[honda9krpm]

it's a little bit amusing to come back to a thread, where I asked a question, 10 hour later and I got a couple of questions in return :eek3:

Around 3/4 of a year before, someone on this forum ran a set of 440cc and reported no significant problem at idle. I can't recall who, may be pferra.....not too sure here. I think he upgraded to larger injectors aldready. It was suprise at the time.
It is slightly logically anyway. The VAFC can tune fuel by around 15%. The ECU can cancell most if not all of the settings in partial throttle by the VAFC (ie close loop). Close loop also occur at idle. So theoretically the ECU could reduce the extra 80cc in the injectors at idle and partial throttle. The extra fuel at full throttle MAY be enough to compensate for the lack of fuel in some sc systems.

Anyway it has been done and I don't think it's that rich to foul plugs or backfire too much ;)

When did you or anyone else run 440cc inectors with the stock PCM?
I will probably never have a chance to use the 440cc. I will use 550cc RC injectrors for my break in period on the new engine and then 1008cc Rochester injectors later on. I will then use the 550cc for my other project on the spare engine.

???? The Stock PCM can not control the 440's with out someother means to remove fuel at low engine speed. You will be way rich at idle/low engine speeds.
OK back to my original question, so how "way too richat iddle" will it be? What make you say that the pcm can't control the 440cc?

[S2000_Europe]

[QUOTE]Originally posted by honda9krpm
it's a little bit amusing to come back to a thread, where I asked a question,

[Slows2k]

PCM= powertrain control module, It's a synonym for ECM, ECU, or simply the engine's computer.

As far as the PCM for sale that's supposedly been flashed, Nobody to my knoledge has removed the PROM chip from an S2K PCM and replaced it with an EEPROM. A stock PCM is not rewrite-able.

I've got a set of 440's, but I'm not going to try and see how bad they perform, without any other means of compensating for them.

H9K, you suggested using a VAFC, which although minimal fuel control, It still is a electronic method of removing fuel from the engine. Using a VAFC is far from just plugging in a set of 440's and seeing what happens.

The S2k's PCM is a speed/density system. It does not have a Mass air flow sensor. The Stock PCM has no idea you are putting more air in it than originally designed. It also has no idea when you change this such as injector size. The PCM's programing is written for stock components, not modified or larger ones. It doesn't require or have any learning ability like the AEM EMS automapping, or a Mass Air flow system vehicle. While it does have some ability to learn and adapt to small changes, such as barometric pressure, Intake air temp, coolant temps, Removing and additonal 320cc of injector flow is a little unrealistic.

There are no direct plug in replacement PCM's other than the AEM EMS, No other Honda PCM's will work with all of the S2k's systems

[AusS2000]

Whilst I agree with what Slow has said and am once again horrified at H9k's unqualified advice I do have to point out two things.

H9k mentions the V-AFC simply to show that the range of adjustment in the ECU must be about 15% as the ECU can tune out changes made in the V-AFC. Fair enough.

The ECU does have an idea of amount of air from the MAP sensor. The combination of MAP sensor and barometric reading gives a good idea of air mass but doesn't compensate for FI as it was never designed to. It also sees the A/F reading and, when in closed loop, will attempt to tune using injector pulse width. The question is, when in closed loop will it compensate for the 440's. Dun'no. In open loop it won't, but then with FI you generally want a richer A/F.

Regardless, I certainly wouldn't be advising anyone to use this method of tuning.

[honda9krpm]

Quote

Originally posted by AusS2000
Whilst I agree with what Slow has said and am once again horrified at H9k's unqualified advice I do have to point out two things.

I wonder who is mechanically qualified on here :rolleyes: ?

Quote

Originally posted by AusS2000
Regardless, I certainly wouldn't be advising anyone to use this method of tuning.

Another unqualified advice too right :D?
I would not call this tuning as such but who care what unqualified ppl say right?

[AusS2000]

Once again you misunderstand. 'Unqualified advice' means to state something without backing it up. It doesn't refer to formal qualifications.

With regard to your second quote, I specifically said I am not advising. Surely I don't need formal qualifications nor a qualifying argument to not give advice. :rolleyes:

[Slows2k]

[QUOTE]Originally posted by honda9krpm

[AusS2000]

LOL, forgot about that!

[honda9krpm]

[QUOTE]Originally posted by Slows2k

[honda9krpm]

Quote

Originally posted by AusS2000
'Unqualified advice' means to state something without backing it up. It doesn't refer to formal qualifications.

since when does a comment with back up becomes a "qualified comment"?
First time I heard such saying.

[Slows2k]

[QUOTE]Originally posted by honda9krpm

[honda9krpm]

We aldready know that you are very qualified slows2k. You aldready mentioned it a few times on this forum. No need to prove that.

