Taphee6

iTrader: (2)

I dynoed 390 HP 395 TQ on this set up. I know it should be around 440 to 460. What is wrong with this set up? Also I ran 11.90's at 115 MPH with a 4400lb Convert.

396 Stroker
4.060 bore Diamond Pistons
11.00 to 1 Comp
3.88 Stroke
237/237 595/595 Cam
Comp R lifters
Comp Pro Mag rockers 1.75
7.35 push rods
Stage 2 heads 2.02/1.60 valves
Flow 286/216 @ 550
LS6 intake
Ported and polished TB
Stage 3 trans
3400 Stall
Mac mid length headers
ATR catback
cutout
HPA tuning
Stock 10 bolt

Timing is at 28 deg with no KR.

The car seems to run like a bat out of hell but it should be around 11.30's and 450 HP. Any ideas.

Camaro01SS4life

iTrader: (4)

Your numbers do seem to be a little low...What octane level are you running the car with?..With 11 to 1 compression the conventional 93 octance probably isnt enough...I also see that you have mac headers...They are good headers, but with your set-up they might be restricting the power output of the motor...I would try goin with a bigger header since you have more cubic inches ...

Kevin

m1key99WS6

iTrader: (1)

Small Heads, small headers, no crank pulley + heavy car =

Tea Stage 2.5 LS6 Heads + Kooks headers + crank pulley + car diet =

98Raptor

I think camaro01ss4life is right on.

I have seen a NA TA with a 396 that dynoed 528wrhp with 556wrtq.
On the juice it dynoed 707wrhp with 805wrtq.

If you have any doubts call Extreme Performance in OKC. 405-721-2430

They have done everything on this car.

Taphee6

iTrader: (2)

Sorry, I forgot I do have a pulley. Also, I ran on 100 octane gas. There does not seem to be detionation issues. I do realize it is a heavy car but it is still missing 40 to 50 hp somewhere. I can't see that being just headers.

Camaro01SS4life

iTrader: (4)

How many miles are on the motor?..

Kevin

Taphee6

iTrader: (2)

500 miles on it. Also, I upgraded the fuel pump and 36 # FMS injectors.

Reboot

iTrader: (5)

What's your A/F ratio? When I first dyno'd my TSP 383 stroker it was also down 50rwhp with a 10.0 A/F. Once I leaned it out the power was there and then some.

My stroker tune was drastically different than my previous tune.

Taphee6

iTrader: (2)

My tuner has the A/F dead on. I forget the #'s but AF and Long trims are right on.

gomer

iTrader: (13)

Have you talked to TSP yet? What did they have to say about it? Did you buy the shortblock assembled from them, or did someone else do the final assy?

Scalpel

iTrader: (4)

A convertible weighs 4400 pounds???? WOW. I thought they were 3800 or so

Taphee6

iTrader: (2)

I bought the short block from TSP and we have talked. They are the greatest to deal with. Jason agrees it is missing HP but does not know why. That is why I am opening it up to you guys. I have been trying to figure this out for months. I am giving this till the end of the race season to figure it out or I am pulling the motor and selling it. Jasons 396 motor put down 485 HP with stage 3 heads through a M6.

The 4400 LBS include a roll cage, iron block and me in the car.

gomer

iTrader: (13)

Besides the headers, which I don't think is costing you THAT much, the only other thing that jumps out at me are the Comp R lifters, pro mag rockers, and 7.35 pushrods... since you are running the R lifters, you could possiby have too much preload. Do you know what it is set to?

Taphee6

iTrader: (2)

Preload is set 4 Thou and done with a dial indicator. What a PITA that was. But it was done exactly to Comps directions...

Comp suggest the 7.35 push rods. I checked the geo and it was dead center on the valve. However, can a 7.4 push rod sit dead center and I am missing lift on the cam? With the Pro Mag 1.75 rockers the lift should be 6.12??? Did I just solve my own problem???

Nope. Push rod length checker calls for 7.35's

gomer

iTrader: (13)

What springs are you running? With the 1.75 rockers you are at .612 lift. Do you have a dyno graph we could see to check for valve float? As long as you used adjustable rockers and set the preload correctly, the pushrod lenght is ok.

Taphee6

iTrader: (2)

Springs are Patriot gold double springs. The dyno graph is not showing any flutter indicating valve float. I will try to attach as soon as I hook up the scanner...

PREDATOR-Z

Those are good to .650 lifts.

gomer

iTrader: (13)

Have you put the 4400lb weight and 115mph trap speed into any of the online HP calculators? Every one I've tried gives me a WHOLE lot more than 390rwhp. Was it a dynojet and also, what was your 60ft times when you ran?

Taphee6

iTrader: (2)

It was a dyno jet. I have not used any online calcs yet. Which do you use. Also, the tuner, HPA, uses this dyno a lot and it is pretty accurate. My first thought was the Dyno was way off but it does not appear to be. Also, the 60 ft was 1.72.

Thanks for all of the responses so far. I cant tell you enouh how much I appreciate them....

MyLS1Hauls

iTrader: (2)

Lets see the dyno graph...I want to see the rpm peaks. IMO, the heads are too small and so are the headers. What did the heads flow at .600"? I'd get some 1 7/8s LTs with true duals. The MACs are choking the motor at higher rpm.