Is my belt slipping

**bandook** · 06-26-2019

picture host ru

There is some residue on the side of the overflow tank. And the MAP and calculated boost fluctuate a little on a wot pull, while my MAF steady climbs. Just looking for confirmation before I buy a belt from someone who's experienced this before. I'm running a 3 inch pulley and current belt is

653 - GTP/GS/SS supercharged with 3.1 - 3.5" pulley (65 7/8")

Should I drop to a 65 1/2"? That's the next size down but it's only 1/4" difference.

**bandook** · 06-26-2019

Sorry, formating got me again. Current belt is 65 7/8 from zzp.

Is there a good replacement I can get from advanced Auto or somewhere local? I've been searching for awhile but haven't found it yet.

**Scottydoggs** · 06-26-2019

those dots of some type of fluid are from a coolant or axle leaking grease, belt catches it and slings it. could even have a stripe under the hood.

**bandook** · 06-26-2019

Only thing leaking is oil pan. Slow leak. I put a smaller belt on it anyways.

Looking at one of your scans what does the MAP do at 100% throttle? I really haven't paid much attention to it because I had a 1 bar sensor on. I put the 2 bar just to see boost. I hit 14psi. But it kinda fluctuates up and down even though rpms are steadily increasing. Maybe it's normal, dunno.

**Scottydoggs** · 06-26-2019

you need to change a map setting or two when you swap the map out. best to get a sc file for your car and compare it with your tune.

**bandook** · 06-26-2019

Sloppy Mechanics Wiki - GM Map Sensor Identification - scale - offset - settings

Yup. I've been using sloppy's values for awhile. Even if the values were off a bit it shouldn't matter when it comes to fluctuating values at wot. It's probably just the nature of the m90. Also may be because I'm near the limit of a 2 bar map. I'd like to see someone else's scan, hint hint. It's all in fun, for education.