Discussion on how bypass valves can affect LTFTs.

[DaleNixon]

With my Cobb SRI/Forge combo I get +7.6 at cruise and +14.2 under heavy acceleration/WOT. I've already sent logs to Cobb and await their answer as to what could be going on.

My AFR's are fine. Also, no backfires and the knock warning isn't too frequent.

[Sacrilicious]

Originally Posted by DaleNixon With my Cobb SRI/Forge combo I get +7.6 at cruise and +14.2 under heavy acceleration/WOT. I've already sent logs to Cobb and await their answer as to what could be going on. My AFR's are fine. Also, no backfires and the knock warning isn't too frequent.

if you're not running rich, then the LTFTs are just where they need to be to account for the way the air flows in the SRI. if you want them adjusted closer to 0, christian can very easily take care of that for you with just a few changes. i had this same problem, and it took christian just one try to drop them from ~14% to <5%. keep in mind, that this is different from the BPV problem, because it simply means that your baseline LTFTs are rather high (which is nothing to panic about)...the BPV problem i'm referring to happens when your BPV artificially takes whatever baseline LTFT you should have been running at and then adds like 5-10% to it...causing you to run pig rich at WOT and bang bang out the tailpipe...=/

Originally Posted by Deadman im runing hks in vta, currently with like 35 miles on the reflash my ltfts are at: idle - +16.4% cruising - -.8%_-2.3% WOT - -.8% Whats the good/bad in this?! :|

well, simply looking at the LTFTs doesn't necessarily tell us if you are having a problem. do you run richer than you expect at WOT? does your car backfire on shifts? if not, then i wouldn't worry about it, but i suspect that you DO backfire on shifts because you're venting to air (makes you run really freakin rich on shifts).

Originally Posted by Phantom I am running a Turbosmart Compact BOV. I will check the AFR's this week and see what I can find out.

ya, if you're running hybrid mode on the turbosmart, you're almost guaranteed to run too rich on shifts (pops and backfires). VTA is guaranteed to run richer than BPV, because you're dumping metered air to the atmosphere...less air, same amount for fuel = rich as a pig. you can either leave it like this and make sure the spring tension is adjusted so that you at least run normally at WOT and deal with the fact that you will pop and backfire on shifts, or you can go conservative and put the valve in full recirc so that it runs as smoothly as stock (clean AFRs and no pops/backfires on shifts...not moreso than stock, anyways).

[Phantom]

Originally Posted by Sacrilicious ya, if you're running hybrid mode on the turbosmart, you're almost guaranteed to run too rich on shifts (pops and backfires). VTA is guaranteed to run richer than BPV, because you're dumping metered air to the atmosphere...less air, same amount for fuel = rich as a pig. you can either leave it like this and make sure the spring tension is adjusted so that you at least run normally at WOT and deal with the fact that you will pop and backfire on shifts, or you can go conservative and put the valve in full recirc so that it runs as smoothly as stock (clean AFRs and no pops/backfires on shifts...not moreso than stock, anyways).

I am currently running my Turbo Smart in full recirc. The popping I was getting I think is from a spring being too tight. Seems bit better now. Still need to work on the spring tension

[Sacrilicious]

Originally Posted by Phantom I am currently running my Turbo Smart in full recirc. The popping I was getting I think is from a spring being too tight. Seems bit better now. Still need to work on the spring tension

awesome... ya, you just need the spring to be a little bit tighter than it absolutely needs to be in order to hold boost. you don't want to go much farther than that, because you will run into trouble from its being too tight.