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Posted by: mjsdt914 May 7 2022, 12:40 PM

Looking to improve the sound of my '74 1.8L ... make is less like a VW Bug ((

Posted by: PatMc May 7 2022, 01:21 PM

V8 swap

Posted by: friethmiller May 7 2022, 01:32 PM

Custom tangerine racing exhaust!

Posted by: Superhawk996 May 7 2022, 01:44 PM

Porsche 6 cylinder.

Posted by: mgphoto May 7 2022, 01:48 PM

Adjust the valves so it doesn’t sound like it has a chain drive, sport muffler and your good to go.

Posted by: Craigers17 May 7 2022, 02:04 PM

https://www.youtube.com/watch?v=bpLaZc6cqnM

Posted by: Van B May 7 2022, 02:28 PM

So many trolls lol

I’ve assessed the main problem with the sound is the small diameter muffler outlet. The exhaust gasses are coming out with too much velocity and give it that beetle pop.

So, however much money you want to spend to address that is the direction I would go.

I myself want more volume and a deeper sound, so The OEM muffler must die.

Posted by: Front yard mechanic May 7 2022, 03:02 PM

Scab your own

Posted by: emerygt350 May 7 2022, 03:55 PM

That's awesome.

I found another 914 owner that was upgrading and gave him a couple cases of ipa for his Ansa. The Ansa is expensive new but man does it sound good and breathe well. I do like the single outlet look though. Maybe a bigger diameter out on the original banana? I assume 1.8s have a banana.

Posted by: wonkipop May 7 2022, 05:03 PM

buy a ferrari?



some kind of sport muffler i suppose.

but being serious. 914s do not sound like beetles.
beetles had twin outlet pea shooter mufflers that produced the chirping sound that beetles have. 914s have the bus sound - no chirp.

what you really mean is how do i make my 1.8 not sound like a bus, when it is a bus engine---
more or less.

there were versions of the original muffler that VW porsche sold back when the cars were new. looked the same on the outside but the internal baffling and chambering was different. i had one on mine when i first bought it back in 89. it was marked with stamping on it. had a deeper tone. it rusted out 20 years ago.

good luck finding one, but its the sort of thing that might pop up on ebay.

these days i run an SS "quiet" muffler i picked up 20 years ago here in aus.
originally for a bus. i reworked the inlet flanges for the 914. you have to cut them off and weld them back on upside down. thats all a 1.8 muffler is. a bus muffler with the inlet pipe flanges welded in upside down when compared to a bus or a 412.

thats a tip for you guys thinking of buying a standard dansk repro muffler.
most listings for the dansk have a rrp almost twice as much for the 914 item as the bus item. if you are handy with a welder and a grinder you know what to do. but it won't change the sound. which you either like or you don't.

......leaves you with one choice - get a custom ss sport muffler.

there is a mob in south east asia making them if i remember right. forget the name of the company. would have to look them up. but i think they made a muffler that could be fitted to the 914 4 cylinder.

Posted by: wonkipop May 7 2022, 05:04 PM

no on a 1,8 mate.

see post above. literally is a bus muffler with a small difference.

Posted by: Brian Fuerbach May 7 2022, 07:08 PM

I have a 1.8 and bought the car with a 2.0 Bursch exhaust system intalled. I wanted to try the stock repro Dansk just for an original look but could not stand the tinny sound. I switched back to the Bursch. Love the deep sound. Looking to get the new stainless version that was just released.

Posted by: wonkipop May 7 2022, 08:58 PM

i hope you got that dansk for a good price mate!


EDIT.
this is the mob in S E Asia i was thinking of but couldn't remember.
taiwan. pricey. don't know how good the product is durability wise.

https://store.vintagespeed.com.tw/914-1-7-1-8L-Exhaust-System-p180686509

system for a beetle is throaty.

https://www.youtube.com/watch?v=EfMASr0iURo

Posted by: Jett May 7 2022, 09:47 PM

These make any 914 sound different…

https://scart.com/en/home

Posted by: Brian Fuerbach May 7 2022, 09:49 PM

Vintage speed could be an option but the dansk is out. I got a good deal on the dansk through ebay and sold it to Ian Karr a couple of years ago, and yes still lost money.

