Changes I did from last dyno (546rwhp on a dyno dynamics) and times in sig:

LS3 valves turned down
New valve guides
Went from PRC .650 springs to PRC .675 springs
Ported the super Vic to match the PRC 237 heads
Electric Water Pump
E85 vs E48
Morosso 4-vane vacuum pump



7:30 go to get my little 9x5 trailer off the wife's TBSS. As I am backing up following the trailer, I was looking over my right shoulder instead of using my mirrors, met my 67 Lincoln vents bumper right where the drivers door meets the front fender.

Get the truck loaded, finish up a couple little things and head to the dyno.


Get to the dyno and the tune is pig rich on the 1st pull.

2nd pull lean it out a bit and look at the vacuum gauge and it looks like it is pulling 14ish inches, made a little more power but still super fat.

3rd pulled leaned it out a little, go WOT and a plum of smoke from the engine bay. Felt fine and figured it was just the vacuum pump pulling oil mist from the crank case. Not quite. Get out and the vacuum pump belt looks half melted. Pull the belt off and the vacuum pump doesn't rotate. Pull the fittings out and notice one was just a bit too deep and tore up all 4 vanes. There is money going in to a rebuild.

Pulls 4-9 lean it out and add a pinch of timing in it. Get to a point where i don't want to put more timing in it and feel comfortable with the AFR but power is not what I am expecting. Lst dyno made 546rwhp (dyno dynamics) and today I am at 476rwhp on a Dynojet.

Pull 10 I decided to try these new plug wires I got. Granatelli has a video on LS1tech where a wire swap on a blown 2010 Camaro made 20rwhp, put the stockers back on and lost 20rwhp. I laughed about it, but figured they have a lifetime warranty, look decent and are double wrapped in burn resistant material. Sure enough, more than 20rwhp under the curve and 20rwhp at peak. 495rwhp.

Pulls 11-12 I left everything alone but uncorked it. Thought maybe that is where my missing power is. Never before have I lost power uncorked, including tq under the curve. Even last time dyno'ing this same motor with same exhaust. I can't believe my eyes, lost 25-30rwhp on both pulls.

Pull 13 I corked it again through the really crappy exhaust and my power came back. How can 3" necked down to 2.5" through turbo muffles make more? I can't figure it out.

So.. Dyno to dyno, I am down 51hp. Only good thing is it carried power better, it doesn't fall off a cliff at 6,700.

I did not put the 1.8 rockers on that I have.

Pic shows the wire swap.


Something just doesn't feel right to me.

Combo:
13-1cr 418
PRC 237 heads
254/260 .630/.625
Super Vic
Edelbrock 1 3/4 stepped to 1 7/8 headers

 

Yeeszh buddy. The good news is that you'll likely go a bit faster down the track regardless of the dyno numbers and there is more power to be had in your combination. What's the lobe seperation, cam advance, cutout location, and primary length/collector size?