I say Hypotheticly because as I have no data logging nor a wideband to confirm.
I posted a while back about tune issues with my car, including a dynograph which illustrated my power band and what I was talking about.
At WOT it shows the A/F getting richer as rpm's increase. And the big sag in my power band from about 3800 to 5000 rpm. I'm curious though. At idle, I can smell the exhaust fumes. Everyone so far has different opinions of the smell, a couple say it smells like oil (yet my car doesn't smoke), others say it smells rich as fuck, and while I was detailing my car last week, the guy at the smog booth next to the car wash said my exhaust smelled leaned out, and gave me this spool about hydro-carbons and a bunch of technical yada-yada bad emissions.
I've smelled 2v exhaust on well-tuned cars, and they smell far different than mine. My exhaust particularly at idle (since I can't smell it at different throttles for the obvious) smells very overwhelming, like you would pass out sitting at a light with the wind blowing the right direction.
I don't know what to say it smells like. I want to say it smells rich.. but if it's actually leaned out, could it be overwhelming as well? I do get quite a few complaints about my exhaust fumes.
Now, is it possible that my tuner may have primarily tuned my car for just WOT, and left the lower rpms in a generalized lean state? Another thing I wonder about is if you have to take into consideration VCT vs A/F? If the cams are fully advanced with no load, what affect will this play given a leaned A/F. Also, if that's the case, did my previous tuner not consider VCT when tuning the mid-range A/F and apply too much timing in the mid-range and that's why I have a sag in the mid-range power band?
Tuning is such a headache.. I aught to get lock-outs for the VCT. At least then I don't have that headache.
I really should be asking my new tuner guy about this stuff, but I'd like to hear what the S197 buffs here have to say, so when I go in for my new tune, I have some knowledge of what I'm looking at while he's tuning.
I really want to understand S197 tuning better and how it all works together, so please help me out guys.
I posted a while back about tune issues with my car, including a dynograph which illustrated my power band and what I was talking about.
At WOT it shows the A/F getting richer as rpm's increase. And the big sag in my power band from about 3800 to 5000 rpm. I'm curious though. At idle, I can smell the exhaust fumes. Everyone so far has different opinions of the smell, a couple say it smells like oil (yet my car doesn't smoke), others say it smells rich as fuck, and while I was detailing my car last week, the guy at the smog booth next to the car wash said my exhaust smelled leaned out, and gave me this spool about hydro-carbons and a bunch of technical yada-yada bad emissions.
I've smelled 2v exhaust on well-tuned cars, and they smell far different than mine. My exhaust particularly at idle (since I can't smell it at different throttles for the obvious) smells very overwhelming, like you would pass out sitting at a light with the wind blowing the right direction.
I don't know what to say it smells like. I want to say it smells rich.. but if it's actually leaned out, could it be overwhelming as well? I do get quite a few complaints about my exhaust fumes.
Now, is it possible that my tuner may have primarily tuned my car for just WOT, and left the lower rpms in a generalized lean state? Another thing I wonder about is if you have to take into consideration VCT vs A/F? If the cams are fully advanced with no load, what affect will this play given a leaned A/F. Also, if that's the case, did my previous tuner not consider VCT when tuning the mid-range A/F and apply too much timing in the mid-range and that's why I have a sag in the mid-range power band?
Tuning is such a headache.. I aught to get lock-outs for the VCT. At least then I don't have that headache.
I really should be asking my new tuner guy about this stuff, but I'd like to hear what the S197 buffs here have to say, so when I go in for my new tune, I have some knowledge of what I'm looking at while he's tuning.
I really want to understand S197 tuning better and how it all works together, so please help me out guys.
