Reedy's Engine Rebuild Bonanza!

[Reedy]

EBC finally arrived today. And Canada post suck.



done a couple of logs already but the base map for the EBC is super low boost and shit just to make sure things are working.

[Reedy]

Here's an interesting update worth noting.


I have been undertaking an E-tune with Stratified for a few weeks now and we have been scratching our heads at the terrible boost response that we have been seeing. This BNR S1 hasn't been hitting full boost until about 3700RPM and has been generally lazy as shit.


So I visited @MPS2NV for a routine leakdown test to check the ongoing engine health.
results were:
1. 190PSI 2% Leakdown
2. 187PSI 3% leakdown
3. 188PSI 3% leakdown
4. 190PSI 0% leakdown


No problems with the motor, that's good news.


Then we had a bit of a poke around the turbo and felt a rattle in the wastegate actuator arm. There was no pre load on the wastegate, and about half a mm of play in it. Pulled it off, wound it out a couple of turns and reinstalled it.


It looks like the pin that connects the wastegate actuator to the flapper has become slightly fatigued and is moving within its seat, but with the extra pre load the boost response has changed dramatically.


Here is a graph (Chicks dig graphs)





Obviously the wastegate was never fully closing, which was exactly the problem that I thought we had.
The turbo will probably need to come out to apply a permanent fix to the link pin, but for now we finally have a boost response that resembles what this turbo SHOULD be capable of.


In the time being, we will definitely need to tweak the tune as the extra boost is seeing some unwanted KR in the upper rev range, but I am just so damn relieved that the car finally has that punch in the guts brutality that I have been missing for so damn long!

Also you should all go and see Mitch for anything that you need done to your car, for all of time. If I was at any other workshop then we never would have had the chance to stick our heads under the hood and poke around the way we did. Other places have just blamed the shit response on my choosing a shitty turbo, and they were right to a degree but didn't even think that something might be wrong with it.

I am fast approaching the point where Mitch is the only guy I trust to do anything to my car other than the most basic servicing work.

[SarcasticOne]

That's the sort of response I'd expect from a 3076 or similar... Certainly laggier than my 3071 was...
Glad you got it fixed up and back to enjoying the car properly!

Sounds like the usual awesome service from Mitch!

Now get that damn tune finished!!!

[Reedy]

Now that the turbo is working we shouldn't take long to finish the tune!

[MPS2NV]

And we all thought you were just a bitch about lag

[Reedy]

Let this be a lesson to you all: I am always right.

[shaneski]

I am fast approaching the point where Mitch is the only guy I trust to do anything to my car other than the most basic servicing work.

.

I have already reached that point. Even basic servicing work you can't do yourself i don't trust anyone even opening the door other than Mitch.

[MPS2NV]

It sounds like a "carton for comments" kinda deal lol

[Reedy]

Did another set of logs last night. She's singing quite nicely right now.

Starting to get a fair bit of high end knock so it looks like we've found the limitation of the fuel. I can see why people use E85 now.

[hermz]

Some good info in this thread. I'm currently trying to decide how to proceed after blowing a hole in my block. So many options and none of them come cheaply.

[Reedy]

Ok a lot has happened these last few days.

I have had a couple more iterations of the new tune, this is close to finished now but there is one big partial throttle problem that we need to find that I will talk about more below.

This weekend I have also done 2 track days, 1 at Eastern Creek, and another at Wakefield Park.
Here's a video of my fastest lap at EC of the day:
https://www.youtube.com/watch?v=C7JAb5NU8bI

My oil catch cans continue to catch very little oil, which is good to see. The valve cover breather one in particular

Oil in my Valve Cover breather can after 2 session at Eastern Creek
http://i.imgur.com/HM2FkG2.jpg

Oil in my PCV catch can after Wakefield Park
http://i.imgur.com/POV1PRt.jpg

Now, onto the big BIG problem that I am currently dealing with.

