LS-3 Lobe Separation Engine Dyno Comparison INSIDE!!
 

I thought it might be a good idea to go ahead & post just a little bit of the data we've compiled from testing camshafts in our LS3 engine dyno mule. For this test we ran our 229/236 LS3 camshaft with TSP intake lobe & XFI exhaust lobe using different amounts of advance & two different lobe seperations. These tests were done same day back to back of each other in hopes of shining some light on what LSA & ICL does on a LS3 based engine. We have data from other size camshafts doing the same basic changes, but this test was just completed last week so I thought I'd go ahead & post this up.

These two camshafts were identical other than LSA & the cams ICL was verified for every test. This is probably the best side by side comparison to date that allows guys to see up close exactly what the different LSA's & ICL's do to the power curve on a LS3 engine.

This is the kind of data that we're working hard to put together for our customers. Anyone who doesn't like the results please don't shoot the messenger, all I did was install the cam & hold the throttle down! :) :)

http://www.precisionracecomponents.com/229236.jpg

Differences Graph Based on RPM

http://www.precisionracecomponents.com/229236dif.jpg

Thats some pretty bad ass data. I watched jason do this same thing with their ls1 mule. Its a pretty sick set-up they had out there. Can't wait for the ls7 stuff.

Cool results. What kind of lift was the cam?

While there is some difference, in the grand scheme of things the differences are minor, especially when the drive train losses are included. Seems that some of the fretting over whether to get a 112 vs. 114 LSA that we see in some of the threads may be better focused on valve events and duration of the cam selection process.

It would be interesting to see the intake duration held fixed and vary exhaust duration to see how reverse split and up affects the power curve. Of course I am just dreaming up more work for you guys. :devil:

I have data going from single pattern to +10 degrees of advance. This camshaft has the split we'll be offering our customers.

Awesome work, the difference screen is something I wish we saw more often. Its soo easy to read, like zooming in, without zooming.....if that makes any sense?!?!?!

Looks like an 80hp gain, w/ no losses??? Nice!!!!!


(If you feel like it..... Open your 111+4 pull, change over to "Difference" and overlay another 111+4. The two 111+4 will lay over as the zero line(blue and red), and then open the rest of the pulls in the same order to align on the colors on both screen shots... Just making it a little easier to read.) :angel:

Engine dynos are great tools, as the other Jason (from Katech) always reminds us :)

In general, these results mostly fit the conventional wisdom that later IVC and more overlap will produce more top-end power. What's interesting is what's happening here in the midrange. The 113+4 and 111+2 have exactly the same intake events, but the 113+4 has a several ft-lb advantage through most of the range. Lower pumping losses due to the earlier EVO? Or is the additional overlap of the 111+2 interacting negatively with intake manifold and exhaust header tuning? Only cylinder, intake, and exhaust pressure traces would tell us for sure ...

you could use this data to tune vvt on the new engines?

Jason, I love the cam comparisons!!

I've got your 408 and LS3 CNC heads as well. I'm undecided on a cam swap as I still have my cam based on 243 heads. I'm going to the dyno FINALLY on Sat. I wanted a base line before a cam swap. I want to swap cams after the dyno tune. Couple things:

1. I asume with the higher CI in my case would produce some more hp/tq.

2. I assume these are flywheel dyno figures.

My goal is 500rwhp period, with good street manners. I think with my LS3 top swap I'll be close and maybe the cam swap would hit my 500 goal. I had 455/455 before the LS3 swap. I've done the following changes since that dyno run. PRC LS3 heads, TSP 1 7/8 LTs, CR 11.1, 4' elec cutout, new ls3 int stage 2 ported by fasterproms...If I had to est a dyno # I'd say 480ish.

So let me know your thoughts. Cam specs in my sig. BTW John R. specd the cam for the LS6 cnc heads I had. Its still in. THANKS!

Did you really install the cams yourself? ;)

Any way to repost this graph. I can't see it.

I second that. What a useful thread that must have been. I have done a lot of research on my next cam and find valve events and LSA and whether to advance or go straight up fascinating. Being a turbo app, I'll likely go for no split like 231/231 or if split somewhere between 224/230 and 228/236. I'd love a straight up 108LSA but the overlap would kill off boost power and driveability.... but the recommended 114 may be too lazy - it's hard to find that sweet spot

No graph showing here either. Would be nice to see, as it looks like it would still be relevant.

Since it's been almost two years since Jason's been on the forum, you might want to send him a PM and hope that the email notification reaches him.

KW

Same here. Very worthwhile thread :::eyeroll:::

You don't think so? It's only the graph we're after….