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Project Turbo Manifold - final design assembly
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Can you see the pics ?
Yes always
19%
 19%  [ 10 ]
No never
45%
 45%  [ 23 ]
Sometimes
25%
 25%  [ 13 ]
What pics
9%
 9%  [ 5 ]
Total Votes : 51

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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sat Jun 10, 2006 6:07 am    Post subject: Project Turbo Manifold - final design assembly Reply with quote



I'm making an equal length turbo exhaust manifold for my 931.

I'm using CAD to design it, and it will be geometrically perfect(Exact Equal Volume, and least amount of bend in the required space.)

I should be able to fit any turbo, including the factory unit, to it.

I'm using it for a GT28RS double ball bearing turbo (T28 Flange).

I'm using 1.5 " Schedule 10 304 SS forged bends and pipe.

I would have used 1.25 " but because of the confined space and having to bend 90 degrees immediately after the manifold, I chose 1.5".

My SS pipe will be cut with a CNC Machine and the ends buttressed for the strongest possible TIG weld. My mild steel prototype version will be cut using a machine I made.

All fittings are machined to fit, then welded. This leaves a smooth clean finish on the inside of the pipe, WITH NO BITS OF WELD TO LATER CRACK OFF AND DESTROY MY TURBO. The company machining and welding the fittings, service the dairy industry, and they donít allow any cracks on the inside of the pipe which might trap contaminants.

I'm welding up each of the individual pipes first, then the manifold flange to the turbo flange, then the pipes last. So it has the least amount of stress after all welding is completed.

Then I plan on tapping holes for exhaust temp probes, and finally have it ceramic coated.


Last edited by OutOfTheBox on Mon Feb 05, 2007 7:31 pm; edited 18 times in total
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sun Jun 11, 2006 3:15 am    Post subject: Reply with quote

Had a busy day today, put my block back in the engine bay to take accurate measurements.

Heres a pic;



Last edited by OutOfTheBox on Fri Aug 18, 2006 12:39 am; edited 2 times in total
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sat Jun 17, 2006 6:18 am    Post subject: Reply with quote

Finished measurements and digitised the area which is available for piping.

I left a 20mm even gap, between the body and where I can locate my manifold/piping/turbo.

I then printed out a scale print of my drawings, and made a cardboard cutout, and fitted it against the block as in the photo below. And checked the gap was indeed 20mm at the sides, and level with the sump of the engine where it also crosses the steering rack. The engine has to smack the steering rack/cross member before my turbo does.

I then using CAD played around and looks to see if it would be possible to satisfy the following.

1. Exact equal Length runners.
2. Tuned to a full wavelength.
3. Collector with long column.
4. Remove the firkin thing, without taking the cylinder head off.

Its was to the mm(thousandth of a caveman inch) possible.

It also seems that the max size turbine housing would be 180 mm, possible 200mm if you use stiffer engine mounts.

I now need to measure the volume of an exhaust port, so I can calculate the required length to make the pipes tuned.


You need to know the port volume to accurately work out the tuned length.

I need to go grab one of my exhaust valves from the engineers so that I can measure my exhaust port volume accurately. (Fit valve fill with oil, measure volume of oil)

Once I have the ex port volume, I will write some scripts to route the pipe.

I reckon that equal length is a TOTAL waste of time if your collector angles of pipes entering isn't less than 40 degrees. This is calculated(for a 40mm ID pipe and 50mm ID flange=40degs), and is dependant on Pipe Inner Diameter, and turbo flange dimensions, and is the
angle required so that each runers airflow is directed at the flange, and not another runner's pipe wall. If you look at the picture below, you will see that the ID of each of the collector pipes, exactlys cover the flange box below it.

VERY IMPORTANTLY that the MAXIMUM difference in angle from one exhaust pulse's airflow and the next will be 40 degrees, IN A SINGLE AXIS, and not 40 degrees in BOTH axis, which it could be if you just placed your pipes, from your ports, willy nilly. But wait theres more......it will also spin in a clockwise direction around the collector, causing a whirlpool effect, that further aids in scavenging.

