Discussion Forum - Northstar Chevelle Club

Ahhh dyno day. One of my favorite parts of building hot rods.

This engine made 545 in it's last version- different dyno (in CA), different exhaust (open pipes vs. muffs), different headers (Schoenfeld race pipes vs. TPI's own Corvette pipes this time). Air wasn't great today either.

Anyway-

It made 540 hp @ 6,200 and 480 ft-lbs @ 5,500. Honestly, pretty much the same power as before (545 hp/500 ft-lbs). A couple horses here or there don't mean much when comparing coast-to-coast numbers.

So, I got back what I had before. Which is what I wanted.

But, I can't help but look at the dyno sheet and note a few things.

First- the flat torque curve. As I said, it makes 480 peak ft-lbs at 5,500. But, it makes 450 ft-lbs @ 4,200 and doesn't go below 450 until 6,400! That's some grunt!

Second- the HP curve. It cracks 500 hp at 5,500 and 530 by 5,900 before getting to the 540 hp peak at 6,200.

Third- the volumetric efficiency. The VE number is based on how much air is measured entering the engine through the dyno air hat fixture on the carb vs. it's displacement.

"normal" engines operate around 80 percent. Good engines creep into the 90s. Supercharged engines deliver over 100 percent because more air is being forced into them than would normally be possible.

My engine was recorded as reaching 100 percent VE at 5,000 rpm. It stayed over 100 percent all the way to redline (6,500), peaking at 109 percent at 5,900!

The quench and chambers are really good, and it only wanted 34 degrees of timing. We went further (up to 37) and it made no more power. Nothing to gain, so we put it back at 34.

Overall, I'm perfectly happy with it. It makes great power over a wide rpm range, makes a bunch of torque down low (we began testing at 2,600 rpm, and it made 356 ft-lbs down there!), and is perfectly smooth and crisp throughout.

I also have to recommend TPI Specialties. They're a great group of guys with top-notch equipment and many years of experience. If you've got an engine build in your future, they will deliver on time with the highest-possible quality. Cool dudes, too.

Okay- now I need to get all the accessories bolted up and get this thing back in the wagon where it belongs. I've got a big road trip planned and I want to get some miles on it before then.