V8 rumble from a flat 4?

[WhirlpoolBrewer]

So, I think we can all agree that nothing sounds quite as amazing as a big engine. This car will probably have super car performance with super car style, but what about the sound? That exhaust note is a huge part of if I think the car is cool or not, and in my experience 4 cyclenders just don't sound nearly as good as 8. Does any one share my concern of the car not sounding like a super car, or am I worrying over nothing?

[Benji]

So, I think we can all agree that nothing sounds quite as amazing as a big engine. This car will probably have super car performance with super car style, but what about the sound? That exhaust note is a huge part of if I think the car is cool or not, and in my experience 4 cyclenders just don't sound nearly as good as 8. Does any one share my concern of the car not sounding like a super car, or am I worrying over nothing?

Yes. The flat4 'purrs' with unequal length headers (the usual) it sounds great, using equal length headers changes the sound a lot but I can't vouch for that, Imp has them and loves them!

[geoffav]

I prefer the exhaust note from a V8 over a 4 banger. Although I'm not a fan of the Viper V10 sound. The idle is nice but that's it.

Keep in mind I'm talking sound without regard to performance!!!

[spaceywilly]

I love the sound of the Subaru boxer 4. I just have a catback exhaust (made by Stromung) on mine and it is a really nice deep rumbling sound and really rewards revving without being obnoxiously loud (although I have set off a few car alarms with it). Harleys only have 2 cylinders and I don't think anyone is complaining about the sound of those. Go to a stage rally race sometime and then tell me you don't like the sound of 4-cylinders :D

Sure it doesn't hold a candle to a great V8 or V10 engine, but I would say it can hold its own with many V8's in the sound department, and absolutely sounds better than most V6's I've heard. I assume you're thinking of Hondas and other "fart can" cars. The Subaru is not one of those, despite the "ricer" stereotype that many people lump it into. I can tell the sound of a Subaru driving down the road from miles away.

[WhirlpoolBrewer]

Yes. The flat4 'purrs' with unequal length headers (the usual) it sounds great, using equal length headers changes the sound a lot but I can't vouch for that, Imp has them and loves them!

Awesome, I hope so. I ask because earlier today I was walking into work when a tuned up corvette wass driving by and really got on the gas. It sounded so good I stopped at the door to hear it half a mile away sounding simply spectacular. I would love to have that kind of effect when I get on the gas. Here's hoping :) .

[WhirlpoolBrewer]

I love the sound of my Subaru. It just has a catback exhaust (made by Stromung) but it is a really nice deep sound and really rewards revving without being obnoxious. Harley's only have 2 cylinders and I don't think anyone is complaining about the sound of those. Go to a stage rally race sometime and then tell me you don't like the sound of 4-cylinders :D

IMHO Harleys sound like bees in a can with a megaphone next to it :(. But you are right, for such small engines, they sure can grab your attention. I'd love to see a stage rally race sometime, I just don't know if there are any in my area. I'd guess they're should be some not too far from here, as I live pretty close to the Appalachian mountains.

[MikeK]

Depends on the exhaust system, I have heard some 4 bangers that sounded really good, Subaru's were definitly one of them, no grapefruit launcher mufflers, also known as fartcans and you will be ok.

Almost forgot, if you ever put a turbo sticker on the car and you start to believe that it made the car faster, sell it quickly.

[spaceywilly]

there is a rally in Linden, TN April 30-May 1. Looks like it about a 4 hour drive for you. It's definitely a good way to see Subies doing what they do best.

http://www.nasarallysport.com/main/schedule

[WhirlpoolBrewer]

Looks awesome. I just penciled it in on my calendar. Thanks for the heads up :) . Oh and yes I was thinking specifically of that old 2 door honda that seems to have been sold stock with an awful fart can muffler. When I hear the word "ricer", that car is the first image in my mind.

[Hondaslayer]

Depends on the exhaust system, I have heard some 4 bangers that sounded really good, Subaru's were definitly one of them, no grapefruit launcher mufflers, also known as fartcans and you will be ok.

