Allen Vos

Hey guys, I'm wanting to give my 09 vette a little more zing, I want to leave the engine completely stock including the stock camshaft. I already have a Corsa Sport Catback exhaust system, and I'm willing to install long tube headers and an H pipe with high flow converters as well as a tune. I would consider a cold air kit if it would make a difference?

Realistically what is the most horsepower I could expect from these mods?

Also any suggestions on what tune to go with or who and what to tune it with?

Garymorris

There's about 10,000 threads on here asking the same thing. Best move would be to do some reading/research then come back and ask any specific questions you have. Otherwise, you're just going to get overwhelmed by endless combinations and opinions thrown at you buy people who may or may not know what they are talking about. Yes, headers, intake and tune are a good first step.

JerriVette

Id leave the headers alone. There is not much hp to be found with just headers, intake and tune.

your car tops out at 190 mph...zero to sixty in 4 seconds...

just install ethe COW booster.

do a search on that ...its 2 hundred installed...

if after that you want headers ...then go for it.

I would suggest a supercharger if you want more power...cost benefit on headers is weak.

jmo

Dano523

You can pick up about 10 HP by polishing the head ports if you want to go that deep (intake manifold is fine on the LS3), about 25hp with long tube header, and about 15 more hp with the retune.

All of which will not matter if TM is still hobbling the motor in instant torque, and running the soccer mom version of OEM throttle mapping.

Turbo6TA

Just to give you an idea ...

My bone stock 2011 GS / A6 made 371 RWHP ... The car has a Net HP of 436, so you can see that the A6 cars loose 15% HP through the drivetrain (436 - 15% = 371)

Then I installed 1 3/4" headers with cats and a dyno tune ... The car made 405 RWHP (34 RWHP increase)
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A cold air kit and aftermarket mufflers won't gain you anything to speak of as far a HP in concerned.

Turbo6TA

BTW ... The M6 cars loose about 13% HP through the drivetrain

Allen Vos

Did you find that the long tube headers killed off any low end torque?

saplumr

Hard to imagine what you’re basing this on. Headers and tune can easily pick up 30-40 hp.

JerriVette

Sorry i did not mean to insult anyones fine mods. I believe the hp increases on dynotunes after a header install and tunes are a little on the high side...

add in the cost of the headers, the install and the tune and i find the cost benefit ratio a little weak.

again..,jmo but if idid not want to crack open the motor...but wanted more power, id skip the headers and just to a supercharger...yes its cost is more but the end result is much more dramatic...

again...just my opinion and not one to insult anyone whose opinion is different...

peace out..l

saplumr

I didn’t take your statement as a insult. Everyone has their own way of analyzing things. Clearly some people install a blower of their choice and leave off the headers. To maximize air flow and power headers have to be installed...sooner or later.

HOXXOH

If all you want is a high HP dyno sheet for bragging, there are plenty on here to copy and photoshop.
However, if you want a real power increase vs a HP number, you have to start by defining your short and long term goals, the budget you have available, and most importantly, how you intend to use the car.
Without that info, you (and we) are just throwing darts in a dark room.

Allen Vos

Sorry maybe I should have been a little more specific,

I'll be sticking with the stock cam and stock LS3 engine, It will be staying naturally aspirated and I have no plans to open up the motor.

I will be putting long tube headers and and a Catted H-pipe. Just not sure what size long tube as I don't want to lose much bottom end torque if any.

Definitely a tune, again , not sure which one or who to get?

Also the COW thing seems like a great idea.

Money isn't a huge object but I need to be smart about it.

It sounds like with these mods I would be siting approx 475ish HP

HOXXOH

I doubt you'd be close to 425 HP to be honest. Stick with a local tuner, since they will be able to do what you need and have a reputation to protect. 1.75 tubes are fine for a bolt-on LS3 and almost everyone uses an X-pipe anymore. A true CAI will give you more WOT power on the street, but won't show much difference on a dyno.

There are several other things you can do for more performance, but without knowing how you intend to use the car, the trans you have, and the power you want, it makes no sense to offer additional advice.

Allen Vos

I meant 475 flywheel HP, 6 speed, street car, so I want it torquey

Spaceme1117

If you have the Z06/Grand Sport type intake, you have the best intake already. All Corvettes switched to this style of intake but I am not sure of the year this happened. If you don't have that style of intake, get a used one. Most other aftermarket intakes are a waste.

Headers with a tune will usually pick up about 20 to 30 hp/tq. And you will pick up most of that throughout the RPM range with no loose on the bottom end. Definitely get cats as it is the more responsible option, you won't loose any power, and straight pipes may be too loud with your exhaust.

The difference between 1 3/4 and 1 7/8 is negligible so most manufactures have standardized on the 1 7/8. 2" would be too big. But definitely get ceramic coating.

For a tune you can find a local dyno tuner. Or there are some very good remote tuners. I have used DiablewTune on several cars and they have all been great.

southofHoustonVette

The COW booster is 200 for the tuner then another fee for this and that. From everyone I have talked to it’s almost averaged to a total of 800 bucks to get everything done But if I use a local guy who tuned them it’s 550 and they tune it on a dyno and retune fee of 60-100 bucks after the first tune

Turbo6TA

None at all ...

bigron1212

Long tube headers, O/R X-pipe, intake along with a tune on a LS3 is proven for 30-50 whp/wtq depending on the tuner and dyno.

HOXXOH

A ported intake manifold will help with that. I went with V-Max, but I've heard good things about a couple others. A ported throttle body may give a better throttle response on an M6, but it made no difference in my 60' times, 1/4 mi times, or MPH with my A6. I'm running a high stall converter, so that might have softened the response.

The Vararam CAI will get you the coldest air on the street. Package it with a paper filter if you drive in dusty areas or those prone to sudden downpours that flood streets.

C5Natie

I went from 380rwhp stock to 420rwhp with headers, Z06 NPP mufflers, Corsa Pro5 intake and a tune.