kotik

Second post about my soon to be head swap. I am in germany, so please bear that in mind.

I bought hp tuners pro to get my car tuned by the tuner in the US. He says wideband would be good, but not fully necessary. The only mods are new heads (no porting), headers and intake. My one friend (that does a lot of modding with *** spec cars) says its almost impossible to get it tuned without a wideband and i can blow up my motor.

I know it would be beneficial to have one, but due to time/budget i prob wont be able to get one (unless absolutely necessary). I will be driving the car hard for the summer, but then moving back to the states in september so i can get a good tune then.

So do i absolutely need the wideband? Im not looking for top hp, just safe tune

Michael_D

Just headers and an intake? What intake? You mean CIA or manifold?

A wide band is an absolute must for wide open throttle tuning, as the ECM adjusts fueling based on MAF and/or VE calibration calculations without looking at O2 sensor output. It looks at O2 output voltage for all other conditions, and adjusts fuel trims to bring fueling back to stoic. Without the WB, you can't see what fuel / air ratio is (when the ECU is not looking at O2 voltage), so you can't re calibrate MAF or VE. All your other idle, off idle, closed loop engine loads can be calibrated off fuel trims without a WB.

So....to answer your question, it depends on what you have changed, and what you want to recalibrate. I'd say you should have a WB, but I'm fussy.

arsautorepair

He should be able to recalibrate the maf with 02 fuel trims pretty well, if he gets those close your command wot afr should be "pretty" accurate. Might want to command the wot afr little rich to be on safe side if your not using a wideband. But to do it right, a wideband is necessary and recommended. If there is any dyno operators in German you could have the wot afr checked and adjusted on the dyno if its equipped with a wideband

kotik

Just a regular cai (killer bee), and long tube headers. I was told that without the port job the heads should flow better than stock anyway.

So i can do without?

I only have 3 months left in germany, so i want to use it othe fullest. Finding a shop that does ls work can be hard/very far away/cost a ********.

arsautorepair

If the tuner is competent with hp tuners and ls tuning, I don't see a problem imho

Michael_D

OK, so as others do read these posts, I'll give you more info than you need, and apparently, more than you will understand.

Once again, you MUST use a wide band to tune WOT (wide open throttle). There is no getting around that. NONE

You can re-cal MAF and VE coefficients by logging fuel trim output for all other engine parameters, because the ECM sees the O2 sensor outputs (which report fuel/air ratio (in lambda), and then adjusts fueling (trims/adds fuel) to get the fuel / air ratio back to where it is commanded to be at (14.7 for gas; plus multipliers for power enrichment, and a bunch or other things). When you go WOT, the ecm no longer looks to the O2's to see where the air fuel ratio is. If I knew how to post a screen shot of a log showing this, I would. But I don't, so you'll just have to trust me. The ECM is running strictly of calculations to adjust fueling as soon as WOT parameters are met. The algorithms used to calculate WOT fueling look up MAF output frequency, which is one of the things you calibrate with a WB under WOT conditions.

So....do not let your 'tuner' fuuck with WOT without a WB. If he does, or even remotely suggests changing WOT cal without using a WB, hit him in the forehead. He will most likely tell you that the stock tune is "pig rich" or some other endearing term, and tell you it "won't hurt" anything to lean it out some.... The stock tune is rich at WOT, but that is with KNOWN engine air flow characteristics. When you modify them, you don't know what the hell you have done until you verify that with instruments, like a wide band O2 sensor that has the range to see the air/fuel ratio that the stock, narrow band O2 sensors cannot see.

phipp85

What is the preferred wide band sensor and gauge to use?

spdmn75

ngk afx is good not too expensive but accurate sensor

Wulverine

I thought I read somewhere that the stock O2 sensors were wide band?

Michael_D

You may have read that, but they are not. All OEM O2 sensors that I am aware of, are narrow band.

Wulverine

Interesting, I agree 100% with not running a mail order canned tune regardless of range of stock O2 sensors.

spdmn75

what octane gas are you tuning to?

kotik

Ok, so im getting my head spun now.

So if my mods are basic, headers and cai, i cant run an etune?

AndreasK

Got the same problem, live in Sweden. Last year my car was tuned in dyno with intake mainfold, big throttle etc. Due to various reasons I do not want to visit the same tuner again.

Now I have put in an other cam, all other things the same. Would a over the Internet tuning be good? I have HP tune.

C6-Z06

Etunes are fine but I wouldn't do one without a wideband. It's not worth risking your engine.