Hi folks,

Does anyone have experience with this cam in a 4.8 in terms of gains below 2500: https://briantooleyracing.com/btr-ca...-30202112.html Specifically what I want to know is how does it compare to the OEM cam below 2500?

I've looked and looked but all the tests/dyno graphs for this cam that I can find start at around 2700 RPM. The graph on BTR's website starts at 2300, but it starts the stock cam at 3500 so it's hard to compare down low. These two graphs do low-ish comparisons, but they don't go below 2500
https://www.motortrend.com/how-to/19...muscle-counts/

I'd just like some information on how the BTR will perform compared to OEM from 1400-2500. My vehicle is a 2004 Silverado, 4.8, with just cold air intake and true dual exhaust. I want to stick with OEM manifolds and OEM stall on the torque converter. Thanks!

 

Get an old MP112 supercharger

Or contact someone like comp cams and have them spec out a custom cam for your goals

 

The only way your going to see an improvement from a camshaft in the low end below 2500 is possibly with an NSR cam. A Stage 1 cam might do similar but they are designed to carry the rpm out not so much to make more low end power.

With that being said, There is no replacement for displacement. A blower would help as well with the low end.

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There is no "baby" camshaft that is going to make a significant change in a little 4.8 engine. I doubt you'll even feel the difference in the "butt dyno". Take these guys advice supercharge, swap to a 6 liter, or just let it be.

 

You will gain basically zero below 2500 rpm. Richard Holdner just tested the BTR stage 1 "truck" cam on a 6.0 and gained basically nothing below 3000 rpm. From there up it made more power. That was with more cubes. A 4.8 might even lose some power/torque down low. Your only option to gain down low HP & Torque is more cubes, or get a blower. Nobody wants to accept that and noobs continue to buy cams attempting to tow better. Gears are a better option than a cam only because it will put you in a higher RPM rage where the 4.8 is better into its power band.

 

here is a dyno sheet of a stock DOD delete cam and the BTR Truck Norris cam which is supposed to have the best down low torque and power of all the BTR cams. The dyno starts at 2krpm. Notice that there are essentially zero gains until after 2500 rpm. slap a blower on that 4.8 and be done. Buy once, Cry once.

https://briantooleyracing.com/btr-ge...orris-cam.html

 

cam motion has some small cams you might want to look into. https://cammotion.com/ls-camshafts/

 

Check out this thread on the LS1tech side about the cam motion . https://ls1tech.com/forums/dynamomet...-22rwtq-2.html

 

Hardcourt, if you can get BTR to give you the advertised (duration at 0.060), I have a copy of DynoSim I can put the cam into and compare to whichever others you want. Problem is I am pretty sure I already asked BTR for this info and they acted like it was a huge secret. I also asked many other of these popular vendors and they act like it is a closely guarded secret as well, which I personally think they like saying that to make you think they are selling some super secret advanced cam profile, since you can always just measure it yourself with accuracy with just a dial indicator when you degree it.

 

I had a copy of DynoSim (pc crash/backup fail/can't find original CD), and IIRC inputting both types of duration, but checking the 0.050 box for evaluation, yielded the most accurate results (I had the inputs dialed I could get the curves and peak values really close on not only stock setups, but most Holdener builds as long as they used a stock truck or pass car intake and accounting for the electric water pump). I think the program takes into account the lobe intensity, but then biases it based on which you choose as primary.

The BTR V2 of that cam is 252/252 @ 0.006". While you're at it, run it against the new Summit-8721R1 https://www.summitracing.com/parts/sum-8727r1. It has an earlier IC than the stock camshaft, but a lot more lift and similar overlap/intake duration. Also slightly more exhaust duration that the BTR, which will help up top with stock exhaust manifolds. It should beat both cams 1000rpm up (although I really question how accurate the program is below 2k).