Ok so i have searched high and wide for the "perfect" sounding exhaust for my new engine and IMO this was the best sounding hands down. I have found an exhaust place that will fabricate this for me, and im now set on a dual glasspack set up like this.
I plan on running a modified version, with some extra pipe after the resonator and a couple extra bends to have the pipes come out the standard exhaust holes on the beetle. Also some extra pipe to create more space around the rocker covers for accessibility... no heater boxes.
I am aware that with this set up i will lose power due to:
a) lack of backpressure
b) unequal pipe lengths not extracting gases from engine efficiently (exhaust pulses).
How much of a difference (in terms of HP) do equal length pipes make to the operation of such a set up, and are there any other solutions that can increase power and still retain this same sound which i love so much.
Are there any other header options for a custom dual glasspack set up that would sound this good and not sacrifice power (i have checked the dual empi glasspacks and they sound pretty tinny and not very nice)... staying away from them.
Also, somebody mentioned a table that helps calculate the pipe lengths... has anyone seen this before?
There's a good few books/articles available on the web regarding exhaust design but even V8's use a connection pipe or crossover section to allow all the exhaust pulses to 'mix', shall we say.
Been a while since I've read this stuff but maybe using equal length and designing each exhaust as if it were a 2 cylinder may allow the engine to work effectively as it's all down to pulse tuning.
Putting it another way, if you take a look at the CSP Python exhaust and how much it bends and curls then this shows what it takes to create an equal length tuned exhaust for the VW flat 4 engine.
Sorry mate, but I will never recommend going that way.
I recently changed exhausts on a 2.2 litre VW that had one small section (about 50mm long) in one primary pipe that was slightly reduced in diameter, also after the collectou on the 1 5/8 sustem, it branched into 2 individual pipes that put two mufflers under the heads and exited out the std tailpipe outlets in the body. These tailpipe/mufflers were too small, they were only 1 1/2" [2x pipes from the collector onwards] so the engine ran hot and pinged profusely with any normal ignition settings.
Put a good exhaust on and the engine runs cooler, doesn't ping with the timing set back to normal spec. and makes shit loads more power.
What I'm trying to say, is a bad exhaust will reduce power, increase engine wear AND make your engine drive badly due to compromised tune.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
matberry wrote:Sorry mate, but I will never recommend going that way.
I recently changed exhausts on a 2.2 litre VW that had one small section (about 50mm long) in one primary pipe that was slightly reduced in diameter, also after the collectou on the 1 5/8 sustem, it branched into 2 individual pipes that put two mufflers under the heads and exited out the std tailpipe outlets in the body. These tailpipe/mufflers were too small, they were only 1 1/2" [2x pipes from the collector onwards] so the engine ran hot and pinged profusely with any normal ignition settings.
Put a good exhaust on and the engine runs cooler, doesn't ping with the timing set back to normal spec. and makes shit loads more power.
What I’m trying to say, is a bad exhaust will reduce power, increase engine wear AND make your engine drive badly due to compromised tune.
i agree. i went from one each side to a merged system. made a huge difference.
Back in the 1960s, Sonic Speed Equipment made exhaust systems for VW engines. After many hours on the dyno [Sonic had an engine dyno], experimenting with various pipe lengths and diameters, Bruce Peters finally managed to produce the same HP figures as a STOCK 40 HP muffler ! After a lot more work, he finally came up with 3 extra HP, using small diameter primary, and tail pipes. Bruce helped me with some useful info. when I built the exhaust for my F.Vee, back then.
It's a "BLACK ART" !
I'd rather wear a Beetle out by racing it than by polishing it!
psimitar wrote:There's a good few books/articles available on the web regarding exhaust design but even V8's use a connection pipe or crossover section to allow all the exhaust pulses to 'mix', shall we say.
Been a while since I've read this stuff but maybe using equal length and designing each exhaust as if it were a 2 cylinder may allow the engine to work effectively as it's all down to pulse tuning.
Putting it another way, if you take a look at the CSP Python exhaust and how much it bends and curls then this shows what it takes to create an equal length tuned exhaust for the VW flat 4 engine.
yeah, I don't think anything used on a v8 applies to a flat 4. each engine layout design requires different methods.
from what I have seen flat 4 benefit from 4 to 1 ? same with inline 4
v8s do best with 2 separate 4 to 1 exhaust systems with a "x" or "H" pipe to increase scavenging on the opposite bank, technically this still makes 2 separate aka twin exhaust system. Huge gains are made, but apply this to other 2 bank engine designs and its seems to kill the power badly.
I think 6 cylinder and similar to the v8 design but not sure?
71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE
matberry wrote:Sorry mate, but I will never recommend going that way.
I recently changed exhausts on a 2.2 litre VW that had one small section (about 50mm long) in one primary pipe that was slightly reduced in diameter, also after the collectou on the 1 5/8 sustem, it branched into 2 individual pipes that put two mufflers under the heads and exited out the std tailpipe outlets in the body. These tailpipe/mufflers were too small, they were only 1 1/2" [2x pipes from the collector onwards] so the engine ran hot and pinged profusely with any normal ignition settings.
