:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: Colin on March 06, 2009, 11:00:39 PM

Title: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: Colin on March 06, 2009, 11:00:39 PM
What do you nogs do?

I'm getting a lot closer to finishing my car and need to make a decision. I have an LC1 that has a narrow band output I can send to my P28, but I know I can just run it closed loop or I can mod the ECU to read the wideband signal (I can't find that tid bit on PGMFI.org, but I know it's there).

Thanks
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: DmC on March 07, 2009, 12:52:42 AM
Man just run in open loop. tune the car carefully and watch the wideband when the weather changes and make corrections where needed
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: marcj on March 07, 2009, 02:23:16 AM
tune it and leave the narrowband disabled.. at least that's what I do..
I don't want the ecu changing any AFR at all on a boosted setup.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 07, 2009, 03:32:59 AM
I always leave it in open loop once it's tuned.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: 98vtec on March 07, 2009, 12:41:33 PM
once you have all the compensation tables tuned, there is really no need for a additional correction factor.  Just make sure you keep an eye on your plugs and replace them when the time comes. 
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: Colin on March 07, 2009, 07:51:35 PM
once you have all the compensation tables tuned, there is really no need for a additional correction factor.  Just make sure you keep an eye on your plugs and replace them when the time comes. 

That sounds like a good plan. I'll just disable the O2 and keep an eye on the wideband. Thanks
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: 98vtec on March 07, 2009, 09:37:13 PM
you will know when the plugs need to be replaced.  Your AFR will go bonkers.  I hadnt thought i put as many miles on the plugs as i actually did so it was weird when you slowly start to the see the tune deteriorate and wonder what is up lol.  I had gapped them to about 40 and the copper wore to about 50 gap clearance lol.  Not to mention i pulled them out and they just looked like they were on the last leg.

replaced the plugs and gapped them the same and uploaded my dyno tune map (fresh plugs) and everything went back to normal :)

btw, the plugs had about 8-9k miles.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: turbo4life on March 08, 2009, 01:37:58 AM
loooks like some of you are having trouble defining open and close loop

open loop = o2 disabled! keep it that way you can run leaner in cruise and save gas  and as long as all the corection tables are tuned you should be good

and if you have a wide band all the time in your car even better i dont and run open loop and had no problems as long as its tuned nicely and carfully
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: Atmosfear on March 08, 2009, 06:41:17 AM
Open loop indefinitely.  As mentioned, keep an eye out when seasons change and also if you road trip and face big elevation changes.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 08, 2009, 03:14:38 PM
Open loop indefinitely.  As mentioned, keep an eye out when seasons change and also if you road trip and face big elevation changes.
Elevation changes cause the most change in AFR I've noticed. I went from FL all the way to WA and my afr's were off by nearly a full point, mostly during WOT.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: ryan89crx on March 08, 2009, 04:24:37 PM
i run open loop full time

41mpg on the hwy  :noel:
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: turbohf on March 08, 2009, 05:09:29 PM
i never run narrow o2 sensors, infact i have a bunch of extra ones lol....
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: foumer on March 09, 2009, 01:14:19 AM
But if the software allows it, you can run close loop under vacuum which will help with mpg.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 09, 2009, 01:44:21 AM
But if the software allows it, you can run close loop under vacuum which will help with mpg.

Not if you tune for it in open loop.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: turbo4life on March 09, 2009, 01:53:02 AM
i run open loop full time

41mpg on the hwy  :noel:

intresting..

set up car ect.

you driving style

cruize speeds?

your loacation flat land?

hope this aint too much to ask for!
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 09, 2009, 02:25:33 AM
I get about 35mpg in the hwy as well. 11:1 h23vtec(206whp/172wtq). I drive an average of 75mph on the highway, even if its posted at 55mph ():). That mpg was the result from traveling from Yakima to Pullman and back. Hills galore and keeping it in 5th the entire way. Did a few spirited runs on some of the hills too. If I drove flat land, I'm sure I could get closer to 40mpg.

