Joe57350

Check it out: Got a 98' GT: Got this from www.steeda.com

Steeda's Patented Timing Adjuster lets you advance or retard your ignition timing up to 10°, so you can tune your car for optimum performance. Advancing your ignition timing can net up to ten horsepower and better gas mileage. Supercharged Mustangs can also benefit by setting the timing back a few degrees, which allows you to run more boost and avoid detonation. We went the extra mile designing this part, to make sure it will fit with Steeda underdrive pulleys or Vortech and Paxton superchargers. Will not work with "piggyback" style underdrive pulleys. NOTE: May cause the check engine light to illuminate if the timing is advanced to more than 14° on 1999 and newer Mustangs.

Will my March U/D pulleys Part#1150 be good to go with the timing adjuster? And also, how will I know how many degrees to put her up. I know I need to turn the ignition over, after installation, and line up the gears, but how much advancement should I place. Will I know what the detonation noise sounds like?

jdaniel

On your car you can go up to 16 degrees advanced because your compression ration is a little lower than the 2001+. In 2001 they raised it to 9.4 to 1 so 14 degrees is the farthest you need to go without causing detonation.

Im not sure if the adjuster will work on the March pullies. I would call Steeda and ask them before you buy.

Detonation sounds like a pinging noise, kinda like rocks in a cola can but a little quieter.

Chopper

Do the pulleys have a dampener built in,or are they piggyback.If they are piggyback style you can't use a timing adjuster because the mounting holes will be used to mount your stock pulley and dampener to the March pulleys.You shouldn't use non damped pulleys alone or you could risk breaking the crankshaft due to harmonic resonance factors.