Posted by: Jett May 7 2022, 09:50 PM

please fabricate some safe jack stands . I love reading about and watching your work

Posted by: gereed75 May 7 2022, 09:59 PM

The Skart on Matt's car from Sweden is the best sounding four ever IMHO.

Posted by: wonkipop May 7 2022, 11:31 PM

never seen a dansk up close and personal. suspect the metal they are fabricated out of might be thinner than originals back in 70s/80s?

"oem" one i have is a bus muffler i got hold of in the 90s and had been on a shelf for a while back then. folks liked sticking hot dog muffler systems on aus buses so no one wanted it. bonus = was stainless steel. not sure where it came from but think it might have been german made. with luck it might last me out. if i was in the market for a muffler i'd be taking a close look at the taiwan jobs. seem to be about $1000 aud from a vw specialist stockist here for the bus version - more or less identical. nice shape and it fits up into the same space as the factory system.

tail pipe diameter looks like it would give @http://www.914world.com/bbs2/index.php?showuser=26011 some satisfaction!
think i might have seen and heard one on a 356 i saw last year.
if it was it sounded good. had a bark to it.

Posted by: falcor75 May 8 2022, 12:27 AM

Hey thanks !

here's a couple of unsolicted movie clips of it.

https://www.youtube.com/watch?v=LLN51EwSGeY

https://www.youtube.com/shorts/jGhv9PJUGRU

The Scart supersound is expensive but worth all the money.

Posted by: Van B May 8 2022, 08:31 AM

@http://www.914world.com/bbs2/index.php?showuser=24231
I think the 914 exhaust leaves a lot on the table. And frankly, I’m disappointed that none of these exhaust shops have never taken a crack at a full system for the street. Maybe the market didn’t support it, but hopefully it will soon.

The firing order on this car and the unequal length primaries mean some crossover work is needed. But getting the length and pairing sorted will really change things.

Posted by: autopro May 8 2022, 11:01 AM

Check out this guy's video at around the 3:50 minute mark. He builds his own exhaust and it sounds pretty awesome.

https://youtu.be/rR5H5g2FMA0

Posted by: mjsdt914 May 8 2022, 12:11 PM

More volume and deeper sound would be good. Do you have a recommendation?

Posted by: Van B May 8 2022, 01:35 PM

Right now I’m set on building my own. I want to pair cylinders 1-4 and 3-2 for a 4 into 2 exhaust. It should sound like a pair of 900cc boxer twins racing each other lol!

As far as buying off the shelf, the Bursch Stainless option will be the best thing going when you can buy it… but it won’t be cheap. Otherwise you’ll just have to shop around and see what you can find. There aren’t many great options TBH.

Posted by: euro911 May 8 2022, 01:55 PM

Posted by: wonkipop May 8 2022, 03:06 PM

i think, but i could be wrong, as its a long time ago i was shown this by my old german mechanic back in the 90s, but a waserboxer (the water cooled boxer in the later buses) had that system. the exhausts ran under the motor and crossed over.
i'd have to look one up and refresh myself. i can just vaguely remember being under the hoist when he had his van (bus) up on it and he was explaining it to me.

no heat exchangers on the water cooled engine.

but the waserboxer had other problems.
did not end up being a popular engine down here.
i reckon there would be close to zero left on the road these days.

Posted by: wonkipop May 8 2022, 03:43 PM

@http://www.914world.com/bbs2/index.php?showuser=26011

what you describe is all done inside the standard bug muffler.
but its very restrictive.

https://www.youtube.com/watch?v=OQlmITr10R8

(i can't believe this guy cut open a nos ernst muffler to make this vid! )

the type 4 mufflers were sort of like this but not, as they had the tailpipe exiting through one of the end chambers.

