Patrick G

iTrader: (14)

Actually, I didn't get to make any changes to my setup when I dynoed at MTI. But my timing is around 26 degrees at peak torque and ramps up to 29 degrees by peak hp. A/F ratio was around 12.5:1 at peak torque and 12.9:1 at peak power. Jayson didn't think I'd left much power on the table by messing with the timing or A/F ratio.

With more time in the future, I will tweak it some more. Then after my warranty runs out on my shortblock, I'm going to spray the bastard.

JakeFusion

iTrader: (7)

Pat, that's great, but I was hoping to see 420-430rwtq at 4800 RPM out of that setup with the high DCR you're running. Of course, it was fairly warm and you can still tune it a bit, and I might still have your October run in my mind somewhere.

Overall though, you've proved your point that a late closing IVC is not necessary to carry power to 7k. Moreover, it can be detrimental to low to lower midrange grunt, whereas optimized VEs create the nice power under the curve. I can only imagine what a larger cam on a tigher LSA with more overlap would have produced.

pianoprodigy

iTrader: (1)

This might be a bit easier to compare the curves.

Patrick, sometimes your RWHP/RWTQ number conflicted (didn't match the formula) so I used the RWTQ numbers (and let my spreadsheet calculate the RWHP numbers) since they are generally easier to read (more linear).

JakeFusion

iTrader: (7)

Ah, very nice.

Viper

iTrader: (6)

Thank you for the ability to test what many of us cannot! Great job Patrick.

SlickVert

iTrader: (5)

Awesome comparison!
Great power for such a small cam.
What effect would having a tighter LSA like 108 have on your power band and or advancing it to +2 or even +4?
Bob

Gearhead1

Ragtop, this is kind of embarassing for me to admit, but I'm 50 years old and I've only had my LS1 for two years. It's been a learning curve for me since I got this car. What applied to the old school cars I've had in the past, doesn't apply to the newer ones (generally speaking) It used to be that, as a rule of thumb on a BB Chevy, 1cc reduction in chamber size was approximately 1/10th of a point in compression. Does that also apply to the LS1's?? I realize that the LS1's chambers are considerably smaller and 1 cc would be a higher percentage of the chamber size when comparing the two. If I'm not mistaken, the chambers in the LS1 heads are 67.xx cc and the Darts are advertised as 63cc. How much will this raise the compression? Will it raise it to an appropriate level or should I run a different thickness head gasket to compensate?? I had planned on using the stock GM head gaskets, but I'm open to suggestions. Again, I apologize for not having gotten the proper software to figure this on my own. Thank you, Mark.

Ling_650vette

iTrader: (1)

Gearhead1, nothing embarassing about that. We're all here to learn from each other, and some people have more knowledge then others. Im 1/2 your age, and Im still asking ?s from people...nothing wrong with education!

Ive been monitoring this thread Patrick, and as others have said we all appreciate the testing you've done in order to bring about these results. Looks like your SOTP feel and guesstimation wasnt too far off from your dyno results. Sounds like a really impressive cam, and its results are showing exactly what you've been preaching

Ragtop 99

iTrader: (7)

I'm not that much younger than you. The 1/10 isn't too bad an approximation. With an .040 gasket that would put you close to 11:1. I'd take the 11:1 compression and design the cam to work with it.

At 11:1 I would not advance the 224/228 110 cam nor would I run the 109 cam. You could get away with 220/224 110 111 and have lots of torque.

gollum

iTrader: (1)

Damn Patrick...Judging by your testing, it looks like LOTS people in this forum are OVER CAMMED (low DCR)

Gearhead1

Ling_650vette, thanks for the moral support. We need more folks like you on here.
Ragtop, Wow!! 11:1 compression with that small of a cam. You couldn't do that in the old days without a big cam and lots of octane!! I guess I need to get on the stick and start researching a lot more. Thanks for the info, you know it'll be put to good use.

Patrick G

iTrader: (14)

Bob, a tighter LSA would have made DCR even higher and overlap even greater. The problem with advancing the cams on a 108 would be too high of DCR for my combination (at 8.73:1 currently) and too early of an intake valve closing point. Keep in mind, my IVC is a relatively early 43 degrees ABDC at .050", but with my overlap biased to the intake side of TDC, the motor pulls cleanly past peak hp and revs to 7000 with ease. It does not run out of breath. A 108LSA with +4 advance would peak around 5800 and would be out of breath by 6400.

cantdrv65

iTrader: (3)

Just noticed Pat, you have the same what appears to be valvetrain instability up high in the band that I saw on my setup on MTIs dyno. Maybe I dont have a problem after all....

SlickVert

iTrader: (5)

Thanks for the educations, that is what I was looking for.
Clearly, your combo power band looks awesome and pulls right up there!
The one we should all strive to duplicate.
Thanks,
Bob

xfactor_pitbulls

iTrader: (16)

Patrick, it sounds like your setup has done pretty well. Honestly I expected alittle more, torque or horsepower. 460/410 is strong, but nothing out of the ordinary. Especially being the knowledge you have in tuning and supporting mods. ****, my 231/237 put down 460/410. My 241 stage 2 head, I am shooting for 480/420 with a few changes. Do you think there is something missing somewhere?

Brandon

1989GTA

How does your dyno graph compare to Patricks? "Area under the curve." He is making the same peak power as you but with 7 degrees less timing on the intake. I think that is the point he is trying to make.

xfactor_pitbulls

iTrader: (16)

Alittle less up until 3500 same as the XE-R cam. I was just hoping for something alittle more dramatic, sure down at 2K rpms there is a large jump in torque, but it really descents by 3500 quickly. But, no doubt it is more fun on the street from a shotgun punch. It just doesnt take very long for a 4.10 geared car to get past 3500 rpms. I am actually going to change cams as well, just dont know which way I wanna go.

Brandon

cantdrv65

iTrader: (3)

My 228/228 XER cam and 237cc heads make 320rwtq at 2500rpms...

67SS&99SS

iTrader: (7)

Very Nice Numbers! Patrick, how would this cam work in a stalled auto? I imagine it would be great. Would a 3500 stall be about right? I am looking at cams for the future, and I really like the power band and torque curve of your particular cam.

Spinmonster

I think some people missed the point with gaining 16-17% at 2500 rpms. The peak power differences wouldnt mean much. It's a small cam. At the very minimum, he demonstrated how the math works in the real world. DCR, overlap, lift, valve events all coming together to do exactly as he predicted. In my book, the man met the goal.