Tonight Quadcam came over and we switched my UTEC from closed loop boost control to open loop boost control to provide constant boost regardless of air density. I asked Shairf and jeremy to tune it in Opne lopp and for some reason they never wanted to do it. So i switched it over and it works perfectly. I am using the Turbosmart BCS. Quadcam has the same setup on his car and his is running fine as well. I think he might have a different BCS. But I'm here to report it works.

 

Hope it all works out for you JET.

 

I've never used anything but open loop.

 

How much power you putting down Jet?

 

565 whp

I was always told by Sharif he could never get it to work and preffered not to tune the car open loop.

 

Why? I have always thought that majority here using the Utec BCS uses the Open Loop. Where you having problem with close loop before? I have always use the Open loop and never really have any problem. Oh I don't know if you call this a problem but in the Winter my boost is about .2 to .3 higher so I just subtract a little to my boost map.

 

Keep me informed as to how it works over time, when the air temps/density change.

I have had no issues with mine in Closed Loop for a year and a half now. I have heard from others that they could never get closed loop boost control to work on higher boost cars..............yours seemed to be perfect last night. I wonder if your heavy wastegate springs help this out.......or not.......

the world may never know........kind of like finding out how many licks it takes to get to the center of a tootsie pop.

 

99% of people use open loop boost control on the UTEC. Closed loop provides feedback from the map sensor so the utec is supposed to adjust the BCS to provide the same boost all the time....open loop boost tuning uses a duty cycle value to adjust the BCS for boost increasing. Closed Loop uses a target value that the utec uses to control the bcs to maintain that level.

I really wish TXS would change the "unit-less" values on closed loop to an actual pressure value. It would be alot quicker to setup and would eliminate the guess work. Maybe some day we'll get that feature in future UTEC upgrades.

 

It sounds like you mean just the opposite: you switched from open loop to closed loop?

Open loop: you set what duty cycle the bcs should operate at
Closed loop: you set target boost, and the computer figures out what duty cycle to run the bcs

 

I'm confuse now. You use Close Loop so did you push Jet to switch to Close Loop? I'm really confuse why Sharif and Jeremy won't tune Open Loop if 99% uses Open Loop as you said.

 

I believe Jetpilot said it backwards. Most likely, he switched from open -> closed loop.

 

Thats so Cool !! does it matter what BCS to use with UTEC ?

Andrew are you still using the TXS BCS ?

Thank u both

 

Nope. Larry asked me to switch his boost tuning from open loop to closed loop late last week. He was not hitting the same boost pressure that he previously had been.....a few weeks earlier.

So, I figured we'd try it out on his. I know some others have experimented with the UTEC closed loop boost control but had problems getting it to hold and maintain higher boost levels. Larry has 1Bar wastegate springs in his Tials, which brough the boost up to 12.5-13.0 PSI on runs with no Boost Control. I started out slowly and made small changes and saw that everything was doing just as it is supposed to.

In the end, the boost levels are the exact same as when Jeremy setup Jet's car (16 psi)...........it's just that the UTEC is using Closed loop Boost Control, rather than Open Loop boost control.

 

I am still using the TXS BCS. I don't know which one he has.

I have turned mine up as high as 12 psi (base of 5.5) on a quick race gas tune. It held it perfectly. I have mine setup up for about 9 psi for daily driving. It as been that way for about a year and a half.

 

Fixed.... sorry for the mix up.

 

on the dyno, i have only had the open loop work correctly. the closed loop did some weird things.

thats why. haha

 

Sharif also tuned mine in open loop and mentioned you have to be careful of boost spikes and be thorough in testing if I decide to switch to closed loop control. Haven't gotten around to it... If your datalogs show steady boost, even between shifts and what not, then I guess you're golden.

 

Yeah.... boost was solid. For some reason I have a dip from 16 down to 15.3 at about 5000rpm we can't figure out, but it recovers in about 3-400 rpm back to 16psi.

The dip occrued even just on wg spring pressure alone without the BCS. Go figure!

 

...........and the dip was occuring prior to switching to closed loop control, too.

I wonder if it has anything to do with the cams or the cam phasing. The car really seems to come alive at that point, too. You can hear it "come on cam."

 

I have my UTEC in closed loop and I have to be really careful with it.

If I go WOT from a dig I have no problems with it maintainting my desired boost pressure.

If I'm past 3500RPM or so and floor it I overshoot pretty bad. As long as you have your boost cutoff set properly and are used to it its not a big deal. One of these days I will either install a "real" closed loop boost controller or switch back to open loop.

I've said all along that I don't believe the adjustable values for the boost controller work - so if your desired boost pressure and your solednoid valve work with the default values then it should work pretty good. However, if you need to tweek the values at all you are out of luck.

I do believe TurboXS said that there would be an update to the boost controller that would convert it to a unit value. I'm waiting patiently for it....