Very nice! Thanks for takign the time to type that otu for us!

 

Patrick,

Great writeup! Are you going to have any detonation problems with that high DCR on pump in texas heat?

That seems like a lot of DCR with low (relatively) overlap for 93 octane and 28 degrees WOT timing.

I am sure you'll get it tuned spot on but I am curious as to what you think?

 

Hm, what do you think about this cam in a 408?

 

Damn if it does that well I will be very impressed.
Looking foward to the results.

 

Chris, I'm going to be doing a lot of heat-soak tuning this week to see how the motor does with its current timing. I have a feeling it will probably be a little happier with less timing once my IATs start getting above 100F.

First thing I am doing is the VE tuning. Get this: I've had to add around 20% VE to my numbers up to 2800 rpm. After that, it starts getting closer to my old numbers. Basically that means I'm flowing about 20% more air at lower rpm than I used to. That's torque you can FEEL! Right now I've been doing driveability tuning. Next I'll do WOT VE tuning. After that I'll do the heat soak tuning. Then I'll do WOT tuning one more time. Then it will be time to dyno. After that, track times. Just don't expect them all in the next 2 days, LOL.

 

With all of your Torque cam info and AFR head flow chart for 225's plugged into desktop dyno, it shows peak hp @ 519 @6500 and peak torque @ 494 @ 4500 with a very high torque average across the board. Not real life but it all sounds reasonable to me.

 

What does this translate to actual rear wheel power numbers?

 

Subtract around 55 hp to get rwhp for an F-body with M6 and stock 3.42 gears. 464 rwhp/439 rwtq...hmmmm....might be close.

 

Patrick, good luck with the new cam! Torque is fun! When are we going to build a stroker - a ton of torque, and very driveable! The bigger motor will only compliment the killer small bore AFRs even more.

Jason

 

wonder what the numbers will look like

 

I saw when you mentioned this cam in another thread recently and didn't think you'd get it in this soon. I think this will be a great cam for us daily drivers who don't see much track time.

 

Pat, why not a diffrent exaust lobe like the T-rak? Just wondering how the softer exaust lobe plays into the equation. Something like a LSK intake, but a XE exaust. Of course keep the .200# similar on the exaust. Like a 223 LSK intake and a 234 XE exaust. .149/.150 would be the .200". This would split the .006" and the .050 by 10-11 degrees, but keep the .200 numbers close.

 

I wanted to maximize the curtain area on the exhaust and keep overlap in check. A 224/234 110LSA cam would have had more overlap at .006" than my current cam. That's why I chose the LSK for the exhaust lobe. Interestingly, Thunder Racing recently made a 223 LSK lobe intake with a 234 XE-R exhaust and mated it with ETP 215 heads. The car made excellent power, even with a wide 115LSA. https://ls1tech.com/forums/dynamometer-results-comparisons/477761-etp-215-h-c-results-pictures.html

 

Tuning has a lot to do with idle. You can tame down a cam by raising the idle speed, adding spark advance, and throwing some fuel at it. In fact you'd be amazed at what you can do with proper idle tuning.

By the same token you can make a stock cam sound choppy if you know how to play with your tune.

BTW, I'm with Patrick on his cam selection. A lot of folks go for peak numbers. They fail to realize what their car is going to be used for. I.E. The max effort H/C car I drive has one use, to go really fast in the 1/4 mile. So, its optimized for that.

Many folks chase that big peak HP number and don't look at area under the curve which is what Patrick, I, and others have been preaching to you for years.

Overlap is power. Many folks are afraid of overlap, but with proper tuning, and the proper ammount of it, it can be your friend. I think many folks would be much happier, and go much faster if they'd tone down their combo.

Let me give you a prime example:

I've got a stock 2002 Z06. If I were going to do a combo for it, I'd want to keep near stock drivability, and not sacrafice the car's comfort in the quest for a couple of peak HP that I'll only use at the dragstrip.

So, I'd look at
AFR 205's
FAST90 / GM90MM TB
Stock exhaust
Crane rockers

For cam selection I'd look at something along the lines of something probably a bit smaller than Patrick's. In fact many of y'all would probably call it a "truck" cam, but it might even have a ton of overlap, and a fairly narrow lobe sep... Keep in mind the peak torque of the Ls1 is around 4800, and the intakes run out around 6200-6500. Yes you can spin them higher. But look at all the dyno sheets and see how they plane out. If you start maximizing area UNDER the curve you'll go faster, even with less peak HP.

Again, its all about what you want to do.

Repeat over and over again... Combination, Combination, combination....

Good work Patrick. Keep us posted.

 

The street tuning is going very well. It's incredible how much power under the curve this cam has. With 245psi of cranking compression and 8.73:1 dynamic compression, I've had to carefully tailor my timing tables to stay out of knock. So far, here is what is working with 0 kr:

4000-4800 rpm: 28 degrees
5200-5600 rpm: 27 degrees
6000 rpm: 28 degrees
6400 rpm: 29 degrees
6800 rpm: 30 degrees

My VE tables are highest between 5200-5600, so it makes sense that this is where I'm most vulnerable to detonation. So far so good. I will report back as I get some more numbers.

 

Have you checked to see if it needs that much advance? I'm just wondering if you'll see the same HP with only say 22-24 degrees of advance?

 

i dont think he's dyno'd it yet to work on tuning the timing. Pat you've got me thinking about trying to custom tailor my cam for more of a DD type cam. I think the lift is a bit to excessive for me, but somwhere abouts a .610-.615 should do it for me...now for a duration cant wait to see track numbers.

 

No Jarrod, I'm only exploring the upper limits of the timing at the moment. Once I know the maximum amount of timing the motor will tolerate on the STREET, I will then adjust the timing down on the dyno to see if it makes more power with less timing.

FWIW, with my TRak Cam and the 234/238 XE-R cam, the motor made more power at 30 degrees than it did at 27, but we're only talking about 2-3 rwhp more. When I ran the Texas Mile, I gained 1.5mph by going from 28 degrees to 30 degrees. When I turned it down to 22 degrees, it lost 5-7 rwhp on the dyno. But with this new cam having so much cylinder pressure, I may find that the motor is happier with less timing. Can't wait to get it on the rollers to find out.

 

How would you change the cam specs for a 62cc AFR 205 head and completely stock exhaust?

850rpm idle, emisisons legal and pump gas?

 

since chris is asking, how would you make it work on a stock head (ls6) motor? full bolton? id like to get an idea of how you'd work it. emissions arent too much of a concern as lift...615 is the max id like to run.