So this spring was busy for my X, I basically took my 400whp pump gas setup and converted it to e85. Since then, I have been battling this issue, and I just can't quite put my finger on what is causing it.

*description of the issue*
Basically what happens is this: if I leave from a stop quickly (say, like in autoX) and get more than 50% throttle around 2500-2800rpm the car just falls on its face. If I leave throttle at 30%, it seems fine. Second gear it does it, third gear through fifth gear it almost feels like compressor surge as the car almost feels like its choking then as boost slooooowly builds the BOV starts chirping and popping and the car sounds like death. I can induce it easily by putting the car in 3rd gear and going WOT at ~2300rpm, by 2800 it feels like its gonna blow apart.

Here's a log of what happens:

You can see that the car is basically choking, AFR goes way lean.


Full Mod List on pump gas:
intake was perrin/aFe stage2
CBRD BBX (stock appearing) turbocharger
Pierburg BCS / Hallman Pro MBC hybrid boost control setup
Custom 2.5" UICP
Buschur Race FMIC
stock intake manifold
stock throttle body
DB Performance Ported Head w/ 1.0mm oversized valves and supertech dual valvesprings
Kelford 214-B cams
MAP stage1.5 shortblock w/ MAP X-beam rods and JE pistons
FiD tubular exhaust manifold
Ported turbo hotside
MAP O2-elim downpipe
Megan testpipe
Magnaflow catback
omni 4-bar map sensor

Fuel:
was DW800's
stock everything else, including fuel pump


New stuff this spring (in order):
DeatschWerks 300-series fuel pump
Primo 3.5" intake/maf with aFe filter
Fuel Injector Clinic 1680cc high impedance injectors
e85 conversion
Primo 2.75" LICP
Kenne Bell Boost-a-pump
Cobb BOV

Basically I did the fuel pump and intake first for our spring dyno day, I didn't notice this issue at that time. Then I got the injectors in and converted to e85 soon after, and threw on the LICP and BAP before getting tuned.

Dyno pulls, check out AFR:
https://www.evolutionm.net/forums/ev...x-bbx-e85.html

So, things that I have tried?
-removing some MIVEC on intake cam. This seemed to help a tish, but ultimately not.
-revert to stock BOV. This helped a little, but not much.
-removed BAP, it is triggered at 5psi via hobbs switch, I figured it was engaging early or something. No difference.
-adjusting Closed Loop LT Trim Control. I had it originally set to 300hz in Mid-> High, then 293 in High -> Mid, but this post by tephra suggested raising it to 350hz in Mid-> High, then 343 in High -> Mid, I even tried 4000hz in Mid-> High, then 393 in High -> Mid, no difference.
https://www.evolutionm.net/forums/8556085-post10.html

Injectors latancies, I'm using the values mrfred posted from the cobb car he did, they work fantastic (I can post them if need be).

MAF scaling, I multiplied all stock tables by 1.39, it is just as linear as stock.

More things I could try:
-nonlinear MAF scaling? Anyone have examples of success with this?
-a different intake?
-different injectors?
-different latancies/scaling?
-possible to tweak the speed density settings somehow?
-**** it, it runs 11's, leave it?

I really want to fix this because while the car does RIP up top it is just sad down low, and I know it doesn't have to be like that. I want a well rounded car/powerband, otherwise I would have bought a 6262!

Thanks for reading!

*edit* added omni 4-bar map sensor, forgot about that.

 

Oh, shane@DB suggested logging maf hz, but I can't seem to find a definition for that for evoscan.

 

Do you have injector duty cycle? Im just wondering because i noticed its DW's.

 

It seems like your FPR is not working... as you build boost, your AFR's start to lean.

I have heard of the primo scaling being finiky, maybe that is causing your issue

 

It's not the DW's I'm having problems with, its the FIC 1680's. Well, it may not be the injectors causing the problems, I don't know!


It seems to work fine the rest of the time, if I ease into it at 4000rpm this does not happen.

 

Lean spool off?

 

Yea its off. It's a 2008, AFAIK its off from the factory, its always been off in my rom, I don't even have the xml for it, LOL!

 

i would try taking out 10* of exhaust cam retard..

also stop logging the temps and speed - they just slow you down...

what are your fuel trims like?

 

I was going to say too much reversion from Mivec mapping but you said you tweaked with that? Usually when I see the same thing in tuning it's from the mivec.

Have you looked at your Calibration Fuel Map? It does take out some fuel in that area.

 

Another possibility is that the 0-6 psi range where it goes from 100-130 load around 3k rpm, you are set to use closed loop via o2 feedback and it just isn't in a range it can deal with.

What do your Open Loop Load High Octane tables look like?

You can try lowering those to 90 or 100 load peak and just calibrate the AFR's via the High octane fuel maps. From the factory my 2011 had 2000-2500 set for closed loop up to 140% load, 3000 rpm was 125%, 3500 120%, and 4000 was 100%. You might be able to make it work with some carefull MAF compensation changes but going open loop is the easier road to take.

 

check ipw 4.528- 6.338 ????

you really miss fuel

 

Fuel trims are perfect. I took out 10° of retard like you suggested, IDK why I didn't try this sooner, before I had only taken out intake cam mivec and not touched the exhaust cam. Gah. 10° and it does it WAY less, I pretty much zero'd it out under 140 load and 4500rpm and the issue seems *mostly* gone, but I can still induce it in 5th gear...I'll keep testing!

Like I said above I only had messed with intake mivec, I guess I really thought that the exhaust didn't really make much of a difference but zeroing it out really you can feel the difference.

I haven't messed with open loop yet, but I think I will try that next, I'd love to get the mivec back in and try to keep the afrs steady somehow.

Sorry, not following you?

 

that's good to hear that it is almost fixed!

 

Eh, it's better but its still not perfect. The car def feels down on power in this area. I can actually TPS 50-100% in gears 1-2-3 from 2000rpm and the car doesn't fall on its face anymore, but the issue is still there in 5th gear. Here's a log from this morning:



BBX seeing 30psi at 3300rpm zzomg! :P You can kinda see how the rpms stop climbing once boost comes on and boost kinda jumps around. Keep in mind this is at only 50% throttle.

I'm going to mess with the closed/open loop settings next.

 

Open / closed loop settings won't matter at 270 load and 30 psi, but wll most definitely allow you to reduce the issues at 100-130 load where your AFR's are going way lean. The lean during spool is causing knock to kick in for a while which will reduce power and usually richen things up until it determines everything is good again.

Maybe reduce the boost to 26-28 psi until you have everything sorted during spool just to put less beating on the engine when it is recovering from spool knock.