Can you make an I4 sound like an old VW?

Rereading old Autopian articles the other day and I came across one on why VWs sound like they do.

And for a lot of reasons (one being shenanigans) I got to thinking.  Lots of people shove liquid cooled engines in them, the 2.3L Ford Lima engine is semi-common.  Is it difficult to get the exhaust to sound like a VW?

There are lots of reasons why they sound like they do, as outlined in the link above, but I would think one of the most distinctive reasons it sounds like that is the:

                      put-put

put-put

that they give off.  I'd think that sound combined with the whistle from the tips would get you 90% of the way there?

Most (all?) I4s seem to have a firing order of 1-3-2-4

Is it doable without sacrificing too much power from your donor motor?

Is creating a cross-plane crankshaft within scope of the project?  Thinking about the Yamaha R1 crossplane motor (which I think they quit doing not too long ago) and how it sounds more like a V4 than most inline-fours would probably help.  The exhaust pulse train of common inline-fours seems too regular and "smooth" to get that VW sound.

Then integrate the VW's exhaust system as close as possible, probably using a 4-2-1 header configuration.  

I bet ITB's or individual carbs would help.  

Crossplane crank is waaaayyyy outside the realm.

However, looking at this:

And knowing they use equal length tubes from the entrance of the muffler to the exit, I think there wont be any significant losses?  Minor velocity loss of exhaust gases?  Sizing of the exhaust tubes might be the biggest issue.

Retard the timing, loosen off the exhaust manifolds and add a referee's whistle to the tailpipe.

My experience is "that sound" disappears if you put a different muffler on a stock vw. So rather than alter the firing order, I'd replicate the exhaust as closely as reasonable possible. Of note, the stock mufflers are quite restrictive. 
 

My dad told me a story once. A friend in high school came over for help with his Toyota pickup. The complaint was low power and "damn thing sounds like a Volkswagen." Turns out the the spark plugs were all loose. Not sure I'd recommend trying that on purpose though. 

The other thing I just thought of. Those little engine bays are noisy. Induction noise from the air filter, the cooling fan spinning faster than the crank, and the resulting noise from all the air being directed through the tower and tins. And that's before we talk about proper valve adjustment. 

Have you tried burning an exhaust valve? 

Tune it for 36 horsepower.

barefootcyborg5000 said:

My experience is "that sound" disappears if you put a different muffler on a stock vw. So rather than alter the firing order, I'd replicate the exhaust as closely as reasonable possible. Of note, the stock mufflers are quite restrictive. 

True duals! Exhaust system has 4 cut outs that run to a put-put exhaust, or a full-race exhaust!

No. No, thats just silly.

Seems to me the most important thing would be to replicate that exhaust routing setup.  The VW has 2 pulses in a row on the left, then 2 pulses in a row on the right side of the exhaust system.  Run Cylinders 1 & 3  to one side (LL), and 2 & 4 to the other (RR) to get the LL RR put put.  Or maybe just dual exhaust it like that?

In reply to ProDarwin :

I think equal length duals with the pattern is key. Follow it up with whistle tips (they go woo!) and I'd be about as close as I could get without a rattling heat shield.

So you want to build an ehaust with true duals, or maybe with a limited flow H-pipe, and 'wrong pairing' double-y headers... Well, what are you waiting for?

They sound way different with a 4-1 or 4-2-1 with the "right" paring. I am with the folks saying put the I4 header in 4-2-1 in the wrong way. You may want to size your collectors larger like you would a v8

We're asking the wrong question though. It should be:

"How do you make an LS-headed i6 sound like a VW?"

In reply to barefootcyborg5000 :

Nah, different project.

Paul_VR6 (Forum Supporter) said:

They sound way different with a 4-1 or 4-2-1 with the "right" paring. I am with the folks saying put the I4 header in 4-2-1 in the wrong way. You may want to size your collectors larger like you would a v8

I don't think the aircooled VWs went 4 into 1, I think there may have been a bit of a balance tube, but I think it was a full true dual.

Would happily be corrected by a VW expert.

Mr_Asa said:

Paul_VR6 (Forum Supporter) said:

They sound way different with a 4-1 or 4-2-1 with the "right" paring. I am with the folks saying put the I4 header in 4-2-1 in the wrong way. You may want to size your collectors larger like you would a v8

I don't think the aircooled VWs went 4 into 1, I think there may have been a bit of a balance tube, but I think it was a full true dual.

Would happily be corrected by a VW expert.

It shows in that article they go 4 into 1 dual-exit muffler, but the exits are far apart.  2 pipes are very close to the left exit and 2 are very close to the right.

In reply to Mr_Asa :

Cyl.s 1 and 3 run through j tubes and join into the common chambered muffler that more or less bolts directly to 2/4. Or at least I'm pretty sure it's a common chamber, having never dissected one before binning it. The tips can be removed at least on the later designs, and that'll do away with the exhaust whistle. 

Not sure it's firing order since 356 and 914 have the same firing order , 

it's more that the stock intake is choking the motor as are the pea shooter tail pipe tips

Add the cooling fan noise  and you have the vintage VW sound....

Can you try putting a couple pea shooter tail pipe tips at the end of any exhaust and see what it sounds like .

Sounds like a fun project

add vaccum leaks?

Unequal length headers and incorrect pairing of cylinders when going 4 into 2 into 1. 

Well, it may end up sounding like a Subaru, but that's getting close to VW. 

I can attest that using the wrong Ford firing order on the 302 in a Factory Five with side pipes sounds a lot like a wasserboxer.  Not enough fan noise and cylinder combustion ring to properly sound like an ACVW.

The funny thing is that it drove well enough that the owner didn't think the firing order was the problem.  After I rerouted the wires so all eight were firing instead of just four, boy howdy would it scoot.

Mr_Asa said:

Paul_VR6 (Forum Supporter) said:

They sound way different with a 4-1 or 4-2-1 with the "right" paring. I am with the folks saying put the I4 header in 4-2-1 in the wrong way. You may want to size your collectors larger like you would a v8

I don't think the aircooled VWs went 4 into 1, I think there may have been a bit of a balance tube, but I think it was a full true dual.

Would happily be corrected by a VW expert.

Sorry for any confusion but I was meaning cars that are more on an aftermarket header setup don't sound like stock ones anymore and it's more difference than just a muffler swap. I have heard a few cars with 4-2 that are side split and they sound "more" like the 'put-put'  stock exhaust than the other types.