Thread: Bad MPG question

Base timing is set correctly (i checked it like 10 times to be sure lol) and ignition timing is spot on at 15*, i was thinking about upping the timing a little but the factory has a small +- of 2 (according to alldata) and im petrified of detonation and with that being said i didnt know if the risk if detonation was worth the mpg im getting ya know? I was looking at the jk ecu but in my area theres only one place i really know of that will tune a b13 and they tune via nismotronic and thats why i was planning on going that route, the plugs were brand new, i tested resistance on the wires and they were spot on so i did not change them, as far as the cap/rotor they seemed in good shape but im prob just gonna put new ones on for the hell of it. What do u guys think about running a step or two hotter plugs? Do u think that would do anything? And i really appreciate the help u guys your the best and really helping me out here!

Actually DET's run about the same if not more timing then NA DE's. Thus when you are running an NA DE ECU with 8.5 compression without turbo, you pretty much need to increase your timing by 5* or so. Even 5* in timing makes a huge difference in power and in getting a more complete burn. If he wasn't getting a tunable ECU already, I would suggest just bumping the base timing to 20* and trying it out. On my DET I saw some good highway MPG gains going from 36* to 38-40*, so I think it is possible.

With 8.5:1 CR NA I would even run 20* base timing with 87 gas. Granted I would monitor knock sensor feedback like a hawk, but I don't think there would be much detonation at all.

@djt560 JKTuning ECU is the NismoTronic ECU. JKTuning is the company that started making NismoTronic software/Daughter boards for ECU's. Getting that ECU is going to be your best bet for a good tunable platform, you will probably be switching to a different MAF and injectors, which all require a retune.

Haha no wonder i felt they offered the same thing lol ok i will try out running at like 18* to start and go from there, thanks again guys youve been a huge help

When you get the ECU, set your base timing back to 15* and then you can add that 3* across board to have the same affect.

Ya im gonna try it out tomorrow, idk if i missed an answer somewhere but how do u feel about a step warmer plugs? I know with boost u want cooler, but i also heard somewhere if your low comp and no boost u want warmer to burn excess fuel. Do u have amy experience/personal opinions on this theory?

Make sure you get your oil changed. I ruined a GA16DE of mine doing the exact same thing you are doing. I would be much more petrified of gas in your oil than of detonation if you were to advance the timing - and you should be advancing the timing asap. No wonder you're getting terrible mileage - SR20 factory ECUs were never meant to be used on 8.5 comp motors

To be safe I would run 7's. But oem DET's come with 6's, if you wont run above 10 psi I think 6's will be more then fine. Also this will depend on your EGT's, timing amount, etc.

Ok 7's are in it now ill just keep them and bump it to 18 tonight and see what that does. Ive been doing oil changes every 1k just to be safe with this new motor and the oil has looked great every time (random but i did 11 oil changes and coolant flushes before the thing even drove a mile -___-)

What injectors are you using

Stock