Car is 1988 Mazda Rx-7 turbo. I am installing a Garrett T04S turbo .96 A/R Hotside, .70 A/R compressor to an undivided HKS cast manifold and I am having trouble figuring out what to do for a turbo inlet/air filter.

The turbo has a 4" inlet. I bought an AEM intake cone, 4" inlet by 9" long, but I'm not sure how to route it. I would prefer to keep the stock clutch fan and fan shroud because they flow more air than any of the aftermarket electric units. This clutch fan and shroud take a up a ton of space though. I haven't even clocked the turbo yet but here are some pics of what I'm working with.




Here's the intercooler piping for the stock turbo laid out so you can get an idea of how much space it will take. I still have to cut it to make it work with the upgrade.



Here is just an empty shot of how much room I have to work with. You can see the fan shroud in front of the turbo. I will probably have to cut at least part of it... the fan blade comes very close too.



Here you can see how big the air filter is in relation to everything else.

Someone has suggested I just put some mesh over the turbo inlet to keep any major debris from getting in and forget the cone. The obvious objections to this are that it will be restrictive and of course that it won't filter sufficiently. But just how restrictive will it be and just how poorly will it filter? Any ideas?

Thanks.

[Edited on June 17, 2007 at 9:35 PM. Reason : .]

6/17/2007 9:35:01 PM

depends on how much and what conditions you drive it in as to whether or not you should filter it. it's hard to tell from the pics, but how would a 45 degree 4" exhaust pipe fitting work? or maybe a short piece of straight and a 90.

there's also someone that makes a real flat but large diamter (6 inches or so) filter that connects directly to the turbo inlet. sticks off maybe 2-3 inches. i can't recall who off hand...



[Edited on June 17, 2007 at 10:27 PM. Reason : .]

6/17/2007 10:24:05 PM

you could do like mine and have a 4" to 3" reducer coupler on the intake side. also, see if you can return that filter and get a not-so-long one




[Edited on June 18, 2007 at 8:56 AM. Reason : ]

6/18/2007 8:53:41 AM

stick the cone straight on the turbo. also, isn't that turbo a bit of a beast for that motor?

6/18/2007 9:26:02 AM

^He can't, thats the problem, thus the need for a connector pipe. Look at the last pic.

How much vertical room you got to work with, cause with the ic piping it looks like you'd have to angle it upwards. Or smash in the base of the cone somewhat. As a last resort, the snorkel.

6/18/2007 10:28:00 AM

I know this is a dsm site, but an intake tube is pretty car non-specific. http://dsm.dejonpowerhouse.com/ The guy can make you something custom as well

6/18/2007 10:49:38 AM

^^^^ a 3 inch reducer would be a bad call on a turbo with a 4 inch inlet I feel.

^^^ The T04S comes on an HKS kit for an FD. It is considered a medium sized turbo upgrade for a rotary engine, especially given that I have a very aggressive street port. It should hit 20+psi by about 4500 rpm I believe, and I will be revving to 7800. I may eventually go for the ball bearing T04Z but it is way more expensive... I got a brand new turbo and manifold for $900 off someone from the forums. Rotary engines are really weird--they counterintuitively like big turbos. The stock turbo on my car is about the size of a Mk III Supra CT26 (a little smaller than a big 16G) and yet it typically holds 6-8psi to redline on my car. See http://fc3spro.com/TECH/TURBO/tmodels.html

^ I don't think any of those would be worth it given how tight of a space I have. I'm better off just getting whatever prebent sections I need, or getting some stuff TIG welded at a local shop.

I've definately decided not to put a screen on there. After looking into it, there is a consensus that it is too restrictive. One Honda forum claimed a loss of ~20 wheel horsepower on the dyno with a screen versus a cone (390rwhp vs 370) on somebody's setup.

I did clock the turbo last night and I'm going to start cutting up the intercooler piping to make it fit. I might have just enough room to fit a filter in the engine bay, but probably not that one. I found a list of all the universal filters that K&N makes http://www.knfilters.com/search/univcone.aspx .

I'll probably buy some aluminum piping and use angled silicone couplers to make it all work. http://www.atpturbo.com has an awesome selection of this stuff. It'll probably end up looking ghetto to an extent though, with some kind of smashing action.

