bigsteff

I need recommendations for achieving 450 rear wheel hp from my currently stock Grand Sport! From what I can gather, it should dyno at 365 - 380. I want to achieve this with bolt-ons and minimal expense. Can I get there with just headers and a tune? The car is an M6 with the NPP exhaust. All advice is appreciated.

BadAV

You will never make it with only headers and a tune; that may net you 40-50 hp. Add a fairly aggressive cam and you have a chance.

Mcrider

Headers with X-pipe should get you 35-50. A dyno tune should unlock another 50. You could add a RAM Air Cold Air Intake like the Vararam Snake Charmer but that will not show on the dyno since it needs movement to generate additional horsepower. Larger throttle body will give you a few ponies as well.

KW Baraka

450hp to the wheels?

You will need EVERY possible bolt -on....and you'll still be a bit short.

Get every possible bolt-on and a medium cam and you should hit your goal in good style.

KW

Omega Doom

nitrous and be done with it lol

Omega Doom

or do long tube headers catless Xpipe muffler delete, UD Pulley, Vararam or Halltech CAI, Fast 102 or GPI rod modded LS3 intake with a NW 102 TB and have it drynoed and tuned on the RPM dyno guaranteed to hit 450rwhp lol

Turbo6TA

When my 2011 GS (A6) was bone stock, it made 371 RWHP (SAE Corrected)

Adding a set of 1 3/4" headers with cats and a dyno tune, it made 405 RWHP (SAE Corrected) on the same dyno.

That's an increase of 34 RWHP
____________________________________

Moral of the story .... Your not going to make 450 RWHP with just a set of headers and a dyno tune.

Bottom Line ... Your going to need a pretty healthy cam and a set of headers to make 450 RWHP from your LS3.

HOXXOH

The big question is WHY. What will 450 HP do for you that 420, 430, or 440 won't?

NORTY

According to the OP's name "steff", she's big...

CJ Willys

i did w headers & a tune.
then I got to 560 rwhp by adding an A&A SC

Turbo6TA

Originally Posted by bigsteff:
I need recommendations for achieving 450 rear wheel hp ... Can I get there with just headers and a tune?

An otherwise bone stock LS3 making 450 RWHP with just headers and a tune ?

I gotta raise the bullshit flag on this one ...

Jlang1

Headers and a tune may net you 40 - 50 HP.... might need more than that to reach your goal of 450 !!!

My C6M did NOT have the NPP option so I installed a Corsa Sport axle back exhaust system. I also installed the Callaway Honker Cold Air Intake system. Those 2 mods got me to 400 RWHP (see attached dyno sheet).

Got it tuned and that added another 14 RWHP for a total of 414 RWHP.... a nice gain (see attached dyno sheet). I would think that another 36 RWHP could be gained (to get your 450 RWHP number) by adding long tube headers and a cam.

However, this is NOT CHEAP !!!

I installed myself:
Corsa Sport exhaust - $1400 on sale with $100 rebate
Callaway Honker intake - $460 with $25 online coupon discount

Just priced out a Cam swap and header installation at Mike Norris Motorsports website:
Cam swap package with tune - $2395
American Racing headers install package - $2395

Obviously if you did the cam swap and header installation yourself you'd probably cut that pricing back at least 50%... still not cheap though !!! HP gets expensive with these bolt ons.... but I'd bet you'd reach your goal with all the above... or be dang close.

Jlang1

Another thought is to just go with the Callaway Cold Air Intake and a set of Long Tube Headers, since you already have the NPP exhaust.... those 2 mods may get you fairly close...and will be a bit more reasonable cost wise. You can always do the cam later if you want.... doing these mods in stages seems to ease the pain a bit.... LOL.

old motorhead

As others have stated, you won't see 450 at the wheels without a camshaft upgrade....or a VERY friendly dyno. A mild, well mannered cam and bolt ons is all you need. A 224/230 115+3 with .600 lift on both sides will get you there and be very daily driver friendly. No buck shake or surge with good fuel eco too. With a stock axle back, it will be hard to tell from stock. With an aftermarket or NPP open exhaust, you will notice the slightly rougher idle.

Jlang1

Did you put this cam or similar in your Vette?
Just curious because that and headers will be my next 2 mods...
my concern with a cam swap is I don’t want to lose driveability and/or idle quality. Also don’t want mileage to drop drastically either...
Any specific manufacturers cam recommendation that would retain these qualities?

old motorhead

I have had a 224/230 114+2 in an LQ9 which is essentially an iron block LS2. It was plenty smooth in an LS2. Would be even smoother in an LS3 with more cubes and the wider LSA on the cam I mentioned. Here's another one to consider: https://cammotion.com/camshafts/tita...222-230-113-3/. I think the 224/230 115lsa cam would make more power and also be smoother (less overlap).

Never a bad thing to check with Pat G and get his thoughts on things. He's a pro and charges a little for his services. Might be the best money you'll spend on your Vette. My advice is free and worth what you paid for it....

Jlang1

Thanks for the info!

WarrenJ

Excellent advise need more input. I’m on a similar path.Fun Street Car\ Parade car.