Posted by: euro911 May 8 2022, 05:35 PM

This is why ... https://youtu.be/af7cW_SP2_M

Posted by: wonkipop May 8 2022, 05:55 PM

ah ok, those things.
good motors, went into shite cars.
every sud and 33 down here stress cracked fair across the inner fenders and suspension mounts. within 5 to 10 years of being new. end of the car - utter crap.

lancia fulvias did the same trick. folks try and fix those for obvious reasons. but its never entirely successful i hear.

there is a twin cam version of one of those alfa boxers lying around in the workshop down here. i measured it once a couple of years ago thinking would it fit in a 14. its a very wide motor and barely fitted into a 33 originally.

Posted by: Van B May 8 2022, 10:09 PM

Well the Bursch are out and I’ll be honest, they look GOOOOOD!
https://sierramadrecollection.com/Bursch-Stainless-Steel-Muffler-914-72-74-p56001.html

I’ve got an email out to Sierra Madre to see if Bursch can make a system to fit 1.8L HE’s. But if not, I may just pull the trigger on these and 2.0 HE’s since I need new ones anyway.

The Tri-Y configuration won’t be the same sound as my idea, but it will still be a nice torque improvement up top… especially since this pipe routing will make the primaries equal length.

Posted by: wonkipop May 9 2022, 03:03 AM

@http://www.914world.com/bbs2/index.php?showuser=7300
we have this lying around in the workshop.
i took some snaps today after seeing why that guy cut open the vw muffler.
think it came out of a sprint. (angular fastback version of the sud/33.
twin cam boxer (quad cam?) 4V heads, fuel injection.
think this one is a 1.7 and good for about 120 hp but don't quote me.
the plan was to stick it in an old sud that has CAMS approval, roll cage etc, and take it to the salt lake in south australia for a bonneville style run.
we are still trying to figure out if its better to stay in 1.5L class with standard sud engine or go big with this one -----cept its not big enough because it bumps you into the 1.5-2.0L category.

its an impressive little engine. this one would need a good going through but apparently it is all there and it was not detonated.

might seem off topic, but if you don't want to sound like a beetle, then maybe its more than a muffler required?

Posted by: wonkipop May 9 2022, 04:04 AM

looks good.

i got to find the stuff that i had on the type 4 mufflers on our cars.
but somehow they are different to the mufflers that went on beetles and type 3s.
the beetle (type 1) and type 3 do the 1 4 and 2 3 join thing as per that vid above where the guy cuts open the beetle muffler.

internally they have the end chambers and same sort of basic structure as earlier type 1/3 mufflers but they don't seem to do the crossover thing that joins up the ideal firing order pairing.

don't exactly know why.
but its the basis of my comment at beginning of thread that a 914 does not in fact sound like a beetle - but sounds like a bus (with a type 4). if you listen to one with a standard muffler you don't actually hear that beat that type 1s have out the exhaust. in some ways its not as interesting a sound out of a standard 914 muffler. i don't know why they changed it for type 4s. but all an early 914 muffler is - is a straight out 411 muffler and same goes for the later ones without the small hot dog muffler and tail pipe that comes out centrally. they must have had a reason? who knows?

Posted by: Superhawk996 May 9 2022, 05:17 AM

What if this isn't just about exhaust?

So much of what defines the VW sound is the clatter of lifters, piston slap, the sound of the fan.

Without a water jacket, many of these engine sounds are much more pronounced than on water pumpers.

Let's face it, air cooled largely sounds VW because that if what people are familiar with.

