the cars you tune. Thanks for the tip, I put together a bone stock 92 si.

[calvin]

I got the EBC activation point wrong. EBC activation is the point where eCtune will start using EBC. Waste gate activation is the point where eCtune will start opening the waste gate. So, EBC activation should be low as possible for fast spool up. And set wastegate activation accordingly, so boost spike will be minimized (lower it)

ebc activation should be at 1024mbar(start of boost) fastspool 100% ebc activation, where you want the boost to start being controlled. fastspool will cut off all post pressure to wg or put all pressure on top port. keeping the wg shut. normally a wg with 10psi spring start to open a little bit at e.g. 5 psi and 10 psi fully open.

[xenocron]

ebc activation should be at 1024mbar(start of boost) fastspool 100% ebc activation, where you want the boost to start being controlled.

Should be, and thats where I have always activated it... TMG, did you ever alter your Activation point to near 0 vacuum and see a decrease in spool time?

[TopMountGSR]

No but I did notice slower spool time a while back when I first tryed to adjust these settings. I orig left EBC Activation, WG Activation and Fast spool all at the default settings and still ran gear dependent boost. We ran it like this for a while and one day I wanted to get the solenoid to stop clicking when the key was on and set EBC Activation at 1000mbar and left fast spool and wg activation to the default and spool time sucked so we just changed it back. Now I have learned if all 3 of these values are setup correctly it makes all the difference in the world, especially with this BB turbo.