I am and most of the other members are mechanically unqualified here.

My questions were related to your comment that the pcm will not be able to control the 440cc and will be too rich at idle. Are you sure and how rich?

There was one person who reported doing so without much problem. He is not mechanically qualified to. In theory the pcm may be able to control it at idle or cruising. I AM NOT SAYING THAT THE PCM SHOULD OR NOT. What make you say that it should not and how rich ?

[AusS2000]

Quote

Originally posted by honda9krpm
First time I heard such saying.

Welcome to the english language.

[AusS2000]

Qualifying statement

[honda9krpm]

Quote

Originally posted by AusS2000
Qualifying statement

Geez so many garbage on the net these days.
No wonder why so many assh@les think they are qualified these days.

Remind me of a confuscious saying, "SH!T HAPPENS, ASSH@LE CAUSES IT"

[AusS2000]

How magnanimous of you.

[AusS2000]

Did you want me to look up 'magnanimous' for you too?

[fperra]

My two cents: Its true that during closed loop operations the ECU will try to correct for an over rich condition brought on by 440 cc injectors. Whether the ecu has enough range to fully compensate, I do not know, although I suspect not. What I do know, is that 440 cc injectors will cause a CEL for short term fuel trim and, eventually, long term fuel trim.

[honda9krpm]

Quote

Originally posted by fperra
My two cents: Its true that during closed loop operations the ECU will try to correct for an over rich condition brought on by 440 cc injectors. Whether the ecu has enough range to fully compensate, I do not know, although I suspect not. What I do know, is that 440 cc injectors will cause a CEL for short term fuel trim and, eventually, long term fuel trim.

hmmmm interesting :thumbup:

[S2000_Europe]

Quote

Originally posted by fperra
My two cents: Its true that during closed loop operations the ECU will try to correct for an over rich condition brought on by 440 cc injectors. Whether the ecu has enough range to fully compensate, I do not know, although I suspect not. What I do know, is that 440 cc injectors will cause a CEL for short term fuel trim and, eventually, long term fuel trim.

let me see if I understand it


if I installs 440cc and keep the original fuel pressure I will get into CEL code, but after, lets say 200 km, fo driving the ECU will be adapted to 440cc erasing the CEL code?

[fperra]

No, it won't adapt. I will know that it is having to constantly over adjust for excessive fuel and will always throw a CEL light.

[honda9krpm]

Quote

Originally posted by AusS2000
and am once again horrified at H9k's unqualified advice I do have to point out two things.

Quote

Originally posted by AusS2000
Welcome to the english language.

Quote

Originally posted by AusS2000
How magnanimous of you.

Well I believe there is a clear difference in qualified advice and qualifying advice.
Correct me if I am wrong since I am not English,
qualified advice means expert advice and "qualifying advice" means an advice from a non expert with some information. There is a disticntion there aus.

FYI I've never been asked for "qualifying advice" ever in court but I have been asked many times for my qualification and qualified opinions on matters. Geeze I wonder what my other colleagues would think if they get asked for qualifying comments by some confused lawyers :D

[Ztec]

This is an informative thread and I hope that the bickering could stop so the people that are reading won't have to sift through so much wasted bandwidth - No offense just please stop trying to force your opinions and stick to the subjects!

[Dezoris]

I want to address the question of low vtec engagement.

The whole concept of vtec was to give the engine "dual personalities"

At low RPM good gas milage, and lower emissions, and at the higher end more power.

We all know what it does. However, mechanically I don't agree that there are no adverse affects of dropping vtec switchover point.

I can only assume that the lift and duration is not extended unless the correct conditions apply as it does in stock form. If you are beating around outside of WOT the car stays on the low cam.

To me this is basic engine dynamics.

If you extend lift and duration, you need more air and fuel.
Not only that, extending lift and duration thoughout the rev band would also compound wear to valves, valve springs, seals, retainers etc.

It is one thing to create power, for race purposes, it's another thing to risk reliability on a car not purpose built for race.

Without a dyno raising the vtec engagement point I see no purpose to it?

You have a car with a lofty power band, very high RPM operation, for race, you stay there, that is where you want your power.

I think the people with this car have some great ideas for tuning it, and others as in this case, are trying to make the car something it is not, forcing it to be that 350z, and ignoring the car's overall gearing and powerband.

If you are building a trailer queen, I am all for it, but I don't understand the tuning agenda in this case.

[AusS2000]

Quote

Originally posted by honda9krpm
Correct me if I am wrong since I am not English,

You're wrong, again, as already proven.

Regardless, my intention was to point out that your statement was not 'qualified' by experience or anecdotal evidence.

And now others with both 'qualifications' and experience have given their advice and 'qualified' it with examples.

If you still think there is reason to argue can we do it via PM?