Last night I was on the highway and got on it WOT and the car pulled hard as usual and then all of a sudden the car pretty much fell on its face and backfired crazy and from what the people behind me said the car shot out a 4ft flame and was dumping black smoke but thats usual (the black smoke). I got off of it and then got back on it and it pulled strong again and then did it again but wasnt as dramatic. From what I saw my AFRs were high 10s low 11s the whole time like usual. I got off the highway and got WOT again from a dig to about 80 and it pulled strong the whole way with no problem. Cars ran fine after and is running fine today too (I havent got on it WOT again though). I was super low on gas last night and thought maybe it was caused from that. The gas light pretty much came on right after the last pull. Any ideas would be helpful.

 

Over boost/load
You hit the "ceiling" in your rom.

 

Fuel cut from hitting load limit or you starved the car of fuel. Second more likely since you where WOT when the fuel was much too low.

 

Doesnt overboostin normally throw a cel? It didnt throw one unless it reset it self b4 I could check it (I have a stupid cold start timing cel from my tune). What would cause my car to overboost its never done that b4? I checked all my lines from my 3port and they seem to b fine.

 

Thats what I was thinking. I never let the gas get that low either maybe thats why its never done it before. I dont have a knock light so Im not for sure but my buddy was looking at my wideband the whole time and he said it never leaned out.

 

Over boost as two components:
1) More psi than the "max limit" (can be turned off, but be wery wery careful)
2) More load than is allowed (total limit is currently at 310 load, but there is ALSO rpm load caps; and yes Rich has a patch for total load, lol)
#1 throws a code, #2 cuts off fuel
Did you happen to log?
And yeah....fuel is a good thing

 

Weather changes can alter your boost. Although, you'd usually see more boost going into the colder months rather than this time of year.

Sounds like fuel cut to me.

 

No I wasnt logging at the time. Why would I hit load limit if I never have before. What would case that?

 

I did the same exact thing when I was attempting to tune the new X turbo. For me it was overboost. I hit it once and it scarred the crap out of me because I wasn't really expecting it, I've got a electronic boost controller now so hopefully it wont happen again in the future.

 

I have a 3port already and Im tuned by Clipse so I dont think its the tune. I looked at all the vaccum lines off of the ebc and they all seem to be ok.

 

It's not a "problem" with the tune, just at some rpm point your crossed over the Load limit, and the car "corrected" you. It's not the over boost you hear about all the time (i.e. torque punch that destroys something), it's more of a moving ceiling.
Here is my current one (sorta, I'm actually patched now, cuz I did that same thing while tuning for my TBE):
[IMG][/IMG]

As you can see, you could have had more load at 6000rpm (as I did) than "allowed", so the car will cut fuel; VERY different from a boost spike.

 

if you were doing this in 5th and/or 6th gears at around... say 3k RPM, it's highly possible to over boost/load because you're staying in the RPM range where spool is most efficient but you're not accelerating through the RPM range fast enough for the engine requirements to overcome the turbo's ability, as a result you build higher boost than normal.

Though in my personal experience, WGDC correction kicks in and cuts boost before that happens (using the ECU to manage boost that is). However, I have had it cut so much boost that the car fell on its face when I had my WGDCC tables set to allow ~large~ corrections for relatively small imperfections.

 

I tried a couple WOT pulls last night this time with plenty of gas and didnt run into that problem so my guess is that it was my dumbass fault for letting my car get that low on gas and going WOT. Ill try it a couple of more times and see what happens.

 

If I have less than a 1/4 tank I don't go more than 60% tps for that reason
Additionally, on track days I won't let it go below 1/2 tank.

 

Yeah I wasnt expecting to be getting WOT and I never let my car get that low on gas.