Almost forgot, if you ever put a turbo sticker on the car and you start to believe that it made the car faster, sell it quickly.

The muffler does not have a lot to do with the tone of the exhaust, only the noise level. Most of the sound comes from the header design. A well designed header on any car just sounds good, whether it's an I4, H4, or V8......

[Benji]

The muffler does not have a lot to do with the tone of the exhaust, only the noise level. Most of the sound comes from the header design. A well designed header on any car just sounds good, whether it's an I4, H4, or V8......

Yes but H4's and V8's etc just sound inherently better in my opinion :D

The only thing I generally like about I4's is induction noise though bike I4's sound great.

[BOB SCHAEFER]

On the way home last week I had someone come from behind, obviously gettin' on it, and was surprised to have a WRX blast by. The exhaust was extremely cool and instantly had respect... Thinking...Now I get it!...Sounded BAD ***!! Now I want one!!

Cheers

Bob

PS I love the sound of a V-8 but this was killer!!

[Jeff Kleiner]

Not a V8 rumble but Subies definitely a sound of their own. Unique and much "throatier" than the buzzy sound common to a Honda, Toyo or Miata straight 4. I think they're cool and have a sound that will be appropriate in the car we're talking about! Here is a vid I found real quick that catches some sound clips taking a WRX through different exhaust mods beginning from stock. After you pull this one up there are a bunch of others in the sidebar.
http://www.youtube.com/watch?v=G6tM-d6SdHI

Cheers,
Jeff

[snakeboost]

Mine sounds awesome with the DNA set up we made for it! They are extremely bassy sounding vs other 4 cylinders. Header configuration makes a huge differanch on the sound by the way.

Steve

[Mike N]

I guess it's a personal preference but I love the H4 Scooby sound, it has that edgy growl, grrrrrr...... that draws people to the classic V8.

[BrandonDrums]

I've had people ask me if my WRX had a V8 in it before. Granted they are people that don't know anything about cars but the Flat 4 w/ unequal length headers really have a nice deep growl to them.

The 2.5L sounds really "angry", the 2.0L is so smooth that up high it almost sounds exotic. I've had both, I love both.

That being said, the consecutive firing order (1,2,3,4,5,6) of the old Subaru EG33 H6 engine found in the old SVX made in the mid 90's is a truely exotic sound. http://www.youtube.com/watch?v=Jsgr8huE8o0&feature=related

The EG33 engine was quite similar to one of the best sounding engines ever made:The Ferrari Testarossa's Colombo Flat-12. It's one of the most unique sounding engines ever made. It's firing order essentially doubles the firing order of the EG33 going 1,8,2,9,3,10,4,11,5,12,6,7 if you can picture that.
http://www.youtube.com/watch?v=FlI9zOoC2ZQ&feature=related

The result is a very smooth sound that harmonizes at nearly all revs giving a really awesome 'scream' at high RPMs. I'd love to see/hear someone put one of those SVX engines in the FFRbaru

The Subaru Boxer 4 gets it's sound from unequal length headers which cause the 2 piston notes from the left side of the engine to have more resonance in the piping than the right. The result is an overlapping pulse deeper in timbre so the 2 sounds 'harmonize' directly with eachother making the engine sound much bigger than it is and funky.

They still sound cool with equal length headers but very much like a smaller displacement engine which they kinda are. The benefit of equal length headers is higher flow which also = much quicker turbo spool.

[Benji]

That being said, the consecutive firing order (1,2,3,4,5,6) of the old Subaru EG33 engine found in the old SVX made in the mid 90's is a truely exotic sound. http://www.youtube.com/watch?v=Jsgr8huE8o0&feature=related


I just had a trouser crises.



