Fmax Stage II surge when over 6800...

Thomas Reynolds · May 25th, 2002, 10:08 AM

You'll have to excuse the cross post from SR20DEforum in another thread but I want to ask some people here about this as well...

When boosting at 10psi (which I just started doing a couple of weeks ago thanks to Greddy Boost Controller) I noticed last week that at about 6800-7000+ there is a surge dropoff of power. I didn't remember ever noticing it before, but on the other hand I don't turn it up to 10 very much. I have the stock ignition and also installed S3 cams at the same time as the controller and have new PFR6G platinum plugs gapped at .025". So am I experiencing misfire? I would've thought misfire would have been popping loud and very distinct, as I have heard other car's do on dyno's...

Frank Orozco was saying his was misfiring until they got the gap .021".

Boosterwitch · May 26th, 2002, 04:46 PM

Quote:

Originally posted by Thomas Reynolds

When boosting at 10psi (which I just started doing a couple of weeks ago thanks to Greddy Boost Controller) I noticed last week that at about 6800-7000+ there is a surge dropoff of power.

Is it an on-off drop above 6800 or does it just drop power above 6800?

You should try gapping the plugs down to .020 and see if it still happens.

Let me know.

Thomas Reynolds · May 26th, 2002, 06:56 PM

Quote:

Originally posted by Boosterwitch

Is it an on-off drop above 6800 or does it just drop power above 6800?

You should try gapping the plugs down to .020 and see if it still happens.

Let me know.

It only drops off it never comes back. It almost feels like you are overrevving a N/A B14 with stock cams, right about where you hear a funny valvetrain resonance like Jay Hassinger used to describe.

May 28th, 2002, 06:51 PM

Put a new set of irdium, or copper plugs in that sucker gapped down to .025.

Running a weak ignition will burn up plugs quick I generally have to replace plugs in my supra every oil change, and myu sentra isn't a whole lot better

.

I recently switched to iridium's, I love them! I can run about 2 psi higher boost with out any misfire or surge.

Thomas Reynolds · Jun 11th, 2002, 09:55 PM

Quote:

Originally posted by ktrends
Put a new set of irdium, or copper plugs in that sucker gapped down to .025.

I talked to Jim at JWT last week and he told me that copper, platinum or iridium would not make a hill of beans difference! It's all copper underneath anyway. Anything besides copper just helps with wear over time.

He really wanted me to throw a CONSULT on it and give him some data. Unfortunately the only one I am near is once a year at the convention, when Mike Kojima sometimes brings his.

Oh well. I'm going to Kansas next year, so maybe I can get to it then.

While I had him on the phone I also asked about the flat spot between 2-3k only when cold and he said 2 things.

1. Disconnect o2 sensor after its warmed up to see if I can replicate the problem and/or:
2. Get him CONSULT Data!!!