james99ws6

iTrader: (3)

Here is my set up:

Forged internal LS1
CP Pistions Flat top -3cc valve releifs
Callies Comp Star H-beam rods
Main Studs
Rollmaster double roller chain (Adjustable)
Head studs
Cosmetic .052" MLS head gasket
Stock Home ported heads (just removed flashing on the runners)
TR 248/242 613/610 110LSA (Reverse Split)
PRC Dual Valve springs
Texas-speed cromoly pushrods (7.4")
stock rockers
Ported throttle body
LS6 intake
Flowtech Longtubes
Texas-speed rumbler catback
28.8 Stock injectors
Hp tuners with a awesome tune (running 32-33 degrees of timing at perfect A/f, with no knock retard)
Spec stage 3 clutch
10 bolt
4.10's
aluminum driveshaft
t-56

362 RWHP

a cam this big should make great power. the dyno graph goes up an peaks 360ftlbs, and 362 Rwhp at like 6200, then starts to come back down smoothly. i talked to thunder, he said that cam in his car made some rediculous power, and pulled like a m/f up top. i take this thing to 7200rpms too, i don't get it. The car feels like it has some good power, but the graph doesn't lie. where could i possibly be looseing power like this. By the way the motor has about 1,000 miles on it. Let me know what you guys think
thanks
james

cyphur

iTrader: (10)

might be installed incorrectly, or your valvesprings aren't able to handle that cam.

also, more timing isn't necessarily good. like J-Rod said, every car has its optimal timing point, and its not always max w/o retard.

james99ws6

iTrader: (3)

well i pulled 4 degrees and lost power up top

Camaro ChriSS

Are you sure the dyno is reliable?

Also, any chance those heads are significantly bottlenecking things? It wouldn't account for the full loss though, thats for sure.

jrp

iTrader: (16)

post the graph.

james99ws6

iTrader: (3)

i am pretty sure that the dyno is reliable, no one else around here has problems with it. i'll post up the graph as soon as i get home.

james99ws6

iTrader: (3)

is anyone having trouble, or even shimming the prc springs?

jrp

iTrader: (16)

the PRC's dont need shimming, they've got enough seat pressure @ 1.800 to handle that cam.

james99ws6

iTrader: (3)

i was under the same impression, could there be a chance that the rings haven't seated yet? i dont think there would be that kind of power loss though. Also if i did install that cam wrong, it would only throw it off 2 degree either way, it still should be making power. i dont get it

jrp

iTrader: (16)

which key way did you install the crank snout on, its sposed to be the one in the center, then you line up the dot on the tooth a couple degree's to the left from the center key slot, thats 0* or straight up.

if im understanding you correctly your setup peaks at 5200, that indicates your valve timing is way the **** off.

james99ws6

iTrader: (3)

i was going for the center mark, i may have messed up. i hope to god thats my problem! ill post up the graph so you can take a better look

james99ws6

iTrader: (3)

dyno graph, and cam specs posted at the top

D3IMOS

You should be making much more power then that. Hell I'm putting down 390.5hp and 428.9tq on my 383 with stock heads and a hotcam.

ablakez28

iTrader: (9)

we tried as high as 35 degrees w/o any knock but also no gain, so we dialed it back to 32-33

we tried more fuel less timing, less fuel more timing, less fuel less timing, more fuel more timing.. either way right at about 4600 on the graph u can see where the power starts to level off instead of continuing to climb..

does anyone know the CR of the motor w/ those pistons with the headgasket?

edit - gj drew, this is toda.. way to log out

Slowhawk

iTrader: (12)

Here is a few idea's
Serious restriction in the exhaust(clogged cats,real bad cat-back)
too much preload on the lifter's.
Cam timing way off but I doubt it because you would have bad P/V clearance problems.
Intake restriction
plug/wire not firing. 1- plug can run smooth but drop serious hp.
Throttle not going 100% open.

james99ws6

iTrader: (3)

look at a comparison of my graph and the real Trex graph, they should be almost identical.

Phil99vette

iTrader: (11)

What kind of dyno was it?? I don't think you can compare the different brands of dynos to each other...Does the car feel strong?
Phil

WS6FirebirdTA00

iTrader: (33)

have u done a compression test?might wanna try something like that and make sure u arent loosing compression anywhere. how does the car run? even though dynos can vary (unless this is a mustang dyno) i would think the power would have been higher. you shouldnt be having any fueling issues with those injectors i wouldnt think either. only thing i can come up with is something faulty int he assembly or impreper install. not saying thats the case just dont know what else to look at? do you have any logs or anything of any wot runs?

J&J Speed Shop

iTrader: (8)

Well a few things come to mind..

1. Tuning
2. Who built the engine?
3. What did you do when you ported the heads. No offense but if you don't know what you are doing sometimes you can do more harm than good.

ablakez28

iTrader: (9)

well the dyno is generous if anything i made 431.7/390 on it a few weeks ago with a t-rex and dont even have all of the boltons. and the tuning is on with this car i can promise that since we have the same tuner. if the timing were to be off would he have ptv issues with 3cc valve reliefs? also his cat-back is the texas-speed rumbler which should be fine.