323i 126.9hp/94.7kW ATW dyno

[astondg]

I had a standalone engine management system put on my 323i a while ago and I didn't think it did much for performance and it was using a lot of petrol (usually 12 to 13mpg but last tank of petrol was 10mpg ). I decided to take it to another dyno place and get it retuned. I have just got it back and it is making 126.9hp/94.7kW at the wheels up from about 116hp when I took it there. Apparently the timing was out by 10+ degrees and I don't know why the mechanic that originally installed and tuned the computer didn't pick that up. That would explain why it felt flat up high, you can see on the before dyno that the power drops off fairly sharply.

This new place also changed the spark plugs and did a compression test:
1. 175-180psi (12-12.4 bar)
2. 180psi (12.4 bar)
3. 180psi (12.4 bar)
4. 175psi (12 bar)
5. 160-165psi (11-11.4 bar)
6. 170-175psi (11.7-12 bar)
Number 5 cylinder is a bit down but he said it was still ok.

Here is the dyno sheet, red is before and blue is after:
http://www.members.westnet.com.au/astondg/Dyno323i.jpg

I haven't been able to try it out much yet but I think it feels better up top, no noticable difference down low so far. Not sure about petrol consumption yet.

Almost forgot, I have the computer which uses a MAP sensor so the AFM has been removed and I have a full 2.5" mandrel bent exhaust and a 6 branch. Otherwise the engine is stock and at about 260,000km (161,000 miles).

Comments welcome. And if anyone has any idea how that compares to a 325 or 323 and also what that power would be at the flywheel that would be good.

EDIT: Note that the torque measurements are in lb (tractive force) not lb-ft.

Aston

[tomstickland]

Fuel consumption should be a lot better with the cam timing corrected.
Power is 130BHP at wheels, that suggests about 150-155BHP at flywheel (15-20% extra).
What is the std 323 figure?

TBH I think you'd be surprised how little difference exhaust tweaks and air flow meter removal make on their own.

[astondg]

Standard 323 is 150hp. So it's only at standard power which is about what I worked out using a 15% loss (I know percentages aren't great but it's all I know). Not so great because I think the zone chips give 5 to 10hp? Still better than it was. This tune cost me 320 pounds though just to get back to standard power .

Aston

[tomstickland]

Well factor in rolling road inaccuries etc, you might have a bit more than standard. I was reading in one of the BMW magazines that they had trouble getting book power from the 323.