set up is 2000 Silverado

Stock bore 5.3, gen IV rods, arp 2000 rod bolts, forged pistons rings gapped to .028
706 heads, arp head studs, ls9 gaskets
texas-speed 224/228 .600/.600 114LSA
TBSS intake w/ 92mm TB
huron speed turbo kit w/ 78/75 billet vsracing turbo .96ar 3" downpipe
4l80e trans with a 2800-3200 stall

on the dyno at 6-7psi it made a whopping 388/399 with 18* degrees of timing and was not really making much more as boost increased. as we got to 15psi with 14* it lifted both heads and a nice little fireball from the engine came out along with all the coolant. made 485/515

what could possibly be creating so much pressure in the cylinders to cause this? im sure the turbo is big enough to not cause a restriction. its wayyy down on power in my opinion

all motor with the factory intake and TB and a smaller cam it made 315/298 moving heavy 22" wheels

any help is greatly appreciated!

 

15psi on 14 deg? What compression and fuel?

 

pump gas and Compression should be around 10.5. Yeah it was probably a little too much timing on 15 psi, but the bigger picture here is what is restricting the setup?

 

Post up the dyno sheet. What plugs and gap? What AFR? Lots of variables here. Who is tuning it? Did you upgrade the fuel system?

 

br7ef gapped .025, afr 11.2. I tuned it and have done several turbo cars without issue. Fuel system is upgrade. 80lb injectors and 340 fuel pump with Hotwire. I think the lifters might be the problem not opening the valves all the way, or something of the sort. The truck is still at the Dyno and I didn’t grab any Dyno sheets cause I was so pissed, but I’ll have them next week when I get it back to my shop

 

What kind of valve springs?

 

btr dual .660 brandy new

 

what power were you expecting? I made 477 with 12lbs, so I dont really think you're not making the power you should be. I had a similar cam too, breathing thru stock exhaust

I cant comment on the timing thing, Im not a tuner. If the IAT is in check and she is running as fat as you say, I personally dont think 14 degrees is too much, but... opinions are like ********

Head lifting sucks. Time for new 5.3 bore Cometics and bolts or studs. Degree your cam, check your pushrods, trunion your rockers and ditch the *probably* LS7 lifters for some Johnsons

 

Is the cam timed properly?

 

yeah but 315 all motor on the stock intake and tb with a smaller cam n/a made 315. Now with even 10lbs with a much “better” set up made 395. Somethings wrong. Something is has to be wrong with cam timing, pushrod length and or lifters

lined up dot to dot