NefMoto

Technical => Diagnostics => Topic started by: ktm733 on November 06, 2016, 08:34:03 AM



Title: [FIXED] rs6 load overshoot like a mofo
Post by: ktm733 on November 06, 2016, 08:34:03 AM
I smoke tested it and no leaks? Waste gates are set to stock breaking pressure, and it has upgraded diverter valves. It's running pig rich at wot which makes me believe I have a boost leak but I pressure tested it and boost leak tested it. These turbos are spinning way to hard, so my guess is the waste gates are not holding the pressure? I wanted to see what you guys think? I'm note trying to request 20psi either, I was shooting for around 14-17psi as youll see in the log.


Title: Re: rs6 load overshoot like a mofo
Post by: SB_GLI on November 06, 2016, 09:54:29 AM
log from a mostly stock rs6 shows maf readings maxing around 330 g/s while yours is 460 g/s.   The stock logs show boost higher than yours as it approaches redline.   my money is on a boost leak.

http://nefariousmotorsports.com/forum/index.php?topic=11244.0


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 06, 2016, 01:04:12 PM
I smoked the living heck out of it. Plus I pressure tested it. What would wastegate a set at the wrong cracking pressure cause? The turbos have upgraded compressor wheels


Title: Re: rs6 load overshoot like a mofo
Post by: nyet on November 06, 2016, 02:19:16 PM
Doesn't explain your rich condition or overly high load. What does ps_w look like?


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 06, 2016, 02:38:40 PM
I can log it tomorrow, but what I meant by wrong cracking pressure is if they were set to low and causing to crack open under heavy boost would it cause this problem? To me it sounds possible as the turbo is trying really hard to make requested boost so duty cycle goes up and the turbos spin harder to try and make requested boost which in terms brings more air but I don't know if that air would cause the pig richness? So yes I would lean towards boost leak. When I smoke test the car it doesn't smoke at 10psi. When I pressurize (apply shop air at 15 psi) the system I think I hear a leak under the manifold but I cant tell if that's air rushing through the intake. Has anybody had any leaks under the intake manifold before? Seems rare.


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 06, 2016, 02:41:50 PM
Another weird thing.... Why am I hitting 200 load? i havent disabled any safety features or even made a load time for 200? As you can see I'm requesting 175? How is this possible, ontop of why am I not in limp mode? I dont even get a code for deviation, I get zero codes? This ecu was sent to daz to remove tuner protection and convert it for manual trans. I just don't see why I dont even get throttle cut with this big of over shoot of load.


Title: Re: rs6 load overshoot like a mofo
Post by: nyet on November 06, 2016, 02:45:06 PM
Because metered air is being lost.


Title: Re: rs6 load overshoot like a mofo
Post by: nubcake on November 06, 2016, 05:09:04 PM
Also log MAFs separately, can help diag turbos being out of sync (or possible DV issues).


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 06, 2016, 07:54:05 PM
Also log MAFs separately, can help diag turbos being out of sync (or possible DV issues).

I did, it's right next to duty cycle. They are very close.


Title: Re: rs6 load overshoot like a mofo
Post by: nubcake on November 07, 2016, 02:53:11 AM
I did, it's right next to duty cycle. They are very close.

You want mshfm1/2, not msabg. Or uhfm at least.


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 07, 2016, 09:43:43 AM
You got it, almost to the shop.


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 08, 2016, 04:11:44 PM
Tested one more time, still no sign of the boost leak. Here is the log with the requested ps_w.


Title: Re: rs6 load overshoot like a mofo
Post by: nyet on November 08, 2016, 04:35:38 PM
ps_w is through the roof compared to pvdkds_w. Even worse, you've maxed it out.

You have a severe boost problem somewhere, or your MAF scaling is just plain wrong.


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 08, 2016, 04:58:39 PM
I'm going to take a video to prove I don't have a boost leak. If I apply any more pressure I'm going to start blowing seals. I understand it looks like a boost leak but what else could cause this.

Backround about the car, the engine swallowed water and bent the connecting rods. So they were replaced by a profession shop. Everything has been replaced pretty much, and it's converted to manual. It has stage 2 turbos installed from a respectable company.

Is it possible a check valve could cause this?


Title: Re: rs6 load overshoot like a mofo
Post by: SB_GLI on November 08, 2016, 06:19:57 PM
You can have a internal boost leak.  If you have charged air recirculating back into the intake pre turbo.  Check valves, something in PCV....


Title: Re: rs6 load overshoot like a mofo
Post by: nyet on November 08, 2016, 08:13:20 PM
You can have a internal boost leak.  If you have charged air recirculating back into the intake pre turbo.  Check valves, something in PCV....

But that wouldn't result in losing metered air :(



Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 09, 2016, 06:28:19 AM
You can have a internal boost leak.  If you have charged air recirculating back into the intake pre turbo.  Check valves, something in PCV....

Diverter valves are upgraded but I might make a rig to push 20psi to them to verify they are holding up. I have extra pcv valves thats are good so I'll swap then over. Thank you guys for the help. Once again with the problem child cars!


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 09, 2016, 06:30:12 AM
But that wouldn't result in losing metered air :(



How do you know I'm losing air? Rich condition?


Title: Re: rs6 load overshoot like a mofo
Post by: nyet on November 09, 2016, 11:19:39 AM
and ps_w


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 09, 2016, 11:45:20 AM
But that wouldn't result in losing metered air :(



Ps_w!!! My live data(boost gauge) followed it my logged variable for manifold pressure showed different? Said peak 16psi and dropped to 8psi. Hell no, the car hit like 23 psi and tapered to 14-12psi. Looks like I have a faulty sensor. Will get back after verifying.


Title: Re: rs6 load overshoot like a mofo
Post by: ktm733 on November 09, 2016, 02:09:53 PM
Thank you nyet for pointing me in the right direction...

Someone installed a 3 bar map sensor and didn't tell me, well no one knew that it was installed.
Time to actually start tuning it now  ;D
Thanks everybody for helping me out.


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: SB_GLI on November 09, 2016, 02:19:08 PM
WTF.  How, why?


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: ktm733 on November 09, 2016, 03:33:06 PM
I honestly don't even know, I'm pissed I was chasing my tail! I hooked a boost gauge up which I should of done from day one and saw it was hitting 23psi! Thats when I'm like this ecu isn't seeing boost correctly. Lesson learned.


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: vdubnation on November 09, 2016, 07:25:00 PM
Cause it was being tuned on a 5120 file  i just went through all the emails and found it.


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: nyet on November 09, 2016, 07:36:59 PM
In recognition of your diagnosis, I've set your negative karma to 0


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: SB_GLI on November 10, 2016, 06:01:35 AM
In recognition of your diagnosis, I've set your negative karma to 0

:)


Title: Re: [FIXED] rs6 load overshoot like a mofo
Post by: ktm733 on November 10, 2016, 06:01:47 AM
In recognition of your diagnosis, I've set your negative karma to 0

I'm in silence, a simple thank you doesn't describe how thankful I am for this action.  I'm going to stop here before you multiply it by two.