The EG33 engine was quite similar to one of the best sounding engines ever made:The Ferrari Testarossa's Colombo Flat-12. It's one of the most unique sounding engines ever made. It's firing order essentially doubles the firing order of the EG33 going 1,8,2,9,3,10,4,11,5,12,6,7 if you can picture that.
http://www.youtube.com/watch?v=FlI9zOoC2ZQ&feature=related

That clip isn't brilliant to demostrate it, this one is better (once he actually takes off):
Ferrari Testarossa (http://www.youtube.com/watch?v=xTsQEinS234)

But I get what you mean, we need H6's in there as well (who said the newer H6's were about the same length as the H4's?) :D

[BrandonDrums]

Yeah, the h6's are only a couple inches longer than the h4's. Look up the Perrin H6 STI project http://www.perrinperformance.com/pages/show/32

The newer h6s are much more narrow than the old. Only .7" wider than the 2.0 4cyl to be exact, at least according to that article.

[Turboguy]

That exhaust note is a huge part of if I think the car is cool or not, and in my experience 4 cyclenders just don't sound nearly as good as 8. Does any one share my concern of the car not sounding like a super car, or am I worrying over nothing?


Given that, outside of Maserati's, the only V-8's I've heard which have that "supercar" sound employ flat-plane cranks and come in the back of Ferraris, I would tend to say you're worrying over nothing.

Subaru's flat-4 turbo actually has a nice low throb to it. Their flat-6 sounds very similar to those legendary engines that come from Zuffenhausen.

[Shaun R]

Any engine that makes awesome power is one I learn to love. True, there are some I love more though.

[WhirlpoolBrewer]

Glad to hear it. I never built a GTM (really wish I had the opertunity to but it would several years before I had that kind of spare $$$$ laying around), but I think they still used the Corvette headers. So assuming that they would go the same route with the Subaru means that I should start looking for models with unequal length headers. Or really, I could probably just swing on by a dealership and pick em up there if my donor didn't have them. Thanks for all the great info!

[TimC]

Make note of the Ford V-8. It sounds totally different when you put the "bundle of snakes" headers on one in a GT-40 than the regular dual exhaust you have on a roadster.

[einy]

Shortly after buying my '10 Forester (non turbo), I pulled both rear mufflers to install a trailer hitch. To be perfectly honest, I rode around like that for a week as it sounded very nice in comparison to the I-4's that I was more used to. Better judgement go the better of me, and the mufflers then went back on, especially to make sure the exhaust fumes weren't able to get into the interior. However, I have not given up on the thought of fabbing up some tailpipes that (permanently) eliminate the mufflers. Point is, given the right exhaust setup, the flat 4 will sound very cool ... !

[Turboguy]

Make note of the Ford V-8. It sounds totally different when you put the "bundle of snakes" headers on one in a GT-40 than the regular dual exhaust you have on a roadster.

You are 100% right. I forgot about that - the 180 degree headers give a cross-plane crank engine a sound very similar to one with a flat plane crank. I've heard a small block that revs to 9500 with those headers and it sounded pretty schweet too.



I always wondered if there was enough space in the GTM engine bay to pull this off? Likely only possible if you dump the cats, though.

[jmimac351]

I had a 2002 WRX with a larger downpipe and Magnaflow muffler. This 4 cylinder sounds like no other 4 cylinder. It is a deep burble that is actually pretty cool.

Bub, bub, bub, bub, bub, bub, bub....

At part throttle it is a rumble. It is nothing like the buzzy, tin can nonsense from a Honda, etc.

No worries with the sound, "trust me".

[jmimac351]

See here:

http://www.youtube.com/watch?v=47NJBTT-1m4&feature=related

[lee4him]

Do some quick searches on YouTube and you'll get a good sense of what these cars can sound like. Check out some that are cammed and you may be surprised at what you hear. I also imagine F5 will develop a good exhaust system which will impress. Now do they sound better than my 4V Mod Motor, to me no, but then again my mod motor doesn't sound as exotic as an Enzo either (Muscle car sound vs Exotic Supercar sound). Guess I'm saying the V8 rumble and the flat 4 of the WRX both have their place. Put a sexy skin on this design and the sound will be tertiary to the look and performance.

[iamsam]

So assuming that they would go the same route with the Subaru means that I should start looking for models with unequal length headers.

To my knowledge they all have unequal length headers form the factory and going to EL is not a very popular mod. Not that you wont' find one with them, but you'll much sooner find 10 other mods on it before EL headers.

