Man, running stoich at full boost! Wow, that would be awesome! How much boost is the 335 building and at what temperatures? As we lean out the fuel, we always see an increase in EGT. So how much higher are the EGT's going in this state, or are they staying in a normal operating range for the application?

I know that the reality is that an engine doesnt care what the AFR's are. The challenge is trying to find out how to maximize the combustion window and utilize as much of the energy as possible. On a standard engine, only about 30% of the energy from the combustion is used. The remaining fuel absorbs some heat from the motor and dissipates it through the exhaust. So the question is really all about thermal management. How hot can this motor get before it starts melting things. Unfortunately the only way we will know for certain is through trial and error. So, how hot are those cylinders getting?

 

Guys, Shiv has been tuning cars for a long time, and he has already proven himself time and time again with more cars then just the Evo. This is coming from a guy that has never purchased any of his products. He knows what he is doing, and is well respected, so believe me when I say he isnt BSing you. This man, and his team, actually create a lot of really cool electronics. They dont rely on the success of others to get the job done, they are true engineers in their fields and know whats going on. So please, can we show just a little respect?

 

Shiv has worked for car manufactures to do OEM tuning for them. He know what hes talking about.

On another note, I have seen Vishnu maps and reflashes that had more than acceptable knock.

 

You have to update your "owned cars".

 

I've seen that much on my Evo and a friend's Evo, both completely stock. Apparently Mitsu deemed it tolerable.

 

^

 

It's funny how e-tuners use knock counts to quantify the solidity of a tune. If knock counts were a good indicator of actual knock, an ECU could be easily programmed to never knock. Not to mention knock sensors would be running all the time and not disabled at low load and at high rpm. It's funny how people overlook these facts. Then again, it is easy to look at numbers and come to the brilliant conclusion that 5 knock counts is better than 6 knock counts. Man, tuning is easy these days

shiv

 

It's better than when they rape with their e-penises!! Those knock counts can really hurt.

Hey Shiv I will be calling to get some upgrades to my wife's 335xi in the near future... BTW, great work on the new BMW engine with your ECU tunes.

Cheers,

-Nate

 

Just pointing out that aluminum transfers heat a LOT better than iron. So that heat you're bringing up doesn't really matter till it surpasses the limit where the effectiveness of aluminum vs iron heat dissipiation is crossed. So if aluminum, pulling this outa my ***, is twice as effective at transfering heat than iron, it could essentially take twice as much heat to cause any real problems.

 

We're starting to go down a slippery slope here, aren't we? While I can understand the irritiation that you might feel, at least take the time to post factual statements, since:

- The ECU never knocks to begin with (unless maybe on wood?), it's the knock sensor that due to excessive noise, detonation or pre-ignition causes the ECU to calculate knock counts

- AFAIK, previous Evo knock sensors ran all the time, under all conditions. I wish that werent' so, since it would make tuning my car much easier. Is the ECU on the X any different - i.e. does the ECU actually ignore knock sensor signals at low load and/or high RPM?

And while one might argue that you simply tune an engine until it stops making more power, in the end it still comes down to knock counts, since once the ECU detects knock (whether real or not) it will start to pull timing, hence it will stop making more power. Perhaps here is where the X will differ, though I certainly hope not, since I really wouldn't be very comfortable with an engine management system that ignores input from sensors designed to preserve the engine's integrity.

l8r)

 

Its easy to simplify what an ECU is doing, but the reality is the algorithms behind the decision making is not so straight forward. What we know to be true, or sometimes true, for the VIII and IX really will have no impact on the X. There is no such thing as a "safe AFR'. All motors like different variables for this, and it can only be found through trial and error. This is basic EFI tuning stuff guys. Check out www.efi101.com and take some of those courses. This will make more sense to you.

The reality is the stock ECU will handle the knock in the car. Its not knock counts you have to worry about though. Its knock events. All you would need to do is use the information we already know about the ecu and monitor the voltage of the knock line. Then of course you need to determine what the threshold is.

This really isnt simple stuff. Figuring out an ECU is not as straight forward as everyone thinks it is. If it was, we wouldnt have had to wait for almost 4 years to get ECUFlash on the market.

 

I agree and I think it is a disservice to the casual forum browser to represent it as anything other than that - i.e. a complex subject that is not to be taken lightly. However, I think we can safely make certain assumptions, such as that the Evo X ECU will have a way to monitor knock sensor activity and will attempt to insure the continued survival of the engine in the face of knock events. Furthermore, I think that it is unwise to assume anything further at this point in time. Things like AFR and timing tolerance certainly changed from the VIII to IX and I would expect nothing less with the 4B11T.

And to give credit where credit is due, IIRC, Shiv was one of the first to point out the tuning potential of the IX platform, just like he is doing on the X. Furthermore, why should a tuner post data that would be considered their intellectual property? Especially when, I'm sure, others are waiting in the wings looking to leverage exactly that type of information.

l8r)

 

just curious, looking at a completely stock X ecu on the dyno, have you noticed a sudden decrease in power around 6k to 7k rpm? what is this due to and why is it happening on a stock x?

nebo

 

^ smaller turbo @ work in the X, hence the anemic top end.

l8r)

 

nope i dont think that's it. some of the graph i've seen at around 6.4 to 6.8k rpm the power drops way low then picks back up after that. if the turbo is out of steam, i wouldn't expect it to pick power back up.

and at redline, the car is only boosting around 14-15psi.

nebo