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Old 03-25-2008, 12:25 AM   #76
spoolindc2
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If I remember correctly, Al @ Dynoflash had a post about this not too long ago... He had that gt-35r 08 sti with a perrin EL header on it, he wasn't making the power he thought he could and a simple switch out of the Perrin to a Agency power? Or some other non EL yielded atleast 20 hp w/o even touching the tune. I know it just dumps back into a small up pipe but the header is restricting...

Overall what a great setup the reverse manifold looks great, but IMO you should get a little more aesthetically pleasing filter!
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Old 03-25-2008, 05:57 AM   #77
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Is it the 28th yet............................

I am really curious to see the difference the coupler makes....
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Old 03-25-2008, 08:30 AM   #78
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Quote:
Originally Posted by shvrdavid View Post
Is it the 28th yet............................

I am really curious to see the difference the coupler makes....
i cant wait too....off topic....where in central pa are you from...im born and raised in mechanicsburg
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Old 03-25-2008, 09:13 AM   #79
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Quote:
Originally Posted by spoolindc2 View Post
If I remember correctly, Al @ Dynoflash had a post about this not too long ago... He had that gt-35r 08 sti with a perrin EL header on it, he wasn't making the power he thought he could and a simple switch out of the Perrin to a Agency power? Or some other non EL yielded atleast 20 hp w/o even touching the tune. I know it just dumps back into a small up pipe but the header is restricting...

Overall what a great setup the reverse manifold looks great, but IMO you should get a little more aesthetically pleasing filter!


Hmm i want to keep the EL header as it benefits the twin scroll turbo that i have atm... I may look into getting a full race manifold which uses 48mm piping rather than the 38mm the perrin uses.. But i think the restriction may be at the exhaust may need to go with 3.5" dump pipe. I could go about putting sensors at different points and mointoring flow by my motec but, the funny thing is, that itll cost more to do that (even though it would be permanent) then to just put a 3.5" section in its place (do trial and error)..

As for the filter what would u suggest would be more aesthetic???


David, i hope to get the car on their dyno on friday but havent had word yet, ill call them tomorrow to make sure my car goes in.. hahahah
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Old 03-28-2008, 11:15 AM   #80
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i hope your getting in the dyno today....let us know
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Old 03-28-2008, 11:39 AM   #81
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I know this has been said numerous times:

That is absolutely choke flow.

The quest is on to find where that point is. You have already realized that the Perrin EL header is one of the points.
Other points of interest:
Wastegate setup
Exhaust ports. You said a little port and polish, right? the factory exhaust ports really choke out at 500whp regardless of cam selection. How much work is actually done to the exhaust ports? As shrvdvd can explain, the gain isn't at the outlet of the port, it's the shape of the port just after the valves that makes the biggest difference. I wish I could sound more educated on this.

I doubt you have any issues with intercooler piping or intake manifold design. It looks really good.

My 2 cents.

Patiently Waiting,
-Dominic
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Old 03-28-2008, 12:46 PM   #82
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yeah, it really is hard to describe port work and changes without out touch/feel and looking

but I know what you mean
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Old 03-28-2008, 06:23 PM   #83
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Quote:
Originally Posted by KitoAutoSport View Post
...Exhaust ports. You said a little port and polish, right? the factory exhaust ports really choke out at 500whp regardless of cam selection. How much work is actually done to the exhaust ports? As shrvdvd can explain, the gain isn't at the outlet of the port, it's the shape of the port just after the valves that makes the biggest difference. I wish I could sound more educated on this....
That about sums it up... You summed it up perfectly...
The output size of the port has very little to do with the total flow potential, and the smaller it is, the better(as long as it flows)...
The smaller size will drastically raise the speed of the flow, helping with scavenging and overlap flow...

The bowl shape is all wrong for high flow rates in the factory casting...
Like Dominic said, it chokes flow above a certain flow rate...
The difference in the flow from the 2 valves in the dogleg port is where the flow choking starts at...

It took me a long time to figure out how to get the dogleg to flow properly...
When you get it to flow at low lift, it messes up high lift, then vice versa...
Getting the flow to merge properly in the dogleg thruout the lift range, is the key to getting power out of these heads...
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Old 03-28-2008, 06:33 PM   #84
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bump...
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Old 03-28-2008, 07:20 PM   #85
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Quote:
Originally Posted by KitoAutoSport View Post
I know this has been said numerous times:

That is absolutely choke flow.

