[AZ-MCRacer]

It is a relatively new platform for these types of mods and I think we are experiencing some issues to be expected with a new platform. Mine seems to work well, but I am not getting boost numbers as high as I would expect. These thing take time and effort to diagnose, and that will be more available to me in the cooler weather coming. Right now pushing for high boost at 105 degree air temp just doesn't make sense. Also, for the summer I have been working on a different project, I m trying to get an e36 M3 track ready for this fall.

On a previous page I shared improved results going from stock to PS2. Lots of things to play with, sod it always a moving target.

[Stück]

Tonight I am going to wire the wastegate arm in the cinched closed position with an uncoated coat hanger, and unplug the diverter valve. I have a spare brand new DV that I bought for troubleshooting, so I will plug in the spare so the DME is happy.

I'm then going to go drive it and see if it will overboost. If it does not overboost and slam the throttle closed the turbo is the problem IMO, plain and simple. With 100% of exhaust gas routed over the exhaust wheel, and the DV disabled the turbo should instantly spool and launch to the god damn moon.... unless it has a mechanical issue preventing it from spinning freely, like drag on the bearings, thrust plate etc. All that is left at this point from where I'm sitting.

[Stück]

Well this evening as told I went home and let the sucker cool off for a minute, the turbo side of the engine bay gets screaming hot on these cars....

I then artfully bent an uncoated coat hanger into a short hook and fished it down to the wastegate arm, looping it over it.

With that in place I pulled it closed with vice grips on the coat hanger wire and wrapped the end of it around a eyelet next to the headlight.

With the wastegate wired closed I saw 21psi in 1st and 2nd to redline. 3rd and 4th hit 19psi to redline. Now this is more effing like it.

I suspect the DME can't close the throttle fast enough in the lower gears to stop a small overboost, but manages to react fast enough in the higher gears to do so. I can feel the throttle closure as it wiggles 18.5-19psi through the RPM band in 3rd and 4th up to redline.

This data was gathered with Dashcommand so I had a real time boost readout, I didn't want to run blind with the datalogger on the OBD. It makes a nice easy to read plot graph output in real time but I can't read that at a glance when hauling ass.

I'm going to head back out shortly with the laptop to get some real logs and go from there.

[$howtime456]

Subscribed. Have a 6 grand coupe and plan on following

[Stück]

Log file as promised of the 25mph 3rd gear pull to redline. Peak of 21.8psi at 6300, tapering to 18.5psi at redline... with HEAVY throttle closure. In this case the throttle closure is 100% expected since I have forcibly removed wastegate control and thus turbo overspeed control. Throttle spent most of the pull at 32-38% open.

Pre-throttle boost is maintained at 22psi from 4500 to 6500. Alex noted that the N55 TMAP maxes out at 22psi, so who knows how much boost the turbo is actually producing, but the throttle is effectively "mom barring"

Boost setpoint and boost actual are making hot sultry love to one another, finally.

Load target and actual are damn near perfect tracings over one another.


http://www.datazap.me/u/jsarette/25m...?log=0&data=14

[Bmw doubles]

That is fantastic news. How are you going to deal with the wastegate?

[Stück]

That's a good question, I have some more tests I want to do, rather tests that I need to repeat. I had previously run the vacuum pump straight to the wastegate bypassing the EPDW with poor results. I would like to carry this test out again and see if I get the same results as I have tonight with a coat hanger.

If I do we are going to flash back to stock tune as a base line to observe behavior and make some adjustments from there.

[AZ-MCRacer]

Glad to see positive progress again! The stock TMAP is only accurate to around 20PSI, the N20 TMAP will fit in directly, your tune just needs to calculate based on the scale to 3.5Bar instead of just 1.5 bar. The 3.5bar N20 sensor sells for around $80.

Glad to see this being a limit you are experiencing.

[ICantDrive4Sht]

This thread is awesome.
Am about to do ps2 swap myself soon

[JakOG]

I assume this means the issue has nothing to do with Pure?
Awesome news

[Stück]

Originally Posted by Jackog

I assume this means the issue has nothing to do with Pure?
Awesome news

Well, it doesn't necessarily mean that.

Forcing the wastegate into the closed positioned just routes 100% of the exhaust gas flow over the exhaust turbine. If the turbo can spin and make boost its going to.

This doesn't rule out a sticking wastegate arm, which I've had issues with on this turbo in the past. A few pages back there is a video showing it binding. It was pretty hard to pull on it with the coathanger to close it, and you can't get your hand anywhere near it from the top between everything in the way and the heat. If it is binding and slowing the reaction time or limiting the control resolution of the vacuum control the turbo is still going to need to be replaced.

This weekend may find more answers depending on how much my free time and Alex's can overlap. Of course as has always been its my preference for it to be -anything else- than having to remove the turbo, so its not like I'm rooting for it to be the problem.

[ICantDrive4Sht]

Any news? I'm impatient

[Stück]

Sorry, no. Work during the week doesn't leave me with much time/energy in the evening and I was tied up this past weekend.

[Stück]

Anyone seen dollarbill lately? It's almost like he ate crow....

Anyway, I'm sitting inside today while Harvey shoves wind blown heavy rain all the places. I'm expecting a new tune from Alex @ MissionPerformance soon that should really get things cooking.

[AZ-MCRacer]

Stay safe! Good excuse to stay inside and build intakes.

[Stück]

Eh, I'm not making more until I have a N55 on a stand with turbo still mounted so I can build something worthy of selling that hugs the block and fits perfect.

Besides, the F10 and F25 are sitting pretty in the garage right now.

[Bmw doubles]

Stay safe for sure and put a Kevlar protective barrier around your rides to prevent storm projectiles

[$howtime456]

my gosh!!

[JakOG]

Hey stuck,

What's happening with your Turbo?

The whole world is waiting on this!
(Or at least the 7 of us in the world with modded F10 535's

[Stück]

I'm a couple more revisions into the new tune with Mission Performance. After the inlet fabrication we pretty much started from a clean slate as all of the preceeding data was captured with a choked inlet.

I'm holding 15psi to redline with the current revision, and expecting the next step up soon. Load target/actual and boost setpoint/actual are actually meeting now! Its all about fine waste gate control now.

[$howtime456]

Originally Posted by Jackog

Hey stuck,

What's happening with your Turbo?

The whole world is waiting on this!
(Or at least the 7 of us in the world with modded F10 535's

dont forget modded 640x too..lol

[JakOG]

Originally Posted by Stück

I'm a couple more revisions into the new tune with Mission Performance. After the inlet fabrication we pretty much started from a clean slate as all of the preceeding data was captured with a choked inlet.

I'm holding 15psi to redline with the current revision, and expecting the next step up soon. Load target/actual and boost setpoint/actual are actually meeting now! Its all about fine waste gate control now.

Awesome!

Does this mean you solved the wastegate issues?