Open loop 24/7.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: turbo4life on March 09, 2009, 03:05:25 AM
wow nice numbers im still debating if  i should trow pm7 pistons in the z6 and use it in my dd.. i have just about 200k on the clock and want the car dead reliable for a long raod trip i want to take to visist friends  1700 miles plus in one direction  and would want outstanding mpg

btw waht kind of trans you running and waht car is this in?
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 09, 2009, 03:39:48 AM
Long ass f22 trans(until I find an H trans) in an accord.

P.S. I drove my car from Florida to Yakima, WA. Saved me tons of gas. Only part that sucked was going through the states that only had 91 as their highest octane. My shit was tuned for 93 in FL :-\.

I'm close to 15k miles now on my setup.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: 98vtec on March 09, 2009, 10:54:25 AM
i have gotten 40mpg on the high way before with my current h23vtec.  All open loop tune.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: snm95ls on March 09, 2009, 12:16:46 PM
43 was my highest on 81 octane with the B17 and cruising at 4K RPM for about 4 hours.

This also included some city driving for a few days after that trip as well.  All with closed loop.

I am NA though.

 :P
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: HiProfile on March 10, 2009, 04:05:09 AM
Most motors can deal with 15-16:1 while cruising w/o knocking or noticable power loss. The deal is the lack of air mass & cyl pressure doesn't create any internal hotspots, and you have a ton of timing to play with. From what smart people say, the VX can cruise in the 16-20:1 range.

Its easy to do a dirty tune just for WOT, plus I changed my setup a lot last year, which is why I ended up closed loop. Still got great milage. This year I'm going try open loop, esp if I get another lc-1 or techedge wb-o2. I'll also use my 16timer bin-switcher in case the afr's go wacky. :noel:
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: d112crzy on March 10, 2009, 04:09:37 AM
F22A's can do 16's just fine :D. I remember I got well over 40mpg on my stock ass F22A.

A huge part on how lean a motor can go is its health. Bad/leaking valve stem seals greatly affect your engines combustion chamber, so I've noticed. I've tuned a few h22's that had a slight back fire at anything leaner than 14.5. I tried to keep it at a constant 14 flat.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: 98vtec on March 10, 2009, 09:58:31 AM
i've seen 17:3 on my wideband and no hickup  :P
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: ratcityrex on March 10, 2009, 10:38:06 AM
My old a6 with the 60/48 and running my afrs at cruise around the 15.5-15.8 and a bunch of timing at right in my cruising bins got me 42.5-42.8 on the freeway in my 90 crx si. I was also running open loop. Im sure I could have gotten more if I hadent got stuck in traffic for about 45 min. I cant wate to tune the b18 and see what I get then.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: BoostForLife on March 27, 2009, 10:54:14 PM
Open loop  and a WB o2 in the car FTMFW.

Every couple of days i got through the map at WOT to make sure the tune isn't off. Mid to high vac is low to high 14s. Keep the mid to low vacuum from high to low 13s.

Get about 35mpg when i keep smashing to a min, b18b1, ls tranny, ebay t3/t4


Freelog sucks for me cuz i can't get the stupid o2 readings right with it. If i at least had crome pro, my tune would be much more consistent.
Title: Re: Keeping ECU in closed loop or wideband (narrow or wide band)
Post by: ryan89crx on March 27, 2009, 11:08:26 PM
i run open loop full time

41mpg on the hwy  :noel:

intresting..

set up car ect.

you driving style

cruize speeds?

your loacation flat land?

hope this aint too much to ask for!
just saw this, only a few days late :P

'89 HF
9.5:1 75.5mm forged d16a6
stock port head
Delta 272
Blox IM
62mm tb
RC 550s
homemade mani
t3/t4 60 trim
3"DP/Exhaust
obd1 with Crome Pro

cable SI trans with .702 5th gear

was driving 171 miles per day round trip. uneven roads, elevation bumping up 700ft overall though.

about 77mph for 40 miles of the trip, then 70mph for the rest. pretty much cruising, with the occasional downshift to pass cars here and there. did this for several months and always managed 40-41mpg on 92 octane. afrs cruising were 15.7-15.9