EJ22 dyno graph

[Guest]

Hi all, I posted a couple of comments in the Dyno top 20 thread yesterday. Not really the place for this High Power Monster (not).

Anyway, i was interested in peoples thoughts on whats causing the shape of the power curve, specifically the surging section around peak, and the various "plateau's" where the power seems stop, level off or even drop before climbing again.

This is a N/A EJ22E, only mods are a K&N panel filter and home made CIA in place of the inner guard snorkel, and a full 2.25inch exhaust, cat-less with UEL headers.

I figure that fuel or ignition deficiencies would produce these effects, but considering the level of modding, i can't believe that the factory ECU wouldn't be able to handle this. Maybe the big surge at peak is knock? Even then it still seems unlikely to me to have that sort of curve shape due to knock, i would think it would have just gone flat when it detected knock. Not recovered 200rpm later to produce peak.

I don't like how the graph logs road speed instead of engine rpm, i guess being a dyno day he didn't want to bother with a crank trigger.

I photo copied the chart and plotted rpm onto it for reference, however this is the original chart. ( I can post chart with rpm it's just messy :-\ ) Peak power is at 4700rpm and torque at 4050rpm. as it is this is about 500-800rpm lower than where the peak's usually occur on this motor.

Main reason i'd like to get a handle on this is i plan on using the EJ22 manifold, injectors and ECU etc on my new 2.5 high CR engine and need it working a little better than this for 11.5:1 CR!

So............ any idea's people? (constructive ideas that is ;D)

[Guest]

What fuel do you use ? For best results you should be running 98 octane. Yes even on a NA.

Do you get an AFR plot ?

It should not be that "jerky"

an afm clean and a can of upper engine cleaner can sometimes result in a smoothing of the torque and power curves.

[Guest]

Yeah an AFM clean occurred to me this avo actually. The K&N prob hasn't done it any favors in that respect.

The Dyno run was done with 95 in the tank. I have never bothered with 98 in this car as there is only i slight, barely noticeable improvement in over all smoothness noted with 95.

I didn't think that 98 was really necessary on an otherwise stock N/A.

I'm gonna go back and talk to Nick, they guy who own's/operates the dyno, on Tuesday and talk with him about it. Maybe another run with an AFR plot will help clarify things.

Whats the best product for cleaning the AFM?

[Guest]

I have seen a back to back dyno test on a 2.5na going from 91 to 98. Approx 20% improvement in torque + power.

Interestingly a 2.5" rps muffler was tested vs Stock. The stock had better low down and top end - lol !

[ReubenH]

I'm gonna go with oil change, spark plug change, air filter clean or change, upper engine clean, AFM clean, and other general maintinence. The mirage i'm driving at the moment does little power surges like that, i reckon it's just an unloved engine that needs a good bath BTW, EJ22's run quite high compression, i NEVER stuck anything but 98 in my old EJ22E. You're probably fine on 95, but i reckon my old 22 ran better on 98 (Butt dyno only though :)

And yeah Qwerty, not the first time i've heard stuff like that. Restrictions in the intake and exhaust make for good low torque don't they? What i'm told atleast.

[Guest]

Its a complex area of 4 stroke performance !

Restrictions or backpressure don't make power.

Its all to do with gas velocity and how that relates to the density of the intake charge.

Also under valve overlap conditions too much flow is also bad for power.

[Guest]

The Ej22E is 9.5:1 CR, not really super high for an N/A engine actually. Generally this one runs on 91 octane week in week out with no real drama's. I put 95 in for a year or so and noted that cost per km was about the same for the more expensive gas, with very little improvment in power.

I put the 95 in a few weeks before this run, and have filled it since with 95. If you think your gonna blow your NA EJ22 up with 91, WRONG!!!!

It has spent atleast 2 out of 3.5 years being thrashed daily on 91

Oil change, plug change, filter clean was all done within the last month. Apart from the AFM clean my car is serviced like clock work by myself with a lot of attention and care!

The exhaust is a puzzling one though. By no means is it super free flow, has no cat but has 2 offset mufflers one with a middle baffle, and a resonator. I think there is probably at worst a 2 inch diameter in one of the flanges as i didn't have a spare 2 1/4 inch when i welded it up.

I dunno, i guess i'm looking for answers from you guys that only another run and logging AFR and ignition advance are going to tell me.

[ReubenH]

Oh, nice, lol. I thought the 22's were higher compression, my bad. Mine was an Aussi spec btw, the car was a liberty LX. it had a little sticker from factory saying "Minimum octane 95 RON" on the inside of the fuel flap. I just preferred running 98 (and i didn't say it'd blow up on 91 if that comment was aimed at me )

[Guest]

i haven't blown it up yet ;D Seriously all 91 will do is make the ecu retard timing more to allow for more knock. Mines done probably the last 70,000km's on 91RON.

[Guest]

I can't find any difference between markets, JDM, NZDM, USDM the only thing that changed CR was the newer phase II 2.2 motors had a slightly higher CR but thats a USDM only engine i think.

[Guest]

Ok,..... time to eat my hat.

ReubenH, how right you were about the fuel. Did a couple of pull's on the dyno today with an AFR plot. (will post chart later) Ran on BP Ultimate and made 6kw more than on Friday's run on 95 RON.

Made it to 84awkw, but what showed up in the AFR plot was interesting. Run's super rich above about 2500rpm and has a oscillation in AFR that looks like i might have a misfire.

Dyno chart will explain what i'm saying when i post it shortly.

[Guest]

Ok for anyone interested.............

[dubbedup]

 forhire said:

Ok,..... time to eat my hat.

ReubenH, how right you were about the fuel. Did a couple of pull's on the dyno today with an AFR plot. (will post chart later) Ran on BP Ultimate and made 6kw more than on Friday's run on 95 RON.

Made it to 84awkw, but what showed up in the AFR plot was interesting. Run's super rich above about 2500rpm and has a oscillation in AFR that looks like i might have a misfire.

Dyno chart will explain what i'm saying when i post it shortly.

yeah 6kw with a fuel change!

[Guest]

yup,

Red line is last friday on 95 (78kw)

Blue line is first run today on 98 (82kw)

Black is M@x Powahhh1!!!!11!! (84kw)

Still a fugly curve though