Besides, what's wrong with VW sound? It is a VW T4 engine after all. As stated previously, a 914 definitely doesn't sound like a Bug

Posted by: Van B May 9 2022, 08:00 AM

@http://www.914world.com/bbs2/index.php?showuser=22428
Did you know Toyota/Lexus contracted Yamaha's services when they were designing the LFA?
It wasn't Yamaha motors either, it was Yamaha music!

I like the mechanical clatter of the VW flat four, but that poppy/squeaky exhaust note does sound like a beetle to me. And thus, I agree with the OP that the sound could use some tuning.

Posted by: Superhawk996 May 9 2022, 09:03 AM

then maybe a V10 swap is in order.

I honestly don't get it. Sure you can play with exhaust note . . . but at the end of the day. Still sounds air cooled VW IMHO. I just happen to like that air cooled sound.

One of the main limiting factor in trying to tune sound is the limited package space for pipes and volume of the muffler canister.

Posted by: Van B May 9 2022, 09:22 AM

Oh well, to me it looks easier than my 996. I had pretty good results with my adventure there too.

A lot of piece meal parts and as the final tune I added the mesh stainless. That was a game changer for the sound. More laminar and a cleaner tone. At +7K RPM it legit reminds me of two Triumph superbikes... but that's mostly because I here the left exit more predominantly than the right. Never heard it from outside the car, but I've heard compliments from those who have


Attached thumbnail(s)

Posted by: ChrisFoley May 9 2022, 03:10 PM

Fred knows what he's talking about.

I do make 1.8L version of my stainless EVO IV muffler for heat exchangers.

Posted by: Superhawk996 May 9 2022, 03:23 PM

@http://www.914world.com/bbs2/index.php?showuser=26011

Looks very nice! Did you do all the fabrication & polishing? I'll look forward to the new improved 914 system.

Posted by: wonkipop May 9 2022, 05:04 PM

very sexy.

nice stuff. whatever ends on your 914 will be pretty interesting then.

-----

you got me looking at things with your remarks pairing 1 - 4 with 2 - 3 in primaries.

something happened with type 4 mufflers where VW stopped doing that inside the muffler as per type 1 and 3.

.. type 4 mufflers feed 1-2 and 3-4 into either side of the muffler and then into a central chamber without the cross over pairing.

i've got the old muffler from mine when i bought it in 89. its either the muffler from new (unlikely i think) or a late 70s/early 80s vw replacement. tempted to take it to the workshop and cut it open. i only kept it for reference to modify the kombi muffler i had.

looking through VW classic germany catalogues confirmed that one of the muffler variants for 411/412, the bus with the type 4 and the 914 up to mid 73 is exactly the same VW part #. only after mid 73 when the 914 goes to single muffler without a central exit tail pipe/hot dog does the part # vary from VW ones.
the explanation for that is simple? the VW ones go to a rhs exit tailpipe and the 914 sticks with lhs. they modify the muffler by welding on the inlet pipe flanges upside down.

we definitely have stock mufflers on 914s that do not create the beetle/type 3 sound.
or even the 356 sound. i am pretty sure that the 356 has the same layout as a beetle muffler but with far less restriction. i was looking at a muffler off a speedster in the workshop yesterday. it is an old german original muffler. its big. a lot bigger than a beetle muffler in diameter. pretty sure it does the 1-4 and 2-3 pairing internally like a beetle muffler did.

i downloaded the TUV approval docs from the dansk europe website for the bus/411/412 muffler. had a cross section. the doc covers the 914 version i assume. i expect to find this inside my old original muffler when i cut it open----but you never know? i'm curious now as to why they altered their philosophy on muffler design with the type 4.

Posted by: ChrisFoley May 9 2022, 05:13 PM

Pairing 1-4 and 2-3 is no better than pairing 1-2 and 3-4. Adjacent cylinders in the firing order should not be paired. It doesn't work well from a performance standpoint.
The correct pairing is 1-3 and 2-4. Front pair, Rear pair.

