A couple of questions

[03sport007]

Do I need to worry about part throttle AFR? First off I don't have a boost guage. I wanted to stay with the sleeper look. I've noticed that if I take off at about 1/4 throttle i can hear the beautiful eaton wine but my AFR stays around 14.7. If I take off closer to 1/2 throttle I get more wine and wheel spin:D and the AFR drops to low 11s high 10s. I guess what I'm trying to ask is it ok to be in light boost with a normal AFR?


I've also noticed that my IAT climds fast as I coast to stop. Why is that? Example: I'm crusing on the highway and as I exit I take my foot off the gas an coast to a stop my IAT will climb almost 8 degrees. What's weird is it takes longer for it come back down but eventually does. Is that normal.

[SC Cheesehead]

Do I need to worry about part throttle AFR? First off I don't have a boost guage. I wanted to stay with the sleeper look. I've noticed that if I take off at about 1/4 throttle i can hear the beautiful eaton wine but my AFR stays around 14.7. If I take off closer to 1/2 throttle I get more wine and wheel spin:D and the AFR drops to low 11s high 10s. I guess what I'm trying to ask is it ok to be in light boost with a normal AFR?


I've also noticed that my IAT climds fast as I coast to stop. Why is that? Example: I'm crusing on the highway and as I exit I take my foot off the gas an coast to a stop my IAT will climb almost 8 degrees. What's weird is it takes longer for it come back down but eventually does. Is that normal.


Do you know what you're running for boost (i.e., what did your tuner tell you when you had the car dynoed)? Or, what pulley combination are you running?

What are you running for a heat exchanger? It's normal to see some variance in IAT after being stopped, or coming to a stop as air flow through the H/E is decreased during these period, but 8* sounds kinda high. I usually see 2 - 3 degrees with a drop within a short period of time after I start moving again (unless ambient temp is 90*+).

[03sport007]

Tuner said about 10 pounds of boost. Im running a stock pulley combination. When I drop the hammer the AFR goes to about 10.9 which Im comfortable with. It's the part throttle operation that I question. At what throttle position, engine load, rpm etc: should the computer go from closed loop(trying to achieve 14.7) to open loop? I guess that question is less black and white then what's a safe AFR at WOT. I'll try and post a video tonight and maybe you could tell me if it looks similar to yours?

I'm running a LFP duel pass heat exchanger that I believe is based on a stock lightning heat exchanger. It seems to work well. I see temps 20-30 above abiement crusing. It's just weird that it's almost a immediate increase in IAT as the vehicle coasts. It seems like it should be the other way around. There is still air moving through the heat exchanger the car is at idle so no boost. Why is temp rising?

Thanks Rex

[SC Cheesehead]

A/F ratio is important, but info I've been given is that it'll be most critical at WOT; was told that adequate fuel pressure was more important, so that's one of the parameters I'm monitoring in my car.

If you're running 20-30* over ambient, that's decent. Eatons will heat sink pretty quickly, and if you're coasting or idling, you're not moving a lot of air into the engine, but the rotors are still "compressing" it in the blower, which is generating heat. Your IAT2 sensor is measuring that heat within the intake system, so again, prolly fairly normal. I'm monitoring mine via my Aeroforce, and see some fluctuations as well under general driving conditions, but haven't really checked closely when decelerating or coasting, I'll take a look next time I have the car out and let you know what mine's doing.

[03sport007]

Here is a video of moderate acceleration.

http://www.youtube.com/watch?v=XHlSjjdr_ic&feature=plcp&context=C4898086VDvjVQa1PpcFOL 2BURfSweN-wDS24YIuHlaafqyELE4qg%3D

Here is one with a little heavier acceleration. Actually got a little wheel spin. You can hear the wine so I'm producing some boost.

http://www.youtube.com/watch?v=XHlSjjdr_ic&feature=plcp&context=C4898086VDvjVQa1PpcFOL 2BURfSweN-wDS24YIuHlaafqyELE4qg%3D

Here one about 1/2 throttle. AFR looks good.
http://www.youtube.com/watch?v=CNxDmnBd8Pg&feature=plcp&context=C4bf9906VDvjVQa1PpcFOL 2BURfSweNxhaUpwUskq57BC1fb_MeS s%3D

Here is one in 3rd gear. About 3/4 throttle

http://www.youtube.com/watch?v=Zbbcs4vpNwk&feature=plcp&context=C4111b39VDvjVQa1PpcFOL 2BURfSweNzSq1GIM4rVXxxngzoxvjz E%3D

Here is a video of my IAT as I coast to stop and then accelerate again
http://www.youtube.com/watch?v=JnqOV4sn0ZY&feature=plcp&context=C4b553dbVDvjVQa1PpcFOL 2BURfSweNxk91C9pDNYKqgD-GSvqtsM%3D

[SC Cheesehead]

Here is a video of moderate acceleration.

http://www.youtube.com/watch?v=XHlSjjdr_ic&feature=plcp&context=C4898086VDvjVQa1PpcFOL 2BURfSweN-wDS24YIuHlaafqyELE4qg%3D

Here is one with a little heavier acceleration. Actually got a little wheel spin. You can hear the wine so I'm producing some boost.

http://www.youtube.com/watch?v=XHlSjjdr_ic&feature=plcp&context=C4898086VDvjVQa1PpcFOL 2BURfSweN-wDS24YIuHlaafqyELE4qg%3D

Here one about 1/2 throttle. AFR looks good.
http://www.youtube.com/watch?v=CNxDmnBd8Pg&feature=plcp&context=C4bf9906VDvjVQa1PpcFOL 2BURfSweNxhaUpwUskq57BC1fb_MeS s%3D

Here is one in 3rd gear. About 3/4 throttle

http://www.youtube.com/watch?v=Zbbcs4vpNwk&feature=plcp&context=C4111b39VDvjVQa1PpcFOL 2BURfSweNzSq1GIM4rVXxxngzoxvjz E%3D

Here is a video of my IAT as I coast to stop and then accelerate again
http://www.youtube.com/watch?v=JnqOV4sn0ZY&feature=plcp&context=C4b553dbVDvjVQa1PpcFOL 2BURfSweNxk91C9pDNYKqgD-GSvqtsM%3D


Looks like you're pikcing up 10* or so from the video, wonder if you may have air in your system? After viewing the last vid, I recall having a similar issue with my car last year, and I ended up "burping" the system, but I can't recall exactly what I did (got some suggestions from Zack that I tried, and that did the trick). Lemme see what I can dig up over the next few days.