I just ran my new engine on the dyno and found out my AF ratio was off the chart. The AF was over 18 until around 4500rpm then it starter reading around 16 until we stopped the pull. I don't know how high it was because the dyno graph only reads 18 to 10 and the reading was pegged at over 18. I have a 11 to 1 383 with ported heads and a 306 cam 30 lbs svo injectors with a mail order tune. I made 336 whp and 356 torque. I spoke with the tuner and he said I should have nowhere near that much torque with an AR ratio that high. I was expecting 400whp and 375T with a AF around 13-14.
What is causing my AF ratio to read like this. Bad injectors or air leaks in the exhaust or faulty wideband. I was the first car to run. Non of the other cars had a crazy AF like mine.
I'm going to get in a wideband to see what the AF is. If there is a problem I'm going to put a bung on each header to see if I can narrow it down to one side of the engine.
I'd post the dyno graph but I can't figure out how to.

 

Sounds to me like something was wrong with the dyno's wideband o2 sensor.

 

Let me guess, you've got a ported MAF?

 

No ported MAF that I know of. I've only had the car for 2 years and it had alot of mods before I got it. I just remembered I don't have a exhaust gasket where the muffler bolts on to the over the axle pipe. Can this cause a higher air/fuel ratio

 

I hooked up the wideband today and everything is alright. My AF ratio was from 12-14.5 depending on throttle position. Thats alot better then the 18+ the dyno's wideband was reading out my tail pipe. Now its time to start tuning some hp out of this engine. I'm not happy with 336whp or the 356t.

 

Agreed you should not be happy. similar setup on my Hawk and I had 405 RWTQ and 365 RWHP. That was with a small cam that choked me at 5600 rpm. the CC 306 should put you to 400 RWHP.

BTW, you don't need a wideband to tune for AFR at WOT. I use it to confirm what I have already dialed in. Another thing on tailpipe widebands, the cat will increase the AFR reading until 3-4K rpm. After that, the cat can't keep up with flow and won't impact AFR, generally.