a buddy of mine put down 465rwhp with a f13/tea 1.5 heads/90/90 intake through a full lt/ory/magnaflow exhaust on norris's dyno

 

I think you need to do compression and leakdown tests to make sure the motor is healthy first. There is no reason why it should be dynoing that low with your setup especially if Cartek tuned it.

 

Here is my mod list:

PRC Stage 1.5 Heads 5.3L (Texas Speed)
Harland Sharp Rockers
Futral F13 Cam 112 LSA
Dual Timing Chain Kit
Mezierre Electric Water Pump
Ported Oil Pump
ASP Underdrive Pulley
Ported stock TB
Stock LS6 Intake
Ford 33lb Injectors
Walbro 255 Fuel Pump
Moser 12-bolt 4.10
Hooker LT Headers
Custom 3" Y-Pipe w/ 3" Magnaflow cats
SLP Loudmouth Exhaust w/ 3" Dynomax Bullet Muffler
SLP Intake Lid
Drill Mod
Spec Stage 3 Clutch

I actually went to the track yesterday and ran 12.667 @ 112 on Nitto 555s. My 60' was 1.950 for that run, after dropping my rears to 20 psi. I consistently trapped 112 MPH...

Can I do a leakdown test myself? I'd really like to know why I'm only getting 370 when you're all saying I should be well over 400.

 

I dont know much about the Texas Speed heads, but my guess (assuming a solid running bottom end) the heads might not be a good match to the F13 cam. You might want to call Futral and ask what would be a good head to combine with their cams.

I personally use AFR 205 heads. They were installed out of the box, no milling or porting.

2 years ago I was running the TR224 cam (small lift verssion), I was putting down 425rwhp.

Since then, I've upgraded to a cam only slightly more than your F13, that is now putting down 480rwhp.

How about that 12-bolt - how much power do they use as compared to the stock 10-bolt??

 

I don't think the heads are the problem.

 

The heads are not the problem here unless some of the valves are fubared. Something isn't healthy in the motor but its impossible to diagnose it on the net. With all the mods he has it sounds like something is hurt in the bottom end because he has all quality parts in the top end.
I have the same heads except the stage 2.5 version and Im making the numbers in my sig. For reference the car made 440rwhp with an MS3 without the fast 90/90, YT's and UDP. I lost a bit of peak power from swapping to a smaller cam and the built 3.90 but gained 10-15 rwhp and tq throughout the curves.

 

Dude... something is seriously wrong.

I would venture to guess the heads are garbage.

I know its not the tuning, because Julio (CARTEK) has been tuning my car for the last 6+ years and I have never had a problem.

5 years ago with a 218/222 568 Lift Cam and posted 853's My car made 396HP through the stock 10-Bolt with 3.73's The car also ran 118 MPH in the middle of June

Later after I broke then 10-bolt I got a 12-bolt with 4.11's and the car dyno'd 395HP. So the losses you are talking about don't fly with me. At the time I also had FLP headers which allowed me to change from cats to strait pipes in the matter of minutes. My car loosed 4 HP on the dyno with FLP Cats. Ones again... something doesn't sound right to me. With no cats, the car trapped 122 mph in March.

You have bigger problems then an un-ported LS6 intake! I would take the money u want to spend on a Fast 90/90 and put it toward good heads.

Good Luck!

 

I don't think PRC 5.3 stage 1.5 heads are garbage. While they might not be the cream of the crop his car is making less than it should cam only so either something is broken in the top end or something is hurt in the bottom end. My car made the numbers in my sig with the same brand and style heads.

 

Before you go swapping parts, do a compression and leakdown test as suggested earlier and post your results. That will be a good start.

 

Just the electric water pump and underdrive pulley alone will make up for what you would have lost with the 12 bolt and cats....

Something isn't right.. Hopefully you get it figured out.. Sounds like you have a pretty nice car..

 

to give you a good idea and comparison my hotcam/bolton car is trapping consistant 113 with 2.1-2.3 60ft tims...and running 12.7...im also making the same power you are..time for a leakdown test

 

I don't think my heads are the problem. They're PRC 5.3L (stage 1.5) ported by Texas Speed. Their flow specs give AFRs a run for the money at about half the price, which is why I got them. I was hoping to have an 11 sec car when all was said and done, needless to day I was disappointed when I learned that my car only put down 370 at the wheels with the new mods.

When you say "bottom end", what could be wrong there that is sapping my power? If the bottom is messed up, wouldn't that spell out catastrophic engine failure, more less? I also don't think my 12-bolt is eating up 25 RWHP.

 

There are many things that the loss of power could be attributed to: Rings not sealing correctly, cam timing is off, valve geometry is off, etc. A compression and leakdown test will aid in narrowing down the search.