Exhausts mass vs power gains

[northernalex]

I'm thinking of getting an exhaust and really like the look of the duel end exhausts but was thinking to myself, how much of that is purely cosmetic and how much is the 2nd exhaust pipe usefull.

Obviously a better exhaust with a wider bore will give you more noise and a few more bhp, but surely if the exhaust is lighter then the bhp will "help" so does anyone know anything about the mass of exhausts and their power gains?

Also bracing, front in paricular. Now everyone has problems with storage space, so remove your wheel - result is that the front understeers quite heavily. So why not kill two birds with one stone, a large, heavy strut bar or plate on the bottom of the car equal to the weight of the wheel you're removing.  Solved, better handling/bracing and more storage space!

Any ideas anyone?

[Tem]

I'm thinking of getting an exhaust and really like the look of the duel end exhausts but was thinking to myself, how much of that is purely cosmetic and how much is the 2nd exhaust pipe usefull.

It's 100% for looks.

One pipe is more than enough for 1.8l engine, even with boost. Most duals only have two tips anyway and the piping itself is single.

[Anonymous]

It's 100% for looks.

One pipe is more than enough for 1.8l engine, even with boost. Most duals only have two tips anyway and the piping itself is single.

Had my twin made by Blueflame, it has two seperate pipes coming from each side of the box, gives equal flow from both sides, more noticeable when cold, I suppose in theory twice the pipe diameter due to the construction. They also can tune, if that's the correct word, the sound and performance - the latter being questionable, expected from the back box.

I know they were talking of making a dual system with twin tips per side, might be worth talking to them. A good bunch of guys.

[Anonymous]

Tem is on about the single pipe that leads from the manifold to the backbox itself.

[Anonymous]

Tem is on about the single pipe that leads from the manifold to the backbox itself.

Not sure, Northernalex is talking about dual pipes / tips.  s:? :? s:?

[Anonymous]

Yeah, dual from the backbox to the end of the exhaust. It's single piping from manifold -> cat -> backbox though.

[Anonymous]

Yeah, dual from the backbox to the end of the exhaust. It's single piping from manifold -> cat -> backbox though.

I think it's best left to Tem to explain what he means, as to Northerns question at least he's got a part answer.

[northernalex]

Hey guys, thanks for your answers/discussions.  I was actually talking about dual tips, I understand that there is only one pipe to the back box.  So if the dual tips thingy is mainly cosmetic? then to increase overall performance it would be better to get a light back box with a single tip?  (and kill those precats hoping mrT doesnt really notice warrenty wise)

[Anonymous]

The precats have nothing to do with the backbox, y'know  s:wink: :wink: s:wink:

Yup, the lighter the better really. Personally I think the MR2 looks 'wrong' without dual tips, but the Kakimoto exhaust does look awesome.

[northernalex]

The precats have nothing to do with the backbox, y'know

OK I'm getting a little lost now, air flows from the engine through the manifold where the precats are? then into the main cat pipe then the back box.  So A cat back system is just the back box and the tips?

Surely removing the precats will reduce engine back pressure as will a new backbox/exhaust system.

I'm confusing myself, 100's of posts and still a newbie!

[Anonymous]

Sorry, I didn't make myself very clear. You are correct in saying that the precats are in the manifold, but I thought you thought (still with me?  s:wink: :wink: s:wink: ) that the precats were in the backbox.

Yup, a cat-back system is exactly as you describe. There is no documented proof that the removal of the precats gives you any performance gain whatsoever, but it definately sounds better (as well as securing the life of your engine). Do the precat removal thing anyway, and think of it as a seperate 'job' to replacing the exhaust system.

[northernalex]

but I thought you thought (still with me? )

  s:lol: :lol: s:lol:   That made me laugh.  Yeah I know what you're getting at.

Right gotcha mate, I fully understand now.  Right now to find a light exhaust. I do agree dual tips look better though.

[markiii]

even teh few pounds that teh H&S is lighter was noticeable when I fitted mine.

I would strongly reccomend the Kakimota as it both looks sweet (for a single exit) and is very light, theres almost nothing of it  :-) :-) :-)

[northernalex]

markiii any ideas where i could find such an exhaust?  Thanks matey  s:) s:)

[markiii]

best bet would be Japanparts

or MRS-Passion

[Chris_h]

There is no documented proof that the removal of the precats gives you any performance gain whatsoever, but it definately sounds better (as well as securing the life of your engine). Do the precat removal thing anyway, and think of it as a seperate 'job' to replacing the exhaust system.

