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Nautical Blue MR2T
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Discussion Starter · #1 ·
3" Exhaust question (just read, not your typical "which is better" thread).

I have an MR2 Turbo and I am looking to upgrade the exhausts. All the exhaust on the market for the MR2 seem to be overly expensive for how much piping it is. On the MR2 forums, I asked how much power a single exit 3in exhaust from the turbo back would be able to flow, without being a bottleneck, and I keep getting what I feel to be are biased answers which mostly say "it wont flow as much as a dual 3in exhaust or even a dual 2.5in exhaust," which is something I already know. When I say 'dual' exhaust, they pretty much go from the downpipe (about where the back of the cabic meets the engine bay) to about where the rear axles are, then splits into two 2.5" or two 3". The dual 2.5" exhaust is $650, and the dual 3" is $800, and thats from any company that makes performance dual exhausts.

My question, is what HP levels are you guys consistantly getting with full 3" exhaust (DP included). My HP goals in the long run are lets say 325RWHP, which might even be several years from now, but I would rather not have to buy another exhaust again at 300RWHP. I was sure you guys made at least that with full 3" Turbo-Backs, but Im just checking to see what you guys have to say.

Sorry if this is kindof out of place, even though it is directed towards Supra owners, but I want to have another source of completely unbiased opinions.

Thanks.
 

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Registered
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583 Posts
first off a single three inch flows better then dual 2.5 well when tested by turbo ford. Next a single 3 inch exhaust shud be more then enough to flow that kind of power.
 

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Registered
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206 Posts
I don't know where this idea of dual exhaust on an L4 was better then Single Exhaust came from....
 

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Banned
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4,172 Posts
must be smocking that crack over there with the mr2 people! dont listen to those fools single 3 is the way to go! tell them to lay of the crack!
 

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Nautical Blue MR2T
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1,520 Posts
Discussion Starter · #8 · (Edited)
Ok I figured. Its just that the stock exhaust is a tangled mess of pipes which goes through a huge bar-type muffler and ends up as two pipes sticking out the back. Many people like this look, and a few companies have duplicated the look by making a short (prolly 2 feet long) 3" pipe that goes from the Downpipe back to about where the rear axles are, then splits into a Y that leads to two mufflers that go thrait out the back.

Here's what the aftermarket dual exhausts look like:


Here's something what the stock exhaust looks like:


Thats just to let yall see how they are designed. Its in no way a true "dual" exhaust, it just has two tips, and the two 2.5" pipes together flow as much as a single 4" pipe, which is where the bias seems to be coming from.

I do admit that because of this, the dual exhausts seem to be dynoing a little bit higher (like 9 RWHP) than single exhausts, but they cost like 800 dollars for about 6 feet of piping, including the two pipes, wheras I can get a full 3" catback for 450, and even cheaper if I shop around more. So I just came here to see how much power you guys are consistantly making with full 3" turbo-back exhausts.

Thanks for the replies.
 

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HKS T51R
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2,732 Posts
i have to admit that dual exhaust on the blue mr2 looks freakin sweet. lol
 

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i would said go with a dual setup, a single exhaust would look really odd on a mr2
 

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Nautical Blue MR2T
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Discussion Starter · #12 ·
Because I asked what kind of power you guys are making with single 3" exhausts.

And I agree that they do look sweet, its just that is an extra 350 dollars I dont have at the moment, that Id rather spend on another 50 RWHP. For me its function over form, and if I can do fine with a full 3" exhaust from the turbo back for ~700 dollars, when it would cost me over 1000 to do the same and look a little better, I think Id rather go for the one that is a little cheaper.
 

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Nautical Blue MR2T
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1,520 Posts
Discussion Starter · #14 ·
Technically, the dual 3" exhausts have been dynoing highest, but the Nur Spec seems to be the best single exhaust. However, it too, is expensive. 680 dollars too expensive... But this is turning into a "best exhaust for MR2" thread.

Again, what power are you guys making with full 3in exhausts?
 

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Republican
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8,421 Posts
sorry they were going off topic... people have easily made 700 RWHP with 3 inch exhaust... when they went to a 4 inch they gained like 60-70 IIRC. I will be runniing around 500 RWHP and I have no problem using 3 inch.
 

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Nautical Blue MR2T
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Discussion Starter · #16 ·
Ckanderson said:
sorry they were going off topic... people have easily made 700 RWHP with 3 inch exhaust... when they went to a 4 inch they gained like 60-70 IIRC. I will be runniing around 500 RWHP and I have no problem using 3 inch.
Ok, thanks. Thats all I wanted to know. This is also 3in Mandrel Bent of course. And I know that there are different boost levels, but it seems that technically, at the same RWHP, the two engines will be flowing the same amount of air, as there is so much energy in a given amount of O2 and gasoline, so a relatively similar amount of gases will be entering and exiting the engine at a given HP, no matter the boost. Anyways.... Im saying that if this is the case for you, I believe I will be running out of compressor map or the turbine housing would become a bottleneck before the 3in exhaust becomes a notable restriction (on the new turbo I plan to get in the next few years).
Thanks for the reply, that was very helpful. Looks like Ive pretty much found the exhaust Im looking for... now all I need are sound clips so I can make sure I wont sound like a Kazoo... and Ill be set!
 

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Republican
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:lol: most exhausts will sound good on a turbo car... it's the N/A's that sound like crap... turbo's are all SMOOOTH
 

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ma70-7m=1JZ
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I know of a few people that have made 600hp + with three inch exhaust.
 

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Dissident
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I say do the duals just because it looks so hot. But buy a mig and do it yourself. The prices you're talking about are crazy.
 

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Nautical Blue MR2T
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1,520 Posts
Discussion Starter · #20 ·
limequat said:
The prices you're talking about are crazy.
EXACTLY! I dont understand why the prices for you're cars are the same if not lower than ours!! A pretty strait single exhaust has like 4-5 feet of piping... Here is a pic of one of the dual exhausts just to show how far it really is from the downpipe to the tip... it is so short for so much money!!




But I think I've found the exhaust Im looking for.

Full 3" which goes to a small buffler and then splits into the dual 2.5" pipes at the end. 470 shipped. About the best I can do without going custom and Id like to avoid that. The other one I was looking at was 450 shipped and I found out it starts at like 2.5" after the DP and increases slowly, which seems kinda cheesy.

Thanks everyone for the help, and I expect this thread will be moved after not too long.
 
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