[crobin4]

I don't have a problem with the way mine sounds. I have stock WRX manifold, decatted uppipe, bellmouth 3in catless downpipe, 3in "cat-back" w/o resonator, and a Borla Xr-1 sportsman "muffler.
The best way I can describe the sound is: below 3500rpm, it sounds like the old 5cyl. Quattro with a free flowing large Diameter Exhaust. Above 3500 it sounds more like a cross between an LSx Chevy and SBC with just a tiny hint of the Audi sound left.

[BrandonDrums]

To my knowledge they all have unequal length headers form the factory and going to EL is not a very popular mod. Not that you wont' find one with them, but you'll much sooner find 10 other mods on it before EL headers.

Almost all subies have unequal length headers, I believe the new legacy gt has equal length headers and no up pipe. The turbo is mounted directly to the headers down low to reduce lag.

I haven't heard how that setup sounds though.

[Gollum]

I think to be fair though, almost any engine can sound "exotic" when you put the right effort into. Any engine reaching the absolute limit of what it's displacement is capable it's going to sound like a wild banshee. Even V6 F1 cars sound amazing. And looking at the exotic companies they've used almost every engine configuration, V12, V10, V8, W16, V6, H12, etc. Even a dual plane crank V8 can have it's own "exotic" sound when done right. Just doesn't have the "smooth" ferrari V8 sound.

Different isn't always bad. And the subie H4 will certainly be a GOOD different for sure.

[Bret]

I'm a committed V8 fan, but the flat4 Subaru has a nice sound too. I wouldn't buy one, but I wouldn't bash it either. There are some really fast Subarus out there.

[riptide motorsport]

I think the exhausts do sound good, gotta get the R's up but they do sound healthy.....Steven

[G35m@]

I did not see it mentioned here but I'm a fan of the BOV sound between shifts when using an upgraded turbo. that sound will always turn heads and when paired with the right exhaust it is a great combo IMO.

[WhirlpoolBrewer]

I agree that the BOV can sound simply fantastic, but for me turbo lag is a bit of a buzz kill. I realize that turbos have come a long way and that from the factory there is very little lag, but its one of those things that I would know every time I step on the gas I'm going to have to wait for the goods to deliver. I've never personally driven a turbod car. So I suppose I'm being a bit unfair, but that seems to be a common topic that comes up with any person who uses turbos. Because turbo lag is talked about so much, it worries me.

[thebeerbaron]

I agree that the BOV can sound simply fantastic, but for me turbo lag is a bit of a buzz kill. I realize that turbos have come a long way and that from the factory there is very little lag, but its one of those things that I would know every time I step on the gas I'm going to have to wait for the goods to deliver. I've never personally driven a turbod car. So I suppose I'm being a bit unfair, but that seems to be a common topic that comes up with any person who uses turbos. Because turbo lag is talked about so much, it worries me.

Sure, the big turbos that take those Supra dyno-queens up into the thousand-plus HP range will have "lag" like you wouldn't believe. But it's quite easy to design a turbo system with very little "lag". Like most engineering problems, it's a matter of goals.

I haven't read it in a while, so my memory is rusty, but if you want to know how to design a turbo system that'll have power everywhere you want it, go read Maximum Boost by Corky Bell. You'll learn how to read a compressor map and select the appropriate one for your goals. And, IIRC, you'll learn that "lag" is different than "spool" - IIRC, one is how quickly a turbo car, in boost, responds to your throttle inputs. The other is the time it takes to get the compressor working. One is a factor of plumbing, intercooler size, and the like. The other is based on compressor choice, manifolds, etc etc.

With only 1800lb to move around, power is not going to be a problem with this car. A nice, smooth turbo system should be quite simple and I'm guessing it'll be exactly what comes out of the donor.

