How much is the AAM reflash compared to the TS reflash???

 

ok guys..
so check this out..
my car was dyno'd
it has y pipe and headers
only mods at the time
it had o2 hooked up
and my reading were anywhere from 14:1 to as high as 15:1
never really dipping below 14.. at full wot up to redline..
am i running ridiculously lean here?

 

Yup. you're very likely hurting your engine at those insanely lean A/F's at WOT. I see it all the time, except it's usually test pipes that do the most leaning out of the mixture.

Please get your fuel curve adjusted ASAP. You should be okay to drive the car around as long as you keep it under low load (cruising). Your ECU should have automatically enrichened the mixture for your o2's closed loop cycles.

 

I don't know off-hand. Look it up on their respective websites; the information is there.

 

Are those tailpipe readings? If so, you are lean, but not dangerously so.

If those are pre-cat readings, I would be VERY concerned.

 

That's not true; even at the tailpipe, that is damn lean for WOT.

On our 91 octane here in California, 13:1 @ WOT is a good place to be in terms of a safe, but power making, a/f ratio. Running at 14:1-15:1 @ WOT on 91 will detonate the motor and cause damage. Running like this will have the knock sensor working full time to act on knock and pull timing as much as it can to prevent further damage.

 

FWIW - I've done a lot of wideband dyno tuning in my day and am close with several top tuners in California. I'm not just making this stuff up.

We've seen VQ's lose their piston ring lands to running in this a/f range.

 

same readings for me.. (done on same dyno on the same day..) I came back to high 12's right at redline however. They sold me some one step colder plugs.

What A/F are you shooting for in a naturally aspirted Z?

 

on 91 octane 13:1 is a good safe ratio for NA cars at WOT.

 

hmmm interesting..
any other way other than reflashing or piggy back to make this go richer?

 

Ya. Put the stock headers back on (i know you didn't wanna hear that).

 

I would run the car at another dyno with another 02 sensor just for comparison before freaking out. Tailpipe sniffers are notoriously inaccurate and I've seen a bad sniffer on a dyno day send 15 cars home crying when all the time it was just a bad sensor. Also keep in mind that on the dyno the a/f ratios will be different than actual street/track driving conditions.

 

I agree. The OP misinterpreted the information. Too little fuel at redline adversely effects performance and is dangerous for engine reliability.

 

Maybe. Tuners attempt to “fool” the ECU by relocating the mass airflow sensor. The sensor sends the “wrong” signal and the ECU adjusts by adding more fuel to the combustion mix. Its a “budget performance” trick that I wouldn't advise for the 350Z.

 

1. One-on-one time with a knowledgeable (I hope) tuner: $75/hour.
2. dyno time. You're tying up the dyno when it could be used to test other vehicles at 3 runs/$75.
3. Software. I understand that tuning software is “vehicle unique.” In other words is you want to tune the 350Z you have to buy 350Z software. How much does the software cost? $1,000. $10,000. I haven't the faintest idea but someone must pay for it. You.

 

I am going to go ahead and dyno, before getting the ecu, as mine blows out the rich dark exhaust at WOT, and see what the ratio is.

Believe it or not, I can actually tell when it is a little lean just by the throttle feel and the engine's response. It's not dead on, but if it's too lean, it will almost feel as if your pushing against something, and the car does not want to go. I have only noticed this after doing mods, before the car adjusted, or with crappy gas.

I know it's not accurate like the wide band, but it is definitely enough for me to back off the gas.

Since the car has adjusted to my current mods, I haven't noticed any issues, and will always get the rich exhaust at WOT.

 

That's probably because "top" tuners (as you put it) will use pre-cat readings for fine-tuning. Too many variables at the tailpipe.

I love how people need to tell you how "right" they are.

I prefer 12.5-12.8 for max power n/a. YMMV.

 

Well put. I would add that you can get much closer to a "street" tune on a load-based dyno.

 

Not much time is needed to fine tune NA engines with simple bolt ons. They don't immediately melt when you have a slightly bad tune like the big horsepower forced induction engines do.

Tuners rely on these tailpipe readings for 600+ rwhp cars. They have no problems with using tailpipe readings for tuning a sub 300 rwhp car.

"Pre-cat" readings don't mean much if most of these cars being dyno tuned are w/o cats anyway. I agree that the closer you get to the exhaust ports, the more accurate the a/f reading...but on that same token, it doesn't vary by a significant enough amount unless there are major restrictions (cats in this case) present in the exhaust path.

I also agree with not sticking w/ one dyno's wideband readings. I encourage going to several as any one of them can be off. When I first ran my 350Z on the dyno and saw 15:1 a/f's I was in disbelief. I took the car to another dyno and put down the same ratio but this time with audible knock.

 

hey guys, do u have to buy a chip in order to reflash the ecu ? i have absolutely no idea about this ,