Red98C5

I have a non modded 2011 LS3 Grand Sport, A6 and I want to know from people who have installed a FAST intake (which one and what throttle body) on a non-modified LS3 and what performance they gained. I can't see where the install of one on a car that does not have headers, cam, head work, gears (mine has 2.73's) or converter can justify the cost. I have no plans on installing headers or cam on the car, so take that into consideration if you are recommending a change. This car is my DD and I am not going to go down the "heavily modded" route, like my last series of cars, so please don't say...when you install the headers & cam...or...converter and gears, the manifold will really come alive...it is not going to happen. The only additional mod going on the car is a set of ported & coated OEM exhaust manifolds from M A Performance as soon as they get them done and I don't expect much from that but it's as far as I want to go.

NAVYBLUE210

I haven't done it myself yet, but based on your usage porting the factory
Manifold and TB are much less $$ and better performance. Both
Comp & Fast said the factory LS3 was very tough to beat.
So with no mods and 2.73:1 Gears unless you do it for looks
I say FAST 102 = Fail for your application.

99Bluz28

iTrader: (35)

I'd also recommend you stick with your Factory LS3 intake. Your next best modification would be a higher stall TC in the 2600-3200 stall range, then if you still want more, gears in the 3.15 to 3.42 range. Either one by itself would still be a worth while upgrade.

6togo

iTrader: (13)

I would say do a factory ported intake and TB from a company like Peak speed they seem to have good results they have a dyno chart for a LS3 they picked up 12-14whp granted that car had headers and CAI but others listed picked up nice gains without headers plus its way cheaper than Fast!