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When I told you to ingnore the comment I ment the statement were I wrote about testing the A/F-ratio in your car. I dont know where I got the idea that you drive a viggen with Speedparts upgrade. Anyway here is some more info about the case.
I purchased a stage 1 up-grade to my Viggen from SpeedParts about three months ago. I ran my car in a local dyno 4.4.03 and here is a description of the problem what I encountered. The engine runs extreme lean at WOT (wide open throttle). We used a SUN manufactured four-gas analyzer to measure CO and lambda. CO reading showed 2 (lambda ~0.98) at 4500 rpms The information is not based on one dyno run, we tried to run the car several times both warm and hot but the result was always the same, engine runs lean. When I consulted the SP about the problem this is what was answered many weeks later:
"One can't measure the CO with a Sun, since it is too fast variations now (the curve on a diagram goes up and down too fast).
A broad spectra lambda should be used to get a proper meter of the CO."
I'm having a hard time believing that the given answer is the absolute truth. I know the CO measurement from tail pipe with the sun analyzer causes delay to the measurement and can cause some deviation, but lambda value showing almost one is out of the ballpark. When the engine starts to pick up rpms at WOT the CO value start to raise like it is supposed to do, but as the engine revs higher CO value starts to sink. We felt it was not safe to run the car any higher that 4500 since it was already running way lean. Behalf of the measuring device, the SUN analyzer applies the following. The same device has been used to measure CO's from Saab 9-3 aero (SP stage 1 package as well) and 9-5 aero (automatic with SP stage 1) in equal circumstances mixtures printed out normal in both cases (lambda round 0.85-0.89). The device is also used to tune many racing cars both rally and track. If one could no depend on the SUN values like SP claims in their answer, I believe it would not be used for racing engine tuning.
Since I did not get any further answers form SP, I tried to change some hardware in the car to make it run richer. I had an adjustable Fuel Pressure Regulator installed to the car. Now after raising the fuel pressure almost 1 bar I was pleased with the results, lambda ~0.85. Now the engine was running rich enough, but the dyno sheet did not print out the wanted way. From the attached graph [url]http://195.237.18.37/dyno/current.jpg[/url]
you can see, what happens. The waste gate starts to do a "pumping" maneuver at lower rpms, now when there are more exhaust gas is present and the set boost/torque level exceeds the ECU set value sooner. I know duping more fuel to the engine by itself is not the solution, there is also something wrong with the ECU software.
One another thing, both my car and the 9-3 aero will knock on high rpms in dyno. I know that the car has a instrument to control knocking, but I'm curious were the limit is set. The intake air temperature was 23 deg, not particularly high, so that should not cause the problem by it self. Also the acceleration in dyno is a bit slower that on highway and I know knocking will encounter sooner. I only use RON 98 fuel.
Tomorrow it has been three months when I complained about the product the first but no progress has been made. I have gotten several answers to my inquiries from SP, but they all state the one of the following:
"I need to discuss this matter with my colleagues"
"I hope to have answers for you soon"
"I'll get back to you hopefully next week with answers"
I guess the best way would have been not to test the product to begin with. I would probably be driving my Viggen instead of writing happily unaware of the time bomb that was ticking in my engine compartment. How big of a deal running lean at WOT really is? It really depends on the way you are driving and were you drive. For an average Sunday user who accelerates hard one or twice now and then wont probably notice that something is wrong. The engine will also tolerate this because the heat stress caused by lean running is only momentary. The same doesn't applies if you actually use your car for "driving", I did not buy the product thinking the following "all show not for go". I take my car regularly to local racetracks a have fun, where running lean is not an option. Also what would have happened if I had taken my car to Germany for holiday? My bet is that the engine would have melted less than 10min from departure on the autobahn.
posted by 192.89.9...
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![http://195.237.18.37/dyno/current.jpg[/url]](http://195.237.18.37/dyno/current.jpg[/url]){kind=link}