How many RPM's with ported champions?

[Rafs-T-Type]

I read in a post recently about making numbers below 5800 RPM's and I can't find it now so I started this thread. It kinda made it sound like there's no power to be had after that. How high are you guys shifting at with these heads? Also my intake is not ported. Would it be worth taking off the intake and having it ported? Should I get it port matched? TIA - Jason

 

[Alky V6]

Depends mainly on the cam you choose to use, not the heads.

 

[Rafs-T-Type]

I wish I knew what my cam is :redface:. I had the engine builder pick it out. I asked him a couple times what he ended up picking, but never got an answer, then his shop closed down. I guess I'll just keep turning it up until it loses power.

 

[big reazon]

Dynotune it and see where you stop making power. Base it on that.

 

[BEATAV8]

My old motor has a 210/210 and ported irons. I would spin it to about 6000. It fits the bill for a motor that makes good power up to about 5800.

Ported heads help when you want to start getting past 5400 rpm and you have a cam matched to the goal.

My new combo has mildly ported GN1's and a hotter 215/220 cam with a goal of revving past 6000 pretty regularly. Probably 6250.

 

[big reazon]

this has been ringing in my head ever since I read it "Boost is caused by restriction boost is the air not making it into the motor" With that said I would remove as much restriction as possible. Wouldn't worry about intake if you haven't already added a big throttle body and plenum

 

[bison]

If you're going over 5800 you should be trapping 134+. if you need more rpm you have to be selective about valve springs. It's not easy to just drop a spring on there without modifying the heads. There are some small diameter double springs that will get the job done though. If you are planning on running 6000rpm and 30psi you will need 885 lifters or solid lifters. Valvetrain gets expensive really quick

 

[bison]

this has been ringing in my head ever since I read it "Boost is caused by restriction boost is the air not making it into the motor" With that said I would remove as much restriction as possible. Wouldn't worry about intake if you haven't already added a big throttle body and plenum

A plenum and throttle body won't do crap to increase low lift and low rpm flow through the intake and heads where it needs it most. It is a definite advantage to cleaning up the port exits on a stock intake when running a decent flowing set of heads. Opening up the ports beyond that does little.

 

[bison]

My old motor has a 210/210 and ported irons. I would spin it to about 6000. It fits the bill for a motor that makes good power up to about 5800.

Ported heads help when you want to start getting past 5400 rpm and you have a cam matched to the goal.

My new combo has mildly ported GN1's and a hotter 215/220 cam with a goal of revving past 6000 pretty regularly. Probably 6250.

If be willing to bet $$$ your peak hp is below 5600 and that it starts dropping off fast over 6000. From what I've experienced the car will go faster if the engine is kept within a couple hundred rpm for as much of the pass as possible regardless of rpm drop on shifts. If the engine makes enough nut to pull higher in 3rd then so be it. If youre at 6000 in 3rd with a 28" tire and your converter is working you're going to be up around 139-140mph. It takes a decent mount of engine to go 140mph

 

[Street Lethal]

A plenum and throttle body won't do crap to increase low lift and low rpm flow through the intake and heads where it needs it most...

Depends on the cam specs.

 

[bison]

Depends on the cam specs.

This is correct. It wouldnt make sense to run a cam that uses more rpm when you cant make crap down low. You will just lose torque down low and narrow the power band.

 

[toomanymodz]

I read a thread somewhere that had a combo similar to mine: GN1's, 218/212, 6765 turbo. The guy did several pulls at different boost levels and the peak power was at 5500 RPM. I think one of the pulls made 728 HP but don't quote me.