OPCrer

Hello,

I have a question:

How the tuner knows that can't go further getting out power from an engine, in this case an LNF ? In other words : How he knows reached the limit ?

Verbatim

iTrader: (1)

internals become externals

blueLNFftw

iTrader: (16)

winner

yellowsupercharged06

iTrader: (3)

What is the purpose of this thread ??

If OP is trying to tune ... Please do not

Im going to assume op is one of those kids who "thinks" his car should be faster

06cobaltncng

iTrader: (9)

let him blow up his car however he wants lol.

ECaulk

iTrader: (6)

This would be the answer.

OP if you're trying to tune, stop right now and start reading about tuning, educate yourself first before just changing the boost to 250kPa and timing to 30degrees

OPCrer

LOL!

I'm just curious.. never will try to tune my car, I'm good crashing my cars but for sure will do worst tuning them.
I got a really smart answer from a tuner that basically say ".. there is no way to find the limit by following a book, only guessing based on years of experience"
That's why make sure to get a large experience tuner before trying to mod your car..

Slowbalt2000

iTrader: (1)

I dont think hes trying to tune his own car. Hes asking a question of how far a tuner can take a car before he knows the tune will turn the internals into externals.

For OP, pretty much if hes going ***** to the wall, once it starts knocking, thats where he'll stop.
Most people who want a conservative tune will keep the stock timing map or have a slightly modified one, but for all out power, one you start to see knock retard, youve pretty much hit the limit with timing at least. Switching to a different fuel could aid in the further advancement of timing.

As for fueling thats kind of self explanatory, it will run its best at a specified afr(not exactly sure how thats determined) but adding more fuel will eventually start taking away from the power.

I am not an expert on this at all, just going off of what i know. There are many tuners on this site that should be able to help you answer this better than i can.

noorj

iTrader: (17)

a good calibrator shouldn't be guessing

blueLNFftw

iTrader: (16)

basically, there is only so much you can do. once your airflow is calibrated, your fuel is dial in, you can adjust timing. Adjust until knock, back off and thats about all it is going to do on the given fuel being tuned for.

noorj

iTrader: (17)

There is slightly more than that, but for torque based pcms like the LNF there is alot more than just wot fuel and spark advance

blueLNFftw

iTrader: (16)

I know, I was just generalizing for him though. He seems just more curious about whether or not there are tangible signs of how far you can go versus guessing.

Short answer OP, there are things that tell you when it is maxed.

AaronJ

iTrader: (4)

To be honest, I hope the tuner is looking at the logs of some start and end speed. Say 60-90, or something. Should be a 3rd gear pull. Stop throwing more timing at it when the 60-90 time doesn't improve because the car is making the most power, and more timing isn't gaining anything. You don't stop when it's at the edge of knocking, good god that would be horrible.

Have any of you ever watched Horsepower TV? It's on Spike on Sat/Sun. mornings. When they are dyno tuning a new car/motor, they keep adding timing until the power doesn't increase anymore, then they back it down a smidge for safety. They never run it up to detonation and then back it down a smidge .

armcclure

iTrader: (2)

"Generally" with boost and pump gas, kr is reached before Peak tq/hp. And I say generally very loosely. High hp builds I require a dyno tune regardless.
I have seen peak power drop with additional timing and no kr multiple times on e85, even at 500whp.

jp1600

iTrader: (2)

^ ah beat me to it, timing doesn't always mean power.

mrbelvedere

iTrader: (3)

the only way to tell if you have reached the limit is on the dyno street tuning is more guessing then anything

zrated89

iTrader: (15)

i see some people are starting to learn that sometimes more timing can hurt. They used to **** when i said i was running 21* and running 12.0 flat and their all like im running 25* and? lol (12.0 1/4 times not afr although ive done that too )