Something's Afoot...., Super Low Power Output & Super Rich A/F

Heres an interesting one for ya.....

[B]Car:[/B] 99 Altezza RS200Z, 6spd 4cyl Beams
Mods of note: RsR Rear Muffler with a dirty great silence stuck up it that i cannot get out!

Issue: Went to do a power run or 3 on the Speedtech Motorsport Hub Dyno here in Wellington. Bolted the thing up, connected hubs, bunged lambda up the exhaust, started fan etc.... sweet, Do run...

result = 82kw @ hubs you're joking right?.... Tell andre the dyno operator to do it again... so he winds it up again...

result = 85kw @ hubs.... ok, one more time... 3rd time lucky....

result = 85.6kw @hubs ..........

Look at the a/f graph... from ground zero up to around up to 3500 rpm its bouncing around 14 & 13:1 which is about right, but when you go past that, it goes insane, and it starts hovering around the 11 & 10:1 ratio mark

Have put the car in diagnostic mode and checked for codes on the ecu, which has turned up nothing.

Have yet to check the timing, but it doesnt look like the timing belt has been changed since factory, not sure if the timing has been adjusted since then. But retarded timing wouldnt cause me to have issues like this. Whats the optimum base timing setting for the beams 3s on NZ pump gas (96 oct)

The figure at the wheels i'd be expecting would be around the 133kw mark at the hubs, after taking the flywheel power (154kw) and allowing for roughly 17% for drivetrain loss leaving that 133kw guesstimate.

133kw - 86kw = 47kw that i've lost somewhere down the line. Some people seem i've spoken to suggest failure of an o2 sensor is a likely cause but IMO something quite serious has gone wrong somewhere down the line for a loss like that to be attained. Surely something as simple as an o2 sensor failure or a cut wire would have thrown a code and been picked up?

As im new to this car/engine combo (more adept to the good ol 4age) this one has me stumped....

Anyone ever seen anything like this before, or could give me a starting point?

Any help welcomed

Cheers
Andrew

Dirty great silencer jammed up exhaust = -47 kW?

i wouldnt have thought an n1 style muffler with a silencer would be any more limiting than a factory muffler

Removing it was always on the cards... just been bumped up the priority order a lil

Dyno out of calabration, in a big way?

yeah u could be right
u could always take it to another dyno JUST to see

Im looking at doing another run on a similar dyno to see if theres any difference (just purely for peace of mind)

Somehow i dont think its the calibration, as no other cars after me (i was first of the morning) did anything out of the ordinary. Also have seen him sucessfully do runs on other altezza's in a similar state of modification (including muzza's) without any issues.

If the car is actually running 85rwkw it must seem a bit sluggish on the road. My car has run 120rwkw on a rolling road dyno and standard the only run around the 85rwkw and feel slow.

If it is a true reading might pay to get the car pluged in and dyno tuned.

It seems a little sluggish, but nothing to cause great concern. When looking to purchase, i drove 2 or 3 different ones and i couldnt feel any real difference between them when road testing them, so i didnt know any different.

Dont get me wrong, i could go get a power fc or safc or similar and get it tuned out, but thats not fixing the problem. It should go better than that with factory gear, so why add aftermarket stuff?

From what i can see the only things i can adjust (other than to remove that silencer) are the timing and plug gaps... which doesnt leave a heck of alot of room for improvement on a dyno.

Are these things meant to run 10 or 8deg base timing like a 4age? or are they slightly higher or lower?

Dumb arse question did he have the traction control off. He tried on mine a couple of times before he discovered the button. It just kept running like crap with it on

Yep, indeed he did. Saw him turn it off before the first run.

That's one of the best dumb questions to ask Muzza.

Only dumb questions are the unasked ones

By the same token, remember a closed mouth gathers no feet!!