The answer is clear. It's not worth it in my opinion to mess with a nb tune. Like it's been said before, you could ask them to steer towards the side of caution, but then you're running rich and not really getting full potential anyway. Just get a WB installed and then take it from there. Best part is, the link I gave you is of one of the best options on the market in my opinion, and their software is nice. You'll end up getting into tuning your car yourself

Here's something else to check out as well.

 

Your other option is to get a dyno tune. We tune plenty of cars that don't have a wideband installed, we use the horiba on the dyno so we always have an acurate log of AFR.

I do, however, have a wideband in my evo and recommend them to anyone who has more than a few boltons for the sake of spotting problems before the get expensive (like a blown motor).

If you don't plan on more upgrades in the future, I would say spend your money on a custom dyno tune. If you do plan on further mods, go ahead and get a wideband now and wait on the tune for a bit.

Also need to consider the ability to log the wideband's output. I personally use an innovate setup with 3 xd-16 gauges, wideband, and auxbox. At a minimum you want to get a wideband that will integrate with mitsulogger or evoscan.

 

You can effectively be tuned with a margin of safety without a wideband if you are 100% clear on your exact modifications, (intake type, walbro, injectors, etc) altitude, octane fuel used, weather and air temperature/humidity. TTP-Engineering has custom tuned IN PERSON from Miami, FL to Anchorage, Alaska and have experience with nearly every mod combination and octane ranging from the maximum sold being 90, all the way to 94 and 93 with 10% ethanol.

Experience trumps all. When tuning without a wideband, we make provisions for a margin of safety whilst improving the performance of the Evo at the same time.

 

I have always tuned with a wideband (WBO2). I have never tuned with a narrowband (NBO2). So I wanted to see how a NBO2 stacks up against a WBO2. The question on my mind was: Can you get an as accurate a tune with a NBO2 as you can get with a WBO2.

So I looked over the bazillion logs that I have and came across two sets of logs where I logged the NBO2 and the WBO2 at the same time. Each session is made up of three back to back logs.

Here is what I found:



In the chart above you will notice that the NBO2 continues to read 0.91 volts from 4500 all the way to redline. The WBO2, however, is more nuanced and the values change from a high of 11.42:1 to 11.20:1. The NBO2 misses all these variations.

So if I was tuning with a NBO2, then I will enter values in the fuel table of my rom based on that consistent 0.91. That might give me an AFR that does not taper by redline. My AFR will be around 11.4:1 from 4500 to redline. That AFR will more than likely trigger knock an my current set-up.

I did not believe that the NBO2 holds so steady, so I decided to check another set of data. Almost the same thing happened. This time, though, the 0.91 votls arrived @ 5500 rpm and held all the way to redline. The actual WBO2 was not constant and varied from 11.44 to 11.20. Again, tuning with a narrowband does not allow you to see that taper.



Narrowbands came to life for a simple purpose: emissions. When the catalytic converter came into wide use so was the NBO2 sensor. Catalytic converters work best over a narrow range of mixture ratio around the 14.7:1 stoichiometric point. O2 sensors were used to help provide electronic feedback to the ECU to help it keep the engine at a mixture ratio of 14.7:1 at whatever operation points it could tolerate it. This was a great help in getting the catalytic converter to work the most efficiently.

The NBO2 acts as an on/off switch. Here is the best explanation that I could find:

That is why a narrowband is so slow to react. At stoich conditions is behaves great since your @ idle or crusing, but @ WOT, it becomes inaccurate for tuning purposes.

Back when WBO2 were expensive (remember the $3000+ WBO2), tuning with an NBO2 was OK. But now that we have cheap and high quality WBO2, the narrowband tuning brings inaccuracy into the tuning process. It might not be a huge inaccuracy, but it is an inaccuracy nonetheless.

 

11.4 AFR tapering to 11.2 AFR at upper rpm is perfect.

For the purposes of eflashing or remote tuning, I feel confident in my tunes with my portfolio of experience based on national continental and non-continental in person tuning maps.

I am not a big supporter of narrowband tuning, however a variance of 0.2 is negligible.

 

First, The cars in question were tuned with a wideband and not a narrowband. You do not get the nuances you get with a narrowband. Let us say you were tuning with a NBO2 only and getting 0.91 volts from 4500-7000. That 0.91v could be 11.4 or 11.2. You cannot really tell. Would you run 11.4:1 AFR on 91 octane gas? I wouldn't.

Second, I will NEVER ever tune with a narrowband. If a customer came to me and asked me to tune their car using a narrowband, I will decline. It is not that I cannot tune using a NBO2. It is that I do not want to do it. It is not good tuning practice to do so. But I fully understand why you would do it, since it is your business and livelihood.

 

couldn't you just keep adjusting fuel until you stop seeing knock in those areas? btw I do have a zeitronix but I think as long as you have a good conservative starting point and make small changes I think you could get pretty close without a WBO2, but I can see how it would be more frustrating and time consuming.
just my $.02

 

Well, I guess there should be some clarification. Tuning with a wideband is necessary.

But say you've perfectly tuned car A with a good safety margin. Now car B with the same setup requires a tune. What do you do? Use the same tune of course. Car to car variences are pretty small. All cars come from the factory with the same tune afterall.

 

For a college professor, I would assume you had better reading comprehension. If you take the time to re-read my post, you will realize that no where does it state that I endorse narrowband tuning, nor do I engage in that practice.

 

If you review the highlighted text, those are some of the factors we take into account when tuning and make adjustments accordingly.

So in answer to your question, "NO" the same exact tune is not used on "same setup" cars. There is no such thing as a "same setup car" in my book.

 

Can you see it now? You did say that, did you not. Tuners MUST not tune w/o a wideband. But I fully undersrand why you do it. It is your livelihood and you lose money if you turn down a customer who does not have a wideband.

 

No I cannot, because it wasn't stated.

The only one who stated anything about tuning with a narrowband was you.

Now that we have established that you would like to contort the text of a forum sponsoring vendor with defamatory intent, can the thread proceed without further interruption or does it need to be moderated?

 

So please explain to us how you tune w/o a wideband and now you say that you do not read the voltage of the narrowband? How do you know what cells to tune? Remember you already told us a while back that you do not log 2byte load since it is not accurate.

Is it guesswork? Hit or miss? I would really like to know how you tune w/o a wideband and w/o logging the 2byteload and w/o reading the NBO2 voltage. Both Touring Bubble and JB assumed that the lack of a wideband meant reliance on a NBO2. I guess they too made that valid assumption.

 

Just wanted to warn you about the nutty professor.
He takes things personal and comes back with a personal view without regard for others, places or things. I had no idea he would be on the forum. Surprise.

 

I am here because I own an Evo. Do you own one? I see you own a Datsun, so why are you here?