EGT & A/F Gauge Question - Honda Prelude Forum

jtrafidlo · 03-04-2003, 10:24 PM

The guy that tunes my car told me it would be a good idea to have a EGT gauge. I'm really not crazy about covering my cockpit with gauges, i currently have four. One of the gauges i have is an A/F gauge. My question is, is the A/F gauge worth having. I have heard that they are not very accurate and is not quick to respond (the reading is delayed). If it is not worth having i would rather replace it with an EGT gauge. Any help here please.

Also, on a turbo application where would be the best place to install the probe?

anubyss · 03-06-2003, 09:23 AM

A/F gauge isn't accurate because the oxygen sensor isn't. The gauge can be a quality one but if the sensor taking the readings is poor, then you can't get accurate info. I chose an EGT gauge over the a/f gauge. Just do some dyno runs with a/f readings and keep an eye on the temp gauge. After you have your base temps, then you'll know if you are leaning out or running rich. You tend to get hotter temps when you lean out and lower temps when you run rich. Just make sure you have good base readings first.

As far as placement goes, I put it right after the turbo. For most accurate readings, I believe it goes on the third runner close to the head. I put mine after the turbo just in case something happens to the probe and it breaks apart (never heard of this happening but just in case). This will kill the turbo if it's before the turbo. Placing the probe after the turbo will reduce the temp you see by a bit though.

Also for some comparison numbers, 1200F at 70mph and 1400F during boost is common.