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Joe Perez 08-22-2007 12:59 PM


Originally Posted by Danimal (Post 142408)
What is the best Down pipe for a Greddy to go with a larger cat and a Ethuza cat-back?

There are really only two options, apart from DIY.

Bell has the sexiest pipe by far, featuring a divorced wastegate tube. $385 for stainless, $285 for mild steel. http://www.bellengineering.net/Pages...ata_parts.html

My pipe was made by TurboTony, who hangs around this forum. It does not have a divorced wastegate return, but is somewhat less expensive and was considered the gold standard prior to the Bell unit. turbotony2k@yahoo.com

Ben 08-22-2007 03:01 PM


Originally Posted by kotomile (Post 142390)
Nah, 3" single. :eek5: It'll be waiting for me in Jacksonville when I go on leave.

What size piping do you run Ben? I think I've decided that matching your HP & TQ numbers is my goal and I'm curious what your setup is.

2.5" Tony to test pipe to 2.75" from test pipe to axle, then either 2 or 2.25" axle back--don't remember. My exhaust is not the model to follow. :gay:
Didn't you get the BEGi pipe? Your DP + exhaust will flow better than mine, so you'll hit peak boost a few hundred rpm sooner. You'll want to have a new WG can waiting for you too.

kotomile 08-22-2007 03:14 PM

Yep, got the Begi pipe. I got that AEM EBC and plan on buying a PNP.. will I still need a stronger actuator?

Braineack 08-22-2007 03:16 PM

sell the AEM and have the PnP control the boost....

since you have a greddy wastegate it still wouldnt hurt to put a helper spring on it, but you should be able to tune the boost flat.

Ben 08-22-2007 03:26 PM

Yes, get a better actuator, especially if you want to make power similar to mine. Fuck a helper spring. Do it right.

Brainy, if you saw my EBC duty cycle table you'd shit. 98% to redline :eek:

krayzrac3r 08-22-2007 03:38 PM

ben what kind of actuator are u running? just curious cuz ima hit the dyno soon and I dont wanna go there with a helper spring on the greddy wastegate

m2cupcar 08-22-2007 03:56 PM


Originally Posted by Ben (Post 142468)
....Brainy, if you saw my EBC duty cycle table you'd shit. 98% to redline :eek:

your before/after mbc/ebc dyno runs where phenomenal... I know this hurting me. My LINK ebc chip is dead. Need to fix it.

on topic-
danimal, I had a flowmaster and when I swapped to what I though was more restrictive no-name turbo muffler, turbo spooled 300rpm earlier across the board. Somebody replied that chambered type mufflers kill turbo spool - they're designed for v8 exhaust pulses and the turbo has none. :dunno:

Ben 08-22-2007 04:16 PM


Originally Posted by krayzrac3r (Post 142473)
ben what kind of actuator are u running? just curious cuz ima hit the dyno soon and I dont wanna go there with a helper spring on the greddy wastegate

whatever came with the greddy

again, I can't stress my replacement recommendation strong enough.
I need to, but honestly I plan to do a engine swap this winter anyway.

kotomile 08-22-2007 05:43 PM

I'd gladly buy another can if I knew what to buy.. as it is though I'm lost on that one.

Joe Perez 08-22-2007 07:00 PM


Originally Posted by kotomile (Post 142528)
I'd gladly buy another can if I knew what to buy.. as it is though I'm lost on that one.

Speaking without the benefit of actual experiance (still using a helper spring and MBC) I wonder if something like this could be adapted to fit:
http://www.atpturbo.com/Merchant2/me...egory_Code=WGT
http://www.atpturbo.com/Merchant2/me...egory_Code=WGT

Biggest problem for me would be that eliminating the need for the MBC would also eliminate my failsafe bypass on the WI system. Still, consistant boost would be nice. Clifford varies between 12 and 15 PSI seemingly at random...

kotomile 08-23-2007 10:54 AM

would this work? (guessing you'd have to get their "adjustable rod end" also)

http://flyinmiata.com/index.php?dept...umber=02-70570

akaryrye 08-23-2007 11:31 AM

I think its really wierd that they are sold separately ... oh well.

kotomile 08-23-2007 11:35 AM

Agree. Looks like a bracket would need to be made (the stock Greddy can has integral bracket, doesn't it?) but that's no biggie since I'd have to build one once I clock the compressor anyway.

How "universal" an item is a WG actuator anyway?

Ben 08-23-2007 11:37 AM

pretty damn universal. It's just a matter aligning the rod and bolting the can down.

Joe Perez 08-23-2007 12:00 PM


Originally Posted by kotomile (Post 142679)
Agree. Looks like a bracket would need to be made (the stock Greddy can has integral bracket, doesn't it?)

Yes, the can that comes with the Greddy has a bracket attached, however even in the out-of-the-box configuration, it's slightly ill-fitting and misaligned.

How "universal" an item is a WG actuator anyway?
Functionally, they're all similar. Just a metal can with a diaphragm and a spring. Spring stiffness and diaphragm size determine the baseline regulating pressure of the can.

The trick is to find one that is dimensionally compatible with the Greddy TD04H-15G setup in terms of:
1- Being able to fabricate a mounting bracket that will mate to the can
and
2- Ensuring that the rod can easily be made to mate with the WG arm on the turbine housing.

FHS 08-23-2007 01:50 PM

I'm looking to replace my wastegate can too.

They are universal in the sense that you can slap it on if you can screw it to the greddy bracket. They are not universal in the sense that your boost will be affected.

I shopped for one on Ebay awhile back based on appearance alone. Unfortunately, even though it looked identical in the picture, it was bigger and the base boost setting was just too high. I was thinking about picking up the one from Flyin Miata but I would like confirmation that it has the proper boost setting.

Joe Perez 08-23-2007 01:57 PM


Originally Posted by FHS (Post 142738)
They are not universal in the sense that your boost will be affected.

True, and I believe that this answer's akaryrye's question as well, insomuch as why they are sold seperately.

Different WG cans will activate at different pressure levels depending upon the design of the spring and diaphragm. The one that comes on the Greddy yields around 5PSI. To increase this, you can either run a boost controller (which prevents the WG can from seeing the true pressure in the manifold) or by simply installing an WG can which is designed to operate at a higher level.

I expect that boost would tend to be more consistant running a higher-pressure WG can, though the oft-alluded-to benefit of delaying the opening of the WG door would be lost. This should in theory cause a slight decrease in the rate at which boost is achieved.

Ben 08-23-2007 02:13 PM


Originally Posted by Joe Perez (Post 142744)
I expect that boost would tend to be more consistant running a higher-pressure WG can, though the oft-alluded-to benefit of delaying the opening of the WG door would be lost. This should in theory cause a slight decrease in the rate at which boost is achieved.

Why, are you assuming that one would run a stiffer WG can without the benefit of a manual or electronic boost controller? I was never assuming that to be the case.

StankCheeze 08-23-2007 02:54 PM


Originally Posted by Wideopentuning (Post 142312)
Why is that? I am not disagreeing...just curious.

Borla ProXS won a 3rd party competition a while ago for flow:noise ratio by a pretty hefty margin. They sound very mellow and flow like a motherfucker.

kotomile 08-23-2007 05:45 PM

Thanks for the answers on the WG guys, very educational.


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