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Discussion Starter #1
Hi all,

I have a JDM MKIV TT, i'm actually located in Hong Kong. The only "downpipe" I can get here locally is the HKS or Blitz. My question is, this is essentially just the "midpipe" right? Whereas the RMM is the whole pipe which includes the front/mid pipe?
 

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Discussion Starter #3
Thanks for the quick reply. My question now is this... Is it possible/benefitual to actually put the RMM in a JDM MKIV? I'm curious about this as the shops I talk to locally don't understand, they already think the HKS/Blitz downpipe is the complete piping.
 

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from what i remember you cannot bolt a udsm rmm into a jdm mkiv due to the different bolt pattern and bends.
 

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Removing the CAT will improve the performance of the car. Just make sure you don't get busted on an emissions test or something.
 

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Discussion Starter #7
Thanks all for the advice, I did not know there was a difference between the JDM/USDM piping. I guess I'll see what there is to do add on to my midpipe then to extract more power outta the engine then.
 

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sorry to the OP for jacking just one question, whats the alternative from RMM downpipe for us JDM people since the bolt pattern is different, is the only way a custom fab one or a HKS then take the cats out with a custom mid pipe?
 

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There is a specially fabricated DP for JDM Supras. But this DP has not the same 3" flow as the USDM DP due to that the JDM wastegate cannot handle the amount of flow that the turbines will produce due to the increased exhaust flow and therefore you may harm the turbos. But instead this JDM DP has a restrictor ring in it to maximize the exhaust flow. I will upload a link for you guys asap.
 

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loss for words
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sorry to the OP for jacking just one question, whats the alternative from RMM downpipe for us JDM people since the bolt pattern is different, is the only way a custom fab one or a HKS then take the cats out with a custom mid pipe?

I just cut the flange off the stock JDM downpipe and had it welded to the RMM one.
Believe it or not. ITS THAT SIMPLE

Bends are the same. The only difference is the flange and diameter.
 

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actually..its also the angle as well. i've tried it ..and its just not the flange.
 

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loss for words
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actually..its also the angle as well. i've tried it ..and its just not the flange.
I didn't do any more than what was stated above. I didn't do the welding, but I did all the measuring and cutting and watch over my friends shoulder as he welded it.
I dunno, could be a difference in downpipes. Maybe I did have to cut an angle into it and i'm not remembering b/c it was so long ago.:confused:

Bottom line is if you get a us downpipe and the flange off the stock jspec downpipe, you can weld it and/or clock it for best fitment.
 

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I just cut the flange off the stock JDM downpipe and had it welded to the RMM one.
Believe it or not. ITS THAT SIMPLE

Bends are the same. The only difference is the flange and diameter.
Yeah but you still have to restrict the boost pressure from reaching over 1,2bar because the wastegate on the JDM turbos aren't as strong as the USDM.
 

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If you are using the stock flange from the JDM down pipe wouldn't that act as your restrictor ring? I did the same thing as mentioned above, cut flange off of JDM down pipe and welded it onto RMM down pipe. Works great and was very easy.
 

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im new to the site and am having trouble finding a downpipe for my jdm supra . also do i need any other mods to support the upt boost from the downpipe install .my only mod is 3'' exhaust from first cat back .
thanks
 
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