Dan,
I was under the impression the Celica unit was identical to the Mr2 except pre cats - and ran 140 to the MR2 138. Now the difference could be down to all manner of things (perhaps a different map) or engine location, hence breathing of engine.
But I thought the emission bits of the MR2 may contribute to the lost 2bhp. Now removing them may not recover the 2bhp as perhaps the celica has a diff map because they are not there?

I stand to be TOTALLY corrected on the above!

[Anonymous]

It's possible, but 2bhp is neither here nor there really. The engines are 100% identical, and I'm guessing that the maps are pretty much the same too. Tbh I have no idea why there is a 2bhp discrepancy between the two, but it could also be down to the more efficient route that the Celica's exhaust takes (the stock MR2 one does go round about the houses a bit, but that's simply because it has to).

[Tem]

Yeah, dual from the backbox to the end of the exhaust. It's single piping from manifold -> cat -> backbox though.

I think it's best left to Tem to explain what he means, as to Northerns question at least he's got a part answer.

I meant just what Ekona said.  s8) s8)

It really doesn't matter (powerwise) even if you had 4 pipes after the backbox. That's not where the exhaust system is most restrictive.  s;) s;)


Unless you also make a custom cat, you cannot have a real dual exhaust. There's only one pipe going into the cat and there's only one pipe coming out of it to the backbox.

Just think about the weight penalty with real dual system, with two cats and two backboxes. Why would anyone want to do that in a lightweight car with a relatively small engine?  s;) s;)  You can get the looks with two tips, including the two pipes from the backbox.

[Anonymous]

but I thought you thought (still with me? )

  s:lol: :lol: s:lol:   That made me laugh.  Yeah I know what you're getting at.

Right gotcha mate, I fully understand now.  Right now to find a light exhaust. I do agree dual tips look better though.

Top Secret exhaust is very light, I could practically swing mine around my head with one arm. (Thats how i checked the weight, technical huh,  s:P s:P  )

Bit difficult to get hold of one though... oh, and its LOUD!

[Tem]

Top Secret exhaust is very light, I could practically swing mine around my head with one arm. (Thats how i checked the weight, technical huh,  s:P s:P  )

Top Secret titanium turbo exhaust is what's light. I still get a chuckle everytime I remember when someone on SC wrote that when he first lifted it, he hit himself with it, cause it was so light.  s:lol: :lol: s:lol:

its LOUD!

SORRY, CAN'T HEAR YOU, I HAVE ONE TOO!  s:twisted: :twisted: s:twisted:

[Anonymous]

I'm thinking of getting an exhaust and really like the look of the duel end exhausts but was thinking to myself, how much of that is purely cosmetic and how much is the 2nd exhaust pipe usefull.

Any ideas anyone?

Tem

The question was very simple, quote above, so why this thread has gone down the route it has is a little confusing, ultimately it's come back to the orginal question - the rear exhaust - so I suppose the question as been partly answered.

[markiii]

Yeah, dual from the backbox to the end of the exhaust. It's single piping from manifold -> cat -> backbox though.

I think it's best left to Tem to explain what he means, as to Northerns question at least he's got a part answer.

I meant just what Ekona said.  s8) s8)

It really doesn't matter (powerwise) even if you had 4 pipes after the backbox. That's not where the exhaust system is most restrictive.  s;) s;)


Unless you also make a custom cat, you cannot have a real dual exhaust. There's only one pipe going into the cat and there's only one pipe coming out of it to the backbox.

Just think about the weight penalty with real dual system, with two cats and two backboxes. Why would anyone want to do that in a lightweight car with a relatively small engine?  s;) s;)  You can get the looks with two tips, including the two pipes from the backbox.

which has been answered hasn''t it?

[markiii]

Obviously a better exhaust with a wider bore will give you more noise and a few more bhp, but surely if the exhaust is lighter then the bhp will "help" so does anyone know anything about the mass of exhausts and their power gains?

strangely this was also asked and answered  s:? :? s:?  

sounds like this thread has gone down just teh path intended.

[Anonymous]

Eventually   s:roll: :roll: s:roll:

[Tem]

I'm thinking of getting an exhaust and really like the look of the duel end exhausts but was thinking to myself, how much of that is purely cosmetic and how much is the 2nd exhaust pipe usefull.

It's 100% for looks.

And here I was thinking this simple answer would've been enough.  s:? :? s:?