legacycentral bbs

Dynoed the old girl today. Here are my results. Tell me what you think and why you think power drops so much after 5500RPMs.




And 2 different vids

Youtube attempt
http://www.youtube.com/watch?v=wR25GQUeP5A

Photobucket attempt

The answer is: you are still running the EJ22T heads.
My dyno plot looks similar in that the power drops off at 5500 rpms.

They suck that bad huh? Good thing I got some 20g heads and intake sitting

the boost looks like its fluctuating alot past 5.5k also, at the same time the power drops off. Manual boost controller installed?

Yup. Turbosmart mbc. Do they tend to do that?

I think it's also important to mention your "rattling" wastegate door

Yes that too. Although I don't hear it under throttle, only when I'm coasting, and only sometimes.
The weird part Rob, is ever since I upped my boost to 6 cliks, I've never heard it. But yesterday, I turned it down all the way on my way to the dyno, and sure enough, it came back. So I turned it up 4 click again, and never heard it again.

Yeah, it looks like you're boost is fluctuating quite a bit. But as mentioned....the heads are not going to help either.

Mod list? power/fuel mods?

curious so i can kinda compare to my car.

ive got a pic compairing the valves on the 22T heads to the set of 25D heads i used, its like compairing a dime to a quarter, litterally.

Mods are 3" turbo back MBC k&n cone Perrin crank pulley td04 06 tmic sti bpv walbro 255

LookAsubie wrote:Mod list? power/fuel mods?

curious so i can kinda compare to my car.

Yours? And what power did you put down?

Your air/fuel bumps down around that point too. The scale on the plot is rather odd.


The small ports in the heads should not have that sharp of change in direction of the power. Power will drop off, but not go from a rising curve instantly to a falling curve. Something else is going on.

93forestpearl wrote:Your air/fuel bumps down around that point too. The scale on the plot is rather odd.


The small ports in the heads should not have that sharp of change in direction of the power. Power will drop off, but not go from a rising curve instantly to a falling curve. Something else is going on.

Enough to make one wonder what the MAF reading is at that point.

No, they used a butt-plug probe and he has a cat. Essentially you can ignore the AFR graph.

Hey Rob I forgot to ask you in the email, what does the cat do for the readings?

rob wrote:No, they used a butt-plug probe and he has a cat. Essentially you can ignore the AFR graph.

Gotcha. That does change everything indeed.

How?!

Florin1 wrote:

LookAsubie wrote:Mod list? power/fuel mods?

curious so i can kinda compare to my car.

Yours? And what power did you put down?

I havent had my car dyno'd yet. But my mods are, 3" catless turboback, perrin MBC set at 11-12 ish PSI, stock vf11, 02 wrx intercooler, perrin lightweight crank pulley, short ram intake, wrx BPV and a walbro 255.

so i should be pretty close to the same numbers as you for the most part?

in the future i will be going either td-05 16g or vf39, 440's, jecs maf, and probably some better heads like people have mentioned. Im curious as to about how much power that setup will make. not sure what ill do about engine manegement yet but i have plenty of time to figure that out.

The measured air/fuel is not the true reading coming from your engine, since the catalyst is burning off some of that extra fuel and associated air. Depending on the catalyst used, the air/fuel reading could be off by one point or more.

ahh ok. thanks for clearing that up.

Yes.... BUT!!!!!!!!!

The AFR may be off a point or two.... BUT IT STILL MATTERS!!!!!

C'mon... Just look at the graph. At 5500 rpm, power takes a crap, AND AFR dumps rich, and boost levels goes even worse....

It is all connected. I suspect a shitty turbo/wastegate/MBC combined with a MAXXED MAF signal.

Yes Doug, it is connected. The posted numbers don't mean literal results, but trends still do have value. That sharp change says something is going on.

oh well, i'm not too worried. She's about to go under the knife. RobTune ECU, sti 520cc, vf22 externally WG, and hopefully a front mount. The boost controller will stay, unless you guys think there's something wrong with it.

i thought with rob tune you can use the stock bcs?