LS2 gained 5hp with FAST 102? HELP!!!
 

Like the title reads, I have a cam only ls2 2007 corvette. The car made 441/446 before i put the FAST 102 intake the car. First pull untuned car picked up 1 hp, after tuner messed with it for a while it got to 5 hp. I read soooooo much that FAST 102 is a must have for LS2 cars that i bought into the hype and very disapointed.

Same dyno, same tuner, 30 days apart, no other changes where made.

Car has
kooks 1 7/8 headers
z06 mufflers open baffle
cam 223/235 615 621 113
vararam
25% underdrive pulley
port TB
STOCK unported ls2 intake

made 441/446 with that setup

added
fast 102 (unported) w/ vmax ring

made 446/447

any ideas?

Sounds like you need a second opinion on the tune. Who installed it?

My LS2 made about 450 with cam, headers, and fast. That was with the G5X1 cam. A little smaller than yours. You're in the ballpark of what the car should be making with those mods, fast included. Maybe your 441 number wasn't corrected?

i think your original numbers were a little high. i have never seen a fast102 go on a N/A ls2 car and pick up any less than 18rwhp. mine gained 22rwhp from the fast and retune alone.

Your original numbers seem wayyyy high. I made 420/390 corrected on a brand new dynojet.

LS2
Livernois Stg. 2 Heads
Livernois Stg. 2 Cam 232/232 595 595 114
Kooks 1 7/8 LT's
Kooks X-Pipe
Halltech intake

I was on an incredibly conservative tune as well. I plan on installing a FAST this spring along with a re-tune. Shooting for ~460whp

Yeah I just looked back. My M6 LS2 made 425 with the G5X1 228/232 cam and LG super pros. When I did the fast it made 442.

You're in the ballpark dude. Your original numbers were just too high. Probably not corrected.

Dyno was done 30 days apart, should have been done same day for a real comparison. also the tuner probably pumped the first number, even a tire rim change can change the number, maybe the v ring robbed power

LS2 M6
1 7/8 Long Tube Headers
No Cats
Z06 Modded Mufflers
Vararam w/V-Ring
Polished TB
Cam 234/238 .625/.610 112+4

Everything but cam:
371/376

After cam:
428/403

If say your first run was high. My next mod is Fast102 as well and I'm hoping to get close to 450.

temp could of made a different or maybe there is a problem with the dyno itself.

:iagree:Numers can be fudged.

I was there watching the orginal tune done on the dyno, first pull was 430/438. After he messed with it a little bit the car made 441/446 CORRECTED. I know this because I am in Louisiana and it was during the cold spell we had so the numbers were actually corrected down to the 440. There was no fudging there!

The tune was done at Lethal Racing by Shawn

Also there was no changes to the car, not even a wheel or tire change.

It's not always about how much HP you gained... did you overlay the graphs? I've seen FAST manifolds not make much more max HP but noticed increases across the curve both HP and TQ.

yes when graphs were overlayed...they looked the exact same. the first pull showed it picked up 1 hp and curve had no changes. he messed with it for about an hour just to get the other few hp out of it.

Poss vacuum leaks?

Well there are other explanations. Potentially your clutch is starting to slip slightly. The shop should be able to overlay your gear ratios as well and see if there is a little slip, could be that maybe the motor is getting a little loose or it could just be the previous numbers were somewhat inflated. Also where is your injector duty cycle at? There are a lot of variables especially going from one day to another as well.

car is an auto trans.

no vaccum leaks...thought that too and everything checked out good

Curious what the car made on initial pre-mod dyno. It sounds like you somehow picked up 120 hp from your first mods.

The initial numbers seem very high imo. Even though your not happy with what the numbers say, take a look at what other guys get with the same configuration and it seems spot on. Also, see what it can do on the track. I'm sure you'll be happier then.

Shawn is a good guy. He's always done my tunes, matter of fact he'll be doing mine when these LTs and complete exhaust gets installed.