the Holley intake will kill a nnbs on peak numbers. That's not his issue.

 

And the NNBS will kill the Holley everywhere else.

 

yes your correct, but not peak which seems what he is concerned about

 

I'm thinking the manifold isn't right for the combo. It's operating out of its "sweet spot".

 

 

Maybe you're right. That manifold needs more cam to put it in its ideal operating range. Is the rest of the valvetrain up for it? Or would a wilder cam put the truck outside of your comfort zone?

 

 

im calling bull. the new tbss intake does nothing but produce torque down low, and up high it produces a very very good amount of power.......where do u want to shift at? where do u need to shift? assuming ur never gonna need to tow anything above 1500-2000 pounds? in order to choose a cam and intake u need to know where you wanna shift........if ur not going above 6300-6400, sell that hi ram. i believe the new tbss doesnt really start to drop off til above 6500 surprisingly.

 

IMO the compression is too low for that cam. I’d knock the stick back ten degrees like a 218/226 EPS or Cam Motion truck cam
And pair that with the long runner factory intake/TBSS or even an LS6 will fully support your 400 horsepower desire.
I’m thinking you’ll gain 40-45 RWHP and turn 12.60 quarter Miles

 

I just looked at the torque curve.

I think it is beautiful. I can't tell how much smoothing is in it, but it looks exactly what you want to see. That engine is running well. 2500 to 6500 is great for a truck, you can't do much better cylinder fill consistency wise.

It may have a tiny bit more power in it if you spun it higher, but I think what you are really looking for at this point is global constants. I.e. compression ratio, fuel quality, intake air temperature, exhaust or intake flow potential to raise that entire curve up a notch. I don't see the cam as a problem because torque is still very flat near redline. I don't see the head or intake as an issue because torque is still very flat near redline. If the head, intake, or cam, were a problem to overall flow, torque would taper off near redline like factory does.


Lets re-evaluate from another perspective so you can get a feel for what info is in that graph. If you notice torque stays mostly flat. that means cylinder fill is fairly consistent through all rpms. It even has that slight peak region right in the center which kinda says "yeah I am degree'd properly too and this is my 101% VE region" It means that all of the parts are working together very nice to give nice full cylinders at each RPM. We don't know how full; if they are, say, 85% full, you have room for 15% improvement in Flow. This would come from exhaust or intake flow mods normally, but in your case I wouldn't mess with anything. 1 because it runs absolutely perfect and 2 because you might already be near 95%-100% full. Compare the torque with other engines of the same size and compression and transmission to get an idea of how full the cylinders are next if you can. If you find another couple engines with the same compression ratio and trans making 50+ more torque than you are then we start looking for a global variable as a cause. It wouldn't be say, a restriction, because restrictions to overall max flow in mass/time units do not limit peak torque, they only limit peak power. A restriction to flow would therefore show up as a high peak torque and a fast taper down- which yours does NOT do. It could be say, a cam phase issue or overlap related, limiting cylinder fill. You might pick up 50+ ft*lbs of torque if you advanced that cam 5* or something silly because it is off somehow with respect to its position. tell me you degree'd it?

 

Here is an example of what a high ram vs a LS6 looked like at 525hp on a engine dyno. The nnbs will be similar to the LS6. The nnbs will be a better intake due to the tq thru the curve but it will not fix your peak numbers if anything peak will come down a lot. Just wanted to give you an example before you go to the trouble of changing intakes and your peak numbers come down even more

 

after looking at that graph compared to his cam specs, I'm thinking maybe its his cam. now, i'm still a newb when it comes to cam specs but his 235 exhaust side looks way higher as compared to his 227 intake side on an NA setup?

 

always nice to see comparison graphs. however, thats a 525 hp motor, were only trying to get to a 400 hp motor right now. def not knocking u for putting up a graph, but the differences between a high ram and factory style intake are much less on a 400 hp build. if u have a 5.7 that makes 450 wheel with an ls6 intake, you slap an unproved fast 102 on there and u "should" pickup 18-25 depending. put a 102 on ur unmodified stock 310 rwhp 5.7, and u "should" get about 12-15. bigger motor will appreciate the fast more, just like a bigger motor will appreciate the hi ram more in this scenario. again, you do have a nice torque curve tho.

 

imo, the cam is a tad high on the exhaust duration. id say if he had stock heads it would be good, but ported 5.3s have a good exh flow so that much duration isn't really necessary unless ur spinning 7 grand. we need to find out when he wants to shift this thing to help us decide how this cam affects his desires.

also it may be time to look at the cam card and see when the valves are opening. i no comp has probably done a lot of ls testing, but id personally go with a company who spends most of there time on the ls platform. comp makes cams for everything so how do we know they sat for hours and hours making tweaks and seeing how it affects things. cammotion, tsp, btr, all companies that spend a lot of time around these motors. when i contacted cammotion about swapping out my cam, they saw a lot of improvements i could gain just buy bringing on the intake valve a little earlier compared to my current cam. food for thought, ur comp grind valve events could possibly be better. now that i think of it, ive personally never seen any builds that make super good power using a comp specd cam, then again u don't see a whole lot on here anyway

 

that is 525 engine hp not rwhp

 

doh. retract my statement. never new short runners made that much difference at those power levels

 

All things considered, I think that the torque seems really low. I'd start with diagnostics first to make sure the engine is healthy before throwing parts at it. Do a leakdown test and see what info your tuner has from the tuning session. Maybe even post the tune file for others to look at for any abnormalities.

 

 

what was the reason(s) for the cam choice and specs?

 

But you would be going the wrong direction if you spin the motor higher, and increase cam duration.

Right now you have a LOT of area under the curve. Torque might be low but you will find and fix the global cause. Swapping the cam for more power upstairs would ruin the area under the curve, specifically the 2500rpm cylinder fill region, in exchange for more peak power on the dyno graph, which you would barely ever see or use on the street in a heavy truck.