Afr's at lower revs

[gav2612]

Hi guys, just looking for some advice. Have a 96 1.8 with JR. supercharger. Bought it in the summer for hooning about in and track day use. It's running smaller nose pulley, fmic larger front rad and oil cooler. It runs well other than some dodgy idling which I'm pretty sure a dual tb set up will sort in the future. Now my question : AFR's at higher revs and WOT are in the region of 11.5 however below 3500 WOT afr's are only in the region of 13.5- 14. Is this too lean for a boosted engine, even for one at relatively low boost levels? Fueling is dealt with by an emanage blue using MAF so I have the ability to modify afr's. I'll probably go MS sometime soon to get better control over fueling and timing and loose the MAF.
Any help appreciated

[gav2612]

Thanks, Yes still at WOT. It's much richer above 3500 revs. Should I be aiming for similar WOT afrs lower down the Rev range as well then or slightly leaner than at redline?

[gav2612]

Boost levels are low at around 5.5- 6psi. Was expecting a bit more with the smaller nose pulley and spent a bit of time making sure the belt was tight and replacing the long routed intercooler piping with an over the rad job. Net gain was virtually nothing or .5 PSI if anything. Its an old original JR charger and if I can believe the former owner(no receipts) the head has had some flow work done and it also has forged pistons fitted. The exhaust is a stainless performance manifold and system with de- CAT, so all of the above may well lead to a reduction in backpressure bringing down the boost levels. Have an MS P&P lying in the garage which I plan to fit soon which will give me some more control and also more accurate boost levels than the current anologue gauge. Thanks for the help.

[gav2612]

Will need to check out the o2 clamp, would it usually be wired at the O2 sensor end or nearer the ecu?
From my understanding, it was only necessary when the car was in closed loop when the EMB wouldn't be controlling the fueling. Would it be closed loop at 3000- 3500 rpm WOT?

[gav2612]

Thanks guys, think you might have hit on the issue. Can't find any spliced wires between the O2 sensor and ecu. My next question then is, how to make an O2 clamp, or where to buy one if I can't? Did a quick google search, but all I could come up with was a user on one of the miata forums in the US selling home made ones. It's either that or I start over with the MS p&p I have sitting in the garage, but to be honest if rather not have the hassle if I can get it running ok with the EMB and O2 clamp.
Thanks again