^ that's what that is from... you can see the actuator at the muffler entrance...... bitchen...

But seriously a single exhaust would be better flowing and lighter ( the Y actually adds back pressure)

Then again i like symmetrical looking cars so the y pipe duals are the only way you can do that with a single turbo.

The 3000gts vr4s are funny to follow in the cold because the condensation comes out one side at low rpm and the other at high rpm.

And lastly twin turbos could have true duals but are less efficient because the compressors push against each-other.... Humph.... i think they do spool slightly faster though.

I'd like to see twin tiney twinscrolls (all alteration aside) on a subaru basically having a separate path for each cylinder to go all the way to the turbine. It would be neat but expensive and probably worthless.

1/20/2011 1:46:26 PM

^^ yeah, but still. they could've designed it much better

[Edited on January 20, 2011 at 1:47 PM. Reason : ^]

1/20/2011 1:46:29 PM

Quote :

"lastly twin turbos could have true duals but are less efficient because the compressors push against each-other.... Humph.... i think they do spool slightly faster though."

BMW N54 engines are true dual iirc. I'll have to check through the documents I have on them

1/20/2011 2:06:16 PM

All BMW inline 6s I can think of are true dual. The e46 M3 has two pipes to the final muffler that has 4 tips. I find that to be slightly more acceptable than one pipe into a Y into two mufflers, w/two tips each. It's retarded, and I will have none of it!

1/20/2011 2:17:45 PM

E46 M3 doesn't have a single turbocharger. apples-to-oranges. new BMW N55 engines are not true dual, I can tell you that. that's one of the reasons why BMW went to single turbo.

1/20/2011 2:25:08 PM

Ah, good point, turbocharged I6...

HOWEVER, 4cyl engine +1 turbo --->4 exhaust tips.

1/20/2011 2:30:46 PM

imho true duals on an inline N/A is the opposite side of the dumb equation, there is no point in it. It is heavier and when high exhaust energy isn't spinning a turbo mixing the cylinder pulses should be a goal not a bad thing. (see H-pipe/ X Pipe V8 cars)

: : : :+
 : : : : = ::::::::  

1/20/2011 2:36:33 PM

bro they have modeling software and proprietary engine data to help them design a true dual system on an inline 6, as opposed to relying on armchair engineering in the automotive section of a college internet forum

1/20/2011 2:59:44 PM

They also have other concerns... like making it sound like a bimmer (NVH) and making sure it fits under the chassis easily without having that huge tube dangling under the car 04-07 sti people learn to put up with when they put on their first aftermarket exhaust. I'm not saying they messed up but its pretty similar to the 08-11 sti setup, it was something done for sound/looks/packaging not performance.

And i messed up in my armchair math anyway... i did 2 2" pipes not 2 2.5" (i doubt they used 2.5 but i would have used it for the benefit of the doubt) but it was still and out-of my ass thought anyway.

And the diesel exhaust comment was made assuming you spent the time making a 4"+ exhaust you wouldn't make one that has more than a couple circles under the car before it comes out the rear :-)

1/20/2011 3:54:18 PM

^^ lol

1/20/2011 4:35:26 PM

You wanna a really retarded exhaust look no further than the S2000:



Besides the car only needing one true muffler, they decided to pull this cockamanny shit within the muflers:



I'd never switch to a single exhaust b/c duals look good, but one muffler would suffice and weigh less to boot. Not to mention a stock S2000 is not very loud for a minimalist sports car.

1/20/2011 5:01:41 PM

did you cut that Y up? i bet there is more ugliness there.

1/20/2011 5:44:54 PM

the s2000 is less wacky than that vr4. at least a Y exists. its obviously cosmetic reasons which dictate muffler size, quantity, and exit location (lol boxster).

1/20/2011 5:56:11 PM

Well yes, the S2k exhaust is retarded but at least each muffler is not also dual tip.

BTW, separating the first three cylinders' exhaust from the other three on an I6 does make a lot of sense from a flow perspective, considering the spacing of the exhaust pulses. And manufacturers absolutely have to worry about more than just optimum theoretical flow through a pipe(s) blah blah, I still don't like that set up, it's so inelegant.

[Edited on January 20, 2011 at 7:06 PM. Reason : Removed picture]

1/20/2011 7:02:30 PM

E39 exhaust
All I'm saying is BMW doesn't have flow as their #1 priority when designing an exhaust and certainly not weight.


The only reason to keep them separated at all is because they didn't take the time to make any uniform runner length so they actually knew where pulses were.

1/21/2011 6:50:18 AM

Damn, that's pretty crappy of BMW. I always wondered what was up with the double bulge muffler that you can always see part of on non M BMWs.

