A/F ratio curve

[DynoDave]

If the tuner spends enough time you can get the AFR's very flat but do you think the engine needs the same AFR at 3000rpm WOT as it does at 8000rpm WOT ?.You need to look at the bigger picture NO 2 engines require the same AFR's and this is due to many factors.Now we could all sit here behind a keyboard and debate which is the perfect tuning AFR for power or part throttle and there will be no real winner as we all use different AFR's for tuning.We are currently looking at and have tested a hi speed 5 gas analzyer and exhaust gas temp setup but more on that setup later.
Regards Dyno Dave

[DynoDave]

Dyno Dave is right on the money

The way I see it is there is too much talk about the correct AFR's now ProEcu and myself have talked about this for many hrs and from our own research and I'm sure the other tuner's on here will tell you there is no perfect AFR but the problem we all face now is the internet sites are telling you guys a different story.All I can say is that I have been tuning engines for longer than some of you guys/girls have been alive and I am still learning everytime I tune an engine.
Regards Dyno Dave

[DynoDave]

YES... that lead to my next question... would that be optimal??

Cuase i see that running abit richer lower makes more power...

can someone explain to me the concept.. i thought that if its optimal its optimal.

Interesting that richer makes more power down low must be a low comp or bad flowing intake or over cammed engine with the incorrect timing s**t I could go on forever about it.What engine combination are you talking about that makes more power richer.
Regards Dyno Dave

[ProECU]

The way I see it is there is too much talk about the correct AFR's now ProEcu and myself have talked about this for many hrs and from our own research and I'm sure the other tuner's on here will tell you there is no perfect AFR but the problem we all face now is the internet sites are telling you guys a different story.All I can say is that I have been tuning engines for longer than some of you guys/girls have been alive and I am still learning everytime I tune an engine.
Regards Dyno Dave

Many hours !! I'd hate to see your phone bill

Too many people get hung up on a number. If you want to start understanding the method, I suggest looking primarily at the torque production on steady load, with a careful eye on A/F and EGT's

[BlitZ]

Interesting that richer makes more power down low must be a low comp or bad flowing intake or over cammed engine with the incorrect timing s**t I could go on forever about it.What engine combination are you talking about that makes more power richer.
Regards Dyno Dave

Thanks Dave,

Engine
The engine is basically a stock R which has been rebuilt, JDM 4-1 headers and 2.25 cat and back (same as stock r), ebay cai(2.75") with K&N

Tune
I recently got it tuned at Hi Comp performance. Props to Joe at High Comp as he did good job and the gains were very noticable. I am just trying to understand more about the tuning side as i like to know whats happening with the car..

The engine produced a stock dyno figure of 112kw (which was fairly high for an almost stock R on the same dyno ~107kw)
After tune i only netted another 3kw, however drivability and response is definitly better...

As u can see in the below graph...
The stock a/f is running richer..
Leaning the mix down low showed no improvement in power.. even slightly less ( however not noticeable)...

[DynoDave]

Something interesting to think about should we be tuning via AFR's or use a 5 gas analzyer to make the best power and emissions?,the reason I ask this question is that when using a 5 gas the difference in the gases from a timing change is mind blowing and from what I have seen to get the gases where they need to be,to get an engine perfect AFR's will have no meaning as we know them and use now.And Blitz I am not going to comment on another shops tune sorry I have known Joe for a long time and like I said before we all tune our own way there is no real perfect way to do it just some guys do a great job and others should never touch a car.
Regards Dyno Dave

[EfiOz]

Nitrogen oxides are an interesting one to keep an eye on. They are usually inidicative of high combustion temps and can forewarn of detonation.

The reality is that will a nice thing to have and probably the absolutely correct way to do it, the same can be accomplished with a proper NGK lambda rig and a good dyno.

[DynoDave]

This was tuned using a handcontroller by the look of it am I correct.
Regards Dyno Dave

[BlitZ]

This was tuned using a handcontroller by the look of it am I correct.
Regards Dyno Dave

nah it was tuned via laptop..

[pornstar]

whats the vtec switchover like? looks like his switching it in way too early and dumping fuel into the table due to this. Hard to say without seeing the laptop file.

[BlitZ]

whats the vtec switchover like? looks like his switching it in way too early and dumping fuel into the table due to this. Hard to say without seeing the laptop file.

Ive questioned him about vtec changover today,.. and i was told it wasnt changed.. quiet didgey.. im going to bring it back and ask for vtec to be checked as the ECU was from another car(a mate of mine) with the cross over at 5100rpm

[pornstar]

Blitz, have you got the file from him? I have both power excel software and the datalogit software if you have either of them on file u can send them to me and ill tell ya

OR, if you have a handcontroller, then just put onto the screen monitor, and then select vti off or on display, and then drive it into vtec, whatever rpm it goes to on is where the vtec is switched too easy