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GA Rocks!
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Discussion Starter #1
Hey everyone,

I am working on my home made o2. I have it working with my fluke
meter. It has the NTK o2 sensor. Well what we have been noticing is
at idle the a/f 15:1. I also notice that at partial throttle it is
pretty much at 14.7:1 Now the question is WOT. Does your display
drop down to say 10.5:1 then starts to climb to 11.5:1? I want to do
some compare with others. My o2 sensor is tapped into the midpipe
right after my turbo.

How many hours of operation is expected of the NTK sensor? I know
the motec unit has 400 hr life. Has anyone compared their wideband
to what the dynojet is reading?

Thanks,
Sid
 

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Sid, the A/F is in closed loop when cruising around. Unless you go above 5 psi, or more than (I think it's) 70% throttle, it'll run that A/F cruising. Once you get on it, when you are under boost, your A/F should ideally be around 11.5-11.8:1. You are then in open loop...
Peter
 

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GA Rocks!
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Discussion Starter #3
houstonT said:
Sid, the A/F is in closed loop when cruising around. Unless you go above 5 psi, or more than (I think it's) 70% throttle, it'll run that A/F cruising. Once you get on it, when you are under boost, your A/F should ideally be around 11.5-11.8:1. You are then in open loop...
Peter
hey peter,

this is what I am trying to figure out is partial throttle and idle mostly at 14.7-15:1. if so that would explain why my car's egt get’s so high during regular cruising. The a/f is 14.7-15:1 during regular cruising. With the AF set to that your egt’s will climb quickly. Now when I am at wot, the car is running more like 11.5:1 and that explains why I am never at anything above 640 C even up to 120 mph. But when I am in 6th going 90 mph my egt’s are at 700 C. I want to ask others do they see the same thing in their car. Do they see the car running at stoich, then a/f falling down and begin to steadily rise up to 11.5-8:1. What about your car Peter? When you were in 6th just going say 90 were your egt's climbing and what were your egt's reading?

Thanks,
 

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There is nothing wrong with your car sid. At 70 mph cruising in 6th i'd be around 610 C. Obviously going a bit faster would make the EGT's climb...
Peter
 

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My WB isn't built\installed yet bu tit's being worked on. 14.7:1 or so while cruising in closed loop is NORMAL - that's what the computer wants for emissions! Unless you've modified the stock computer this is what it will shoot for in closed loop.

WOT on the other hand... my car went PIG RICH on the dyno using their WB. I'm talking like 10:1, possibly worse in some points. The leanest it got was when #2 came online and it popped up to 12:1 before diving into the basement again :rolleyes: Apparently the FFCD was done so this may be some part of it - I'll be reversing that soonest!

As for lifetime - MOTEC sells (for$300!) the same UEGO used in an OEM Honda. That O2 can be gotten for $117 from some 'net parts places (ahem). Go over to TechEdge.com - if you're building a kit I ASSume that's where you got it but if not that's a good site to check out (OZ-DIY-WB). I've got a handful of their kits (cheap!) and two display units that are being built - hope to install one soon... An AEM ECU will follow so I can get my A/F out of the basement! :(
 

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GA Rocks!
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Discussion Starter #6
BLKMGK said:
My WB isn't built\installed yet bu tit's being worked on. 14.7:1 or so while cruising in closed loop is NORMAL - that's what the computer wants for emissions! Unless you've modified the stock computer this is what it will shoot for in closed loop.

WOT on the other hand... my car went PIG RICH on the dyno using their WB. I'm talking like 10:1, possibly worse in some points. The leanest it got was when #2 came online and it popped up to 12:1 before diving into the basement again :rolleyes: Apparently the FFCD was done so this may be some part of it - I'll be reversing that soonest!

As for lifetime - MOTEC sells (for$300!) the same UEGO used in an OEM Honda. That O2 can be gotten for $117 from some 'net parts places (ahem). Go over to TechEdge.com - if you're building a kit I ASSume that's where you got it but if not that's a good site to check out (OZ-DIY-WB). I've got a handful of their kits (cheap!) and two display units that are being built - hope to install one soon... An AEM ECU will follow so I can get my A/F out of the basement! :(
Thanks a lot for you post. That is good news. The motec unit has a life expectancy of only 400 hrs. I wonder how accurate the ntk sensor would be since it has a life expectancy of 10,000 hours. My unit is pretty much built except for the display. We are using a FLUKE voltmeter and doing the conversion while we wait for the display to be completed. I am going to have a datalogger on the car within a couple of weeks and we will be able to monitor and log, fuel pressure, rpm, egt, a/f, boost to see the relationship and make sure everything is working.

My car is pretty rich as well. Thanks Peter for your post on what your car reads at that speed. that was what I wanted to know.

Sid
 

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Any trouble building the heater circuits?

I was having trouble building my heater box - ended up farming it out a friend who's got more experience. Today he was bitching pretty hard about the instructions and claimed it could've been engineered better. Did you have any trouble building the control box? Supposedly commercial versions are available cheaper these days but for $300 :rolleyes: Since they're probably not much more complicated than the $60 (+or-)box I've got opted for the TechEdge kit. After hearing my friend's comments I'm curious as to other's experiences with it.

When mine is done I will probably be hooking it to an AEM ECU. At that point I'll be able to run it on a dyno and compare what the dyno A/F meter sees vs mine. Then I'll just have to decide which is more accurate. Would hate to find out the hard way and will probably tune "rich". 11.5:1 is what I've heard as a number. On the dyno this last trip I was MUCH richer than that (sigh). The FFCD was probably patially to blame, I've got some work to do putting it back to stock it seems before the AEM goes in. Hope it's not too delayed!

What are your plans? AEM or some other way to tune it?
 

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GA Rocks!
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Discussion Starter #8
Well I just got my CC bill. 120 for sensor and 70 for kit with display. $25 in small parts like box and connectors. What you should do is use a piece of aluminum and put the hot SOB on it. That is what we did. Put it towards the edge. Seems to work fine. We ran a bolt through the screw and use that to hold it in place when it is in the box. I picked up ABS plastic box from Radioshack. Goto the handheld radio department. The only problem we had was it was missing one piece. Very tideous work but wasn't hard.

I have a vpc and afr. That seems to do the job for me. Anything under 12 seems to be the magic number and give enough safety margin. I run 11.5-8:1. The dyno will be a great idea. please post your results.
 
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