Trying to gain HP while remaining civilized.. Experience needed!

[CBVLS6]

I am looking to get a little more out of my V. The car obviously has potential but feels a little choked up. I am looking to put down around +400whp and would like to do so as quietly as possible, which is an oxymoron in itself.

I was wondering if anyone is running a header/hi-flow cats/CAI/cam/pushrods/tune on their stock exhaust to keep the noise down?

I am thinking with all of this I should be able to hit the mark and with what I have been reading so far about the available exhaust options the BB is the only one that may even offer a gain in HP. I am aware that at that point the stocker will be the most restrictive point in the system but I think with the header and new cats its tone should change dramatically.


NEXT..

Instead of the above listed options run a s/c instead. I am starting to become suprised by the price of all of these "small" upgrades and their collective prices once all installed and am beginning to think just waiting and buying a s/c system, wether it be a centrifugal style procharger, or a eaton/roots style blower.

Any opinions and experiences welcomed.


Thanks.


- Colin

[04CTSVFLA]

all the exhausts available for our cars add power. With a cam, your cars going to be dying to breathe. I believe your going to need an exhaust for airflow if your trying to go pass 400 with just a cam + bolt ons.

[rand49er]

IMHO, I think the hi-flo cats add more to the idling growl than either my headers or Corsa. At WOT, it's the Corsa.

I know some guys are supercharged with stock headers and cats (ronr), but have a Corsa. It's really pretty quiet until you jump on it.

The CAI is a worthless effort for our cars ... stock does good job. And, sorry, don't have any personal experience with cam, rockers, etc.

[darkman]

Originally Posted by 04CTSVFLA

all the exhausts available for our cars add power. With a cam, your cars going to be dying to breathe. I believe your going to need an exhaust for airflow if your trying to go pass 400 with just a cam + bolt ons.

I have been researching the question of whether power gains on the LS6 must necessarily include radical changes in air flow to and from the engine. At this point I am not yet convinced that either the air input system or the stock exhaust are all that restrictive. This is evidenced by the dyno runs folks have made available on CAIs, exhausts and headers. The relative gains are not significant. In fact, many of the "improvement" levels fall into the range one can see from two dyno runs on the same engine with no changes. I am not saying that better intake and exhaust are without benefit. However, I suspect (subject to some additional research) that one can get good gains with: a larger TB, better intake manifold, modified heads, a good cam (perhaps a solid roller) and a tune while leaving the induction plumbing and exahust system stock.

[CBVLS6]

Thanks to all for your replies.

I am just a little wary to go all out with the exhuast flow this early into the game. Every car I have owned until this point I have gone all out on and although they were sick fast, they were LOUD.

The CTS-v is the most powerful stock, yet the least powerful car that I have owned and I can tell that with a little work it could be a monster


I just want to do it right the first time and save myself the headache of wasted money and pointless endevours.

How effective are larger TB's and new intake mani's, from my limited knowledge I have gathered that the LS6 intake mani is quite sufficent for flow and what kind of gains could be expected with swaps?

[Luna.]

Originally Posted by CBVLS6

I am looking to get a little more out of my V. The car obviously has potential but feels a little choked up. I am looking to put down around +400whp and would like to do so as quietly as possible, which is an oxymoron in itself.

NOS is quiet...and you could easily get 400+ rwhp. No other mod needed. And it's cheap.

Originally Posted by CBVLS6

Instead of the above listed options run a s/c instead. I am starting to become suprised by the price of all of these "small" upgrades and their collective prices once all installed and am beginning to think just waiting and buying a s/c system, wether it be a centrifugal style procharger, or a eaton/roots style blower.

Any opinions and experiences welcomed.

A supercharger isn't necessarily quiet, especially from the front. It will scream, but that's the benefit of a supercharger!!

[Staxxin]

I had the exact same feeling and approach to modifying my V. I achieved a beast without compromising any amenities or making the car overly intrusive. It’s loud when you want it to be but during normal driving you have a nice low muscle car tone but not too loud- zero drown.

The setup I have is a Maggie, stainless works long tube headers matted with Random CATs tied to a Magnaflow catback.

My recommendation would be to go the Maggie route, you won’t be disappointed. The car can easily be a daily driver but it can also be a complete animal when you want it to be- just push the pedal a little more .

Good Luck on your decision!!

[The Tony Show]

Originally Posted by CBVLS6

Thanks to all for your replies.


I just want to do it right the first time and save myself the headache of wasted money and pointless endevours.

How effective are larger TB's and new intake mani's, from my limited knowledge I have gathered that the LS6 intake mani is quite sufficent for flow and what kind of gains could be expected with swaps?

If you don't want to waste money, forget the intake manifold and intake filter kit. The LS6 manifold flows fine unless you get a huge cam, which I doubt you'll do since you want to be stealthy about it.

A well chosen cam and Scorpion roller rockers will get you 400hp at the wheels with the stock exhaust and intake. The only other change you may want to make is getting rid of the factory intake tube that runs behind the radiator, as it has a huge divider inside it to keep it from crushing. Folks who have replaced that see 5hp on the dyno. You're going to get some cam thump at idle- there's no way around it, but this would be the least noticeable setup.

Headers, cats and catback give decent gains on these cars (maybe 30hp), but if you want a mostly stock sound that's the way I'd go. Find a local shop who specializes in LS series motors- don't trust a Ford or Rice tuner- get someone who works on 'Vettes, T/As and Camaros.

[wildwhl]

Keep stock airbox, drop in a better filter.

Maggie with good tune.

RT cats.

You're there.

WW

[HushH]

Yep, I'd have to say Maggie, even with the whine, will be the quietest way to 400+ rwhp.

[heavymetals]

Maggie, UUC shifter and a Steath tune.

All you need but not all you will want.

[StealthV]

...says the biased guy with TWO Maggies.

[heavymetals]

At least I use mine.

Some people think theirs is a canvas and they're Picasso.....

[Natedog]

Originally Posted by Staxxin

I had the exact same feeling and approach to modifying my V. I achieved a beast without compromising any amenities or making the car overly intrusive. It’s loud when you want it to be but during normal driving you have a nice low muscle car tone but not too loud- zero drown.

The setup I have is a Maggie, stainless works long tube headers matted with Random CATs tied to a Magnaflow catback.

My recommendation would be to go the Maggie route, you won’t be disappointed. The car can easily be a daily driver but it can also be a complete animal when you want it to be- just push the pedal a little more .

Good Luck on your decision!!

I can attest to this... it sounds like it would be a rediculous beast all the time... but it's not at all until you get on it

[wildwhl]

Originally Posted by heavymetals

At least I use mine.

Some people think theirs is a canvas and they're Picasso.....