somethingclever

iTrader: (1)

Car is a 2005 CTS-V.

I am wondering if there are any gains (mid-range and peak) in swapping the intake and throttle body out for something else.

346" LS6
11:1 comp
ported 243's (no flow sheets but professionally done)
Custom comp cam 3633R/3475R which is 228/238; .600/.613; 112+3
Kooks 1 3/4 LT's, off road midpipe, cutouts
K&N FIPK

stock TB
stock ls6 intake


I am getting a retune on the car and thought before I do that maybe there could be considerable gains on the intake side. Since the cam is not common, it may be difficult to say if the engine will like the larger intake tract or not.

HCI2000SS

iTrader: (2)

Probably around 15 hp

7GRANDGERNADE

I've seen gains from 17-22 when ported

05RavenV

^ this

BandDirector Blk98ZM6

iTrader: (21)

I've got a stock crate LS6 longblock swapped into my '98 Z28. I put down 385.9 RWHP with an LS6 intake and stock ported TB (as well as the usual bolt-ons). I swapped over to the FAST 92mm and Nick Williams 92mm TB and then got back on the dyno and put down 400.1 RWHP. This has all been within the past month too. My FAST 92 was NOT ported, just as it came out of the box, and I picked up roughly 15 RWHP with it.

somethingclever

iTrader: (1)

are these peak pickup's or also mid-range?

The V is a portly car at 4000lbs with driver....mid-range is good...also the car is a DD...and rarely is at hp peak.

Thanks for the feedback so far.

redbird555

iTrader: (14)

The FAST will begin to pul away from the ls6 around 3500 rpm. The torque in the midrange will improve a lot which is more of what you'll "feel" driving around tq gains are usually anywhere from 15-25 depending on the setup. The hp there maybe roughly 5-10 more but will keep pulling away as rpms climb. It's def worth while if you have the money and I'd say your car would greatly benefit from one.

Chris25

iTrader: (1)

Those are nice numbers really making me want to ditch my LS6 intake for a FAST 92.

svede1212

iTrader: (3)

You have almost the same setup I had and a FAST 102/NW 102 netted me 18 RWHP

I had 228/232 .612/.600 111
CNC'd 243s
LTs
42# greentops


I also optimized my exhaust system adjusting my mid-pipe (collector) length and switching to Borlas and gained 30+ ft/lb RWTQ at 2,000 RPM

somethingclever

iTrader: (1)

those are some pretty respectable gains...especially in the mid-range where I need it the most.

I just wish those pieces of phenolic and dbw TB's weren't such big money! After that I would end up needed more injector too. doh!

BandDirector Blk98ZM6

iTrader: (21)

I'm also on shorty headers and still have the stock cats. I'm very pleased with my numbers after the FAST 92. I was on a quest to hit 400 RWHP without touching the internals of my LS6 and the FAST 92 got me where I was hoping it would!

svede1212

iTrader: (3)

Here ya go. An A>B comparison

Goosecaddy05

you can get played easily from people trying to sell you on the fast intakes... realisticly you wont gain more than about 5-7rwhp even with a ported one... the flow of a ported fast 92 is only about 7-10 cfm higher than a stock ls6 manifold... totally not worth it for the money in my opinion... and i have a ported fast 92 done from Vengeance racing

HCI2000SS

iTrader: (2)

If this was a max effort build, or you just had money to burn I'd say sure...go for it. Otherwise imo they really aren't worth it

svede1212

iTrader: (3)

That's amusing seeing you posted this right after I put up a composite graph of the same car on the same dyno disputing your statement. My comparison is from my LS6 manifold that had the neck ported out for a 80mm TB too. It's entirely likely you didn't see results because you have a bottleneck somewhere else holding it back.

BlueBird346

iTrader: (13)

I think they're worth it. Especially if you can find one used. I haven't dynoed mine to see what kind of gains it gave me, but everyone who has has convinced me.

Always2Slow

iTrader: (8)

Did he cut the pulls early on those setups or did you start running into valve float?

Always2Slow

iTrader: (8)

Sounds like you have crappy heads. On a bone stock motor you will pick up everywhere. The more mods you have the more your going to pick up. A ported Fast is worth alot more than 7-10 cfm by the way and its where you actually need the CFM as well.

01MAROONz2890

Damn dude pass whatever you're smoking....

First off an ls6 intake in stock form flows 247 cfm give or take. A FAST 92 flows 265 out of the box unported and a FAST 102 flows 272. Both gain quite a bit when ported but even 5-10 cfm will show a measurable dyno gain


LS6 Stock Intake
.100 72.2
.200 141.7
.300 204.4
.400 227.4
.500 247.7
.550 256.0
.600 260.5
.650 269.5

Fast 92 - Stock
.100 71.4
.200 144.7
.300 205.9
.400 235.7
.500 259.0
.550 270.8
.600 272.6
.650 276.2

Fast 102 - Stock
.100 74.4
.200 150.7
.300 211.9
.400 241.7
.500 265.6
.550 271.7
.600 274.0
.650 278.4

Rise of the Phoenix

iTrader: (27)

OP, guess you need to ask yourself if the gains are going to be worth the cost. There are gains to be had, that's been proven, but only you can say if it's going to be worth it in the end.