KingPin1094

iTrader: (12)

I have a 2002 camaro m6 stock rear with a 408:

408CID
forged bottom end with wiesco flat tops 3cc valve relifes
10.5:1 compression
EPS 236/242 .629/.629 114+2 LSA
L92 heads with minor port/polish work
LS3 intake (stock)
92mm TB
85mm MAF
SLP flo pack (soon to add an SSRA)
TSP 1 7/8" headers with 3" true duals

On a mustang dyno i made 440whp and 420 wtq


I also took it to the track, and on a 100 degree day ran 12.63 at 117.5.

Rise of the Phoenix

iTrader: (27)

Are you planning on adding a turbo/supercharger in the future? Reason I ask is because I see you went with 10:5.1 compression. If not, you're leaving quite a bit of power on the table.

topendrunner

iTrader: (1)

mustang dyno or not that is not good. something is wrong.

jleews6

iTrader: (2)

The dyno looks good but the real numbers (mph) dont seem right. My ws6 went 114 with just a lid,filter and mac headers through the stock cat back. I would go back to the track and work on the mphI would think you car should be able to run in the low 120s at full weight.

KingPin1094

iTrader: (12)

I was worried about piston to valve clearance, thats why its relatively low for NA. I have the motor out and its gonna get bumped up closer to 11:1.
I agree, i expected to see the low ET cause it couldnt hook at all, and would even lose traction in the 1->2 shift some times. But i think i should be able to get 125 out of it. Im gonna go back on a cooler day and see what i can do.

KingPin1094

iTrader: (12)

The tuner said that if i change the intake so i make power up higher, and put a rear in it with some better gears i could potentially see 10's. My buddy has a C5 vette and he dynoed 420 on the same dyno and he runs 11.1 at 123

KingPin1094

iTrader: (12)

I just found out my compression was actually at 10.3, i miss calculated. i think im gonna take it up to 11.5:1 and retune.

weldermike27408

good luck and keep us posted

KingPin1094

iTrader: (12)

Does anyone know what kind of gain that will get me?

HCI2000SS

iTrader: (2)

I read somewhere that a full point increase in compression will give around a 3-5% gain. Not sure how true it is...

KingPin1094

iTrader: (12)

I just calculated my DC at 10.3 static compression, and based on my calculations my dynamic compression is at 9:1. From what i understand thats already a bit high. So if i raise my static compression to 11.5:1 then that would only raise my DC higher closer to 10:1 which may cause detonation and the tuner will have to pull timing for it to run right. Any thoughts on this?

quik01ss

iTrader: (24)

If I were you go back to a cathedral port head and bigger cam I made around this power with my 347ci. IMO I just don't like a ls3 style head on a 408 or smaller but if u were to boost this it'd be fine if you're trying to do something n/a I'd go another route.

Johnnystock

iTrader: (6)

Plp are making 450-475rwhp all day with cam only ls3. Something is wrong. What is the weight of your car? My LS2 Camaro has a smaller cam but will make 450rwhp.

Go back on a better day and maybe it will be better...

Silver408z

iTrader: (1)

Did you change the valves in the heads? I know the square port heads fit on a 4.030 bore but seems like I read there really wasn't enough room and caused valve shrouding. The shrouding hurts the air flow into the cylinder. That's why some of the companies make small bore ls3 heads.

Also are you sure you have a 92mm TB? Isn't the GM factory intakes 90mm? If you have a 92mm TB then your air flow into the intake could be messed up.

KingPin1094

iTrader: (12)

I was thinking of switching back, but i really dont have the money to switch to cathedral right now.

No i didnt have the valves changed. Pretty sure. I dont know what brand but its cable driven. And the intake opening is larger than the throttle body.

moeZ28

iTrader: (7)

I made 446/405 w/ a 6.0L LQ9, L92 heads milled .020" (10.7:1) and a G5X3 112...

Rise of the Phoenix

iTrader: (27)

I think you'd see a big increase with some TFS 235cc heads and a matching cam/intake.

topendrunner

iTrader: (1)

i made 465/432 with stock bottom lq4 at 10.5 comp, 230/238, stock ls3 heads, stock l92 intake, 1 7/8 lt, 92 tb, 6spd w/ 4.10s. this was on a dynojet but should be right with you on a md. I think your cam is installed wrong or the tune is off. Something is deff wrong but its not the heads/intake. Im only on a 4.0 bore so your 4.030 is also not the problem.

James@ShorTuning

Nearly an identical combo made THE exact same HP AND TQ on my Dyno Dynamics. I don't recommend those heads on anything smaller than a LS3 bore.

stumprrp

iTrader: (2)

Whats the raceweight? 117.5 @ 440 WHP would make me think 3600+. My last car has a 430 RWHP 6.0 with 3.42 gears and couldnt budge 116. Car was almost 3800 pounds.