been reading up on greddy turbo kits and it seems that everyone agrees that the downpipe,internal wastegate, and exhaust manifold limits it to about 300hp with a REALLY good tune. how hard would it be to change it to an external wastegate? i would like to make the turbo system still LOOK like a greddy one more or less so incase i get pulled over for driving a japenese car. also how hard would it be to replace the downpipe with a 2.5 or a 3 inch one? can anyone recomend an exhaust manifold that looks similiar to greddys but works better? or can i get the one from greddy bored out a little?

 

The downpipe would be a fairly easy thing to conceal, but hiding an external wastegate would be a bit harder. There are a few options that you could investigate. I believe it's ATP that makes the integrated turbine housing with a Tial 44mm flange. That would be one way to hide the external gate. Your other option is to simply purchase an internally gated turbo like the GT28rs and hope it doesn't creep on you. As for the exhaust, you could try any sort of 3" but be a little picky on the muffler. Finally, i'm not sure how strict the local 5-0 is, but an electric exhaust cut-out may be a decent solution to your exhaust restriction. That would allow you the flow of an open downpipe and the ability to change back to a full, quiet exhaust when the cops are within earshot...

 

cops are bored in my area and sneaky so the cut-out is out. as long as i'm not putting the waste gate right on the exhaust header im sure i coud find a way to hide it. i heard that i could put it on the downpipe?(Not sure if it was correct or if i read it wrong). any suggestions about the exhaust header or should just leave it the stock greddy log?

 

also can i take the internal wastegate off and use it as an external? probably a noob question i know very little specifics about turboes other than the basic 'compressed air=more air"

 

nope.

 

cool thanks for not bashing was expecting a 'stupid noob' in there lol. are downpipes turbo specific or will it fit any turbo on a GSR as long as its designed for a GSR?

 

All good, downpipes are not only turbo specific but also application specific.

To further answer your question about going from internal to external forget about the fact that you cannot use an internal wastegate externally the real problem is the size of the internal gate, most of them have ports that appear to be 25mm or less in diameter, they simply cannot flow enough exhaust gas to properly control boost, Tial's smallest external wastegate is 38mm and as such can flow much more exhaust gas to control boost much better.

Back to your downpipe question though the most common ones used on honda's are 5 bolt (aka Ford style), 4 Bolt, and V-band.

 

The wastegate cannot go on the downpipe lol. We all start somewhere. The wastegates sole purpose is to help control the amount of boost that the turbo will produce. To do this, it is usually located on the manifold to control pressure before going into the turbo itself. Like Schister said, there are options available to have the wastegate flange located directly on the turbine housing itself, or a larger internally gated turbo all together.

Internal units are built-in to the housing and can never be removed, they can be closed though.

What I think you MAY have heard is that after running an external gate, rather than dumping it to the atmosphere, you can dump it into the downpipe, which is quieter and cleaner.

Best of luck to you. I hate Cali. lol

 

I am using the Greddy manifold and intercooler core from a kit I picked up for an H22, but since its in a civic the piping will not work..

I am going to use ATP's 44mm ewg turbine housing paired up with a t3/60trim compressor and stage 3 turbine wheel.

Going to be making a bellmouth downpipe (rotating the turbo from Greddy's design) and 3" exhaust.

You didn't post up your setup, but I will have pictures up here in a couple of months (moving and having a kid so things are going slooowww right now)

The problem with Greddy kits is mainly the turbo sizing, not so much that as to the boost pressure ran. The td05/6-18g (18g with a 20g 3" compressor housing) is good for about 350whp with 8-1 compression (IE my WRX) but that is at 24psi on E85.

Since H/B's use higher compression and cast pistons its not practical or safe longevity wise to run that boost pressure, so basically your running the Greddy turbo under its efficiency range.

A 50trim turbo from atp with the ewg t25 housing (made for stage 3 wheel and a .72a/r) would suite a B nicely on the Greddy manifold (which is probably the nicest cast manifold made for the H) Or the same setup for an H with a 60trim compressor.

The DP is the Most restrictive part of the setup, then its the turbo and then its the manifold (I'd say the Greddy manifold for the H (not the B different design) is good for 400whp and not a bit more)


Read this it has some good content for a nOOb!

http://auto.howstuffworks.com/turbo.htm

-Jerod