Yes the valve job was not completed at the point when the pic was taken because of how far down the throat gets cut when the 1mm os valve job is done.

As far as deflection he assured me that would not be an issue in this head, I ran it very hard for 2-3000 miles and never had an issue with it other than in hindsight I know it was way overkill for a 400hp car.

The engraving did suck

 

Ok - we tested the Headway Performance head last evening and the results are not very good

My 40 psi power went from 808 to 775 uncorrected

Speaking with Ramon we theorize that my .63 a/r T4 back housing may be resulting in too much manifold back pressure and thus when we step up to the freer flowing head the resulting bottle neck may result in reduction in cylinder flow

I am keeping an open mind and I am willing to expore all available options

My next step is to take a measurement on manifold pressure and swap to a .81 a.r back housing I have on hand

Sadly, it seems that achieving the optimal combination does require a great deal of effort

Al

 

Are you measuring pressure @ the manifold with these tests? Can you post pics of the ports and heads?

 

I am going to install a bung either in the manifold of turbine housing to measure the pressure

Al

 

Lost power going to a ported head! Damn that is nutz. It's amazing how revealing a bit of testing is.

Can't jump to assuming the head is bad I guess though. But I'm struggling to figure out why a ported head would make less power. Only reason I can think of are all those fancy things that I don't understand well like velocity, tumble and swirl, etc. And if any of those are the reason why the stock head did better, then presumably that means the stock is better for your application Al regardless of turbine housing.

Are the stock head and the ported head the same height? I'm thinking of one head was skimmed a lot the cams would be degreed differently?

 

Velocity I would assume.

Smaller ports should encourage the air to move through it faster. The consequences are various getting the right combination of a bunch of them is crucial to making more power throughout the rev range....

Scorke

 

and I just bought a Stage 3 head

 

I am not surprised at all. If a head is ported the wrong way you basically just ruin the head.

 

I wouldn't go assuming that the head is no good just yet... Even if my money has always been with work focused on short turn and the bowl primarily. I have always felt that to be the best route, but didn't think the testing would show the headway head to lose power across the board. Would of guessed mostly moving the power band too far to the right with small gains/ diminishing returns. None the less this is good info, and I hope that you plug away at finding the answers. Al, I have a fresh head ready to bolt on if you want to try it

 

The theory I am woking out now is that the ported/ cnc / big valve head is flowing so much more air that it worsened a pre-existing condition of too small a turbine housing. At least that is what the head guy is thinking.

I have worked tonight to install a larger a/r turbine housing - moving from a .63 a/r to a .81 a/r T4 back housing

Its too late to dyno now and I have no oil on hand so testing will have to wait for tomorrow

I am very determined to see if the head guy's theory is accurate or not

Al

 

I have not yet tested the Buschur head which has always worked well on all cars I have tuned with it

I am only working thus far with the Headway Performance cnc head

 

I am also not quick to jump to answers and conclusions

A few principles upon which I am working

# 1 - Keep an open mind

#2 - Report the truth and what happens even if it makes someone's product not look good

#3 - Exhuast all possibilities before reaching conclusions

In my mind, a well ported head with larger valves should make at least the same power up top as the stock head and should spool perhaps slightly slower

In this case the spool up was identical

I have to post the dyno sheet later - the power was the same in the spool up - fell under the base line in the mid range and then matched the base line at 8,000

I appreciate the offer to test a head and would certainly test any head

One thing the head testing may be doing is exposing some weakness in my set up

The T4 flanged header is questionable and just may not work on the 2.0 L engine with the turbo I an running

With the stock head previously the .81 a/r back housing did not work that good - it was kind of laggy on a T4 with this turbo and I have concerns that the end result may not work well

If I do not get anywhere with this combination - I have the Gt42 sitting ready to go back on the car and will conduct the testing with that turbo

One step at a time is the only way to reach a valid conclusion

Al

 

I was wondering if you were maybe going to try both heads with a larger turbo. I for one appreciate the testing. It is a lot to put your car through. I have thought about doing back to back dyno testing before, but not currently being employed in the business, and the side work I do is more of a hobby than a second income, I can never justify it. E.T.s have been good enough for me so far ha.

 

Did the curve change at all? Did you have to adjust anything in order to maintain the 40 psi? Can you post the contrasting dyno sheets?

 

Off topic but just had to say I love the names of these head companies:

HeadGames
Hi-Aspirations
Headway Performance
etc