how to copy and improve the D-series Greddy turbo kit
 

customer wanted basically a replication of the Greddy D-series cast manifold and downpipe that would flow better and be lighter.

here is the manifold improvement:
http://i47.photobucket.com/albums/f1...h/DSC08474.jpg

you can see in this pic that the #2 and #3 runners on the cast manifold have severe restrictions in them with the indents for the bolts. you can't get your finger through the ports because they are kinked so bad. i made a jig based off the cast manifold to place the turbo in the same location. i only used about 3/4" of straight pipe on this manifold on the #1 runner off the head flange, everything else is made from elbows. the plasma cutter came in real handy for doing the collector part of the manifold. i started with the outside runners first, then did the inside runners. i've also done other short runner manifolds starting with the middle two runners and to be honest it isn't much different doing it one way or the other.
http://i47.photobucket.com/albums/f1...h/DSC08479.jpg
http://i47.photobucket.com/albums/f1...h/DSC08475.jpg
http://i47.photobucket.com/albums/f1...h/DSC08480.jpg

here is a temporary jig i made up to copy the downpipe... you can see the cast elbow and the section of the downpipe i cut off so i could use the bottom section of the downpipe and just basically fabricate a new elbow and attach it to the lower section of the dowpipe. the only part of this jig that is welded is the angle iron post in the middle holding the bottom section of the downpipe to locate it as it is not joined to the rest of the downpipe. i just tacked it in place. the other post is completely clamped to the table and i used a couple small pieces of angle and some clamps to keep everything in place. on the turbo end, i just clamped it to the table. it worked out well for this application because i was just doing a one off. if i were making lots of these i'd make a fixture for it that i could throw on a shelf some where.
http://i47.photobucket.com/albums/f1...h/DSC08468.jpg
http://i47.photobucket.com/albums/f1...h/DSC08469.jpg

here is the new elbow tacked in place:
http://i47.photobucket.com/albums/f1...h/DSC08472.jpg

here is a comparison between the elbows... you can see the hole in the middle of the cast greddy elbow... this was going to be a problem for putting a bolt through the flange into the turbine, until i discovered i could just put a stud in the flange and modify the turbine housing to accept it.
http://i47.photobucket.com/albums/f1...h/DSC08487.jpg
http://i47.photobucket.com/albums/f1...h/DSC08482.jpg
http://i47.photobucket.com/albums/f1...h/DSC08488.jpg

the cast elbow doesn't even have a 2.5" outlet like the rest of the downpipe... i made my hole in the flange oval with a contour perimeter matching that of a 2.5" circle.
http://i47.photobucket.com/albums/f1...h/DSC08483.jpg

here is the modification i had to make to the turbine housing for the stud, just drilled out that hole and counter sunk it to clear for the weld around the stud and cleaned up the other side:
http://i47.photobucket.com/albums/f1...DSC08484-1.jpg
http://i47.photobucket.com/albums/f1...h/DSC08485.jpg

there's always room for improvement!

Re: how to copy and improve the D-series Greddy turbo kit
 

That is some nice work right there ! I would strongly recommend you try and talk your customer into putting an external wastegate on there. One of the major problems of the Greddy kit is boost creep. My Greddy kit would run higher and spike constantly. It was supposed to be a 5.5psi wastegate but used to spike to 9 - 10psi and then fall back to 7.8psi. Now with my ramhorn and 38mm Tial, rock steady 5.9psi. At worst if he doesn't go for an external gate, opening up the hole behind the flapper might help with it a little bit.

That set-up right there will be a huge improvement and he will notice the difference right away.

Re: how to copy and improve the D-series Greddy turbo kit
 

wow Aaron, really nice work! Send that to greddy

Re: how to copy and improve the D-series Greddy turbo kit
 

Thank you for posing your work. Very interesting.

Re: how to copy and improve the D-series Greddy turbo kit
 

excellent work!

Re: how to copy and improve the D-series Greddy turbo kit
 

Good stuff Aaron!! Is that inlet flange a bit banana'd or is it the picture?

Re: how to copy and improve the D-series Greddy turbo kit
 

That's some nice ---- right there. Was the whole purpose of doing this so he wouldn't have to change his intercooler piping?

Re: how to copy and improve the D-series Greddy turbo kit
 

yeah, it is just the pic. i took it to the belt sander after everything was done.

actually, the guy already has the exact same setup on his car already. he bought a whole complete second setup with the intention of porting the manifold, turbo, putting a different compressor wheel on and porting the dp cast elbow... i guess he decided to instead go with a whole new mani/dp combo and just do some reworking on the turbo. he is happy with the setup, but just wants a little more oomph without making any drastic changes. he is still running ps and ac.

Re: how to copy and improve the D-series Greddy turbo kit
 

That manifold looks like a real pain in the ass. Looks great though. If you find anymore of these people with more money than sense and you start getting backed up feel free to send a couple my way. ;D

Re: how to copy and improve the D-series Greddy turbo kit
 

i feel my pricing is very reasonable. i'm not about to start doing this stuff full time though... it is just filler work that i like to do for local customers on occassion. ;)