Put a good exhaust on and the engine runs cooler, doesn't ping with the timing set back to normal spec. and makes shit loads more power.
What I'm trying to say, is a bad exhaust will reduce power, increase engine wear AND make your engine drive badly due to compromised tune.
Agree with everything Matt said plus with a 1776, 1 1/2 inch primary pipes would be much better for the rev and power range.
psimitar wrote:There's a good few books/articles available on the web regarding exhaust design but even V8's use a connection pipe or crossover section to allow all the exhaust pulses to 'mix', shall we say.
Been a while since I've read this stuff but maybe using equal length and designing each exhaust as if it were a 2 cylinder may allow the engine to work effectively as it's all down to pulse tuning.
Putting it another way, if you take a look at the CSP Python exhaust and how much it bends and curls then this shows what it takes to create an equal length tuned exhaust for the VW flat 4 engine.
yeah, I don't think anything used on a v8 applies to a flat 4. each engine layout design requires different methods.
from what I have seen flat 4 benefit from 4 to 1 ? same with inline 4
v8s do best with 2 separate 4 to 1 exhaust systems with a "x" or "H" pipe to increase scavenging on the opposite bank, technically this still makes 2 separate aka twin exhaust system. Huge gains are made, but apply this to other 2 bank engine designs and its seems to kill the power badly.
I think 6 cylinder and similar to the v8 design but not sure?
You didn't really read what I wrote properly. I said even V8s use a crossover or connecting pipe for them to work properly but with correct pulse tuning open end straight thru pipes that are seperate for each bank is possible for great power.
Therefore, with time invested you may be able to do this to the flat 4 as 2 two cylinder engines? Depends if you have the time and inclination to play with things.
As for the 4-2-1 and 4-1 debate. 4-2-1 gives better lower and mid range power for road use but 4-1 gives better top end power. Only reason no one has bothered doing a 4-2-1 for the flat 4 is that it's a very tricky engine layout to be able to tie the first primaries together as 1&3 n 2&4 have to merge whilst keeping within the required primary length. Much easier to use the entire primary length to tie all 4 ports together. 🙂
Runs cool, goes great but I agree with everyone that it could go better with a 4 into 1. I'd definitely do that for any kind of racing.
I think dual systems on a vw are not the same as a two 2cyl engines because both cylinders on each bank fire consecutively. That's what gives it the unique sound I suppose. You'd have have to join the 2 at the front of the car together and the 2 at the rear together to get it even, but it not practical.
cnfabo wrote:Yep those vintage speed sure do sound nice!!!!
Yep
Here's my Vintage Speed exhaust on my 2 litre. There is a touch of IDA induction too 😉
Vintage Speed do a heater box version for a more stock engine, the system in the vid (on Bluey) equal length header version AND a competition version that links each bank together with a short pair of primaries that then go into the ends of the normal VS muffler. Col ran one on his 2332 and it made more bottom end as well as top end but changed the induction noise enormously from the 1 5/8 merged 4-1 previously. http://shop.vintagespeed.com.tw/s.nl/sc.12/category.6/.f
I like the Vintage Speed, to me it's a bit 'retro' and in keeping with my '59's theme. They definatly have clearance advantages over most extractors and the big muffler like factory VW and Porsche use is an inherently strong design. I also wanted to try one out to see how much power can be made using one. I'm going to one day test a 4-1 to compare on the same engine
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
There is no such thing as the "perfect" exhaust. I've made some systems (usually for my bikes and friends) that have booming low end torque but lose over 10% up top, and so feel noticeably slower. I have been known in the past to make up a 4into4 set of pipes that are inexplicably quicker than expensive 4into1 race pipes down the 1/4 (just don't try to get much out of it anywhere else.........). I have also made systems that have outperformed expensive systems by very good manufacturers, a tuner is able to do this because the manufacturer doesn't use camshaft timing, compression ratio, fuel octane, etc, etc to build an exhaust.
They DO however, make quality systems that work very well, look great, last for years, and usually fit. I have a sneaking suspicion they also don't set their hair on fire while welding the thing up on a concrete floor! Hahaha!
The difference between a "tuned" hand-made system and a good quality system from A-1 or Vintage Speed (who I like personally, quality product made by enthusiasts) however, is likely to be less than 5% across the board.
Yes, less than 5%. That's about 4HP on your average warm 1776. Is it worth it for you personally?
Pick one that you like the sound of, that is a quality piece.
Enjoy. 👍
Interestingly few years back I got a peak at a exhaust system on another forum that was being developed for the type 4 on an in house engine.
its was a 4 to 1 with very careful considerations taken into its every component of its design. Engine ended up peaking 284Hp N/A, power was also gained everywhere else. can't exactly remember the gains, but I think its started off at 250hp with one of the top of the line off the shelf systems.
this system is available but only for type 4, costs around 3k and only if purchased with and engine.
71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE
