So are we also saying that gains from my exhaust are still there?

 

I am. Others may disagree but the best way to know is to continue to make measurements.

 

Exactly unless those that want to sell you a warrantee voiding tune can show a customer's car with dyno sheets proving the gains disappear over time...

I'm still waiting to see a customers dyno verifying GIAC's claims of exhaust systems gains being nullified by the stock ECU tune..

 

I think there's some confusion, and maybe I can clear it up. What Austin is saying is correct. The ECU does have preset TQ limits and it WILL adjust (and even close the throttle) if those TQ limits are exceeded. The thing is...adding an exhaust will not bring you anywhere near what those TQ limits are, so in my opinion the gains would remain as long as you don't exceed the TQ limits.

We have seen this happen and I can tell you that the behavior Austin is describing is absolutely true and it does happen. Browse through the forum...look at the few people who've tried strapping on a set of GT30 or GT35 turbos onto the 997.2 and compare their power output to cars with full bolt-ons. I think you'll see something very interesting there...they all make the same amount of TQ.

 

Installing an exhaust was the start of this line of questioning not slapin on a set of bigger turbos....
Still none of the tuners are posting dyno sheets to back up their claims...
A little dyno
proof goes a long way when making claims....

 

Gee, finally..........................

 

Your original post in this thread...

Your original question just specified "hardware"...not what kind of hardware. Austin comment was also not made in this thread. My last comment essentially agreed with what you're saying, so I'm not sure what the argument is anymore?

You're obviously on a crusade of some kind to prove that tunes are bad. That's great, it's your opinion, that's fine. It's your choice...but at least try to be a little respectful of those who don't agree with you.


I'm confused...

If you think I'm admitting that your piggyback won't revert back to stock power levels, I'm not. I'm simply saying minor hardware modifications won't. Apples and oranges there.

 

You just did admit it. You said if it was within the limits and I am confident that the piggyback tune is within the limits. I haven't seen any degradation of the performance over time and you have never backed up your claim with any data. If you are saying that my FVD piggyback loses it's effectiveness over time then you need to prove it otherwise you are subject to making false claims about another product in writing. That has a legal definition.

 

A piggyback is not a hardware modification. Adding an exhaust system does not alter ECU input signals...these are two totally different things.

 

Still haven't answered the claim...

 

My god, how dumb are you? Of course it does, think about it for a second and if you can't figure it out then get off the board and the thread.

 

How dumb am I? How about you think about it before you insult me.

The ECU of the car is programmed to operate in continuously variable conditions of altitude, ambient temperature, fuel type, intake temperature, intake volume...etc etc. It will always adjust to variations in those things and in order OPERATE WITHIN SET PARAMETERS that is was programmed for. A free flowing exhaust may change one of those input signals but as long as it's within the set parameters in the programming, the ECU will adjust. It does this to protect the engine and to insure the most consistent performance possible in any given conditions.

A piggyback specifically alters a boost signal without compensating in any of the other 100 lines of code that need to be adjusted for that false boost signal. If you'd really like to know how it works, why don't you call the maker of your piggyback and ask for a schematic of their unit. That might be a real eye opener for you. I've agreed to show the the professional courtesy of not specifically naming their product, but you sir, have officially just lost the rights to any courtesy from me.

 

It's not an insult, it's a serious question and apparently you do now realize that the signals do change as a result of adding a bolt-on. Ergo your previous statement was incorrect and you admit it in the following response.




Now with respect to boost, this wasn't part of the discussion to begin with. You are making unsubstantiated claims about how piggy backs operate and suggesting that the makers of piggy backs are all misrepresenting their products. This for example is an unsubstantiated and false claim. In fact they will alter the other signals to compensate for the change in boost.

You have failed to provide any proof for the above statement. Of course how could you unless you developed the piggyback in question. Maybe you wouldn't but I am quite sure others do.


I don't need to call him because he called me and confirmed that I was correct on the previous thread. I have a M.S. Eng. in Signals and Systems from the University of Texas at Austin. What we are talking about is called an independent observer or a Model Reference Adaptive System. It's a way of developing a set of controls that can be used to implement changes in the control parameters given different operating environments, i.e. loading and environmental conditions. I took a course in Adaptive Control Design from Karl Astrom when he visited UT during my graduate degree program. I am familiar with the ingredients in the design and implementation of a piggyback. I am not sure you are.

 

The whole discussion wasn't about piggyback vs tune to begin with, you took it there.

You're assuming my claims are unsubstantiated, when the reality is I actually have quite an intricate knowledge of EXACTLY what it can and can not control. We've been approached many times by almost every piggyback manufacturer who wanted us to use their unit, and yes...I've seen behind the curtain (so to speak). A piggyback absolutely can not control things like PDK tq limits or any of the other control units in the car that effect final engine output. You can have 10 engineering degrees, but unless you also have a deep knowledge of performance engine programming and the same years of experience that we and GIAC have, those degrees aren't worth the paper they're printed on in this case.

Bottom line...you're happy with your piggyback, fine. Enjoy it...I've said this 100 times. That's why there are options. If you choose not to believe anything I say or to buy any product I endorse, that's your choice, and I can respect that. That's why you have choices....I respect yours so just move on and let it go already.

 

Hey I just want to see proof that the gains from an exhaust and Y manifold change are auto corrected out.....I took off my warrantee voiding piggyback..