I have a question ?
Will a JDM downpipe be direct fit replacement to the stock Turbos and stock exhaust system on US 94 FD?

 

yes

 

its exactly the same, except no converter/tumor

 

Yes it will but the big question is why would you want to?

The JDM downpipes have to content with fitting in with the steering rack while the LHD downpipes do not.

Here's a pic comparing all 3. From left to right: LHD dp, stock dp, and rhd dp respectively.

 

Well because I have both a after market stainless and a JDM and I am planning to replace my stock downpipe with one or the other and can't decide which one.
I know some of the stainless ones have fitment issues at the turbo connection as far as the stud lengths etc.
Also it seems the stainless one (Mazda Trix) is about 1 1/2 Inches longer in length than the JDM!

 

That's a USDM stock downpipe, a jdm one looks just like the hks, minus its 2.5" and has some metal shielding covering it..

JDM pipes also dont weigh 22 pounds

J.

 

not really sure what you are getting at because honestly I am not understanding your post. In the picture from left to right: That is not a stock USDM DP (no precat), The second one is just stock (I don't remember if the USDM stock DP's are identical to the JDM stock) also that is not just shielding its a pre-cat, the third is just HKS designed for RHD vehicles.


I can't confirm nor deny the weight since I didn't take the picture. But I do remember that when I removed mine it was not light due to the pre-cat and what the pipe was made of.


But to be honest that picture was just meant as a pictorial of how the RHD pipes have to be able fit with the steering rack in the way. Also since the conversation was never about weight I paid it no mind and didn't bother to remove what the original posted stated.

 

I'm in the market for a new DP as well and was considering getting a FEED but it would seem that a Tri Point Engineering DP might actually be better in this case?

 

define better.

the HKS and stock downpipes are nice because they fit nicely, you can remove the pipe without removing the studs from the turbo. some of the tubular downpipes need either the studs to come out, or you need to lift the engine, or some combination. also some of the cheap tubular DP's hit the body.

the HKS and stock DP's, have a front cast section though that is pretty narrow so that the DP can fit a RHD car, the tubular ones are a smooth bend, or a very wide section like the FEED pipe. a nice tubular pipe should offer slightly more flow than the HKS/stock.

then there is price, the FEED pipe is $$$$, the ebay junk is cheap, and the HKS is in the middle.

 

Better Performance, Less Weight, Faster Availability, Cheaper.

From your break down above it would seem the Tri point straight pipe design would be all of those when compared to a FEED DP?

 

What he's saying is that the JDM downpipe - the factory one that came on cars in Japan, does not have the pre-cat and looks similar to the HKS one plus a bit of heat shielding. It is lighter and flows better because it doesn't have the cat.

Reading the OP I understood he was asking about the JDM downpipe as well, and not aftermarket DPs that fit RHD cars.

To answer OPs question, yes - any FD downpipe you come across designed for factory twins will fit your setup.

 

Personally I'd look for these things in a dp in this order..

*thick, true flanges and good welds
*a mounting ear for the downstream bracket that goes to the transmission. They don't all have them.
*LHD version.
*stainless is nice but you'd be hard-pressed to ever wear-out a good mild steel dp.

Regardless, if the dp is off the car, it would be a no-brainer to have it jet-hot coated IMO.

 

i would buy the HKS because it fits the car.... the FEED DP is 68,000y, its almost $700 before shipping, so its double the money of anything else

 

And if money were no objection?

 

gotcha

 

Bonez. RX7.COM | 1993-1995 Rx7 Exhaust (330)7-ROTARY

 

I have an HPI downpipe for sale atm identical to the feed downpipe.. Shoot me a pm if anyone is interested.

 

I have run both JDM and US made aftermarket downpipes. Really, there's a negligible power difference if any.

I'd rather have the nice fit of the JDM downpipe with the cast head - SO much easier to install and remove.

I have a Knightsports dual tube downpipe -



I got it all discolored and crappy looking for CHEAP. Had a second O2 sensor bung welded on for a wideband, sent it to Jet-Hot, and it looks better than new. I swear I picked up power with it as well. Fit is great of course.

My downpipe recommendations -

- Get a JDM downpipe. HKS is the most commonly available used.
- Get a used crappy looking one. It'll be cheaper. As long as it's solid and not dented/busted you're OK.
- Get a muffler shop to weld an O2 sensor bung at the end of the dowpipe. About $20.
- Send it to Jet-Hot for the 2000 degree ceramic coating. Stuff works GREAT and is BULLETPROOF. A grinding stone on a bench grinder can BARELY take this stuff off. It won't flake or discolor with heat either.
- Replace any damaged or removed studs with new studs. Get the 14mm copper high-temp lock nuts from here:
M10-1.5 Exhaust Lock Nut Copper Plated Steel 14mm Hex

Good to go there.

Dale

 

Great info Dale, thanks.

 

This is an interesting post, I have the USDM Downpipe with cat and thinking of replacing it with Greddy TR Downpipe since HKS is discontinued. But my main question is: will the exhaust sound increase when I install the Greddy TR downpipe? it looks like the HKS downpipe.
I currently have the RE Amemiya Sports Cat as the mid pipe with HKS Hi-Power exhaust with the USDM dp.

 

It will typically get slightly louder and change the tone a little bit as well as hear the turbines just a little more. Wouldn't be too noticeable if you had the stock main cat on it but I don't know how much it would increase since you have the RE-A sports cat.

 

I put a JDM DP (265 ps version, with heat shield) on my '95. Direct fit, no drama.

The car was in California at the time, and I went with the JDM because it looks almost exactly the same as the USDM DP (it's basically just skinnier.) and it has a good chance to pass a visual smog inspection.

Whatever you do, hold onto the original DP with the cat.