thunderstruck507

iTrader: (18)

They were also testing mostly stock cams meant to go in cars in that test I believe.

I am running Kip's drop in 205/210 5.3 cam which on paper looks a lot like the old ls6 cam but it was designed to properly work in a truck rather than a lightweight sports car with a manual transmission.

With a stock stall and stock gear it still feels snappier right off idle and by the time the converter is fully engaged around 1800rpm it feels noticeably stronger and continues to build from that point and peaks around 5500rpm but carries out well.

A mismatched cam of any size will lead to subpar results IMO. I do not feel I would be nearly as happy if my truck had the ls6 cam as I do with the truck cam.

kinglt-1

iTrader: (26)

I believe all tests were done with a 5.3 LM7 utilizing the truck intake.

The crane 200/200 showed no loss below 2500 and +14 by 3500rpm.

The 210/218 had a loss of -10 @ 2500 and -9 @ 3500.

Here is the article if you want to sift thru it.

http://www.hotrod.com/how-to/engine/...st-comparison/

poltergeist 02

iTrader: (65)

There is nothing wrong with the ARH ORY. You can actually ask them to put a 3.5" outlet on it for no extra charge.

kinglt-1

iTrader: (26)

I agree there is nothing wrong with a ARH ORY... I was just mentioning a list of things I would consider in a build if using a max effort cam like the Hellion.

Pharcyde50

iTrader: (11)

The Hellion would do well with some 4.30 gears also. I'm running a 234/242 with great results torque 447 peak and 350 at 2500 rpm. I milled the heads and decked the block to up compression.

scotty2000ss

iTrader: (2)

Are 4:30s available for the stock 10 bolt? Is that even a good idea lol

When comparing dyno results to different gear ratios how much is lost when having lower gears?

redbird555

iTrader: (14)

True but you have a 370 thats 24 extra cubes and it makes a big difference. I agree with everything else though, although 4.30's are like glass in a 10 bolt.

You can usually subtract 5-7 for high ratio gears. And yes 4.30's are but they are REALLY weak I would go 4.10s. If the rest of the car is built right then 3.90's to 4.30s or anything in between wont matter a whole lot. I'd focus on getting the compression up into the 11.5 range and porting some 243s or aftermarket heads

99Bluz28

iTrader: (35)

I think part of your problem is focusing too much on dyno numbers. How many other dyno have you had it on to compare your initial hp/tq dyno graph to ? Your also running a very large cam with stock SCR which normally equals poor low-end power..Why..? Because with that cam the IVC is at least 50-52* , and the DCR is likely under 7.5, and you really need better flowing heads with a cam that size. here's what I'd do, send the heads off to Advance Induction for their High CR 219cc Full CNC Porting Package. With at least a 11:1 SCR and the improved flow from the cnc porting you should see a nice bmp in hp and tq. I'd also get a set of 4.10 gears in the rear.
Keep in mind that (with all else being equal) a larger intake duration will always push the power-band up higher in the rpm range and as a result low-end power will suffer. The only thing you can do to keep the power-band lower to a limited degree with out going with a smaller intake duration is to have the cam ground on a narrower/tighter lsa , and have more advance ground into the cam or advance it with a adjustable timing gear set.

scotty2000ss

iTrader: (2)

I've been on the same dyno after every mod I've done to the car. I don't have the luxury of taking the car anywhere else nor would I seeing I take it to New Era Performance (:

It's hard not to get caught up in the numbers seeing after I put the cats on I was down almost 12/15 with that cam. But now after someone pointed out with that much overlap on the cam, I run the risk of damaging them. I'm yanking them off and can't wait too see how the car reacts with all the winter mods.

patSS/00

iTrader: (6)

This info has sort of disappeared over the years.
I didn't know the 01-02's had a slightly smaller cam, they also had a lot less spark timing across the board which is not what I'd expect from the smaller cam. Also they must have had bigger .006 durations to get the overlap to get rid of EGR that 98-00 had.

big hammer

Necromonger

JakeFusion

iTrader: (7)

I can't believe I never posted in this thread back in 2014.

Lol.

That Hellion cam with Cats, low compression... no supporting mods. Yeah. I can see it being a giant dog turd.

But for anyone wondering, a very late IVC will contribute to terrible low end. As will excessive overlap. You can't build cylinder pressure if all the intake charge is being pulled through the exhaust at idle or reverting burnt fuel back into the intake manifold.

For anybody looking to make torque... in a 5.3L keep the IVC around 36 degrees to build cylinder pressure and bring the overall peak HP down a few hundred RPM. And the 346 would be around 40 or so. Then you set your EVO properly to carry power past peak or to enhance the torque peak. And that relies on the cylinder head exhaust efficiency, the exhaust valve, the headers, and exhaust itself.

The intake is fairly well set with the plastic manifolds. Their harmonics create a 4800 peak torque and 6300 peak HP number. So trying to push the valve events too far away from those ends up with dog turd performance. In either direction.

But let's take a balanced set of cam events for a 347. That peaks at 4800 with torque and 6300 with power. Carries it out nicely, but generates a lot of off-idle torque. What would that look like?

Well an IVC of around 45 in a 347 creates that 6300/4800 peak with an EVO of 55 carrying it out another 500 or so RPM while maximizing torque as an example of creating a profile that makes power everywhere. And there's many ways to get there to create the total overlap wanted (which affect drivability and performance). More overlap means more power at the expense of being able to drive the car. But all of these profiles would generate similar cylinder pressures with the same compression.

The overlap and the IVO/EVC tell us where those cylinder pressures occur: higher overlap and overlap that biases toward the intake makes power later (but may not move the peak - just carry better), whereas lower overlap that biases it toward the exhaust will make a little more torque down low (but retains similar peak torque and peak HP RPM areas, but would fall off up top faster). And if you center your overlap you'll make good power everywhere without enhancing or exaggerating either end of the powerband. But then the trick is to get the overlap right for the power and drivability desired.

So what about the 45 IVC and 55 EVO combo? Here's 5 cams that produce the same valve events. We now can play with IVO and EVC to get the duration/LSA needed to achieve a stated goal.

240/248 108+3 28 degrees of overlap biased toward the intake - monster cam that produces explosive topend
234/242 111+3 16 degrees of overlap biased toward the intake - top end screamer
230/242 112+3 12 degrees of overlap biased toward the exhaust - explosive midrange
226/234 115+3 0 degrees of overlap balanced - excellent street manners and good power everywhere
224/224 118+5 -12 degrees of overlap biased toward the exhaust - stealthy with a lot of torque

All would work best with 11.5:1 CR assuming using the same lobe (50 degree .005 to .050" ramp rate).

That's the best way for me to describe how you can affect torque and drivability using different cam profiles. And all would peak around the same 6300/4800 range in the same motor. But would drive differently and either carry the power out longer as with the two bigger cams or generate more explosive midrange or lowend grunt with the smaller cams. But again, that's with the same IVC/EVO. You can play with those to get huge swings in performance too.

So as the last example, a 42 IVC cam would need less compression. So it may not make more torque than the smaller cam above with more compression. So it comes down to what you want. Maybe you want a chop in the idle and don't want to run high compression? Or you have a 5.3L? Then move the IVC down to get the cylinder pressure building early. And go through the same exercise again to set overlap how you want it to achieve the outcome you'd like in terms of drivability and where the power comes on the hardest.