The quest is on to find where that point is. You have already realized that the Perrin EL header is one of the points.
Other points of interest:
Wastegate setup
Exhaust ports. You said a little port and polish, right? the factory exhaust ports really choke out at 500whp regardless of cam selection. How much work is actually done to the exhaust ports? As shrvdvd can explain, the gain isn't at the outlet of the port, it's the shape of the port just after the valves that makes the biggest difference. I wish I could sound more educated on this.

I doubt you have any issues with intercooler piping or intake manifold design. It looks really good.

My 2 cents.

Patiently Waiting,
-Dominic

Before i start answering some questions.. Car has hit an issue which wont be solved for a few weeks as the workshop is already under the pump with other cars.. So once thats sorted ill update and elaborate further later on..

Now to answer some questions..

Dominic,

What do u mean by wastegate setup causing a problem??

Do u think that its beneficial that i increase the Dump pipe section to 3.5" over the 3" currently there??

Dominic, shvrdavid and Micah: Have u guys got any pics to show or send me what u think the ports should look like?? Id like to compare them to my car and see any differences..


Now going back to the cam timing.. I have AVCS so isnt timing done electronically??? So i wouldnt be able to tell if it was out by a teeth or two by pulling off the cam cover???
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Old 03-28-2008, 07:51 PM   #86
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Quote:
Originally Posted by engineerx View Post
^^^ What he said +

The Perrin EL headers make nice power on the smaller turbos, for a large turbo like the GT40, the diameter of the runners on the header are too small in my opinion. They might be restricting flow to that large turbo. I'd try a different header. Didn't read whole thread, maybe some1 suggested this above.
I agree, get some headers made for big twin scroll kits. Full race or Ultimate racing make decent pieces, but kinda pricy. Do you know what the flow is on your heads?? CFM and Lift??? Have you thought about ditching the AVCS and going oversized on the valves???
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Old 03-28-2008, 08:24 PM   #87
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Quote:
Originally Posted by tino View Post
...Dominic, shvrdavid and Micah: Have u guys got any pics to show or send me what u think the ports should look like?? Id like to compare them to my car and see any differences..
Looking into dogleg port...


This is my highly modified dogleg runner... (use at own risk, this can't be done to some castings... Ask me how I know...)


This is the strait one...


The exhaust seats do not have final cutting in the pictures above...
There isn't much left of the factory seat now, but it should hold...
They are now .060" seat face with rounded entrance to the port...

Here is a crappy picture of what is left, (or not) of the factory seats right before final machining...




Quote:
Originally Posted by tino View Post
...Now going back to the cam timing.. I have AVCS so isnt timing done electronically??? So i wouldnt be able to tell if it was out by a teeth or two by pulling off the cam cover???
It isn't a matter of being off a tooth, or AVCS... It is being off a few degrees one way or the other...
With the timing marks lined up perfectly, they still can be "off centerline"...
That's what people mean by asking if you degreed the cams...

Even with the timing marks lined up on everything, it will most likely not be where the cam card says it should be...

Manufacturing tolerances allow for a certain amount slop... This can be more than you would first think...
Depending on which parts have slop, in what direction, things end up, not where they should be...
Machining the surface of the heads and or block adds to the problem as well...

Here is a link to a basic rundown on how to check the cams...

How to degree a cam...
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Old 03-28-2008, 10:03 PM   #88
tino
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Quote:
Originally Posted by jerry curl View Post
I agree, get some headers made for big twin scroll kits. Full race or Ultimate racing make decent pieces, but kinda pricy. Do you know what the flow is on your heads?? CFM and Lift??? Have you thought about ditching the AVCS and going oversized on the valves???
I dont know the flow of the heads but the lift of the cams are 10 degrees i think..

Im running 1mm oversize valves in the exhuast..
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Old 03-28-2008, 10:04 PM   #89
tino
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Quote:
Originally Posted by shvrdavid View Post
Looking into dogleg port...


This is my highly modified dogleg runner... (use at own risk, this can't be done to some castings... Ask me how I know...)


This is the strait one...


The exhaust seats do not have final cutting in the pictures above...
There isn't much left of the factory seat now, but it should hold...
They are now .060" seat face with rounded entrance to the port...

