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Interesting Fact About Putting Wideband In The Tailpipe

Rolls

By Rolls,
in Engines & Forced Induction

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skylinecouple Experienced

skylinecouple

Posted
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When you're tuning you hold on every cell to see what's happening then make adjustments. Doesn't matter how long it takes the exhaust gas to travel as you adjust by cell on constant load. Unless you're a wizz and can make changes in less than 3 seconds. (some tuners would have you believe they can)By the way, 3 seconds ? Ahh, NO. Only if at boost you have a 25mm exhaust.

Learn to tune your own car so you tune for every day over a period of time rather than the hour your car is on the dyno. The weather changes, fuel, heat and engine condition. If your motor blows it may be that these conditions changed and the tuner actually got it right only at the time it was tuned. I think Nismoid is about to tell you how rediculous worrying about the time frame of the exhaust travel is. Shhhh, here he comes, let's see if I'm right. :yes:

SargeRX8 Grand Master

SargeRX8

Posted
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This is why I run my wideband in my tail pipe. If the tuner likes, they can compare the ratio with what they are getting at the muffler but surely most would know there is some delay from what just came out of the manifold to what is being shown at the tail pipe...

GTScotT Grand Master

GTScotT

Posted
Posted

Havent you seen the tailpipe squiggle lines on Initial D and Wangan? That means the gas is travelling very fast.

3 seconds would not translate to squiggle lines IMHO.

Rolls Grand Master

Rolls

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I think Nismoid is about to tell you how rediculous worrying about the time frame of the exhaust travel is. Shhhh, here he comes, let's see if I'm right. :yes:

Well if Motec and Ford seemed to think it was enough of an issue to measure it and adjust their tuning to suit, then I'm going to guess it isn't ridiculous.

GTScotT Grand Master

GTScotT

Posted
Posted

Well if Motec and Ford seemed to think it was enough of an issue to measure it and adjust their tuning to suit, then I'm going to guess it isn't ridiculous.

There goes all credibility right there.

PM-R33 Grand Master

PM-R33

Posted
Posted

It wouldn't be the hardest thing to calculate a rough figure of the time if some one knew how to do it for a turbocharged engine.

Going off of very rough calculations I did with simple figures for a NA engine (2.5L engine at 1000RPM) I get around 4m/s out of a 3" exhaust - so around 1 second of travel.

That's just using some basic engineering formulas I can remember.

Would love to see some one elses complete working equations on it though, would be quite interesting.

I'm just not 100% sure on how above atmospheric pressure (boost) effects the formulas with an exhaust housing slowing down the airflow?

Rolls Grand Master

Rolls

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Just because one person at a company says something that doesnt make it the official company policy/opinion.

But it gives some credibility to asking the question and doing testing to see what the result is, it also doesn't give you guys a reason to be cocks about it.

GTScotT Grand Master

GTScotT

Posted
Posted

Furthermore, does this mean most of us now need to go and retune our cars as were probably tuned 3 seconds out?

Does this also mean I will shave 3 seconds from my 0-100?

That would mean some of us will be defying physics.

You should start a thread about defying physics.

joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted

Would be curious to hear STATUS' opinion on this.

trent tunes cars with both methods. depends on the application... he said it makes fuckall difference :)

GTScotT Grand Master

GTScotT

Posted
Posted

No but I would suggest you get a class in english comprehension : p

So I can impress people on forums. I'll get right on that.

Then I'll use my 'new found' literary skills and talk about reinventing the wheel on SAU. :wave:

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