turbo charged 3.4 dohc....430 rwhp!

[timg]

I don't believe in tuning a car for max power and sacrificing reliability to do so, That's just a poor method of tuning, if you want more power change the configuration to do it properly and not in that fine line of destruction.

Agreed. In many cases, you can reach maximum power before you hit knock. If you're on a load bearing dyno when tuning, this is easy to prove. I typically find the best timing for power and then back off a degree or so. I may lose a few horsepower, but it's insignificant and hopefully will allow for a larger safety margin in case of bad gas or component failure.

Tim

[NateD4]

I know the early rods have survived 2 fuel cut detonations at full boost in my car (3.1 iron head) and after a severe detonation at 21psi in a local friend's 3.1 iron head. Both with t04e 60 trim turbos, his had a hole in the #6 piston I could stick both thumbs in, mine sounded like a cannon, then instant rod knock. How's that for testing?

Its really a matter of fatigue life of the parts. A stock rod will work up to a certain point. But the more you push it the less reliable it becomes. That was my main point I guess....

Keep in mind the OEMs dont' want warranty claims, BUT they also have to worry about cost and making a 100K mile warranty.

So for certain applications stock rods may not be ideally suited...

[NateD4]

I don't believe in tuning a car for max power and sacrificing reliability to do so, That's just a poor method of tuning, if you want more power change the configuration to do it properly and not in that fine line of destruction.

How do you find the edges of the engine's limits during tuning without venturing into the fine line area?

[3400-95-Modified]

How do you find the edges of the engine's limits during tuning without venturing into the fine line area?

I'm not even going to humor you with an answer to that, you only seem to want to prove everyone's opinion and theory's wrong so no matter what I say you will rebuttal it again, its not worth my time.

[TGP37]

How do you find the edges of the engine's limits during tuning without venturing into the fine line area?

I know you know this answer, lol. More then one way to skin a ricer......

[NateD4]

I know you know this answer, lol. More then one way to skin a ricer......

Yes, it was mostly a rhetorical question. I don't see how you can properly tune an engine without venturing into the fringes of the tune. I certainly don't know how you know the "limit" of timing advance at a given condition without getting detonation. The question really becomes how long the engine can live at that zone or when tuning. I guess it depends on how hard you want to wring the engine out.

I guess it's a personal goal of mine to tune near the fringe so I plan around worst case. I can understand not everyone does that....

[NateD4]

I'm not even going to humor you with an answer to that, you only seem to want to prove everyone's opinion and theory's wrong so no matter what I say you will rebuttal it again, its not worth my time.

I'm not trying to prove everyone wrong. I'm more interested in real information. However, I see a lot of data flying around here some of which I wonder how it is substantiated. I personally like to know where the limits of my designs/builds are. Not everyone is interested in that. But I think most people are here to learn, to exchange data and gain a better understanding of what they need for their goals, or to learn from other's mistakes. Maybe I'm wrong about that...

[ForcedFirebird]

How do you find the edges of the engine's limits during tuning without venturing into the fine line area?

I'm not even going to humor you with an answer to that, you only seem to want to prove everyone's opinion and theory's wrong so no matter what I say you will rebuttal it again, its not worth my time.

Nate seems to think we don't know what we are doing, even though we HAVE pushed the limits of our motors. Guess we have to be engineers to know how to modify cars.

Worst part is, he's telling us what we are doing wrong, and have been doing it wrong all these years.

[SappySE107]

Yes, it was mostly a rhetorical question. I don't see how you can properly tune an engine without venturing into the fringes of the tune. I certainly don't know how you know the "limit" of timing advance at a given condition without getting detonation. The question really becomes how long the engine can live at that zone or when tuning. I guess it depends on how hard you want to wring the engine out.

Its mostly a rhetorical question to someone that has all their answers in their head regardless of education or experience. If you ever read a book by an expert, you would already know how to find the best timing advance before you hit detonation, especially at the level of power we are discussing (if you forgot, this is about a 3.4 DOHC with 8-12 maybe 15 psi of boost).

I'm not trying to prove everyone wrong. I'm more interested in real information. However, I see a lot of data flying around here some of which I wonder how it is substantiated. I personally like to know where the limits of my designs/builds are. Not everyone is interested in that. But I think most people are here to learn, to exchange data and gain a better understanding of what they need for their goals, or to learn from other's mistakes. Maybe I'm wrong about that...

You see a lot of data flying around and wonder if its real, but you have no problem telling us a TGP has a forged crank (it doesn't), it isn't a 981 casting (it is) and other shit you have only heard before. If you would shut up with your opinions, and ask questions, you might actually learn something. Telling us we aren't engineers so you don't care what we say is exactly why no one wants to discuss anything with you.

[NateD4]

Its mostly a rhetorical question to someone that has all their answers in their head regardless of education or experience. If you ever read a book by an expert, you would already know how to find the best timing advance before you hit detonation, especially at the level of power we are discussing (if you forgot, this is about a 3.4 DOHC with 8-12 maybe 15 psi of boost).



You see a lot of data flying around and wonder if its real, but you have no problem telling us a TGP has a forged crank (it doesn't), it isn't a 981 casting (it is) and other shit you have only heard before. If you would shut up with your opinions, and ask questions, you might actually learn something. Telling us we aren't engineers so you don't care what we say is exactly why no one wants to discuss anything with you.

Enlighten me on the tuning question. This may be something I've never come across before. Or maybe just tell me what book to look in, I can read about it...


As to the TGP you are right (I think) in that it isn't the 981 casting. My memory tells me it had a different number on it. For some reason my memory also tells me that it was forged. BUT, that could be wrong. It might have been cast from a different alloy. I'm sure you've had one in your shop. So, if you don't mind, correct me. What's the casting number on it and what process did they use to make it?

[timg]

Try EFI University or any of Greg Banish's books. The EFI 101 guys have been tuning for decades and Greg Banish has worked with OEMs (GM, Ford, and Chrysler and probably others) on factory calibrations.

If you want a place to start, look up MBT. Like I said earlier. If you're tuning on a load bearing dyno, most engines will reach a power plateau a few degrees before they hit knock. On something like a DynaPack, Dyno Dynamics, or even Mustang dyno, it's easy to see. If you don't mind spending the money, attending something like EFI 101 is a whole lot cheaper than blowing an engine.

Tim

[SappySE107]

TGP uses a 981 hand selected crank, nothing really special at all about it.

You advance spark until power drops (use a dyno to go for max spark advance using this method, otherwise find a known safe tune and stick with it) , then back it off a few degrees. You should NEVER see detonation, especially on a boosted engine.

[TGP37]

The biggest mistake I read often is when people get power hungry and turn up the boost to show off. I believe an essential skill would be that of will power to resist the erroneous ideas we all have from time to time.

[NateD4]

What fun is it unless you can crank the boost up. How much boost is too much??

[SappySE107]

What fun is it unless you can crank the boost up. How much boost is too much??

Depends on how good you are at tuning, and what parts you use. Seeing as how RFRE isn't posting and none of us have done it, you are basically wasting your time with such a question. The guy that started this thread says he wants 12-15 psi. Is that not enough? Start a thread. If you haven't understood from my replies, and my PM to you, stop posting in threads about things that aren't on topic. If this was about max boost, we would be discussing his options already.