[Edited on June 18, 2007 at 3:16 PM. Reason : .]

6/18/2007 3:06:08 PM

i prefer to use the term "precision crushed"

6/18/2007 3:12:27 PM

btw dirty just got software to tune the leggy.

6/18/2007 3:16:58 PM

yeah a reducing coupler is not ideal.. but are you looking to eke out every last hp from the turbo/specific psi? I'm running a GT30R to around 350-380whp with a reducer like that, no problemo

[Edited on June 18, 2007 at 5:31 PM. Reason : ]

6/18/2007 5:31:39 PM

problem solved

in all seriousness good luck with the project, should be a beast.

[Edited on June 18, 2007 at 6:05 PM. Reason : ]

6/18/2007 5:56:38 PM

Maximizing intake flow is critical. I am maxing out the turbo--Apex'i Power FC standalone engine management, 720cc primary / 1680cc secondary injectors, 20+psi and 400+rwhp or bust. This car will not see pump gas. Hell I'm selling my nonturbo to fund the rest of the shit I need for it like tuning sessions and an electronic boost controller.

I will probably end up using some of those angled couplers though. That's a good idea.

[Edited on June 18, 2007 at 9:27 PM. Reason : .]

6/18/2007 9:26:06 PM

all that for 400whp?

6/18/2007 11:08:56 PM

I am intentionally overbuilding it. There are much cheaper and easier options to make close to 400rwhp on this car.

[Edited on June 19, 2007 at 2:23 AM. Reason : .]

6/19/2007 2:22:08 AM

overbuilding by adding a huge turbo will just cause a lot of lag.. dunno much about rotaries, but you should be able to hit 400whp with a smaller turbo than you have

6/19/2007 11:33:18 AM

Update:

i've got this 80% figured out now. It turns out that there is just enough enough room for that long 9" filter to fit. I bought a 4" 45 degree aluminum elbow and 4" coupler today. I cut out a little bit of the stock fan shroud and I managed to get the elbow and coupler on. Now I just need to cut maybe an inch of piping off to get the filter to fit.

There is 1-1.5 inches between the intake and the intercooler piping, as well as 1-1.5 inches between the intake and the clutch fan, but it should all just barely fit once I cut the intercooler piping a little more.

Now all I need is to get the oil lines hooked up and some misc wiring. And Apexi needs to hurry the fuck up and get me my Power FC after 3 months of backorder bullshit.

7/15/2007 7:57:08 PM

have you upgraded the cooling system on this thing?

7/15/2007 8:39:37 PM

uh yeah

It has an aluminum fluidyne radiator. Not cheap.


[Edited on July 15, 2007 at 8:53 PM. Reason : .]

7/15/2007 8:51:52 PM

Quote :

"overbuilding by adding a huge turbo will just cause a lot of lag.. dunno much about rotaries, but you should be able to hit 400whp with a smaller turbo than you have"

Like Ray said...this is an agressively street-ported wankel. These engines STOCK have extremely high exhaust gas temps, and some serious port velocity. I'm interested in seeing how this setup fares. Shame I'm not in town to check it all out.

7/15/2007 11:36:01 PM

whatever happened to your love for dubs?

7/15/2007 11:39:12 PM

^^ yes a 60-1 turbo like the T04S I'm putting in is one of the most common turbo upgrades for a turbo rx-7. It's not considered a large turbo for this motor. Hopefully you'll see it at least runnning soon. My Power FC finally shipped from Japan.

^ I might throw some dubs on my Q45 some day. it's ripe for it.

[Edited on July 16, 2007 at 8:23 AM. Reason : .]

7/16/2007 8:22:23 AM

finished it. here's the crappy cellphone pic. you can see where the intercooler piping is not connected--I will be getting that welded. Now I need to finish up my oil lines, finish installing t-bolt clamps on the intercooler, and do some miscellaneous wiring for the Power FC before it finally gets here. Then the upper intake manifold comes off so I can install 1680cc secondary injectors, convert to stainless steel fuel lines, and install an aftermarket fuel pressure regulatator.

8/1/2007 1:29:30 AM