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The mkiv Supra Owners Club

AFR of 10, bad i guess


Fargo

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Guys, just fitted an FCON V (already setup for jspec bpu i understand) and at WOT im seeing an AFR of 10 (via aem) i understand this is not good correct.

 

At idle 14.7-15.4

 

Have noticed though since fitting the overall drive is better, throttle response is crisper.

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Isn't 10 the minimum reading on the AEM gauge ? therefore possibly richer than indicated which might not be so clever - you may benefit of datalogging (if possible) or perhaps dyno'ing to get an accurate AFR curve.

 

Yup, wont go lower than 10, it could be very rich, get it checked out.

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Sounds good to me - nice and safe.

 

You could see a V Pro mapper about it, BUT, you'd probably have to buy a whole new map as they tend to be locked down (or did you have it fitted?)...would the cost be worth it?

 

It's safe and it works...I'd take that!

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got it used from bolabag, have pm'd to see if its locked, have got an ex Tdi tuner available to remap at £80 an hour, from what he has told me hks dont support the fcon v due to age and comms issues, however they will do a deal on a newer version (rz i think he said or the newer IS version)

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Oh my god :blink:

 

Don't start it again until you get a base map loaded at the VERY least. Ideally get it on a trailer and take it to your mapper. It's insane to start it without even a base map for your injectors. You are very lucky you've not melted a piston, though a leakdown test is advisable after this.

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Doesnt running too rich cause bore wash overtime?

 

Bit of a difficult one that, in theory yes you would expect very low AFRs would cause accelerated bore and ring wear over time, but as far as the 2jz lump is concerned i.me not convinced, mainly due to my findings on front main seal/oil pump problems, as if the oil can be fuel contaminated enough for the oil pump to be worn, then how can compression and leak down tests show a good seal, yet a worn pump?

Also going on to other types of engines, and in particular V8 and older carb engines, which can run very low AFRs as std yet go on for mega mileages.

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10's on boost at over 5k do not cause bore wash but if it is running say 10's on cruise and idle when its warm then it will over time.

 

The stock setup runs 10's on boost just the keep the cylinder temps down as with the cats in place the cylinder temps will get very hot on boost.

 

Pretty much all forced induction stock setups run 10:1 on boost at the high RPM.

 

Damn Vauxhalls run low 9's after 6k on some of their models

 

Ryan

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