BigBoyWS6

Engine: 390ci GenIV at 10.2:1 cr
Cam: 234/234 .621/.604 115+4
1 7/8" LTs
4L80E

PRC 227cc CNC ported Small Bore 3.9"-4.0" ((((with a ported LS6 intake and 90mm TB)))
Flow: .650" 330 CFM / 236 CFM
199-SSPRC227CNC PRC 227cc CNC Ported Small Bore 3.9"-4" Cylinder Heads (texas-speed.com)

or

Go RECTANGULAR PORT:
PRC LS3 Aftermarket 260cc ((((with an LS3 intake and 90mm TB)))
Flow: .650" 372 cfm / 240 cfm
199-SSPRC260LS3 PRC LS3 Aftermarket 6-Bolt 260cc CNC Cylinder Heads (texas-speed.com)

grubinski

Street motor with a single pattern cam …. I’d go 227s. Weekend race toy, 260s.

BigBoyWS6

Im trying to make as much N/A RWHP as I can before boosting it with a single turbo.

But N/A or boosted…….why wouldn’t the better flowing head always be the choice? Air in….air out as fast as possible, right?

Roll racing will be the race of choice…..and 1300 RWHP with the turbo I’m using is the power goal.

BFK86

iTrader: (1)

I don't think you'd really be taking full advantage of the PRC rec port heads with that cam. If you want to run those heads I'd step up cam and to a short runner intake. The cathedral port setup would definitely benefit from a FAST 102. I wouldn't waste my money doing the TPIS 90mm throttle body, put that toward a FAST.

BigBoyWS6

So 227cc heads and a FAST intake with 102mm TB.

And that will be optimal staying with my current cam……for the turbo set up also?

wannafbody

iTrader: (2)

I'd run a split duration cam with more duration on the exhaust.

grubinski

Two things made me go that way. I think the single pattern cam will exhale easier on a cathedral port head because the I/E flow ratio is better. That head would also give you better port velocity and snappier response just driving around. The cam being relatively mild made me think you had street manners in mind.

BigBoyWS6

I don't mind a little lope. But ultimately this set up will be boosted with a rather large T6 single turbo, like in a few months. I need a better top end. The more N/A power and the most efficient flowing top end I can get, the less psi needed to reach my goals.....right.... My goals are a lot, 1300 RWHP with this turbo:
Forced Inductions. FORCED INDUCTIONS V5 BILLET S491 CRC 102 TW 1.32 A/R T6 Housing

If I need a cam change because of the heads and to have a better turbo cam, I'll change it also.

cdubbzz

iTrader: (11)

Max RWHP doesn't win races, highest average HP does. K bye

wannafbody

iTrader: (2)

The rec ports will make more power above 6000 rpm especially with a shorter runner intake.

BigBoyWS6

ok…..I want MAX RWHP throughout the rpm range.

lol

BigBoyWS6

well, maybe I started the thread out wrong. I was always told to make as much RWHP as possible, then go ahead and boost it, and you will make more power boosted in the end.

I ultimately want the best head that will fit best for boost, in the end. I plan to spin it to 6800.

I want to do this upgrade now. Along with a new intake and TB to match. I was told a 90mm TB is all I need for boost. Of course, if I need a better spec’ed cam I’ll go ahead and do it, even though this cam is brand new.

01CamaroSSTx

iTrader: (3)

No argument that bigger air pumps produce more power.

wannafbody

iTrader: (2)

While this is true, adding too big of ports with too big of a turbo can make the car lazy and unresponsive until midway up the tach. You don't want your torque curve looking like your hp curve.

01CamaroSSTx

iTrader: (3)

Absolutely, the right combination is key.

gnx7

iTrader: (28)

If you are going boosted with the healthy turbo don't even worry about trying to make MORE POWER below 5000rpm. That turbo will make more power than you can use once it makes boost for the most part until you are in 1:1 gear. I have a Precision 88mm T4 on a 376ci setup running MAST LS3 heads, LS3 intake and I can't even use the power until 4th gear ramping it in by boost/time in each gear (T56). The LS3 intake is a great intake for boost. I've spun it as high as 7800rpm even though it hits an airflow wall just under 7000pm... it will carry the power... it just starts to fall off. I would keep shift points under 7200rpm if you aren't using big $ lifters for a long an happy valvetrain life.

4thGenCamaroZ28

How did you come up with 10.2: 1 compression without heads?

BigBoyWS6

I had to get my car on the road. Picking it up today at the shop who did the install, towing it to my tuner, with my new engine done and ready to street tune it tonight.


My engine was assembled using my old heads. LS1 ported, old as dirt, flow 304@.650. I couldn’t stop the install till I found new heads.

This same shop is going to install my T6 Huron Kit. Hopefully in just a couple months. I’ll have him do the head swap, LS3 intake and TB.

Im pretty sure im going LS3 style. Still trying to make a choice.

Ising a compression calculator O think it was right around 10.2:1.