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-   -   Where to get 2.5" exhaust? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/where-get-2-5-exhaust-935790/)

jpieps 12-27-10 07:43 PM

Where to get 2.5" exhaust?
 
Hey guys,

I know lots of people ask about exhaust systems, but I think I have a somewhat original question. I have heard people talking about getting 2.5" exhaust components made. I am confused at this point. Are these people getting a shop to literally make a 2.5" diameter metal tube to certain specs to use as an exhaust system? Where would one go to get something like this? How much is this going to cost? I am not particularly knowledgeable when it comes to exhaust systems. I am going to search more to try and get a handle on what I need to obtain ( I don't even know how many or which components to even get ) to have a nice exhaust system, but if anyone can recommend any particularly useful threads, that would be great.

Thanks,
JP

DarrenTRS 12-27-10 09:50 PM

There are only 2 readily available exhausts made for the SA/FB that I know of and those are Racing Beat [header to tailpipe] and RP Performance [cat back and test pipe]

But considering the price of buying a bolt in exhaust from Racing Beat at damn near $1,000 as well as being heavy as sin, most people opt to simply piece together their own combination of resonators and mufflers then have it welded up.

Things to consider:
Mild Steel or Stainless
Mandrel or Crush bent
Mufflers/Resonators: Packing and Flow Design
Size of mufflers and resonators
Are you planning on getting a header? this will greatly increase the noise level of your exhaust.
How much do you want to spend?

I would simply suggest that unless you are in dyer need of such an exhaust that you really hit the search engine hard searching "exhaust setup" "best muffler" things of that nature and see that there are a TON of options out there but there are also a ton of horror stories with exhausts that would work perfectly on a regular car. Be prepared to spend coin on a good setup, find a reputable shop who does quality welding and fabrication and opt for quality parts like mandrel bent tubing, stainless if you can afford it and stainless steel packed mufflers because you're exhaust WILL be used and abused.

xShiFTx 12-28-10 12:02 AM

If you're looking to buy and weld up some mandrel bent tubing you should check out Columbia River. I have had great experience with them.

http://www.mandrel-bends.com/catalog/

Like mentioned above, there is a lot of thought that goes into an exhaust system and it is not cheap.

PercentSevenC 12-28-10 01:31 AM

Columbia River is a good place, I've ordered from them too. But I like to get 2" and 2.5" exhaust pipe from Racing Beat since they're a convenient source for .120" wall (11 gauge) pipe and mandrel u-bends. Using thick-walled pipe drastically reduces noise leakage, which is a big issue with NA rotary exhaust systems.

As far as mufflers go, I highly recommend Racing Beat's universal mufflers. Very effective at sound reduction, and the build quality is astounding for the price. You'll also want a presilencer or two, but unfortunately Racing Beat's 2.5" presilencers are application-specific and much more expensive.

jpieps 12-28-10 04:20 PM

Thanks for all of the replies. You are being very helpful. I am going to spend some more time searching and googling the various terms that you gave me. Now I at least have a place to work from. I will come back to this thread if I have any more questions. Thanks again.

JP

-BTW I like your sig Darren.

jpieps 03-16-11 05:27 PM

Raising this from the grave to ask more related questions. If I should have made a new thread, let me know. I just figured this would be better for people who search in the future. Can I get these things fabricated locally? What kind of shops do I even look for? Where should I look for the pipes that I want to use? I might not have the dough for a new exhaust system right now, but I want to get everything straight. So would a RB header---> presilencer (2 maybe?)---> 2.5" Pipe (fabricated, this is where the shop comes in)---> RB universal muffler work? Would that be an acceptable exhaust set up? Is there anything I would be missing? Would the shop have to fabricate a pipe for in between the header and presilencers? I really don't know a lot. Any help is greatly appreciated.

PercentSevenC 03-16-11 06:28 PM

A lot of cheap muffler shops will use thin, crush-bent piping. Make sure they use mandrel bends, and as thick-walled as you can get. You could probably just bring in some Racing Beat pipe and bends and have them weld you up something. Best ask around in your regional sub-forum to see what shops are recommended.

If you like loud, you can get away with a single presilencer, but I'd personally use two Magnaflows under the car with the RB universal in back.

Jibaro 12A 03-16-11 06:56 PM

I've bought 2.5 mild steel from my local shop. I did my own welding at home.

jpieps 03-16-11 07:17 PM

If I use the RB stuff, won't it be heavy like their bolt in exhaust? How thick is good? (Please give me one bare min. thickness and one ideal thickness if possible) And what all do they need to fabricate? Can I attach the presilencer straight to the header, then have them fabricate something from there back to the muffler? Thanks a ton for being patient.

PercentSevenC 03-16-11 08:18 PM

Certainly don't use anything thinner than 16 gauge (.065" wall). The extra weight of the 11 gauge (.120" wall) RB pipe isn't really that much. Worth it for the extra durability and noise reduction, IMO. It's the gigantic mufflers that make the RB systems heavy (even then, they're not THAT heavy).

The first presilencer might need a bit of an angle correction, but should be pretty close to the header outlet. Note that if you get the FB header, it collects to 2", so the collector will have to be cut off and redone in 2.5" anyway. If you get the FC collected header, it collects to 2.5" so you don't have to worry about that.

jpieps 03-16-11 09:34 PM

So, really it just comes down to common sense... I get the components, find an arrangement that will make everything fit in the correct order under the car, cut the pipe and then have it welded together. It doesn't really matter how far apart the components are, as long as they are in the correct order? Also, since the pipe I am using will most likely be mild steel, is it recommended to pain it so it doesn't rust as fast, or is there some other treatment?

PercentSevenC 03-17-11 01:34 AM

I use VHT's "FlameProof" exhaust paint. Works well enough.

jpieps 03-17-11 07:49 AM

Did you use all three steps-primer basecoat and clear?

PercentSevenC 03-17-11 12:03 PM

Heck no. Just a couple of coats of the spray. It's an exhaust pipe, not a fender. Normal paint just burns off anyway, that's why you have to use super high-heat ceramic-based stuff.

j9fd3s 03-17-11 12:35 PM


Originally Posted by jpieps (Post 10521197)
So, really it just comes down to common sense... I get the components, find an arrangement that will make everything fit in the correct order under the car, cut the pipe and then have it welded together. It doesn't really matter how far apart the components are, as long as they are in the correct order? Also, since the pipe I am using will most likely be mild steel, is it recommended to pain it so it doesn't rust as fast, or is there some other treatment?

the old school way is just to buy the RB header/presilencer, and then you can run any pipe after that you want, although thicker will be quieter, either 2.25 or 2.5 into your choice of muffler...

jpieps 03-17-11 01:00 PM

@ PercentSevenC--Ha, thanks. I just didn't know if you had to use all of the steps to make it more long-lasting.

@j9fd3s-- How does that differ from the exhaust setup I am considering? Sounds about the same to me.

Jeff20B 03-17-11 01:03 PM

Clean off any oil or rust from the pipes before you paint them. That's the only prep you need to do. Well, just oil really. The paint will work on rusted surfaces somewhat. Just wire brush off the really loose stuff.


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