1/21/2011 8:26:16 AM

^^I've taken that U-shaped center silencer piece out of E39 M5. It weighs about 50lb. Just that center piece. It is nuts.

[Edited on January 21, 2011 at 9:24 AM. Reason : f]

1/21/2011 9:23:52 AM

My e39 540i weighed less and made more power than a 350z at Roebling Road's scales.

The M5's "u shaped piece" is flowing on both sides however, and is a true dual set up to the tail pipes:
http://m5board.com/articles/montecarlo/ssheadee39comp2.jpg

Also, on the 6 cylinder car, considering the firing order -1,5,3,6,2,4- even a two piece log manifold would be OK, think about it... Now the rest of that exhaust looks atrocious, but it's there to be quiet, not to show off like the STi. The 6 cylinder 5 series BMW doesn't even have a visible exhaust tip, much less one pipe into 4 tips...

1/21/2011 10:12:14 AM

on an I-6 a log manifold with single scroll turbo will get the job done, but it's hardly the most efficient design. BMW did a study on different turbocharging arrangements when developing the N54:



The twin turbo design has the best compromise of power and response, and using vacuum-controlled wastegates (as opposed to pressure) they can control backpressure to improve fuel economy:



but it's also more expensive. With the N55 they ditched the twin turbos and from a cost perspective replaced it with Valvetronic (complete elimination of a throttle valve), which resulted in improved fuel efficiency and emissions.

[Edited on January 21, 2011 at 10:42 AM. Reason : .]

1/21/2011 10:40:23 AM

Cool, back to subies though, I think a twin ko4s setup would be neat to see but I don't think left right is the best way to split the fireing order so the piping would get stupid long.

1/21/2011 11:08:39 AM

you could have two twin scrolls low mount turbos, one for each bank. firing order is 1-3-2-4, and cylinders are

rear
3 4
1 2
front

but that would be expensive and complicated.

1/21/2011 4:21:38 PM

Hard to find twinscrolls that flow under 35lb/hr so if i was shooting for 700hp that would be awesome

1/21/2011 5:14:19 PM

new sti sedan... still quad piped.

1/24/2011 7:48:02 PM

I can tell from the picture it has a blown ringland. How do I know you ask? It has a STI badge on it!

1/24/2011 9:11:01 PM

Badump tishhh

What's the next car gonna be ?

1/24/2011 9:15:15 PM

Currently considering e90 ///, Cayman S, Evo VIII or IX, and e36 ///...

The first two are unlikely. Evo is the most likely.

1/24/2011 9:24:58 PM

Visuals:

1/25/2011 12:07:55 AM

Well, the problem is, e36 M3's just won't get sideways...





What, what are we talking about?

1/25/2011 12:20:47 AM

lol those are all good cars... i hate evos though.... well i hate transverse mounted engines in general but i guess thats just a personal thing.

Good luck let me know how much the new engine cost once its installed.

-foo1

1/25/2011 6:35:14 AM

^ Have you driven one? Really driven one? It will actually make you forget everything you have ever assumed about the car. Or perhaps make you not care.

1/25/2011 8:12:14 AM

Not really, i have driven one, but i don't drive other people's cars like i would my own.

I have ridden in one while the shit was being flogged out of it and I'm not going to lie it is pretty impressive.
Still, not really my cup of tea mostly for stupid reasons and philosophies i have about cars.

What made you choose the STI over it originally if i may ask ?

I know you probably won't be modding the car much but keep in mind the EVO has its own basket of catastrophic failure possibilities although most are transmission related.

1/25/2011 8:38:17 AM

Chose the STI for more livability. That and the hatch is just plan sexy as fuck.

Yes evos do have their problems too, but from what I have seen they mostly limited to transmission problems. On top of that, they break after fuck nut and his friend launched the car time after time with bolt ons etc.

I really haven't seen a problem as streamlined as ringland issues in the STI. Maybe RMS on 996s? I bet the failure rate is even higher on STIs though.

Lastly, I just replaced the fucking engine in a car. How much worse can it get?

1/25/2011 8:48:42 AM

Lol true although subie and evo bottom ends are cheaper than clutches for some cars.

1/25/2011 9:30:13 AM

Are you willing to buy an Evo with bolt ons? Good luck finding an unmodified Evo VIII or Evo IX, especially Evo IX.

The Evo X has been growing on me. I wasn't down with the looks at first but now I like them. I don't like the fact that they added additional weight over the IX, but the engine is far superior to the stone age 4G63 in almost every aspect.

