full exhaust

Heading out to first race of season here in Utah. This year I have full exhaust hooked up (3" dual w/ dynomax mufflers) behind my 545. Be interesting to see performance difference from open headers. Last May ran 11.13 - 11.15 @121.5 mph

If they are bullits you have about as good of free flowing exhaust as you can get. I'm sure it will pick up some if it is dueled all the way out the back because of the bends. My guess 1.5 tenths

I have them turn down in front of axle. They are the "angled " straight thru. I don't think they are the bullet mufflers. I also added small block front coil springs and tightened the rear shocks . Should be fun.

glenevans wrote:I have them turn down in front of axle. They are the "angled " straight thru. I don't think they are the bullet mufflers. I also added small block front coil springs and tightened the rear shocks . Should be fun.

Keep us posted................

Just got back (early red light ), car slowed down to run 11.27, 11.29 @ 118 - 119 mph. Never went above 120. About where it runs in 99* July weather.

Jetting time

Running 83 front jet, 90 rear (1050 , non-dommy 4150). Try 81 88 ???

4400 feet elevation.

Yeah I'd try down jetting like you said and watch the mph to see if it picks back up. Was the 60' any better or worse than before?

I'd expect it to actually slow down a tad as it did from open headers to full dual even with quality mufflers.

60' did slow a bit. I pulled a couple plugs and they were noticeably darker than usual. Went two sizes leaner main jets, three on idle and high speed bleeds. Next outing is the may 17 , see how it goes .

Also balanced front and rear tires, had vibration around 1000' mark. Was shakin' pretty hard.