Posted by: Van B May 9 2022, 05:48 PM

@http://www.914world.com/bbs2/index.php?showuser=22428 . I would call that a lightweight fab. I bought the headers used and deox’d and electro polished them with a home brew of OSPHO, battery acid, and oxalic acid. The mid pipes were new test pipes that I install cats in. And the mufflers I found on Craigslist and did a the same treatment on them as the headers. Then I did the work on the tips.

The finish you see there is the Jet Hot ceramic polish finish

@http://www.914world.com/bbs2/index.php?showuser=24231 . I just don’t think the muffler on our cars is anything more than a price point. Nothing about that exhaust was meant to optimize sound or performance.

@http://www.914world.com/bbs2/index.php?showuser=209

You may have overlooked when I said I was thinking of a 4 into 2 (2 into 1) and that I was thinking of a particular sound. I understand why you made the design choices you have for your product. But I certainly don’t agree with what you say as “the correct way”. There are many design factors that come into play. 4-2, 4-2-1, 4-1; the length and diameter of the primaries, mids, and collector. On a short mid pipe, the pulse can be into the final collector before the adjacent pulse shows up.
But in general I would agree that your order should generate slightly more torque all else being equal.

Posted by: wonkipop May 9 2022, 06:05 PM

right

so a type 4 muffler is still not ideal pairing.
pairs 1-2 and 3-4. or seems to from drawings.

and neither is a beetle/type3.
it appears to pair 1-4 and 3-2 in crossover muffler.

Posted by: wonkipop May 9 2022, 06:12 PM

@http://www.914world.com/bbs2/index.php?showuser=26011 - i think you're right.
hence the more truck like sound, at least to my ear, when compared to a beetle.

it probably got something to do with decibel levels.
not so much in the USA but perhaps germany?
i think the germans were fairly strict on noise levels at that time (and still are?).

i can recall reading something about air cooled vws being a real problem to get through mandated standards for noise levels because all the sound was concentrated in one place at the rear of the car. air cooled clatter and exhaust gave the db meter a real punch as the car did the drive by test. conventional cars aside from having water cooled engines also spread the sound reading over a greater distance.

type 4 muffler might be as much about passing a db test as a price point?

one thing i do know is an old speedster sounds a lot better out the stock standard factory exhaust than a 914.

Posted by: VaccaRabite May 10 2022, 11:27 AM

@http://www.914world.com/bbs2/index.php?showuser=209 's exhaust systems start at the head and replace the heat exchangers with headers. You have to go back to when Chris and Jake were working together, but there are dyno charts somewhere in the archives that show Chris's headers actually making power as opposed to just noise which is what most the muffler options at the time made. Plus they are sexy as hell.

The Triads work really well too, don't have a VW sound, retain your exchangers. But they are loud and heavy.

Zach

Posted by: 930cabman May 10 2022, 03:46 PM

Who wouldn't want to go this route?? but the $3k + is just too much for this cheapskate. I will be trying my hand a fabricating a set

Posted by: wonkipop May 10 2022, 05:13 PM

even more in $aud! then add freight on a heavy item!!!!

won't be going there. you guys are spoilt for choices.

vintage speed muffler is interesting option to me if i have a spare grand at some stage.

i've got good ss heat exchangers and i like my heater! headers are not ever going to be on my list.

looks to me like vs 2.0 muffler is the same as 1.7/1.8 - a good thing.
have worked out just how different the 1.8 muffler is from the orig factory 2.0. the 2.0s got a scaled down 911 muffler. and to be honest i hardly ever take the engine past about 4200/4500..........not much happens to make it worth it!

i think if @http://www.914world.com/bbs2/index.php?showuser=25791 got hold of one of v s mufflers or a tangerine racing one (looks in principle the same and chris foley is a local usa manufacturer - support your national industry) he'd get a good sound. which might actually be more VW-ish when you think about it - but in a good way. the type 4s definitely got the raw end of the prawn when it came to mufflers and noise regulations.

