HybridKOOP

I know several of you are making big power in a variety of different setups. This question applies ONLY to those who have dyno'd their motor before and after extensive headwork with the same amount of boost, compression etc.

In my efforts to build a 500hp street car this winter, I am debating buying a B16 head and Portflowing it, or simply buying a brand new ITR head which comes with a great valvetrain, cams, mild porting etc... and just using that.

It seems that in my opinion, the extensive headwork people pay for alot of times doesn't quite yield a significant power difference. I also believe I remember hearing Viren say a stock Type-R head can flow enough for 500whp.

Any input from any of you? Maybe some dyno plots with differences? Thanks.

- Louis

jinxproof99

stock type r heads flow nice. if you know where to get one new, but at dealer cost and then sell the cams, you've got a great head for a good price.

HybridKOOP

Karl... I assumed Type-R cams would be excellent for boost once the overlaps dialed out a bit... no?

I can get the head for about $1200 brand new, shipped. (NO PM's about it, thanks!)

EDIT: I view the $1200 as not bad... considering I'd have to spend about $500 for a clean B16 head, $400 for ITR cams, and about $450 for springs/retainers. Thats $1350 for a head with stock ports, used. ITR's $150 less, ported. Make sense?


[Modified by HybridKOOP, 4:05 AM 9/2/2002]

jinxproof99

i doubt anyone can get a brand new type r head for less than 1200, in the box, and not hot. thats pretty much mechanic price from the dealer. i would sell the cams for like 500 and buy gsr ones for a 100. someone would sell them for that i'm sure. but as for your ???, i've heard the type r cams are fine for boost. but i have no personal experience with that. either way, the type r head is a factory ported gsr head. can't beat that.........well, for the most part.

HybridKOOP

Factory ported B16 head

jinxproof99

you know what i'm sayin'.....lol.

AB16A2T

Well a friend is hooking me up with an LS head for $50 so I am going to send that out for port polish, hey for $50 I can't complain.

Ltech

stock b16 is good. But you it done right then send it to port flow. It cost me 2g to port and polish, replace the whole valve train. If I could go back I would just use the stock unit.

ekb18c

A stock head will hold up on 500 whp, however a ported head will help you achieve 500whp easier. Think about it, by porting the head you will be allowing more air to flow through, faster! We had customers who gained 30 -40 whp on big turbo systems with just our ported heads. Portflow is good also, as well as BRE.

HybridKOOP

I don't doubt the physics of it... and that a ported head WILL show an increase of power... my questions -- how much? By the time I would be done at Portflow, I'd have about a $1500 dollar bill to pay to him, is it reeeeeallly worth a possible +20 horsepower for a street car...

This is also why I'd like to see dyno plots... my guess is that the power increase may only be in the high high end of the RPM band.

VaporTrail

you'll make the same power on a stock head that a ported head will make. It'll just be with more boost.

jinxproof99

for a street car, 500 hsp or so or less, i'd keep the head all stock except for springs and retainers. use the 1000-1500 you'd spend at portflow on something else.

nothing against portflow. if i were building a race car, i'd send my head there. i just think unless you have major cash to spread around, then the stock heads fine.

Arturbo

I totally agree with you here. I think people spend way too much money on head work when they only need just springs and retainers.

art

jinxproof99

........and more boost!!!!!!!!!!!!!!!!!!

PWRVTEC

So what type on springs would you need to upgrade too?

jinxproof99

crowers, skunks, whatever. ya gotta rev to at least 9000 rpms.....don't ya?????

PWRVTEC

Hell no I am happy with just my 8300 on stock springs, I only make power to 8100 then it starts falling. So maybe I will just upgrade retainers...

Dublocivic

You have to also consider the fact that you will need more seat pressure if your cranking up the boost. If you dont upgrade the springs then you'll blow them off their seats with high boost.

littlebluecrx

put better retainers in the head I had a brand new type r head 2 years ago , I ran the **** out of it 9000 rpm from april till september, then it droped a valve , retainer cracked.Jason

X2BOARD

I don't have dyno numbers, but I ran a stock B18B head on 10 psi and then had that same head ported and polished and re-installed the stock valvetrain. The job stole about 5-10 Hp down low, below 2.5K (my estimate) But gained well over 20 Hp in the 4K to redline rpm band, with a tremendous surge of power at 5K. The PnP job was mild/agressive on the intake and aggressive on the exhaust, with chamber work done and shaved valve guides. The results were phenomenal, especially considering it was on a stock valvetrain.

I ended up turrning down the boost to 8psi, the car seemed to run faster at 8psi w/ the ported head, than at 10 with the stock head.

Keep in mind, this is on an LS head, stock cams.

BTW, although a B16 head is very similar, almost identical to and ITR head, it is not the same head and the ITR is made from a different cast.

X2