[subyrod]

^^^ agreed. I have owned my 2002 wrx with 280hp on the stock turbo (about 15psi). When you're rowing through the gears, lag doesn't really come into play. Being a 4 cylinder turbo, when I compare it to other hopped up Honda 4 cylinders, the "lag" of a small 4 cylinder getting up to teh revs where it'll make power, the turbo suby motors are killer responsive and make great power. They're not v8's, so that right now response won't be there, but man, when the turbo is on the wick, its a blast. It's a different feeling than the linear feel of a v8 (I've own and driven a few hopped up Mustangs).
Whirlpoolbrewer, you just need to go drive a turbo 4 cylinder. :)

[JJ'snakepit]

This should give you another example...
http://www.youtube.com/watch?v=u8_UPW7Eg88

[WhirlpoolBrewer]

^^^ agreed. I have owned my 2002 wrx with 280hp on the stock turbo (about 15psi). When you're rowing through the gears, lag doesn't really come into play. Being a 4 cylinder turbo, when I compare it to other hopped up Honda 4 cylinders, the "lag" of a small 4 cylinder getting up to teh revs where it'll make power, the turbo suby motors are killer responsive and make great power. They're not v8's, so that right now response won't be there, but man, when the turbo is on the wick, its a blast. It's a different feeling than the linear feel of a v8 (I've own and driven a few hopped up Mustangs).
Whirlpoolbrewer, you just need to go drive a turbo 4 cylinder. :)

Lol, alright then, so whos gonna let me play with their donor? Just kidding, but I wonder if this is one of those times when instead of renting a car, I should just swing on by a dealership and pretend to be interested in buying... :)

[Gollum]

Sure, the big turbos that take those Supra dyno-queens up into the thousand-plus HP range will have "lag" like you wouldn't believe. But it's quite easy to design a turbo system with very little "lag". Like most engineering problems, it's a matter of goals.

I haven't read it in a while, so my memory is rusty, but if you want to know how to design a turbo system that'll have power everywhere you want it, go read [u]Maximum Boost[/i] by Corky Bell. You'll learn how to read a compressor map and select the appropriate one for your goals. And, IIRC, you'll learn that "lag" is different than "spool" - IIRC, one is how quickly a turbo car, in boost, responds to your throttle inputs. The other is the time it takes to get the compressor working. One is a factor of plumbing, intercooler size, and the like. The other is based on compressor choice, manifolds, etc etc.

With only 1800lb to move around, power is not going to be a problem with this car. A nice, smooth turbo system should be quite simple and I'm guessing it'll be exactly what comes out of the donor.

As an example to put things into perspective, my ancient of days datsun turbo motor is 2.8 liters, and has a smaller T3 turbo that runs out of breath at around 300hp. Motor is currently only set to run 7psi right now and which will get this engine to around 200hp. I have no intercooler, just about 15" worth of pipe going from turbo to throttle. I can build full boost instantly anywhere over 2000rpm. The engine doesn't "feel" like it's really starting to make power until 4,000rpm. The issue in my situation, is a crappy EFI system. Converting over to megasquirt would net me about 20-40peak hp but probably a good 20% extra torque under the curve. Even with my crappy EFI though, when in a "racing" condition there's never and "spool time" and only a hint of "response lag" that is extremely easy to adjust to. On MS EFI that response lag would be less than half, making the car feel more like an NA motor that's just breathing through too small of an air filter.

A stock STI motor pushing 400 crank hp on the stock turbo will hit full boost by 2,000 easy. What's really surprising about the newer turbo on this motor is that it's still a journal bearing design and that even with a good sized intercooler still has so little spool lag and response lag. You can be cruising along at 35mph in 5th gear and then downshift to 2nd and break all 4 tires loose immediately (and don't forget the weight that has to be overcome in a STI to do that). I wouldn't call that "lag"....

So yes, design design design design design. Corky Bell's book IS A GREAT book. He pioneered many of the things seen in OEM setups today, like recirculating BOV valves aiming the air right back at the compressor wheel to keep the turbo spooled (just one reason not to give into the cheesy BOV sound). Even though the book is a bit dated, the principals still apply. The main difference is that the turbos we have today have a wider compressor map, meaning it's less likely to end up in surge territory when spooling. They'll be much more responsive and have higher rpm limits.

[eagle98ak]

When my 06 2.5l wrx was stage II (downpipe plus tune) it was making peak torque at about 2800rpm and had zero lag.