Just installed a 4.5# supercharger and i'm getting bad detonation after ~4k Rpms. I can get into it as much as i want below that and it runs fine. I'm running the stock tune now and the spark plugs, wires, and opti are all fairly new(maybe 10,000 miles). Still have the stock coil. I had a little bit of missing before the supercharger at the track in the same rpm's but it was hardly noticeable. At that time i was running a Hypertech Stg.2 Chip. I took that out after installing the SC. Any suggestions will help. I'm gonna get an MSD coil tommarow and put it on.Thanks
-Dennis

 

You may need to pull some timing out of your tune. If it's a stock tune, you may have too much. Also, you running premium fuel? If not, then do.

Ken R.

 

Always use 93 Octane, I just put an MSD coil on and it is still doing it. How would i know if the timing needs to be adjusted. I thought at 4.5# you could just run it and be fine.

 

my car was doing the same thing last night.. started breaking up above 4k.. felt like it doesn when i dont have my booster pump on... like it was running out of fuel but the pump was on and working when i got it home i installed my new A/F guage and its not leaning out with the pump on but today i didnt notice it breaking up it happened last night wile i was in a little race on the highway BTW im NA but im putting a 6psi SC on next week so im concerned about this as well plugs and wires are new BTW but i was thinking maybe opti

 

When my car was NA it had a little miss in it at the same rpms. So of course the sc is going to make it worse. I'm gonna change the plugs and gap the Plugs to .032 and try that.
BTW: When my opti went bad it had a dead miss. I don't know if that is what they all do.

 

You need to lower your gap, add more fuel (are you running an FMU or bigger injectors?), and/or adjust your timing tables.

Just realized you were running speed density... Yuck.. good luck



Mike

 

Bought new plugs, lowerd the gap to .035 and it runs great. Thanks for all the help guys.

 

cool ill try that as well.. i just installed new plugs about a month ago and gapped them at or just slightly more than .050 like they are sappose too be so im gonna get some colder plugs and gap them at .035 with some beefer wires and probably an MSD coil possible a new cap and rotor...would that be advisable too replace just a cap and rotor on an opti that should have around 190k but still runs good or should i replace the whole thing? im not very familiar with the internals on an opti

 

When i changed my opti spark i went with the stock replacement only beacause i was on leave and i needed it asap to get back in time. I just read somewhere that a hotter ingition system is bad on the factory opti, so I guess i'll be getting the msd soon. I think i'll probably just go with the cap and rotor from MSD. I dont know the difference between the cap/rotor and the actual msd opti. But i did read that it isn't that hard to do the cap and rotor though.