Posted by: Maltese Falcon May 10 2022, 05:48 PM

Chris...looks like the fabrication dept. didn't get the memo regarding proper Pairing of T4 tubes; this set of "Headers" is pictured on the Bursch iGram page.
Maybe they are just after Sound and not Perf ¿?
Good craftsmanship on the TiG work, polished T304...anticipating RWHP (independent before/after) dyno testing results

Posted by: wonkipop May 10 2022, 06:09 PM

@http://www.914world.com/bbs2/index.php?showuser=2755

marty, what does that crossing join of the pipes do?

Posted by: Maltese Falcon May 10 2022, 06:29 PM

In all of my decades working on different exhaust designs, systems, installs, race or road cars; I've used X or H pipe merges only in the post-collector /pre- final muffler. X and H pipes tend to balance the exhaust= nice throttle response. These X merges appearing on the header pipes could be there for pairing just ahead of the secondary piping (not in view) which will lead into the final muffler / perhaps looking for more torque with a basic Tri-Y design. Their instaG also states that a custom type of HB can attach around these primary pipes; so the X might just be there to generate a bit more heat (surface area) for the HB's.

Posted by: Van B May 10 2022, 10:02 PM

I love Bursch craftsmanship. TIG welding has been a part of my life for most of my life so, for me it’s art. But I have to be honest, the design of those headers is silly.

Further, after looking more at the Bursch muffler, I realized that they claim “equal length” when in reality, the long primaries (front cylinders) are made even longer by the muffler.

Posted by: wonkipop May 11 2022, 12:26 AM

@http://www.914world.com/bbs2/index.php?showuser=25791

there is this.
dansk sport muffler for 1,8

https://www.fvd.net/de-en/17091403/sport-muffler-914-4-17-l-and-18-l-1970-74-dansk-painted-galvanized-steel.html

its got a bit of a description with the ad in that link that implies that though its the same externally as all the other dansk mufflers its got less constrictions to flow inside it.

its interesting as i am almost sure this is what was on my 914 in 89 and i took off in about 2000. i've still got it and when i shine a torch into the inlet holes where the HE pipes join up i think i can see empty chambers rather than the feed pipes that go into the standard quiet muffler that dansk do and which i posted drawings of.

i think i will cut open that old muffler i still have just to see whats in there compared to the documented standard quiet type 4 muffler.

i reckon back in the day there was a standard offering that was a quiet muffler.
but if you wanted one you could get hold of a sport muffler. looked exactly the same but had a deeper and louder tone. with less restricted flow, though that would have been pretty academic given its still a vw muffler. but they probably sounded better.
its been a long time time since i had the one on mine and it was pretty shot towards the end and just sounded like a bad muffler. but i think i recall when i first go the car it had a nice deep tone. the s s one i now have sounds tinny by comparison - esp since its combined with ss heat exchangers. though it does improve in tone when its warmed up and hot i have noticed.

Posted by: Superhawk996 May 11 2022, 05:45 AM

For the OP.

Plug & Play. Shameless plug for someones F/S over on the classifieds. You even get a sound clip.

http://www.914world.com/bbs2/index.php?showtopic=359580

Posted by: Superhawk996 May 11 2022, 05:48 AM

You guys are killing me . . . it's a VW type 4 engine . . . there was a reason they were never used in F1

Yet, I still keep reading this thread

Posted by: Van B May 11 2022, 06:49 AM

Ha! I have negative zero sympathy for you my friend! My entire career has been an exercise in futility. By comparison, nit picking exhaust design is pure recreation lol!

Posted by: wonkipop May 11 2022, 08:06 AM

f%ck off. i've got a 76 hp cigarette lighter flame throwing mini monster that needs at least another 0.25 hp extracted from it, no matter the cost.

