Evil Aviator

Who makes that divided downpipe for the TII that has a backing plate with separate runners for the wastegate and turbo, and then collects them into the midpipe?

dr0x

Ive seen pics of that. I always thought it was just a customized racing beat unit.

bl|nk

that's what i've seen to.. always been custom job or maybe some small place made it? either way it's probably one of the best designed downpipes for the FC w/ stock turbo.

gsracer

I'm almost certain that was custom.

Evil Aviator

Darn, my friend wants one but doesn't want to pay the big bucks for a custom DP.

NZConvertible

I had mine custom-made.

Evil Aviator

So did I, but things like that are extremely expensive in the US.

Ryde _Or_Die

Ya I believe that was custom. I don't really see too much point in it for a stock turbo. At least not worth the price tag your going to get.

NZConvertible

Considering the problems the stock turbo has with boost creep, I can't understand why more people aren't making them. Anything that increases wastegate flow reduces boost creep, so the stock turbo is the perfect application.

BLUE TII

iTrader: (9)

I'm looking to unload mine as I had to adapt a HKS GT external to my turbo- and need more WG...

I did not join the WG and DP flows at any point, rather I

made a slug to divide WG from turbo (only part I am keeping ) and

then have a backing plate w/ 2 1/4" hole that the WG flappers open up into for longer than stock WG travel (can see into WG passages from outside when actuated!).

A WG downpipe and presilencer mount up to the backing plate to keep it quiet at idle. But they are little 2 1/4" crush bent pipe.

I also have a little RB 2 1/2" downpipe presilencer that would work better for the WG now that I think about it... I could work that up to fit onto the backing plate if they are interested in doing it that way.

I ran open air- no WG DP and presilencer since it was boost creeping even this way and so never developed the RB DP/presilencer idea.

Ryde _Or_Die

I have a heavily ported WG passage and a larger flapper door welded on. I can't get past 7psi when my boost controller is set all the way down.

novicaine

I welded on a larger door on my stock wheeled ser4 turbo and ported the hole big enough to wiggle my thum in(tech!). With 3" TB exhaust,intake,tid,and ported tb I can hold 6psi or 12lbs with my turbo xs manual boost controller. I am hopiing this wg setup will still suffice with a 60-1 stock rebuild.

RETed

KSP Engineering used to sell one - about $400 equivalent USD.


-Ted

pinkfloyd

i have never seen this...could someone post a pic...pleez

BLUE TII

iTrader: (9)

I have had no luck getting old pics out of this forum yet...

It basically looks like an over and under downpipe arrangement, either collected or not.

Some people weld a section of pipe of the turbo to divide flow, but I winced at the thought of welding on cast iron that gets red hot. My divider just drops in and I sealed it w/ high temp antisieze the 2nd time as it sealed w/ carbon the 1st time and was hard to remove.

Evil Aviator

It looks like they don't have it anymore. Um, what is written in red under the DRAG MACHINE lettering at the top left? I'm hoping that my translation is wrong, lol.
http://www.ksp-eng.co.jp/ATTAIN/menu3/index.html

Thanks, but he's going to need that slug because he is not capable of making one himself. Besides, he pretty much likes to stick with factory-made items for some reason. Personally, I prefer custom parts, but he is not me.

See NZConvertible's explanation.

Ryde _Or_Die

But doesn't everyone agree that a largely ported WG passage with a larger flapper door welded on is easier/cheaper and just as effective? I mean 7psi? How much lower can you go? Another guy just said 6psi above. Buying/making a custom downpipe is going to cost over $300 more than likely. Most people can port the wastegate themselves and many can do the minor welding as well. And if not it won't cost much to have a machine shop weld a flapper door on. Just the my thoughts.

NZConvertible

I paid ~US$300 equivalent for my custom one, but wouldn't pay that much again. They had the new flange laser cut, so it looked like a work of art but was half the cost of the whole thing. There are much cheaper ways to cut a steel plate you'll never even see!

Sure it's cheaper and easier, but overall it's not as effective.

Forcing the wastegate gases to merge with the gases exiting the turbine and then turn into the exhaust pipe causes a huge amount of turbulence. This restricts flow from both the wastegate and the turbine. That costs you power, simple as that. Dividing the flows removes that turbulence, reduces backpressure and frees up power.

While a wastegate port may be sufficient for a stock turbo, what about hybrids with large compressors? BLUE TII will tell you it just ain't enough.

I didn't get mine because I'm having boost creep problems, I got it because my stock downpipe cracked and needed urgent replacement. I took the opportunity because knew this was what I wanted to eventually have. It isn't necessary, it's simply better than the stock arrangement.

gsracer

It's a cool design, but I'd much rather have a larger wastegate flap wedled on and enlarge the wastegate hole much bigger.

I guess it all depends on how far you're going with the car. As far as the hybrid remark, he has the bnr stage IV...not the typical to4b compressor wheel/housing slapped onto the stock s4/s5 turbo. I wonder how bad the creep is for all hybrid owners, that would be interesting to find out.

NZConvertible

And you can still do that. The dual DP is not something you get instead of enlarging the wastegate, it's something do as well as the wastegate, for even better results.

Porting the wastegate won't increase power. A dual DP will.

RETed

Not necessarily...
The merging of the wastegate exit to the rest of the exhaust off the turbine outlet also disrupts the spiral flow of gases out of the exhaust. Spiraling gases is not the quickest path out the pipes.


-Ted

gsracer

Marginally perhaps, but that's going through a lot of trouble for a stock or near stock turbo. I'm simply saying my first option would be a bigger wastegate flap, if that didn't work then I'd move onto the dual DP, and if that didn't work I'd finally just weld on a big honking external wastegate

NZConvertible

I'm not sure if you're agreeing or disagreeing with me.

Either way, merging the two flows downstream at a nice angle is still much better than the two flows hitting each other at 90deg inside the housing.

Dropped it off in the morning, picked it up that night, paid the man his money. No trouble at all...

RETed

heheh, sorta kinda not really?

You are right about the merge angle - 90-degree angles is not the best for flow!



-Ted