if you are running to lean with the motor show knock?

 

Maybe. Depends on "how lean" and the boost/timing/load along with the lean condition.

 

what im trying is to say is if im running to lean ill knock?

 

Depends on how lean, how much boost, and how much timing is in the tune.

I have seen gas as lean as 13.0 not affect power or knock. I normally like 11.8-12.0 and it is not any less tolerant than 11.0. I have also had FPR lines blow off and while I dont spend a ton of time at full boost and extremely lean but we have had 1 or 2 28-29psi pulls that are also 15.0 or so without the FPR reference. No knock.

That being said the best thing to try is to avoid it.

 

u can run 11.8-12 on pump 93?!

i thought 11.1-11.3 is the most

whats FRP mean? ha

 

see and that confuses me cause then how am i supposed to know via wideband if its dangerous state or not ??

 

FPR is Fuel Pressure regulator.

Pumpgas here is 92 octane. Most of the time you run richer than that or cant run leaner I should say, its because ALOT of fuel slows the burn rate and keeps knock away. Poor solution for the most part.

Like I said, I have watched knock, knock voltage, EGT, etc. and havent seen any reason to run rich. Vice versa, I am not the guy that says 12.5 is ideal because I have seen 6whp from 11.0 to 12.5 changing nothing but AFRs. The 6whp was from 11.0 to 12.0 and no change from 12.0 to 12.5 in power. It does keep the bumper a little cleaner and less people think I have something wrong with my motor since they cant see visible smoke

Road racing is different and should be richer in order to keep the EGTs lower over time. Street pulls and drag racing can be tuned differently however. The difference in EGT isnt much from what I have seen but a little adds up when you are beating on the car for a long period of time versus the 9-11 seconds most drag passes or street pulls tend to last.

 

Pick a number that the majority seems to accept and tune for that. Feel safe because its what everyone else tends to tune for.

11.5-11.7 is the normal number for the record.

Ignore what the crazies do if it doesnt feel right to you. Wait and watch said crazies and see how often they suffer failures or seem to have to retune the car. If they dont seem to be breaking due to tune related issues, reconsider if they are crazy or not. If they dont seem as crazy, retune YOUR car to what you now feel might be acceptable.

Anything over 12.0 is crazy to me unless its on racegas or E85. I have yet to see those crazies (12.5 on pumpgas) do anything that convinces me I want to join that particular club.

 

Nobody on this forum, no matter however experienced can tell you when your engine will start knocking.

Every engine will be different based on climate, fuel and your modifications.

The best practice would be to lean it until you start seeking knock, and if your still not happy with the a/f graph, you should then take some timing out and continue taking fuel out until you are happy with your a/f graph.

 

You wont see knock from going lean unless you repeatedly beat on it at that level. I think I outlined the ranges to be in. Timing/Boost is going to be the one thing that you need to focus on to avoid knock like Negativegeforce mentioned.

 

I am asking because I am confused, I thought spool up should be around 12.5? On 91 octane pee water at 5800 ft. elevation for a DD is 12.5 unsafe under any boost?

 

as a rule of thumb you shouldn't' be anywhere near 12.0 on pump gas...sure you can by reducing boost or timing but it's asking for trouble. Shoot for low/mid 11's and wrap your timing/boost around that.

as you're spooling up at low boost it is acceptable to be in the 12's briefly

 

Spool/low boost- 12.5-13.0, full boost 11.5-11.7. I always hear how 91 octane is different and it needs to be rich but thats because its being used to supress detonation. It is really amazing how tolerant our motors are to being lean. I had an Evo on the other day that was running 13.0 under boost when it got to the dyno. The whole time I had been doing the remote tune his wideband had said mid 11s. I am not sure exactly how many pulls were done at 13.0 but I know at least one was and it was knock free.

Richened it back up to 11.8 and picked up a little power and some piece of mind.

Since most people leave the lean spool on these days worrying about AFRs during spool isnt anything that you can adjust unless you play with the lean spool tables anyway. The factory has it REALLY lean during spool to my tastes. Some fuels (E85) likes it rich during spool for best torque. There are alot of variables to consider and the one that really messes with people the most is how new the wideband sensor is.

 

Timing is what hurts motors, not fuel.