octane booster

[markaboo929]

this is a 2003 grand cherokee 4.0 with 10,000 miles on it that i used to replace my worn out 193,000 mile 88 renix motor.the 03 is controlled by the 88 renix ecm set up.i have retained the 03 tps and used an adjustable "map" adjuster box to compensate for the different linear movement on that tps as opposed to using and modifying the 88 tps to work.easier to just replace when needed-no messing with bushings and such.the reason that it detonates is that i have the timing WAY advanced from stock to get the power i like/want from this motor and that is why its pings.i know that this motors head design has smaller exhaust ports than earlier years-but i have mated a 99 exhaust manifold to it to get rid of the dual exhaust manifold design.well here goes for the mods i have made to my 88 renix ecm controls=an adjustable map sensor for the air fuel ratio,an adjustable map box for the tps.high altitude crank sensor that has been slotted for advancement adjustability,a crane hi 6 ignition system that includes thier recomended coil and 11 mm plug wires,an adjustable spark box for gm engines that has the same 5 volt square wave pattern the ecm uses to control timing via the ignition module,99 exhaust manifold that has larger tubes than the 03 exhaust ports,no cat,free flowing muffler(terminator brand from pep boys)i have header wrap on the muffler to stop my carpet from frying-yes i thought about it and determined that the wrapped muffler has increased the exhaust temp in the headpipe-which means higher head,combution chamber temp increase as well.today i have installed 1 heat range colder spark plugs(ngk)and like i predicted the slight throttle ping that i was experiencing has just about disapeared.don't forget that inceasing timing in affect increases compresion-sort of-but combustion chamber pressure.and creating additional chamber temperature.so the colder plug deal has worked.i think i will try to back off some on the additives now that i have found some interesting results from the colder plug heat range.i'll keep posting on the updates.if anybody is interested in the spark unit i am using let me know so i can help you set it up.