1/25/2011 3:09:12 PM

I'd love one of the Direct injection cars... i think it would be a completely new/cool thing to learn how to tune

1/25/2011 3:11:40 PM

I know of multiple IX MRs that have never been modded. You just have be very meticulous combing through the crap out there, but they definitely do exist. I don't really have a problem with a couple bolt ons if it came down to it.

The 10s have grown on me as well. I think the front end looks very aggressive. That being said, they're slower than the IXs.

1/25/2011 3:31:03 PM

http://raleigh.craigslist.org/cto/2157006548.html

THIS! lol BigT's next car!!

1/25/2011 3:55:18 PM

If he gets an e36, it'd be to keep it cheap. That certain e36 does have some nice goodies on it, but too bad about the #of doors + being a 95

1/25/2011 4:22:48 PM

So my WRX got totaled by a kid who t-boned me in an intersection. Got the insurance money and want to go STI this time around. Which generation do you guys recommend? I didn't follow all the changes throughout the years but I seem to recall the '07's getting weaker control arms but also getting a taller 3rd gear (faster drag strip times, whoop dee fucking do ).

Also, arghx, you got a write-up on VF39 vs. VF43?

1/25/2011 4:25:18 PM

I know of an '08 with updated pistons and materials. Freshly replaced engine by Subaru.

1/25/2011 4:28:25 PM

it all comes down to price for me. any of them would be an upgrade over a WRX (6-speed, beefier tranny, DCCD, etc), so dont have a particular preference for one generation over another.

[Edited on January 25, 2011 at 5:13 PM. Reason : ]

1/25/2011 5:08:22 PM

The proper number of doors is two.

1/25/2011 6:32:29 PM

You have much to learn young one.

1/25/2011 7:27:23 PM

The new wrx is as fast as the sti car & driver actually gas the wrx going faster down the straights only losing ground in the s turns due to the sti's stiffer springs sways and dampers. But the 2010 sti had a light weight edition for 32k. That would be the one I look for who needs sat-nav and power seats in your toy???
Or buy big-t's and ask him to put stock bore cosworth pistons in.

1/25/2011 10:16:34 PM

Quote :

"Which generation do you guys recommend?"

'04-'05, maybe '06 if you like the looks... just make sure you remove the banjo bolt filter for the oil feed line because it will clog and blow your turbo. Still, it depends on your budget and what you are looking for. Those earlier STi's IMO are the best looking and certainly the most hardcore in many ways. I think these are the lightest as well. They're also going to be hard to find in good condition.

Having driven a completely stock one I can tell you that they are loud and very stiff compared to other completely stock performance cars. You drive it and it sounds like somebody put an aftermarket intake on it (you can distinctly hear the whine of the turbo) even though they didn't. It feels like somebody put aftermarket suspension on there but it's actually stock springs and shocks. There are a few little stupid things wrong with those years like strut noises.

VF39 vs VF43: basically the same turbo except for the turbine housing. VF43 has a little bit different wastegate and turbine housing casting. I had some pics somewhere but I can't find them. There are a bazillion turbos you can put on there instead of those stock ones. The STi and earlier WRX fitment gives you many options.

[Edited on January 26, 2011 at 10:32 AM. Reason : .]

1/26/2011 10:29:31 AM

Quote :

"The proper number of doors is two."

fo' doo's fo' more hoes was how it was explained to me.

1/26/2011 10:34:49 AM

Yeah from what i've read the 06 is the most solid car 07/08 the least but the tranny gearing blah blah blah... its not just for drag racing every time you're in those gears the car pulls harder longer.

The HTA 68 seems to be the stock bottom-end favorite.

Basically 18g power/spool on pump gas but then a lot more room to grow when you kick the octane up.

1/26/2011 10:50:48 AM

Just test drove an Evo X. Fuck that car.

They took a ballsy nimble feeling track monster and turned it into a soft bloated daily driver with some power. Out of sheer principle I could never own an Evo X.

I would rather drive my 08 STI than that. The STI may be soft like the 10, but it feels like a much smaller car, and is more fun to drive imo.

1/26/2011 6:12:02 PM

I've driven an 04, an 05 and the 08 STI, I think the 08 feels very well sorted, rather neutral and extremely forgiving (w/out feeling neutered like the earlier STIs) IMO. Evo 9 MR is an excellent car, but the 10 (bench racing) seems like it'd be garbage (/bench racing), I know that I have no interest in anything from Mitsubishi produced after the EVO 9 MR. Keep in mind that as awesome as that car is, it's also super annoyingly uncomfortable, buzzy and frantic...

1/26/2011 6:56:22 PM

Quote :

"...it's also super annoyingly uncomfortable, buzzy and frantic..."

perfect?!

1/27/2011 8:11:05 AM