I need some honest (non technical) feedback on the topic of adding a cam that provides the lopey sound we all love vs the drivability. Doesn't seem like I can get any "real" facts on this topic.
I am considering having a cam done on my 427 (LS7) this winter. I am constantly led to believe that in order to achieve that great sound there are inherent drivability issues associated with it, namely "surging".
The only (again, not technical) way I know how to describe it is in "Stages" (i.e. Stage 1 cam, Stage 2, 3, 4, etc..).
I don't strip or track my car, but want it for the sound, street driving and ocassionally "getting on it". I've never taken long road trips, etc...
It was recommeded to use a Comp Cams (Stage 2, actual specs n/a, but designed for LS7's), by my mechanic. He insists that with a more agressive Stage 3 (that will provide an even nicer lope) there WILL be surging.
Again, with no "technical" descriptions/answers (I'm not a mechanic) is this true? I listen to alot of sound bites from fb, youtube, etc... that have these great lopey cams (which are typically Stage 3 and greater I'm assuming). So do you mean to tell me everytime I hear a radical cam in a vette (or any car for that matter) these cars are strictly being run on a strip? I would doubt it. I need to, however, gain a better (again non-techincal understanding) of what is the break point of cam (great sound vs drivability).
What would be a perfect cam for a 2013 427 (LS7, obviously manual) that would provide great "lope" and still be drivable? Brand, spec?
Thanks so much for the feedback and info really appreciate it.

 

In general the better the sound (lope) the more the surging. I had a massive great sounding cam in my C6, however it surged all the way to 2500 rpms. I spent a lot of time tuning it and I liked it. Most would not put up with it.

It is a personal preference of what is the proper balance for you. Keep in mind that type of camshaft does nothing for your low end rpms. It does not improve your present performance until high in the rpm range. Great performance on the street requires a lesser cam.

 

Get out and drive some big cam cars. No one can tell you what is acceptable to you. Over camming a car is an easy way to ruin the car. Poor idle, surge, bucking and crap gas mileage just for sound is not a trade off I will ever do again. Had a big cam and never again. My tiny cam idles and drives like stock and I wouldn't change that for a car that sees the street.

 

What I did here. AHP 116 offers a little lope and great drivability

 

I've met too many people who modded the fun out of driving their cars, especially with big cams. I did a medium sized can in my C5. It was 227/230 651/615 111+3. It took the third tuner 3 weeks after I had to also add a 3000 stall converter to properly tune the car for daily drivability. Car sounded mean as heck with catted long tubes and Corsa Sports. It didn't buck but it hated being driven under 40mph. The car did shake at idle, 850 rpm I believe, and always felt like it wanted to launch. Would not do again for a street car. Just my 2 cents......

 

I actually went with a custom cam grind in my ls3
my cam is meant to be a smoggable cam,,,
many people here in Ca have this set up in their ls3/7 and love it ,,,
It has very little surge and drives great ...only issue I have is when im in cruise control the cam doesn't like certain speeds ..no big I just raise or lower the MPH .....
Side note this start was a cold start

 

It's a real mistake to chase that sound in a car that you want to keep running nicely on the street.

And the reality is that those extreme cams give up a lot of low and mid power over a more modest cam, which is how you will use the car 99.99% of the time.

 

Agreed 100%! Started with a medium sized cam and later went with a "blower" cam that is much more driveable.

 

rule # 1 if you pick a cam for the way it sounds.... you might be an Idiot

 

I have a Lingenfelter GT19 Cam on my 2007 Z06. Here are the specs: 227/239 duration @ .050 lift - .678/.688 lift with 1.8 rocker 114 CL

It has a nice, lopey muscle car sound. It is not too aggressive, but it is very clear there is a different cam on the car than stock, both when at idle and at aggressive throttle. Comp Cams grinds their cams and I would consider it a "stage 2" for your purposes. It is meant to be very driveable and I consider it mild to mildly aggressive. They also make a GT21 that is more aggressive and will give issues at idle. I honestly think the GT19 is perfect for the LS7. I have been on multiple long trips with the car, and no issues whatsover with noise, power or general driveability. I have little to no surging and at idle it is clear it is cammed but holds idle just fine and is not an issue at all. I am in stop and go traffic all the time and it is very "streetable". Press the "go-pedal" and she screams. Not sure if they are still grinding hem but you could give them a call.

I would be happy to take a video of my car at idle and with some throttle application if you like. The car also has LG Headers.

 

disagree. No might be about it.

A cam is a performance part not a sound part. Can shopping off YouTube clips is a sure way to make a stupid choice.

 

Contact Pat G for a custom spec'd cam. I have a 232/240 @ 112 in my LS3, C5 Z06 and it drives great. It all in the tune

 

stage2 blower cam from Arun@CCP here.226/238 605/615 lift @115lsa.not too big.

 

Can you guys describe what you mean by surging?

 

Car acting like you are getting on/off gas at either no throttle or light throttle. So you hold throttle at say 10% but it acts like you are going from 0-30% over and over again. So you have to put in the clutch, add more gas, or downshift to get out of that RPM range to avoid it.

 

Thanks Unreal. It sounds like these engines are very sensitive to low vacuum.

 

Here's mine with a 110º LSA/25º overlap cam.

I've driven it in New York, Chicago, Las Vegas and San Francisco with it. It does surge a bit at 1500 RPM's but I can live with it.

 

It isn't even low vacuum which is a different issues.

 

So what would be a threshold of a big cam vs a small cam? I'm currently running a 227/239 .629/.623 @ 114 and it's very drivable. I get a small amount of surge under 1400 or so, but not enough to worry about and the power added is well worth the minor hassle.

Where would a cam like this fall in the hierarchy for comparison sake?

 

I have done alot of research on this very topic and have come to the conclusion that around 8-10 degrees overlap is about the limit where you start to feel the effects of the cam on an 6.2L. From what I've gathered with a really good tuner a cam in this range will be able to drive very close to stock. When you start going a little more overlap then this is where you start getting some surge. Also the bigger the engine the more overlap it can take while still maintaining driveability. So an Ls7 can take a bigger cam then a 6.2 while still behaving.

Your 227/239 114 cam has 5 degrees overlap which is why it is very nice to drive. When I was going to stay nitrous I had a 230/238 113 cam which was specd by Pat G with 8 degrees overlap, which was about the limit of a nicely driving cam from what i'd gathered.

And of course there are some people who can drive a cam with 30 degrees overlap and call it "street friendly"