I have an issue at partial throttle where the car can't seem to decide between full throttle and no throttle. This is really bad on corner exits where the car will suddenly boost and then cut out during what should be smooth throttle application. It makes corner exits highly unpredictable, and feels to me like some kind of hysteresis loop that it's getting tripped up on.

Luckily I was able to replicate it a few times, particularly when driving in a straight line after exiting a corner. In the video below, I am slowly accelerating and then holding the throttle as steadily as I can and the engine starts to stutter very badly. I also took a few datalogs of this phenomenon with my AP to see what is going on.



If you take a look at the datalogs located here:
https://dl.dropboxusercontent.com/u/...it/Stutter.zip

You will see that it looks like the accelerator pedal is jumping about, but I am actually holding it as steadily as I possibly can while the engine carries on with this hysteresis buggery.


Theories I have had thus far:
1. wiring loom problem/loose connection - Altho given it happens at a specific RPM/Throttle combination this could be some kind of harmonic/resonance issue.
2. pedal position sensor problem (I have logged the car on flat ground with the engine off and this seems to be fine)
3. throttle map problem (Most likely, given it's a new tune and this hasn't happened before)
4. wastegate flapper problem (Possibly still loose in its seat after the fix we applied above, particularly when it's marginal on opening)
5. SWAS buggery (apparently Cobb's SWAS removal solution is not very good, but that doesn't explain the straight line ****ery)

[allo80]

I vote 5. In the datalog5 there are two sections where your AFR's are pig rich, which is visually confirmed in the bond 007 smoke screen coming from the back of your car. SWAS can kick in even in a straight line when tyres are scrambiling for grip and richens the AFR to bring power down. I have logs where in 2nd gear in a straight line my AFRs will rich into the 9's. I dont think its 3 as when you graph your Accel. Pedal Pos. (%) vs Throttle Position (%) the TP tracks the APP, there were no unusual jumps unless you kept it dead steady. I dont think its 2 as the APP values didnt really jump around too much whilst you were steady on the part throttle. I can also add antother possibility, a loose air straigtener inside the maf housing.

Also, what were you able to find out about the quality of Cobb's swas removal solution?

Just had another glance at the logs, the boost and Waste gate duty looks interesting. in datalog5 youre making boost with zero wastegate duty from 8 seconds to 11 seconds. That might point to issue 4.

The plot thickens

[Reedy]

New theory is possibly the BOV operating when it shouldn't. Since switching to the 3 port EBC I am taking my boost source from the BOV vacuum line so that might be screwing with the BOV operation.

[SarcasticOne]

You can build boost even with 0 wgdc
"Spring pressure" on a bnr s1 is in the 10-14psi range from memory...


Could also be a MAF calibration issue... In datalog 5 you go really rich around the same MAF voltage early on in the log...

Edit: nvm, just checked datalog 10, happens at a different MAF voltage... Seems something is is happening post turbo to take air away

[Reedy]

I busted out the bike pump yesterday to check the WGA, it starts opening at about 14PSI.

The fact that this is only happening at low boost adds weight to the theory that my BOV is opening when it shouldn't. Perhaps the EBC is bleeding off just enough air for the BOV to open slightly? Altho at 0 WGDC it shouldn't be doing anything at all.....

[hermz]

That's crazy rich. My money is on SWAS. Your fuel trims don't suggest a boost leak to me.

[Reedy]

For those playing at home I have some more video. Starting at the 3 minute mark you can see a lot of this partial throttle stutter again on corner exits. For some reason that R34 brought out the worst in my car but you can see this crap happening all over the circuit.

[hermz]

I still think SWAS.

Also, that looks busy! I would've been crapping myself I was that white Evo stopped in the middle of that corner with a handful of cars hurtling towards me.

[Reedy]

Yea Eastern Creek isn't a big deal tho cause the track is so wide. You can't drive around the outside of people at Wakefield Park that's for sure.

[Reedy]

I still think SWAS.

Mid by swas do you mean swas delete? Cause that was supposedly removed with my etune but I've heard that the Cobb swas delete is not very good.