86GT 347STROKER

New to this forum! Wondering if this issue has to do with a tune issue or not running a high enough fuel mixture.

Engine Specs: Stock Block
347 cubic inch 11.04:1 Compression Ratio
DSS Main Girdel Support
Eagle Forged Bottom End (+5cc pistons)
190cc 11R Trick Flow 56cc (ported)
Trick Flow Track Heat upper lower (ported/polished)
BAMA Tuned Piggy Back Chip (A9L computer)
TKO 600

I am currently trying to figure out the timing in relation to octane rating. I can provide all information that is required.

Buck Sergeant

Very nice package GT. I would start the timing at 34 degrees at "total advance." I would not go over 38 degrees total advance. With that compression I would use nothing less than 97 for easy driving, and 109 when making a trophy pass. As far as the hesitation/rich smell, I would check my spark plug gap, I like 45, set timing, and fuel regulator pressure.

86GT 347STROKER

I am currently running at 12 degrees base timing and the motor likes that sweet spot.The motor idels around 900-950 rpms. I am not sure of the “total advance” timing I am running at this point. The motor is definitely running rich, I can smell it. Currently running a mixture of ethanol free 91 and 100 octane to a calculated 94 octane rating. I didn’t want to go crazy and try straight 100 octane at first. The piggy back chip I have is set up for 93 and that was my fault for not giving the right information to BAMA. The plugs are Autolite AR3923 gap set at 45. Regulator set at 33 at ideal and 39-40 with vacuum line removed. Thinking my whole issue could be the tune and octane not having a high enough rating to resist detonation in the cylinder but not sure. Any thoughts are greatly appreciated.
Sorry for the long post just need advice.

Buck Sergeant

GT, I think we narrowed it down to the spark plugs. I use the 3923 in my 87 foxbody with 331 stroker, when on the juice. When not on the juice I use 3924 at 0.045. Maybe your plugs are slightly to cold? To set "total advance." Have someone hold your engine rpm at 2500, this is lock out, and then set the timing mark at 34 degrees. Everything else looks good. Also, I like the TKO 600.

mjr46

lol, I can smell it...............You're nose can not determine rich/lean especially if cats are removed...........have to run a koer test? the ecm will flag rich codes if in fact it is rich and if you have a wideband you can verify rich/lean and when it is/where it is at.

Buck Sergeant

86GT, good idea with the KOER test. While you have the lap-top hooked up, might as well do a KOEO to eliminate any other problems that are being hidden. Good luck hunting.

wbrockstar

If lean or rich codes are present,the following link might help you trouble shoot their cause.

http://sbftech.com/index.php/topic,29771.0.html

64bit

Found your problem.

Go see a real tuner.