No, you did, go look back up the thread.

I didn't say they did and they don't have to in order to add power within those limits.

This is your opinion, you are entitled to have it.

I actually wasn't talking about the piggyback. I was talking about IPD plenum and exhaust to begin with, just like the topic of the thread. Go back up the thread and read who first said piggyback, hint, it wasn't me. LOLOLOL!!!!!!!!!!

 

Staying on topic..

 

I think modern day ECUs are highly complex and it monitors almost everything that a car does. I think it would be very difficult to answer your question because of the following reasons:

1. Almost all dyno plots are done on the same day when an aftermarket exhaust has been installed, to show how much horsepower the bolt-on has added to the car. This is good business for any tuner, to showcase how much power their product has added to the customer's car.

2. Almost no one would re-dyno their car 3 months after they had installed their bolt-on exhaust just to verify if that added horsepower has remained with the car.

Certainly, no exhaust manufacturer will be willing to do it because it is just bad for business. What if the numbers are less than before? Moreover, when you re-dyno a car, the dyno number isn't comparable to the original baseline from 3 months ago (eg. different climate conditions, different gas, etc)

My experience is that modern day ecu takes time to learn and adapt to any kind modifications you make to the car. In an ideal world, you want to have a real customized software flash to incorporate all of the hardware modifications you have made to the car.

 

True but they would run a quarter or 0-60 or 60-130 three months later and if the exhaust made a difference, it should still make a difference.


It might be bad for business not to do it if people are skeptical that the gains remain. However, I think most people buy the exhaust for sound and not any HP gains. Your last point is a really good one about dyno numbers and it's why I prefer to use a Vbox to verify performance improvements. To date, my car performs as well as it did after adding the bolt-ons. That is why I am not buying the ECU adapts away gains arguments, my data says otherwise.


What exactly does it learn and adapt to? I keep hearing this but really am not sure where it happens because I certainly haven't noticed it on either my M5 or my 991tts.

 

Saying that using the same dyno on a different day or month with the same car will give different readings is BS.. The dynos have correction software for ambient temps..
I've been tuning my own cars on the same dyno for the last 10 yrs. summer and winter base numbers are within 2-5 whp...
The fact that no one checks is because guys with money will never admit they made mistakes...

If they don't have dyno proof for their claims then they are just selling chumps BS....

 

I agree with your point on getting the 0-60, 0-130 numbers to verify performance gained over the course of time.

As for the ecu adapting, it happens all the time. If you ran your car at a track all day, your ecu will know and start adjusting various parameters like A/F ratios. Or simply, if you took off your exhaust and ran it without a cat/muffler like a straight pipe, it will adjust itself to try and run within a certain parameter. Most likely, it will give you a check engine light within 10 mins of driving

 

This would be temporary and would revert with driving conditions I would think. I understand this to be part of what the MRAS control is designed to do.


Right and this is where the change you made would result in operating conditions outside the limits the ECU is designed to handle. That would be an example of a bad mod or a bad tune. My point is simply (and has been all along ) that any tune needs to keep the engine within it's programmed operating limits. Those limits still provide for making a reasonable amount of additional power.

So far my piggyback hasn't caused any CELs and I have run it for about 3500 miles. I did have issues with my Dinan piggyback and I think eventually the dealer took it off after I traded it in to them. Plenty of people in the M5 group are having trouble with both piggybacks and flash tunes. If I get a CEL on this car, the piggyback is coming off and that will be the last tune I ever do.

 

What is the "mistake?" If you are buying a tune, you aren't doing it because you are worried that you will lose the 10 whp gain you got from your new exhaust. You are doing it because you want the additional hp and tq that the tune gives you. I don't think anyone spends $3k on a tune to "keep" 10 rwhp. They do it because they want another 50+ whp. So I am not sure anyone is making a mistake by getting a tune (putting aside the warranty risk that people have to assess for themselves).

Nobody is disputing that tunes provide performance gains. That much can't be disputed.

I currently have no clue whether my exhaust gains are still there. I never ran a before/after dyno. I took my car to the strip twice after the installation - ran a best of 11.3 @ 126 at Englishtown with the traction control killing the runs and crappy 1.8 60' times. Then ran three months later with better tires and got a best of 10.8 @ 128 at Atco with a still subpar (for a 991 TT) 60' time. I don't know that I would consider either time a benchmark against which to measure the next performance mods. I can only say that if I go back to Atco on a 75 degree day and run a 10.5 @ 128, something must have helped.

 

If you have your own dyno that's a different matter. If you have to take it somewhere then you really can't control for variables in the dyno environment. Many places can't even do a AWD dyno, there isn't one here in Austin. This is why I like the Vbox data. You can adjust for incline, and DA figures if you know them.

 

Have you checked Cobb Tuning in Austin? Not sure if they have a dyno there but their other locations def have awd dynos.

 

No but ATXAutosport works on my car and I asked them if they knew of a dyno I could use and they said no one in Austin has a AWD dyno that they know of. I was interested in doing a dyno after adding the mods.

 

Here...let the dumb guy help.

http://www.dynojet.com/DynoCenters/D...sa_distance=25

Pro-Tech Auto has a 424xLC2 AWD DynoJet.

 

Thanks, I think I will schedule one today.

Well, no answer on the phone and their website doesn't exist. Not sure if they are still in business. The others listed won't work though? It needs to be the 424xLC2?

 

This is taken directly from Europipe's website, a very reputable exhaust company for Porsche:

"The ECU of the new Turbo is adaptive so all the initial gains of our sport exhaust are gone after a couple weeks of driving. From then on the maximum output at full throttle is the same as stock. What remains is the added hp and tq at low rpm and midrange as well as the sharper throttle response."

Even an aftermarket company admits the 991 ecu is adaptive and the maximum hp at full throttle is wiped out after a few weeks of driving

 

Love Europipe, and I see their statement as probably an admission that is not good for their business. But it doesn't mean that they are correct. We may never know.