Posted by: 930cabman May 11 2022, 08:21 AM

"negative zero sympathy" is that something like "double secret probation"

Maybe I should stay away from this post

Posted by: ChrisFoley May 11 2022, 09:07 AM

Do you have any idea of the sound level of a Stage 1 Silencer? Friends and neighbors will hate you and if driving for more than 5 minutes on the highway, ear protection is recommended.
Although that is a great setup for autocross or de.

Posted by: Superhawk996 May 11 2022, 09:22 AM

Oh - now there’s new criteria?

Posted by: Van B May 11 2022, 10:07 AM

ra·tion·al·ist
/ˈraSH(ə)n(ə)ləst/

noun
a person who bases their opinions and actions on reason and knowledge rather than on religious belief or emotional response.

This is why no one likes rationalists lol!!!

Posted by: g911 May 11 2022, 10:16 AM

Could you speak up, I wasn't listening as you were droning on and on...or maybe that was me?

Posted by: vitamin914 May 11 2022, 11:17 AM

After awhile it isn't that loud... but why is everyone whispering... pardon me?

Loud pipes save lives, or so they say. One thing, it doesn't sound like a bug and it doesn't sound like a fart can like on some Hondas.
Could be a wee bit quieter for my tastes. It does get to be somewhat annoying after an hour or so on the freeway.

MSDS headers ($583), https://www.msdsinc.com
Hindle custom (motorcycle) muffler ($280), https://www.hindle.com

Posted by: Jake Raby May 11 2022, 12:19 PM

Lots of other factors create the character of the engine note the T4 has other than the exhaust. Usually the intake note of my engines is louder in the car than the exhaust, and the components and clearances I use change the mechanical notes as well.

Usually what makes a T4 sound more like a VW than a Porsche is the valve train clatter, which can be altered with components and clearances.

So what "VW noise" are you trying to cancel out?

If I have learned anything about T4 engines over the last 28 years it has been the correlation between exhaust sound and performance do not go hand in hand. If the exhaust is developed for sound, it'll usually suck for performance and engine tune ability. The latter is the most important, as rich running is directly indicative of poor exhaust design. When testing exhaust systems I can tell within one dyno pull if they are worthy a damn or not, and that is all based on the shape and specifics of the air fuel ratio curve. If an engine wants more fuel to reach 13:1 AFR I know that exhaust is a good design, if it wants less fuel then I know the exhaust sucks.

I see engines that act lean in the way they behave, but indicate overly rich fuel mixtures. These are the worst exhaust designs of all. I see this primarily when people (including me 20+ years ago) attempt to try a 4-2 exhaust design with these engines. This does not work, no matter how the cylinders are paired. It sounds like a sick Harley, runs rich, and can't be tuned- period.

To me you either choose sound or performance/ efficiency/ tuning. The guys that choose the former never really realize what they leave on the table for performance and tuning. They do wonder why the engine has higher than optimum CHT and OT (oil temperatures) and why the engine averages 10 MPG all the time. They wonder why the oil turns black from soot in a couple hundred miles, and they wonder why they have issues with blow- by compression. They wonder why their air filters (dual carbs especially) are soaked in unburned fuel spray from stand- off.

They never correlate exhaust with any of this. I know that ALL of this is impacted by exhaust design in relation to the T4. Having designed many systems for my 996/997/Cayman engines over time I'll say that these engines do not follow suite and they have completely different rules when it comes to design. Just like my 4.1L 993 based engine loves a pair of 3-1 pairings with a nice detailed collector makes it completely different than that of the M96/M97/9A1 engine that has proven to hate this.

Admittedly, most of my direct experience is not with engines that retain stock heater boxes since these generally don't perform well enough for even my least performing engines. Due to this the systems that utilize basic/ stockfish mufflers aren't my forte. Today I start with 180HP at minimum from what I build and the design changes I have made to the engine internals in regard to camshafts and cylinder heads with my generation 7 engines no longer really like the 4-2-1 design like they used to in the earlier days. Today a short primary 4-1 usually makes the flattest torque curve and best peak power at the same time, if the collector design is correct. I started changing things around back in 2010 when I developed my "Evil Twist" T4 conversion exhaust used mostly in 356s/ 912s then VW conversion applications.