Here is a crappy picture of what is left, (or not) of the factory seats right before final machining...






It isn't a matter of being off a tooth, or AVCS... It is being off a few degrees one way or the other...
With the timing marks lined up perfectly, they still can be "off centerline"...
That's what people mean by asking if you degreed the cams...

Even with the timing marks lined up on everything, it will most likely not be where the cam card says it should be...

Manufacturing tolerances allow for a certain amount slop... This can be more than you would first think...
Depending on which parts have slop, in what direction, things end up, not where they should be...
Machining the surface of the heads and or block adds to the problem as well...

Here is a link to a basic rundown on how to check the cams...

How to degree a cam...

Thanks mate, ill have a read its hard to tell what u have done without comparing back to a stock head..ill try and dig some pics of a stock head to look at..
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Old 03-29-2008, 12:18 AM   #90
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Quote:
Originally Posted by saintluciascooby View Post
48mm , I thought the clearances would be similar maybe it wont work in the end !!!!
I will let you know, I did go to a Tilton pedal box to get rid of the brake and clutch master cylinder to give lots of wiggle room
Do you have picks of the Tilton pedal box? Does it allow you to retain the ABS or do you require a bias adjuster?
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Old 03-29-2008, 12:21 AM   #91
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Would the APS kit be any better than the Perrin as it allows a twin scroll set up to be fitted in a RHD car but I'm not sure about the diameter of piping.
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Old 03-29-2008, 01:10 AM   #92
tino
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Quote:
Originally Posted by 05gtSTi View Post
Would the APS kit be any better than the Perrin as it allows a twin scroll set up to be fitted in a RHD car but I'm not sure about the diameter of piping.
APS has the same diameter as the perrins asfaik.. The upipe is the issue for RHD.. Which i have already sorted out, so could easily go full race and just mate it to my upipe..
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Old 03-29-2008, 01:39 AM   #93
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I must say I feel for you Tino as you've had to wait on the build it's self then the on going issues that have risen after the completion. Its definately a game of trial and error some times with everyones input and definately a lot of patiance. I hope it all works out for you as I'm sure a lot of people are watching your progress with a keen eye on your results
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Old 03-29-2008, 06:51 AM   #94
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The pedal box has separate front and rear cylinders and the bias bar is built into the back of the box I will snap some pics in the next few days.
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Old 03-29-2008, 09:27 AM   #95
tino
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What do u guys think about these heads?? Not mine

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Old 03-29-2008, 01:41 PM   #96
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every professional porter that i have talked disagrees with knife edging the divider they all say it creates bad turbulence . and whoever ported those extended the divider, i am not a pro porter although i do my own personal porting but i dont think those ports are gonna work very well but thats just my opinion.
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Old 03-29-2008, 02:57 PM   #97
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Originally Posted by MRX WRX View Post
every professional porter that i have talked disagrees with knife edging the divider they all say it creates bad turbulence . and whoever ported those extended the divider, i am not a pro porter although i do my own personal porting but i dont think those ports are gonna work very well but thats just my opinion.
It does make turbulence, with air...
But remember that there is gas there when the car is running....

Ask anyone who ports heads how that knife edge works on a wet flow bench...
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Old 03-29-2008, 06:16 PM   #98
tino
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Originally Posted by shvrdavid View Post
It does make turbulence, with air...
But remember that there is gas there when the car is running....

Ask anyone who ports heads how that knife edge works on a wet flow bench...
So david, are u saying that it would work or saying that it wont with those heads??
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Old 03-29-2008, 10:20 PM   #99
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Quote:
Originally Posted by tino View Post
So david, are u saying that it would work or saying that it wont with those heads??
They should work...

Here are what mine look like, you could cut yourself on the divider...




My divider is further down the port than the heads you posted a picture of...
I can tell that my heads, and the ones you posted were ported very differently...
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Old 03-29-2008, 11:21 PM   #100
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one or two wastegates? either or, i'm going to go with turbine back pressure as mentioned before. Looks like you are filling the exhaust very well, and it has nowhere to go...

personally, i would have never started with a 40 too - hate to break it to you, but the car will never reach its potential with that slug. 37 or 42 man.....i'll never take that option in between. It simply does not work as well as the options around it.
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