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This is a question for the experts who have been there, done that. I have a very low mileage 2011 Z16 coupe. Wixom built forged crank LS3, M6, NPP, dry sump, coolers, etc.
I want to add 100+ hp, without significantly affecting driveability and reliability. I know the usual headers, cold air, t-stat, tune gig applies, but I wouldn't expect those mods to get me where I'd like to be.
I also don't want a blower on a 10.7:1 motor, and I'm not a NOx guy.
So, a cam, some headwork, and what else??
How much gain in a good aftermarket exhaust compared to the NPP?
What should I expect to spend on just the parts to get this done?
TFS 255 professionally ported heads
G6x3 Cam with 112 to 114 Lobe separation. (pretty choppy.....but you're have a M6)
Fast 102 ported intake
Stock (Or Any) Exhaust With Cutouts
Hi Flow...or eliminate cats
Good Tune
Higher ratio rear (3:90s?).
presto......you're over 500rwhp with a streetable vette.
If you do the work yourself....your looking at 4000+ dollars in parts. Figure in another 2-3k in labor for a good shop to do it. (Blower might be a smidgen cheaper here) :-0
Last edited by JimiHendrix; 10-31-2014 at 12:21 PM.
Reason: meant TFS 255 heads...not smallish 225 heads
TF 225 professionally ported heads
G6x3 Cam with 112 to 114 Lobe separation. (pretty choppy.....but you're have a M6)
Fast 102 ported intake
Stock (Or Any) Exhaust With Cutouts
Hi Flow...or eliminate cats
Good Tune
Higher ratio rear (3:90s?).
presto......you're over 500rwhp with a streetable vette.
If you do the work yourself....your looking at 4000+ dollars in parts. Figure in another 2-3k in labor for a good shop to do it. (Blower might be a smidgen cheaper here) :-0
I agree if he's wanting 500rwhp, but 525-550hp is only 450-475rwhp. This can easily be done with the Trick Flow 255 LS3 heads, a Crawford modified intake (no need for a FAST), 1 7/8" long tube headers with or without cats and a cam with -10 degrees of overlap. That's a stealth idle and near stock street manners, but at least 475rwhp. The G6X3 is a very dirty cam with lots of overlap. It makes strong power, but it's not the DD type of cam the OP is looking for. You'd want something more like a 222/230 118LSA +4 cam.
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
Originally Posted by Garry in AZ
I want to add 100+ hp, without significantly affecting driveability and reliability. I know the usual headers, cold air, t-stat, tune gig applies, but I wouldn't expect those mods to get me where I'd like to be.
I also don't want a blower on a 10.7:1 motor, and I'm not a NOx guy.
Garry
Stock displacement....it's going to effect driveablity, at least it won't drive like a stock car I'll put it that way.
I think the most we have done on a stock LS3 short block is 539rwhp on pump gas (ported LS3 heads, FAST 102/102, G6X3, our 1 7/8 headers, full 3" exhaust, underdrive pulley...)
Most on a built engine, 100 octane and stock displacement was 569rwhp.....ported LS3's, FAST intake, 102tb, G6X3...
Guys, he's not asking for 525-550rwhp, just flywheel horsepower. That's baby stuff with killer heads and a stealth cam. All you need is 450-475rwhp. With the TFS heads, milled for higher compression and an RCR modified LS3 intake, I promise, you can make 475rwhp+ with a cam with -10 degrees of overlap at .050". That would pass smog in any state, be wife/GF/client approved and return excellent fuel economy. Without the good heads and intake, you'll need a much dirtier, choppier cam to make 475rwhp.
Thanks for all the replies. I should have been more clear, I'm not expecting 525 at the rear wheels. I'd be happy with 450-470 at the wheels.
I do not want to change pistons, and I do not want to buy new heads. I was hoping to simply clean up the stock heads. This means no significant decrease in compression ratio, which means a blower is a bit of a waste. If I was going to heads with larger combustion chambers or changing pistons, a blower would make much more sense. All of that however is beyond the budget.
I'm hoping to acheive 450 rwhp without spending more than 4K on parts. Possible?? I will do the work myself.
I was right at 500rwhp with Kooks headers, Airaid, and a Spinmonster cam thru a base M6. Numbers you are looking for are easily surpassed with bolt ons and a camshaft.
I did 124 in the quarter with 437 rwhp in a bolt on (and lighter) base M6. I'd say 450-460 rwhp for 125-126.
All the OP needs is the bolt ons and a mild cam.
I was kinda thinking about those same numbers, but I haven't done a legitimate dyno pull since a 381 rwhp one 5 years and several mods ago. Although I have run quite a few 125 and 126's with just bolt-ons, adding a cam should put the OP well over his goal. He could hit the lower end of the goal with just the right bolt-ons and a good tune.
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
Originally Posted by Garry in AZ
Thanks for all the replies. I should have been more clear, I'm not expecting 525 at the rear wheels. I'd be happy with 450-470 at the wheels.
I do not want to change pistons, and I do not want to buy new heads. I was hoping to simply clean up the stock heads. This means no significant decrease in compression ratio, which means a blower is a bit of a waste. If I was going to heads with larger combustion chambers or changing pistons, a blower would make much more sense. All of that however is beyond the budget.
I'm hoping to acheive 450 rwhp without spending more than 4K on parts. Possible?? I will do the work myself.
Thanks again for the advice and insight!
Garry
If that's the case, a set of long tube 1 3/4" headers, cold air, underdrive and something like our X1 cam would do that. Give you a nice little lope at idle and drive almost like stock.
That was from a 2008 M6 car.....the baseline graph already had our 1 3/4" headers on it and stock NPP exhaust.
Thanks for all the replies. I should have been more clear, I'm not expecting 525 at the rear wheels. I'd be happy with 450-470 at the wheels.
I do not want to change pistons, and I do not want to buy new heads. I was hoping to simply clean up the stock heads. This means no significant decrease in compression ratio, which means a blower is a bit of a waste. If I was going to heads with larger combustion chambers or changing pistons, a blower would make much more sense. All of that however is beyond the budget.
I'm hoping to acheive 450 rwhp without spending more than 4K on parts. Possible?? I will do the work myself.
Thanks again for the advice and insight!
Garry
I'm 423 rwhp and 425 rwtq with the same vette as you, with NPP exhaust and 1 7/8" LG Super Pro Headers and high flow cats. They only charged about $1800 installed and tuned.
I'm sure a mild cam and FAST intake would probably get what you are asking for, along with headers.
10-31-2014, 11:10 AM
525-550 HP from naturally aspirated LS3?
I was kinda thinking about those same numbers, but I haven't done a legitimate dyno pull since a 381 rwhp one 5 years and several mods ago. Although I have run quite a few 125 and 126's with just bolt-ons, adding a cam should put the OP well over his goal. He could hit the lower end of the goal with just the right bolt-ons and a good tune.