The simple test of an equal length manifold would be to spray a hose pipe down one of the port headers, if any water leaks back out of any of the other ports instead of all coming out the turbo flange, then you will have the opposite of scavenging, and your manifold is shit.

Better still, attach ball bearing turbo, and use an air gun positioned in front of manifold runner, fire a one second shot, and time how long before turbo stops spinning. Do this for each runner ???

The drawing I overlaid over the photo, is skewed, because the picture is not front on, but it shows you that a full length collector is possible, along with the turbo and piping.

The bottom of sump, is the front portion, that holds no oil, that sits above the cross member. The bottom of the turbo, is the compressor outer limits, so the turbo oil return will be above the bottom of the block, and will be able to use the exisiting, defrothing return.





Last edited by OutOfTheBox on Fri Aug 18, 2006 12:41 am; edited 5 times in total
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Fri Jun 23, 2006 5:17 am    Post subject: Reply with quote

I'm keeping a diary of my modifications here;

http://porsche924turbo.blogspot.com/


Last edited by OutOfTheBox on Sat Aug 05, 2006 10:36 am; edited 2 times in total
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John Brown  



Joined: 07 Nov 2002
Posts: 903
Location: Leesburg VA

PostPosted: Fri Jun 23, 2006 12:47 pm    Post subject: Reply with quote

Paul:

Really enjoyed the blog. Can't wait to see what you come up with on the manifold.
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John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82
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N-Dub  



Joined: 16 Jan 2006
Posts: 219
Location: Salt Lake City, Utah

PostPosted: Fri Jun 23, 2006 3:31 pm    Post subject: Reply with quote

You should make multiple of these. You could probably sell them pretty well for a pretty heafty price.
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'87 951
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sat Jun 24, 2006 12:12 am    Post subject: Reply with quote

"money be the root of all evil"

Its amazing how quickly a good engineering project, will turn into a bitch fest, once money gets involved.
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Sat Jun 24, 2006 2:48 am    Post subject: Reply with quote

OutOfTheBox wrote:
"money be the root of all evil"

Its amazing how quickly a good engineering project, will turn into a bitch fest, once money gets involved.



Well, if you're up for giving them away, then that always works for me.
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flosho  



Joined: 01 Jul 2004
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Location: Eau Claire, Wisconsin

PostPosted: Tue Jun 27, 2006 12:49 pm    Post subject: Reply with quote

Any updates on this project at all?
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Fri Jun 30, 2006 11:38 pm    Post subject: Reply with quote

Updated my project.

Will start making a prototype this weekend..


Last edited by OutOfTheBox on Sat Jul 15, 2006 9:42 pm; edited 1 time in total
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Sat Jul 01, 2006 3:05 am    Post subject: Reply with quote

:drool:


Can't wait til you get a prototype mocked up.
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Fri Aug 04, 2006 6:56 pm    Post subject: Reply with quote

Finished my cutting and jigging machine.

Finally started to make the prototype

Full details here





Last edited by OutOfTheBox on Fri Aug 18, 2006 12:44 am; edited 4 times in total
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Fri Aug 04, 2006 10:12 pm    Post subject: Reply with quote

Finished the 8 collector pieces. See top drawing.

This machine rocks !!!!!!

It only took 15 minutes and check the accuracy

Full details here





Last edited by OutOfTheBox on Fri Aug 18, 2006 12:46 am; edited 7 times in total
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Sat Aug 05, 2006 1:55 am    Post subject: Reply with quote

This is like a bad dream..

a ssweet thread like this and none of the pictures show up!!
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genikz88  



Joined: 29 Mar 2006
Posts: 64

PostPosted: Sat Aug 05, 2006 2:05 am    Post subject: Reply with quote

flosho wrote:
This is like a bad dream..

a ssweet thread like this and none of the pictures show up!!


Agreed!

BTW, great thread. More people need to use PUNCUATION and PARAGRAPHS. Thank you!
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'88 924S
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