serx7 Posted October 14, 2016 Share Posted October 14, 2016 I think MTB mentioned his tune is locked. I presume that means it's vendor/pwd protected such that when he tries to open it in ATR, it throws an error like "Unable to load map file. Invalid 'Base' map file. Please verify vehicle and vendor of map file." Another way to try to get an idea of the MAF scaling would be to log MAF Voltage & MAF (g/sec), and do some smooth, very gentle roll-on acceleration from a slow, low rpm/low throttle cruise condition, then plot the MAF V and MAF (g/sec). It might not be exactly what the MAF Scaling is w/ IAT Comp potentially in play, but if IAT remains pretty much steady during the datalogging I'd think it would yield a decent picture of what the scaling looks like. Link to comment Share on other sites More sharing options...
Max Capacity Posted October 15, 2016 Share Posted October 15, 2016 I'm rather tempted to put on my stock intake, adjust a COBB OTS tune for my injector setup, and see what happens. Did you do this yet? I think this idea was mentioned earlier in this thread, put the car back on a known good tune. I'm not a Tuner, but I would think that would be a good starting point... 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
MTBwrench Posted October 16, 2016 Author Share Posted October 16, 2016 Finally updating this, since I now have a free seven minutes to do something other than cram for exams... Things I've done in the last week: -Installed GrimmSpeed TMIC -Replaced leaking BPV with a Turbosmart Kompact BPV (full recirc model) -Flashed basemap v.3 These have *mostly* fixed my issue. The TMIC and BPV made a huge impact on my long term fuel trims, so there was deifinitely all kinds of air being lost there. After flashing to a moderately revised base tune, A/F ranges are still weird(correcting for idle in B range) but my tip-in issue is significantly improved(almost un-noticeable) and it randomly leans out way less often. It definitely has far less power, even in vacuum, but its very smooth now. I have not made my own basemap yet. I want to, but sadly I don't even remotely have the time. I sent a few detailed logs to the tuner and his response was "yeah, it just looks like it needs to be tuned. Here's a revision, go easy on it until it hits the dyno" So, I guess I've done my part, now we patiently wait for my dyno day to see if it really is tune. MTBwrench's Stage 3 5EAT #racewagon 266awhp/255awtq @17.5psi, Tuned By Graham of Boosted Performance Everyone knows what I taste like. Link to comment Share on other sites More sharing options...
lilredwagon Posted April 25, 2018 Share Posted April 25, 2018 Bumping this super old thread - MTBwrench, was it the tune afterall? I'm intermittently having the same stumbling issues you described here, and am wondering if I should be attacking it with my wrenches or my laptop. Thanks! Link to comment Share on other sites More sharing options...
relative4 Posted April 25, 2018 Share Posted April 25, 2018 The tune will inevitably have SOME effect, but the results are not the same from one car to another. Step 1: center the FPR's vacuum reference. Step 2: smoke test. Step 3: highly variable depending on your car's setup and behavior. Link to comment Share on other sites More sharing options...
MTBwrench Posted April 29, 2018 Author Share Posted April 29, 2018 Bumping this super old thread - MTBwrench' date=' was it the tune afterall? I'm intermittently having the same stumbling issues you described here, and am wondering if I should be attacking it with my wrenches or my laptop. Thanks![/quote'] Indeed it was the tune. Once we got things on the dyno, as per usual, it was realized that my wagon wanted to be treated a bit differently than others in certain load/rev ranges. It was ultimately determined that I have a massive "water hammer" effect going on at specific harmonic points, and we couldn't do much on the spot besides adjust compensation tables and other tuning witchcraftery. I was told that the effects were magnified enough that tuning wouldn't fully fix it. Which is fine... fat injectors running small pulse widths, CNC rails, and braided lines take a lot of the frequency absorbance out of the system. I noticed that the stumble is very temperature dependent. Magnified in summer, less so in winter. My ultimate solution? Attacking with wrenches. 14" of rubber fuel line added between the FPR feed and the rail... it's rather redneck, but it works well. MTBwrench's Stage 3 5EAT #racewagon 266awhp/255awtq @17.5psi, Tuned By Graham of Boosted Performance Everyone knows what I taste like. Link to comment Share on other sites More sharing options...
lilredwagon Posted May 1, 2018 Share Posted May 1, 2018 Thanks for the response, this is very valuable info! Specifically, the temperature dependance. Me, I've been tuning around it. I found that the stock boost controller on this small turbo isn't that precise, in that there is a fairly loose margin of error between targeting and what it hits. And of course, when it's off target, it goes into the Turbo Dynamics corrections, and then we have more variables. Point is that I think my stumble was partially because of boost control and boost compensations. I feel like it was correcting in a crude way causing spikes and hesitations, which end up tripping a misfire code. After a couple days of focusing on it, I have it pretty leveled of and running smoothly... but it's been cold. I guess we'll see what happens when it warms back up. I have extra fuel hose to add as a last resort. Link to comment Share on other sites More sharing options...
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