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Alan L Alan L is offline
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Join Date: Apr 2006
Location: New Zealand
Posts: 3,261
A pressure gauge mounted on the WUR - for the purpose of tuning - is how you would normally set the mixture. Then you have the idle adjust mix screw for idle mixture. The AFR will give you the actual mixture, throughout the rev range. So if the idle is a bit rough it should show in the idle AFR. You can adjust then - but by ear when the engine is happy is as good a guide as any as the AFR various engines are happy with varies with engine. The AFR will show you the boost dump rich fuel mix also and you may like to tweek that using the Leask rpm switch - delays the dump.
The WUR mounted gauge (you remove it after setting pressures) also gives you cold pressure as well as system fuel pressure. You need that gauge to be able to set those. Trying to tune just on AFR if the other pressures are wrong may lead to tuning problems you can't sort.
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 09-18-2017, 06:35 PM
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