Target afr vs Wideband afr?

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Wade
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Target afr vs Wideband afr?

Post by Wade »

I've got the calc ve and ve table pretty close. But looking at the logs my Wideband afr vs target afr is still off.
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Dylan
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Re: Target afr vs Wideband afr?

Post by Dylan »

Definitely close for sure. How's it feel to drive? If you find yourself chasing your tail a bit have a look at the charge temp it'll be playing a bit here. Given the new intake manifold it'll need work.
Wade
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Re: Target afr vs Wideband afr?

Post by Wade »

Yeah it's not too bad to drive. I've found at cruise, it's surging a bit. I'd say it wants to be a little more richer at cruise with the 284 cam. I've also found that under acceleration it's running way too rich. I'm thinking I might need to start working on there ignition timing as I haven't done anything to that yet. I'd say your right about the charge temp to, when I cold start it's running rich till it gets up to operating temps than afr's come back to where they should be.
Wade
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Re: Target afr vs Wideband afr?

Post by Wade »

I'm working on plumbing the wastegate back into the exhaust at the moment. You can see in the log, when the throttle closes I'm getting a lean spike and I've turned dfco an de off so I shouldn't be getting that. Another thing I want to do before I play with the charge temp, is to relocate the intake air temp to where it was from factory.
Wade
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Re: Target afr vs Wideband afr?

Post by Wade »

I'd also like to fit an exhaust gas temp setup before I start playing with the timing
Dylan
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Re: Target afr vs Wideband afr?

Post by Dylan »

Bit richer at cruise speed can help but also lowering the timing can to. Low 30's at cruise can work well on a decent cam.
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Holden202T
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Re: Target afr vs Wideband afr?

Post by Holden202T »

without seeing other things like map reading and rpm its hard to say much about your lean spike on throttle close, it might well be its just going into a part of the map that you haven't fine tuned yet ?

I agree with Dylan, it could be too much timing making it surge, but also at what rpm is it cruising ? I did a 286 cam for a mates 304 and it hated anything under 2000rpm cruising, I did find though richening up the AFR's to about 14.2-14.4 in that area helped it a lot, being an electronic auto I was also able to change shift points to stop it upshifting till higher in the revs so it got over the areas it didn't like and similarly adjusted the lockup converter speeds the same, but you might not be in that position!

The 284 shouldn't be as bad, but if your around 1500rpm cruising its probably not going to be too happy there at 14.7
Wade
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Re: Target afr vs Wideband afr?

Post by Wade »

I'm running a th400 with a shift kit but will be putting in a manual valve body and transbrake. I'd say the lean spike is just the 60mm wastegate opening as it's not plumbed back in yet. Once I plumb it back in that'll rule that out. Surging is low rpm, I'd have to look at the logs again but I'd say between 1500-2500rpm. When it does it the afr's are changing between 13 and 14.7
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Holden202T
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Re: Target afr vs Wideband afr?

Post by Holden202T »

wastegate shouldn't cause it ....

upload a log of the issues and we'll have a look for you.
Wade
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Re: Target afr vs Wideband afr?

Post by Wade »

I'll have a lot ok when I get home. The rego is due on the car and I'm doing a bit more work on it now. So won't back into tuning it till after Xmas I'd say. After Xmas I'd like to get it running half decent than rip into putting the ignition module and ls coils
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