I have a 89 dohc zc in my crx I've been running a 50 wet shot and want to up to a 75 . My plugs look good every time i cheak um and oil looked good what do yall think the dohc is stock I'm running an 88 teg ecu not chipped and the plugs r to step colder ngks I took to deg of timing out and have full exhaust . The cats my dd and I don't want to hurt it bc its a new and strong motor but need advice stay at 50 or go to 75 thanks.

 

75 should be fine. keep your plugs clean and go colder if you want to be really safe and retard a little more. I would run some octane booster if you cant get higher than 91 at the pump in your area.

 

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