Technical tublar manifold

[le1gh]

whats the difference between the 2, pros and cons ,as im going to build my own soon and dont no which way to go see pics

 

[jjhepburn]

From what I can see the first one would be MUCH harder to make. But the second one doesnt look like any improvement over the standard one (might even be worse because of heat disapation).

From what I know a consideration when making the header is the lengths of the pipes to where they join. For one you want them to all be the same length. Second you can tune that length so that it aids extraction of gases (hence extractors). I cant remember how you work out the lengths though... I think its something like the volume of the pipe should be the same as that of the cylinder??? Someone else might be able to enlighten us. I know a guy who made proper extractors for his racing bike and it made a HUGE difference.

If you want proof that a simple pipe isnt ideal just have a look at an F1 engine, the exhause has a weird intestine shape.

One problem with making exhaust manifolds for Lampredi engines is that these isnt much space... So you need to be very precise.

 

[The Ran]

First to me looks like it's trying to keep an equal pipe length, iirc this is to reduce back pressure (or uneven pressure I guess). I can't see that being a major problem on most engines though. In reply to hepburn, I don't think they aim for a certain length when designing the pipes (can't see it making much difference anyway) but rather make them all as long as the longest one.

 

[jjhepburn]

Resonance tuning is where the pipe length and diameter become important. You apply wave theory to the flow of exhaust gases. What you are aiming for is a vacuum wave happening at the same time as an exhaust valve opens.

Theres lots of webpages on the topic and as I said I dont fully understand it.

 

[le1gh]

cool thax for info here a pic to see how im getting on will be slow as it not the easy job

 

[antsuno2]

to do it properly you need to make a proper jig to get it bang on i'l try and find you a link of a guy who makes them mainly jap cars Ant!

 

[le1gh]

to do it properly you need to make a proper jig to get it bang on i'l try and find you a link of a guy who makes them mainly jap cars Ant!

have made a wooden jig if you could find the link ,thx boss
its just the collect the 4 pipes into 1 have got different ideas what to do but which one to do :bang:

 

[Gav F]

i swear i read somewher e tat the length of the pipes dont matter on turbo engines?

 

[Platoon]

the length of the pipes will change how fast the turbo will respond when u push the throttle, longer pipes = slower boost so careful with modifying these things!

 

[Adrian Bravo]

Nice idea with the wooden jig

 

[SteveNZ]

i swear i read somewher e tat the length of the pipes dont matter on turbo engines?

Of course it matters, just like an NA engine. However the turbo engine will still make good power with a log manifold simply because its turbocharged.

 

[the mk1 kid]

Great thread - i was going to try and make one, but found one on ebay a year ago, which i still need to fit after swapping from the T2/T25 etc flange to the round IHI/mk1 jobby.

If you need any pics (mine is of the more equal lenght variety) then give me a shout.

Pic here: http://www.turbocollective.net/phpBB3/viewtopic.php?f=10&t=1661

Good luck!

Tom