I finally re-dynoed yesterday after being flashed in January.

The reason for the delay has been ongoing boost control problems on my IX. First, the Forge UNOS MBC was causing my boost to fluctuate up and down. This was ultimately tracked down to it being somehow dirty from the manufacturing process and in need of cleaning and greasing.

In it's place, I have a turbosmart MBC until my Hallman arrives.

Unfortunately, my turbo is not holding good boost to redline. I'm hitting the desired target of ~21psi peak, but it's tapering down to around 15.7psi at redline, robbing me of a good 20-30whp. It should be able to hold close to 18psi I thought, so I'm not sure what's going on. I don't know if the MBC is sucking, the wastegate actuator needs tightening, or if I have a lame turbo

Anyway, this is my bone stock baseline run:




and here are the post dynoflash + mbc results:




I'm getting the expected torque in the midrange as the boost reaches it's target peak but then i'm losing power in the top end due to the extreme boost taper

Here's the Boost + AFR plot from the above run:



Note that I also have the high rpm leaness that cij911 saw after his flash ...

Looking for thoughts on why I'm not holding good boost ... and the AFR looks a bit scary to me ...

 

What is interesting is that we seem to both be hitting peak torque at 3250 RPM, but your boost is at peak and then starts tapering, whereas mine does the first spike then dips a little and then peaks again at 4700 RPM and then falls to ~16.88 PSI.

You are making making ~14 ft-lbs of torque more than me ....If only I could get the better spike and then both of us have a slower / better taper. I think with both our setups it is the MBC and we should go back to an EC BC.

Are others experiencing the same problem? Also, we both are running stock exhausts.

 

Joshd,

Are you sure your MBC is install correctly?, are the lines pinched anywhere?, you don't have to have the MBC lines pinche to loose boost the BOV line could drop you boost as well.

I have a mail in flash from Dynoflash and a UNOS MBC on the Evo 9 and I have no problems with the boost, it holds very well. Maybe you should install the harder spring.

My .2c


Carlos

 

Is this a mail in flash or custom?

 

Chris, here is your boost/afr plot:



You are actually tapering to about 17.8 right before the operator let off. That last drop down to 16.88 was after he let off the gas.

So you're holding a bit more than 2 psi to redline, which explains why you are pushing 25 more whp ...

As for the 14 ft*lbs of torque comment ... it's only for a brief spike of the turbo boost, then my turbo quickly tapers more than yours and you're pulling away from 4500 to redline ...

 

Josh great reults however loose the "turbo smart mbc" and get in the hallman or forge

The extra large bleed hole in the turbo smart creates problems with boost taper on the very sensitive IX

 

Yeah I've been over the install 20 times, and so has Warrtalon ... it's installed correctly.

I had orginally purchased the Forge UNOS, but had problems with boost wavering all over the place so I took it off and tried Warrtalon's Hallman, which worked much better. The shop (TSF) later cleaned and greased that Forge unit and say they got it to work.

Unfortunately, Clay was moving and needed his Hallman back, so I ordered a Hallman through TSF to replace the Forge. They didn't have any in stock though, so they loaned me the Turbosmart unit until it came in.

I don't think there is a stiffer spring for the Turbosmart. And I'm reaching target boost anyway, it's just not holding.

 

It's a base flash. It's the same one cij911 has.

 

Thanks Al, I hope that's it.

Frankly, the whole boost control situation has been really frustrating ... and since that's where most of the power increase comes from, it's obviously important to get it working right for good results.

The recommendations have gone like this:

- get MBC
- ECU control is superior so get 'V4 boost control'
- back to get MBC in person, so took that advice and got Forge MBC
- in the process of debugging that not working well, I was told to crush my BOV, which I did and now have a hard time avoiding compressor surge ... and it didn't fix that problem
- then you post about IXs needing an EBC like the AVCR
- and now back to MBC

just a little frustrating ...

 

What's with those AFRs climbing to 12.0:1 up top? Are you guys running out of fuel?

 

Somehow your point is lost on me

Your car is running very well indeed as compared to stock so obviously the reflash is doing its job

If you want more top end power you need a very good boost control device as on the IX the MIVEC makes holding a flat or gradually tapering boost very difficult

The Forge is still the # 1 recomended unit. As you did not buy yours from me, I am at a loss to help you. I would have just swaaped it out for a new unit.

in any event, you seem to be very frustrated with your automotive modification journey. Sometimes it does take a little bit of efforts to set things just right.

 

It looks like as the boost is falling down to such a huge extent when they approach 7,000 rpms the load referenece is dipping into a partial thottle mapping area

Not to worry at 15 psi they wont have any problems

When they get a decent boost device that holds 18 psi at the top end the a./f will flatten out

 

the 2nd guy has 18psi and 12.0:1 AFR at 6880rpm. I dunno, it just looks like he is running out of fuel or injector because of that sudden spike in AFR.

btw, I am not talking about your tune at all.

 

It is possible

There were both base flashes

it is also possible that he had a mis fire which can create a similar blip in the a/f chart

I was not there to do the dyno or a/f testing so i can't comment

Bost base flashes appear to be working well on the dyno they just need to sort out the issues with the boost control and the cars should be running well

Cheers

 

My point is that the results aren't that great. I'm 25 whp down to a similarly equipped car (cij911) and I have spiking AFR in the high RPMs, which seems potentially unsafe?

I realize the 25whp is due to boost tapering too much and has nothing to do with the flash. However, the frustration comes from trying to follow your recommendations for boost control which have changed from mbc->flash controlled->mbc->ebc->and now back to MBC I guess?