BlackGT

I got the wideband put in last night (Thanks Bayley!) and after some fiddling, here is my 4th gear pull (at 16psi). I was getting some knock on the early runs, so I backed off the timing a few degrees. Comments are welcome. I left it slightly rich as I need to tune the timing curve next. 6-14_4th_gear.pdf

Sounds plausible, wow I bet I was running really lean. Good thing I kept the RPM's low. So, why do we log AFR's off the factory O2 anyway if it is useless under boost?

DA table is all COBB stage 2 Here is a log from last night, 4th gear from 200-6200 rpm. It is not happy up top, do I have too much ignition advance for the boost and IAT I am running? 4th_gear_pull_long.pdf

You are so right, I will have access to a wideband this weekend, so I hope to get some traces done with that, but this is interesting: I modified the primary fuel tables to add less and less fuel, the idea being if I made small changes and logged it each time at lower rpm's, I could tell when the AFR started to lean out above the 11:1. But I've gone all the way to 12.22:1 in the map, and the logs still say 11:1, so something is WAY out of whack. I'm getting more fuel in the engine than the ECU is asking for. Me thinks it is my injectors. I have the DW 650cc's. I set the fuel injector scale using the process from COBB, watching the fuel trims at idle, but this only really scales the lower ranges of the injectors, what if they do not follow the same scale up through the duty cycle range....

3rd gear shifting to 4th log attached. It is warmer out now, and it seems that the load has increased. WGDC is very low since I have a 15psi actuator on the VF39. 3rd_gear_log.pdf

Ahhh, I see.

It IS your car, it is present in all Subaru's.

I did log a 4th gear roll-on back in post #227. Maybe you did not understand because it spoke metric.... I made about 3 runs yesterday using a more sedate 3-4 shift, and no more pulled timing!!! YAY! Moral of the story: shift slower to go faster. Thanks!

As much as I don't like that answer Christian, it makes a lot of sense as to what I am seeing. The 3-4 shift is the easiest one to execute quickly, so quickly, it seems, that the Subaru ECU gets pissed off. I will log again tonight with more civilized shifting. If you are still tuned in, what is target boost for a Cobb stage 2 WRX STi? XX tapering to XX ? And how much base timing at 2.5 load and 6000 RPM? thanks for chiming in!

I have a stock intake, I have not altered any of the maps from the Cobb stage 2 91 octane map, except for the WGDC and I richened up the fuel at 2.5 load and higher.

Back to the problem at hand: my car sucks, its probably my fault because I was logging in Bar, and it would all go away if I was logging in psi.

Ok, Here are 2 logs. I just installed the 15psi actuator, so I set the WGDC to 0 so I did not overboost. The boost pressure is similar, maybe a little higher, than when I had the regular VF39 actuator in there with a .043 pill, and 90% WGDC. I think this is all the air this turbo will push... I expected more. On to the Logs, the first one is running up through gears 2-3-4, and you can see that as soon as I shift to fourth, the dynamic advance goes all negative. The next one is a log only a couple seconds after the first, only I kept it in 4th gear, let the car slow down, and logged just a 4th gear pull---->notice there was no timing pulled (but I did not go quite as high in RPM as the first), there was actually advance added! Thanks for your help! LGT 2-3-4.pdf LGTlog4th gear.pdf

I'm listening! I've wondered why the delay was changed to zero on V1.16. Mine is at zero right now. The only knock event I've ever logged has been on a hot day, during a shift, with like 12% throttle and engine vacuum. I'll try different delay values tonight. I'm still confused about why my load is lower than the rest. I could hit load 2.4X with the VF40, then only 2.54 with the VF39.

rao, I just re-read and have to clarify, I was not saying that it was 60 degrees coming out of the cold end of the intercooler, I meant to say that it was a cool day out, it was 60 degrees outside ambient air. Even in 60 degree weather, the IC out air is still close to 100 degrees under boost. But my point was that in 100 degree weather, the IC out temp would be more like 175 degrees, and then I could see it pulling a bunch of timing.

Thermocouple probe.

Yeah I know what an intercooler is for. My point was that the intercooler was not heat soaked, it was a cool day, which lowers the tendency for detonation or pulled timing. My load sounds very low compared to the rest of you, what parameters does the ECU use to calculate load? What kind of MAF voltage would you guys expect to see with a VF39?

I will attempt to post a datalog tomorrow, I do not know Airboys software, is it something available here or on the web? My calculated load peaks at about 2.54 (at around 3500-4000rpm) while logging, do you have a gigantic turbo or something to get above 3?

When I see the retard is after the shift when the throttle is at 100% in 4th gear. If I go to a little better resolution on the data logging, I bet I could pinpoint exactly when it happens.

I disagree that the only cause is overheating the air (I know the air is hot, but there must be something else), and here is why: - It is cool (60deg) when I am doing these runs, and I make sure to cool down the IC before I do a logging run. - It is only at 17.5psi. - It happens like a light-switch, it goes from dynamic advance in third, to dynamic retard in fourth gear, always during the shift, and it only takes .2 seconds.... I guess I should turn down the boost and see if it happens at say, 15psi. thanks for the discussion

I built it myself, have built a couple of them. Also, use a VF34 and come up with what TDC calls a 35bb, put an 18G wheel on it and call it a 40bb. I built them about a year ago, was going to try to sell them if all went right, but decided against it since the only reasonable way to do it is to get used VF39's, and who wants to buy a used VF39 for their nice LGT?

I've been tuning for the past few weeks with ST, and I've got a few questions, would appreciate it if you guys can help out. Car: 2005 LGT M/T, VF39 with LGT fitment and Perrin LGT TMIC. HFC in the COBB downpipe, SPT exhaust. 1) With my VF39, I can't get the boost higher than 17.5psi tapering to 16psi, even taking the WGDC's up to 95 percent, and making the bleeder (pill) smaller. I have a 15psi actuator I am going to try next, but I think I have seen people tuned to 20 psi on a stock VF39 actuator. 2) For ignition tables I'm running Cobb stg 2 91 oct tables, but I Always run 93 octane fuel. I see a good amount of dynamic advance added in first, second, and third gears, but then as soon as I shift to fourth, I see 5.5-7 degrees of timing removed!!!, even on cool days (shown as negative number). So my log goes from dynamic advance added in the top of third gear, to retarded only 0.2 seconds later. Anybody else ever have this and what do you think the issue is? Did the ECU see some knock during the shift to fourth? It happens every time. thanks!

Sounds like the AFR's I'm used to, I was just surprised to see 10:1 on the TDC dyno graphs. Thanks

Hey, what AFR do you guys shoot for while on boost? Cobb says start with a very rich setup of .68 Lambda, which is 10:1, and I've looked at a few TDC dyno charts which show about 10:1. This seems really rich to me... Do Subaru's just like this much fuel? Thanks, Jeremy

Nope, no spooling issues, I have yet to get it fired up, waiting for one more piece to get the engine back together. I have 650cc injectors, and a good fuel pump. Gives me a little headroom.