on a turbo car a ported head comes in to play when you cant run anymore boost, or need to make the same power on less boost. For street cars on pump gas I like a ported head so we can run less boost to hit the power goals, the spool is faster, less heat, etc.

For drag race cars.. spool up time isnt that important and in a case like Carey's the turbo is more than capable of making the power it needs, changing boost a little isnt going to make the car go any faster. His setup also shows what a good intake manifold can do for a s2000 motor.

All that being said we've tested the RLZ heads we use and 75-100hp gain on our stock valve head is not uncommon on a turbo car assuming the turbo can keep up.

In the op's setup the big intake valve isnt going to help on the 87mm bore, the cylinder wall will be shrouding the valve.. it'd make the same power on a stock size intake valve

 

You will make more power on a Ported Head, but it's more power @ less boost. It only works if you have enough turbo left...

It's like this, if you have a stock head...you might max the turbo @ lets say 30psi. In this instance, adding a CNC Head will yield little power...but you will make it at less PSI.

Boost is the restriction the the intake...it's backed up flow, with nowhere to go. When you do things, like port the head and put a bigger intake manifold on...you lessen the restriction on the intake...

Therefore, you make more intake cfm with less restriction...therefore making more power with less 'boost'. A ported head makes things more 'efficient'...so some setups will benefit, where other wont...

If you free up the intake side, you need to do the same on the hot side...so bigger A/Rs, bigger Downpipes, etc...put a 4piston head on a maxed out Stock Motor/Greddy Kit...it's not making 100whp.

Anything you free up on the cold side, has to mirror the hot side...ideally, you'd be logging EMap(Turbo and Downpipe), Turbo Impeller Speed(and actually have proper compressor maps), and 4xEGT.

There's no free lunches here.

 

Nice build!

That intake manifold looks nice! what kinda gains are you expecting with it?

 

Love 4piston stuff

 

Good discussion guys. And this is my thought process behind it all. Making things as efficient and safe as possible. Yes we all known 1000whp can be made on a stock intake mani, stock head, all that stuff. But I want to look for improvement and not do another cookie cutter build. If the addition of the larger intake manifold and reworked CNC ports allows me to make power at a lower boost level that means boost can be increased on the smaller 68mm turbo and make the power FASTER and more EFFICIENTLY than a larger turbo. If it was a dedicated drag car I agree a massive turbo on stock head would more than get the job done. But I'm trying to do something different do we all have some actual data to get out of the mindset that stock cams, head, and intake are "best"

 

And I agree. The car will be running the AEM 4 channel wideband and emap sensor. Also thinking about doing a small 50-60 direct port dry shot of nitrous to help bottom end since car is going to be vtec killer on oem cams

 

Man Oh Man what a build! Top notch shit! I hope it is a tax write off for your shop$$$$$$$. Subscribed!

 

Being different gets expensive.

We don't run stock cams, head or intake. Just stock ports. In no means have I said it's the best either. We (and anyone) could absolutely pick up HP with a ported head. And will eventually run one. But at 1300hp and climbing, we all are curious how much further we can go until it's a restriction (we are getting really close by the way) Especially when you add methanol to the port volume. I'm not just speaking in theory, we have tons of actual data to support any claim or thing coming out of my mouth.

Our major concern with it honestly is structural integrity of the port. Especially on the exhaust side. You get dangerously close to water jackets on this head, and depending on the casting some are worse than others.

 

The castings do vary quite a bit. We had to put 0.040 back in the roof of the exhaust ports due to a few breaking through the water jacket. Getting the intake port big enough to really work with a 1mm oversize valve takes some creativity to say the least. Honda didnt leave much room

 

I completely agree carey, and have a huge amount of respect for you, your team, and your race program. I'm not looking to set any records here just try something different.

Tax write offs?! Smh I wish... I'm just a joe blow in a garage I rent for a couple hundred bucks with some buddies. I have ZERO shop backing or support in that area.

As far as port thickness goes this is what Josh at 4piston recommended to me. ...On the k-series castings I like to do our 156cc ports due to keeping the wall thickness high for large amounts of boost(over 1000), for the all motor cars doing a 163cc port is no problem but the walls do start to get thin in spots. Now from the factory the s2000 ports are larger than the k series so we can achieve a 163cc port on an s2000 and keep the wall even thicker than a standard 156cc k series port which has been proven to 1200-1300hp. Not an exact quote but that is the info I was provided with regarding wall thickness. If he wasn't comfortable doing it at 4 figure power levels it wouldn't have gotten done.