dynoed 93 I/H/E

[chriswtx]

I dynoed my car this weekend and am quite happy. Anybody know why it runs so lean? I even moved up the fuel pressure by 10psi. Is this normal for a NA car? My mods are listed plus colder thermostat and timing set at 18deg BTDC.

 

[KGP]

I'm far from knowledgeable on AF, but your chart looks whacked. If stoichiometric is ~14.7:1, your reading shows fuel starvation. What kind of sensor was used and where was it located?

 

[chriswtx]

yeah, I was begining to question the A/F line also. It was a dyno day with a bunch of other people waiting so I did not question it. They may have had problems with it. My plugs dont show any signs of running lean.

 

[sjs]

Yep, it looks wrong, especially given the very nice power curves. Might be interesting to check the charts from other cars after you that day. Perhaps the sensor ingested some oil. Ben's car choked mine when a turbo seal failed causing the sensor to drift leaner and leaner. Another possibility is an exhaust leak allowing fresh air into your pipes ahead of the sensor. Too bad you couldn’t try from the other bank once.

 

[ctnsupra1]

It's odd that you're running lean like that. I wouldn't think you'd need more fuel (i.e. a bigger pump) but the A/F says that you do. be careful though, you're car will run real nice when it's running lean. Coming from many turbo cars, they've never felt faster than when I was running lean and then you go and melt something... Just try and get that A/F down to 13.5:1 to 12.5:1 (at least I think that's what NA engines tune for).


Conor

 

[chriswtx]

its got to be a bogus A/F line(problems with the sensor). The plugs and exhaust tips show signs of plenty of fuel. Even more sense I added 10lbs of fuel pressure...

 

[NetViper]

Did you DYNO the car before the mods? Those numbers are strong for a 93...

 

[chriswtx]

I bought the car with the mods. I just did some fine tuning and added cat replacement pipes. I am going to dyno it again in april on a different dyno to compare two different dynos at the NSXtexpo gathering in austin. The only change may be the addition of a Tiatec GT exhaust. Hopefully I will have the same results or better.