ignition timing and EGT's

[bcjammerx]

I sticky all threads like this...I need to get a chipped ecu and play with my stock engine...see what I can do.

[d112crzy]

Mother fucking stickied.

[bcjammerx]

gah...subscribe...should be stickied

[dbsharp]

I remember doing calcs for a friend and a .020" mill on F22B DOHC head would increase it from 9.2 to 9.4? Am I missing something?

I don't know what I did the first time, but reentering the data into your calc gives me 9.6:1. That is assuming that I have 47.5cc combustion chamber. I am going to measure it next time the head comes off, I think I am going to measure the intake and exhaust ports too. My chevy friends have been asking me about that.

[HondaFan81]

I don't know what I did the first time, but reentering the data into your calc gives me 9.6:1. That is assuming that I have 47.5cc combustion chamber. I am going to measure it next time the head comes off, I think I am going to measure the intake and exhaust ports too. My chevy friends have been asking me about that.

According to Jose, the JDM F22B has the compression increase over an F22ax in the pistons. Therefore, I would think the JDM F22B head is similar to F22ax, that being 50.5 cc. It would be nice for someone to find out measure water into the CC with valves closed and thread sealant on a plug or something similar. A rough estimate should point in the right direction.

[HondaFan81]

And cisco..timing doesn't make/break a tuner..
How a tuner utilizes the timing on X vehicle with Y setup..does..

You're just taking it into more detail, but my point still remains. Tuners by definition need a wideband and assuming their setup works appropriately, all should be able to set AFRs. However, ignition timing is another story and there is not a tool that tells you and answer in black and white. So two different tuners with same tools/equipment/motor/vehicle can get different power outputs due to their ignition timing experience/setups.

Honestly, I don't think this thread is anything special. It is one of the more thought provoking ones lately. I think there is much more potential in this forum, we just have to harness it. I agree with MRX, I'm not on as much for same reasons, but I still keep in contact with those true enthusiasts.

[WiKKeDV16]

Ha agreed..you guys need 2 stick around more..it gets rather dry around these parts ..

[d112crzy]

According to Jose, the JDM F22B has the compression increase over an F22ax in the pistons. Therefore, I would think the JDM F22B head is similar to F22ax, that being 50.5 cc. It would be nice for someone to find out measure water into the CC with valves closed and thread sealant on a plug or something similar. A rough estimate should point in the right direction.

I COULD do that. I have an F22B head laying around, but it's disassembled. Maybe it'll give me motivation to build my own spring compressor.

[HondaFan81]

I COULD do that. I have an F22B head laying around, but it's disassembled. Maybe it'll give me motivation to build my own spring compressor.

You have been the JDM F22B man in my book, it would put an end to all of it and only contribute to more accurate specs on hybrid motors as well.

I've been trying to contribute as much as I've learned on F22ax and more on my laptop.

[HondaFan81]

Carlos, finally viewed that ignition timing table image, thank you and it helped!

Aight, after some NA EGT research, here is what I have. Let me know what you all think.

NA motor:

idle 750-800 F
cruising 1200-1400 F
WOT 1200-1250 F


So this is what I've come up with for a decent tuning methodology (step # 3 on dyno only).

** Note: Good habit to error on richer AFR and colder spark plug selection. **

1) Set idle (ignition timing and AFR).
2) Set AFRs properly across map.
3a) Advance ignition timing for max torque across map, then back off timing some.
3b) Listen for detonation (i.e. DIY det can to enhance hearing) throughout tuning.
3c) Referencing EGTs do help with ignition timing and detection of potential detonation conditions.
4) Inspecting spark plugs for correct heat range, AFR and ignition timing.
5) Adjust as necessary.

[dbsharp]

I have one with valve springs and all sitting in my garage. I just need to get a few things and i will measure the cc and port volume.

[WiKKeDV16]

Carlos, finally viewed that ignition timing table image, thank you and it helped!

Aight, after some NA EGT research, here is what I have. Let me know what you all think.

NA motor:

idle 750-800 F
cruising 1200-1400 F
WOT 1200-1250 F


So this is what I've come up with for a decent tuning methodology (step # 3 on dyno only).

** Note: Good habit to error on richer AFR and colder spark plug selection. **

1) Set idle (ignition timing and AFR).
2) Set AFRs properly across map.
3) Advance ignition timing for max torque across map, then back off timing some.
4) Listen for detonation (i.e. DIY det can to enhance hearing) throughout tuning.
5) Referencing EGTs do help with ignition timing and detection of potential detonation conditions.
6) Inspecting spark plugs for correct heat range, AFR and ignition timing.
7) Adjust as necessary.

Your thought process seems good.. a few questions/point of views


1. Your egt range.. you positive that's at the header? And not inside the head? I mean one would think forced induction cars would boast higher egts than all motor?(I've datalogged 700-900 Correct as needed.

2.I feel (it may be obvious to you, but I say this for the novice that's gonna read over this thread.) That part 4 of your process belongs tied together with part 3. While achievcing maximum torque via timing adjustments. One must use a det reference throughout the entire process. (Not just dyno) sure you will only see peak tq on a dyno and tune for it on a dyno..BUT like joser has mentioned you can detonate as low as 2krpm under WOT.

[HondaFan81]

Your thought process seems good.. a few questions/point of views


1. Your egt range.. you positive that's at the header? And not inside the head? I mean one would think forced induction cars would boast higher egts than all motor?(I've datalogged 700-900 Correct as needed.

2.I feel (it may be obvious to you, but I say this for the novice that's gonna read over this thread.) That part 4 of your process belongs tied together with part 3. While achievcing maximum torque via timing adjustments. One must use a det reference throughout the entire process. (Not just dyno) sure you will only see peak tq on a dyno and tune for it on a dyno..BUT like joser has mentioned you can detonate as low as 2krpm under WOT.

I re-numbered the process to reflect your points. That is what I meant, but did not represent it well.

I'll do more research on EGT NA ranges, if you find anything different please share. I did notice that combustion events within cylinder reach 1800 F, so I did not think these ranges are that far off. EGT probes are recommended to be placed 3 inches or so from the cylinder head on header primary.

[19dabeast85]

I know a turbo diesel engine is a whole different ball game, BUT some of the theory is the same as far as EGT's are concerned....

In general, the lower the EGT, the more efficient your engine is at any given rpm. Reason for this is because heat=energy. Less heat in the exhaust equals more heat consumed by the combustion equals more energy transferred into forward motion.

I have no experience with N/A EGT's though so I cannot comment on the expected ranges. I promise you that a near perfect tune will also result in the lowest egt's because this is the point at which the engine is most efficient. Hope this helps or sparks ideas or maybe is information you already knew. w/e

Also: WOT egt's are going to be higher than any other operating point of the engine, generally. correct?

[dbsharp]

Also: WOT egt's are going to be higher than any other operating point of the engine, generally. correct?

not necessarily. I have heard more than a few people report that they have higher egt's under part throttle. I imagine that the heat energy in the exhaust is greatest at wot. Temperature and heat energy are two different things.