havent read thro all 5 pages but just want to add that you can get the HKS downpipe with full open neck, u just need to specify that when u buy it from ur supplier as it is not the standard sold item which IS closed neck

It sticks out 32mm for the Vf29, and allow 10-12mm to be welded into the flange plate , so you have something that is 42~44mm long all up .


Michael

I thought I would give modding out my JDM STB Foresters stock 2" system a shot, A friend gave me his 2.25" WRX downpipe, I knocked out the cat, and just got in from the muffler shop having my added bits welded up, heres a few pics before the bead grinding and smoothing has started. It really looks horrible in these pics but its actually all cut and fitted neatly.

http://users.multipro.com/maynard/jkdp1.jpg
http://users.multipro.com/maynard/jkdp2.jpg
http://users.multipro.com/maynard/jkdp3.jpg

My approach was to cut open the flange to full mouth size, cutaway the wastegate side of the stock pipe, and add in a bent sidewall over on the far wastegate side, fill in the top and bottom spaces and add a splitter. I now need to go over it to cleanup and smooth edges.

I do have a question , Why are you guys plugging the sensor hole and not just reinstalling the sensor? What is the story behind leaving out the sensor?

[Edited by Joth - 4/14/2003 7:47:14 PM]

the downpipe I used has the sensor hole to accomodate use for the later cars. The earlier cars like my 94 wrx have the sensor in the header so thats why I blocked the hole on the d/p.

Looks... well a mess but good too..

http://users.multipro.com/maynard/jkdp1.jpg
http://users.multipro.com/maynard/jkdp2.jpg
http://users.multipro.com/maynard/jkdp3.jpg

JGM :)

hmm could use a bit less wire in the mig feed and do stop start runs, would look more like a tig weld, the idea is all good though :)

Michael

Haha, well, what the heck, I went through it with my dremel etc and smoothed it all out. No pics of the 'after' yet. Today I had it set back on the de-catted downpipe and installed it. So far its great, alot better low end pre boostup, when I step down, boost hits earlier and rages up to 10psi in a blink, the acceleration between 100-160 is faster than before, and I havent stretched it out any more than that yet.
A very satisfactory state of things for the stock 2".

Hi all, managed to do the downpipe splitter mod today.

First pic shows what happens when a workmate leaves their toolbox unattended;)..who me angle grind the lid off, dunno what you mean:D.

http://upload.turbosport.co.uk/getpi...2639180477.JPG

Cut the plate out, dimensions 34mm wide x height (height of d/p neck), also rounded the corners off.
Once located 19mm right from centre of top hole above wastegate area and 22mm right from centre of bottom hole below wastegate area I made sure it protruded 22mm out(where it will fit into back of turbo), leaving 12mm to fit into the d/p and be...

http://upload.turbosport.co.uk/getpi...2639628776.JPG

....welded into place.

http://upload.turbosport.co.uk/getpi...2639470830.JPG

side view showing 22mm of plate that will be located in back of turbo

http://upload.turbosport.co.uk/getpi...2640346050.JPG


Many thanks to Michael South(it's his idea), the dimensions and help via email.

I would have fitted the downpipe tonight but couldn't find somewhere that sold a bolt big enough to block the o2 sensor location hole. Prob have to wait til monday when i can go to an agricultural shop:rolleyes:

Coming very soon... DIY det cans using hands free mobile phone microphone and amplifier which plugs into cigarette lighter.

James

[Edited by jameswrx - 2/8/2003 11:35:22 PM]

tried a selection of sump plugs all too small, spark plugs too, i'm sure they welded the wrong size nut onto the d/p, should have welded it up really

edited to say; it's exatly 3mm, it looks thicker in the pics because the leading edge on show had a small lip round it. After i welded it in I filed the lip off to the same thickness as the rest of the plate.

[Edited by jameswrx - 2/8/2003 9:15:44 PM]

JGM, think th pics are deceptive, heres a shot from above.
The hks one is litterally a solid plate (covering the wastegate) that mounts to the turbo and a hole the size of the exhaust bore


http://upload.turbosport.co.uk/getpi...2952268810.JPG

Your right about comparrison but i've changed it so much recently I couldn't be bothered to do it twice for this d/p.
It would only be conclusive on the rolling road and I wouldn't have rr'd it anyway so I'm just going for it. If it turns out better than the hks I'll be happy. The guy that told me about this mod is a very experienced chap and from what i've seen i'll take his word.

edited to say: the splitter only sits in the d/p 12mm, just enough to weld it, it's not blocking the wastegate the splitter part goes into the back of the turbo and splits the gases there making the flow better from the start.
james



[Edited by jameswrx - 2/8/2003 10:41:16 PM]

IMO open neck with splitter fitting to back of turbo is going to better than twin dump because as you rightly say the gases are going to mix up in the 22mm(tdo5) space between back of turbo and d/p plate before they make their way down the d/p.

The important thing here is i'm not splitting the d/p really but splitting the gap in the back of the turbo, as I said before there is only enough of the plate in the d/p to weld it in.


[Edited by jameswrx - 2/9/2003 10:55:44 AM]

27mm is the amount the plate will protrude from the downpipe, this is the depth from the back of the turbo to where the d/p starts, you'll need..

..another 12mm for the plate to be welded into the mouth of the d/p, therefore..

..an overall width of 39mm, I presume your running v30 turbo then?

RE the slant of plate: The main thing here is if the bolt layout is the sam as for the td05?, the dimensions are from hole centres, see below. From what Michael says it fits against a ridge on the back of the turbo. I'm pretty sure the bolts are the sam on your car but don't quote me.

http://upload.turbosport.co.uk/getpi...3522510814.JPG


James





[Edited by jameswrx - 2/9/2003 11:35:58 AM]

James
The pics and all look great , the position for all the turbo's is the same.

The main thing to do is gring that big edge of the 3" pipe inside away , the step looks small but at the gas speed there it is very important, if you can feal lips or edges with your finder then grind it smooth ;)



[Edited by msgofaster - 2/9/2003 9:17:02 PM]

LOL @ Pete - well, that wierd looking tube is all titanium - all 5.3kg of it (well, the flange to the front pipe is steel ;) ) - that's "only" about 10kg less than std according to the schpiel. Supposedly developed on their rally cars, too. Probably sounds something like the S202 as well (i.e. earth shatteringly loud :D).

edit for spelling + to add some extra waffle ;)



[Edited by AJbaseBloke - 3/11/2003 3:03:28 AM]