Hemby207

Well ill start with the breakdown
2000 z28
motor
-Ls1 bored .010 over
-eagle rotoating assembly with diamond pistons
-all arp studded and bolted
-clevite h bearings
-texas-speed ported shimmed oil pump
-ls2 timing chain and kit
-Aftermarket casting 15 degree heads flow benched 340cfm .600 lift
-2.08 intake 1.6 exahust manley valves with bronze seats and manley .650 lift double valve springs, titanium retainers. 10.5-1 compression ratio.
-manley push rods
-yt race series adj. roller rockers with link bars (i know i know valve float)
-cam is 244/248 .621/.612 110lsa adv under degree check total 28 degrees
-Professional products typhoon 96mm intake (i know they suck)
-Texas-speed 96mm throttle body
-Pacesetter long tubes
-Texas-speed 3inch y pipe
-Borla catback
-slp air lid
-no emissions equip. not cats blah blah blah.
fuel system
-fast 48lb injectors
-racetronix 255lph pump
-fast fuel rails
tranny
-fully built 4l60e from phoneix transmission in weatherford
-3500 stall brazed triple disc lock up and antiballooning plates
-all coolers and ness. hardware
rear end
-built 10 bolt 3.73
extras
-Bmr tube k upper and lower arms
-slp 3-point sub frames

First pull had valve float after 6500 when limiter was set to 7250 so we dialed back the limiter to 6500. The a/f flat at 12.5 at WOT. Timing set with no knock counts. In 3 runs a flat torque curve? BUT anyway we ended up with HORRIABLE #'s 393.2 hp/ 333.9 rwtq at 6500 rpms. EXPECTED WAY WAY more atleast on the torque side but heres the graph...



Come to find out the torque coverter was NOT locking up and caused overheating problems that ended up burning the trans on the way home. Anyway under warrenty was fixed i replaced the yt rockers with gm factory rockers and went back to stock length push rods to solve the valve float. Changed the intake back to an ls6 a friend of mine had laying around, then put a factory throttle body that has been ported on. The exhaust was changed to a pacesetter y and magnaflow catback just cause i liked the sound better and is waiting to be re-dynoed and tuned tomorrow.

My point is im a 21 year old that really dosent make much money, i work 92 hrs a week in a lube shop. Built the whole car in a barn on jack stands with hand tools while doing the basic tuning on hp tuners with data log collections till i got the car to HPP. i built and blueprinted the motor and rear end only thing i didnt build was the tranny. I dont have awole lot more money to be shooting in the dark with so any help on why so low please chime in, any help at this point will be appreciated.

bayer-z28

iTrader: (14)

That cam is just ungodly large, for one.. But it should still pull better numbers then that.

Update this with the new numbers when you get it re-dyno'd. I'd partially blame the Typhoon intake. What MAF?? The SLP ID lid is only 90mm, so there is a very slight restriction. But will work better with the LS6 intake. The slipping trans is also an issue. You've just had a bunch of stuff going wrong there. Can't really read the a/f graph too well either.


What Y-pipe did you get from TSP? The older design or the newer, better merge, design?

Hemby207

The older with the almost 90 merge but the pacsetter is much more smoother in transition thats why i changed it over. The maf is factory but the mhz are still within range. Also the cam is big but the good heads with high rpms are what i expected to make it performe.

Hemby207

The tranny after being rebuilt under warrenty was put back in then the car was hauled on a trailer to Xtreme horsepower for the tranny tune (them and phoneix work hand in hand so made it where they could talk back and fourth on the tuning). Now we will find out tomorrow.

30th t/a

iTrader: (51)

Who ported the heads and whats the history on them?
Why did you choose that cam?

Bigger is not always better

bayer-z28

iTrader: (14)

78mm MAF on a 96mm mouth is a pretty good bottleneck. The MAF freq may be fine, but you may want to look into an 85mm MAF. Not as much of an obstruction. I may have one up for sale soon. (SD coming soon)

mike c.

iTrader: (1)

Who's heads are on there?? You only stated aftermarket... What compression you running? Your mass is factory. I gained 9hp removing my factory on a head and camed car for a 85mm. Your intake sucks too. i also think your cam is too much. Who choose these parts?