Mufflers do make a difference, since sound wave control is a definite factor with everything related to exhaust. What really woke me up was buying a much bigger flow bench (Superflow 1020) that can really show the differences in flow characteristics between mufflers. What I learned quickly on this bench was sound and volume don't go hand in hand when it comes to muffler design, and "back pressure" is often misunderstood as a factor that doesn't even exist.

These things said, any engine 2270cc or larger has every factor heavily impacted by exhaust design. If you get the exhaust wrong, you botch the entire engine combination.

I think that it is ok to create an engine that sounds like nothing else. People spend all their time trying to make the car sound like something it isn't, when they should be embracing the uniqueness. If you identify the unique sound and behaviors as "flaws" it means you are decreasing the individuality of the 914.

That's just my perspective, and most won't agree with it.

Posted by: Superhawk996 May 11 2022, 12:30 PM

Quotable.

Posted by: Van B May 11 2022, 12:42 PM

You broke my heart with this observation Jake lol...

Posted by: Jake Raby May 11 2022, 02:05 PM

My very first T4 engines ran like crap. They got hot, ran rich and had no power. I absolutely could not figure it out in 3 different cars that were T4 conversions. The same combinations in a VW bus would run great. Those 3 cars all ran an exhaust that was really easy to build as a 2-1. Use a pair of bus F pipes, slap on a better collector, and go straight into a pair of mufflers I would run out the back of the car.. When that didn't work I removed the mufflers and ran a stinger... It got WORSE!

When I removed the dual 2-1 set up and swapped to a 4-1 the car was even slower... because it was way too lean. I had pulled so much fuel trying to get the AFR correct with the 2-1 that when I swapped to the 4-1 I was 4 jet sizes too lean.. Back then we didn't have Wideband O2 sensors and barely had a narrow band. It was so archaic that it had different colored lights that indicated enrichment, and that was the only way I figured it out. Once I corrected the AFR the engines were completely different than with the dual 2-1.

Then the timing the engine wanted changed, and fuel economy doubled. The oil wasn't black in a matter of miles, and I didn't have blow by so bad that I needed a catch can attached to the engine anymore.

Learning things the hard way is the only way. We do not learn lessons from successes, only failures. That's why more than 2.5 decades later I remember this experience so vividly, and try to express it to others.

Posted by: Van B May 11 2022, 02:20 PM

Definitely appreciated. Especially prior to investing money and labor into a dead end.

Posted by: wonkipop May 11 2022, 03:00 PM

@http://www.914world.com/bbs2/index.php?showuser=1095

thats a good read.

Posted by: euro911 May 12 2022, 11:00 AM

Looks a lot like a Subaru motor ?

Posted by: wonkipop May 12 2022, 05:51 PM

very similar looking.
a very different sound.
twin cam per head 4 valve version has around 130 hp.
motronic injection.
think the one lying around in workshop came out of a late 33 II.

there was also a 1.7 two valve version with later version of L jet on it. 110 hp.
no carb versions.

earlier smaller capacity 1.5 L versions have a nice twin 2 barrel carb set up.
a mate of mine had a 33 sportswagen with that engine.
good engine - a shite car. bus like steering wheel mounting angle and pedals that were too close. you could never get comfortable to drive it. it cracked in half across the front before it even had a chance to rust out.
alfas = one of the few cars that did rust out in aus.

we are thinking of jamming it in this and going to lake gairdner.
probably the last sud left in aus that didn't rust away or break in half across the front.
crazy covid stuff wrecked those plans + this year rain filled the salt lake.
might still try and do it.


dimensionally the engine would fit in a 914. but then there is all the water cooling stuff you have to do.