how much of a redline increase do you think I would see with pnp head, or would it be better to go with a zpi stage 2 head and get 8500 redline

 

I wouldnt up the redline unless the internals of the head are replaced as well

 

whats everyone infatuation with a very high redline??? You want that go and get an early model s2k and rev to 9k....

Make power down low and you will be happy

 

well unfurtuanally to make a supercharged car as fast as a turbocharged car you need to increase the revs. Curtball if i were you i would go with the zpi stage 2 long block.

 

agreed, raising your redline isn't just as simple as port and polishing the head.

you'll also need to probably upgrade the valvetrain, eliminate the rev limiter, and adjust vvti among other things.

plus, just because your motor can rev to 8000, doesn't mean your tranny, gears and synchros will like shifting that high.

has anyone (not a pro-racer) actually raised the redline?? i'd be interested to know, since i'm planning on building the motor NA over time.

 

im getting my head built up this summer and although i love zpi and there stuff. im gonna go with a local company that builds f1 and nascar motors. does the tc even make more power after 6200 rpms ? to 8k ? i was either thinking of waiting for cams and just buy the 1mm oversized valves and titanium locks and retainers. as well as upgraded springs.

 

oh I know more is needed, I'm gonna get a stage 2 zpi head installed anyway. I was just wanting to know what out come would come from the pnp. but I'm only wanting to rev out at 7'500 rpms anyway, cause I doubt the tranny would withstand the 8'500 for long. and if you check my other ost I'm doing a stage 2 zpi internal build on my motor. just wondering though what's the difference and benefits is and between the stage 2 short block and the long block

 

building the head on a stock short block doesn't make much sense. remember, building the head only ALLOWs for more airflow and higher rpms....if you have a stock motor, it can't pull in enough air to justify having a built head.

ie. you probably wouldn't get much gain at all from just building the head on a stock short block.

if you went with 11 compression pistons though, you'd get a real nice gain.

 

long block:
ZPIracing race rod bearings
ZPIracing race main bearings
Scion OEM rear main seal
Scion OEM head gasket
ZPIracing ARP head studs
ZPIracing low compression pistons
ZPIracing forged rods
ZPIracing 1mm oversized valves
ZPIracing double wound vale springs
ZPIracing titanium retainers
ZPIracing locks
ZPIracing street port and polish
ZPIracing 3angle Valve job

short block:
ZPIracing race rod bearings
ZPIracing race main bearings
Scion OEM rear main seal
Scion OEM head gasket
ZPIracing ARP head studs
ZPIracing low compression pistons
ZPIracing forged rods

difference $2500

 

I'm not build the head I'm building the motor

 

Long Block = ???
Short Block = ???

Price is one diffence, what is the difference between the two?

 

short block is just the bottom end, the block itself. Pistons, rods, crank, cylinders, etc.

Long block is the entire engine, aka. block + head.

 

ZPI doesn't list a total gain from either a short or long block rebuild. What would be rough/ugly estimates on something like that? Dyno sheets anyone?

And the phrase keeps up to its meaning:
You learn something new everyday

 

NA long block will probably put you somewhere around 200-215whp with supporting bolt on mods and afr tuning.

NA short block probably around 180-200whp with supporting mods and tuning.

if you are NA, its probably not worth the $$$, hp gains, and effort to build the head imo. unless your plan is a fully built motor

 

Ok so getting to 200whp NA is a more expensive route then going boosted. However if at some point in time if/when I decided to get the car boosted it would be more of a gain in the end anyways.... right

Plus almost every racer goes boosted, why follow?