Havent seen it mentioned,, but what spark plugs and gap are you running?

 

Ngk tr6 gapped at .28
I throwing 7s I'n gapped at .28 while i change the springs. Will they be too cold? Or shud i stick with the tr6s?

 

I'm running br7ef gapped at .028. I got tired of messing with those tr6s blowing out spark.

 

Stock48 hit it on the head....small exhaust side. My setup peaked around 5200 and actually lost power after that. Turbo is out of steam.

 

I doubt that's my problem. I'm only running 9lbs, i posted my dyno graph and u can see it start to lose power at 4800 then completle cuts out at 5k then falls straight down.

 

a little update for everyone. check pushrod length and lifter pre-load while we were in there. turns out i need 7.350 pushrods. thats something i should have checked when i was doing my build in the first place. you live and you learn. so i should have another update next week when i get my pushrods in along with the springs!

 

I apologize if i missed it, but what is the problem (other than not making power up top)? Are you experiencing any issues that you can "feel"?

 

With LS7 lifters you should be using shorter pushrods. Some don't, but if you want the correct preload then you should be running shorter pushords. I used 7.350 on mine. But I doubt that was your issue.

 

Swapped to lunati .650 lift dual valvesprings and 7.350 pushrods and no more cutout!! Pulls hard all the way up to 6100. It's fun now! Of course I'm only on 9lbs with about 16* timing, gonna swap to tial wastegate and bov and run around 13-15lbs

 

Nice! I wonder if it was the rods or the springs.