Turbo Location

[Stevo_J]

i was just looking into different locations for the turbo and was wondering if anyone knew of a reason why people mount the turbo at the exhaust end and not the inlet? are there any reason why you couldnt do it?

[Stevo_J]

i was just looking into different locations for the turbo and was wondering if anyone knew of a reason why people mount the turbo at the exhaust end and not the inlet? are there any reason why you couldnt do it?

[Rob86]

Possibly because its the 'done thing'...

Or possibly because the system lag caused by exhaust gas traveling from engine to the turbo outweighs that of charge air traveling from compressor to inlet...

Those 'remote mount' turbos used by mini-truckers in the US are reportedly extremely laggy...
It is generally considered a mark of a good turbo manifold if the runners to the turbo are as short as possible. This seems to be done by racers all over the place.

[Z]

The exhaust manifold between head and turbo gets very hot (red, yellow, white...).

This can make things catch fire. So either it has to be insulated with "exhaust wrap", heat shields, etc., or else just keep it as short as possible, and bring the inlet pipes to the turbo.

A long exhaust manifold also grows even longer with temperature so you have to be more careful with its mounting. Vibration can also make this long pipe crack - then big fire! A long inlet manifold is just some aluminium or plastic pipes, with some rubbery joints and hose clamps. If any small leaks, then no big problem.

Z

[Marshall Grice]

I'd say the main reason is you're trying to extract as much heat energy from the exhaust as possible. The longer the header is the more energy is lost. The very large delta T's mean lots of energy is leaving the header pretty damn quickly. Also a smaller volume header(ie shorter) will spool faster and have a faster response overall.

On the intake side you're trying to keep the air going "slower" to allow more heat to transfer out thus increase the density.

edit: ok not so much keep the air going slower rather just delay it's entry into the engine so it can cool as much as possible.

[Kirk Feldkamp]

Ever try hanging out a 10 pound mass from a silicon hose? It doesn't stay there for long. http://fsae.com/groupee_common/emoticons/icon_wink.gif The simple answer is that you really can't hang the turbo from the compressor housing, it's just not designed to do that.

-Kirk

[Andycostin]

Could also be the fact that it's worthwhile sticking an intercooler and plenum between the compressor and the intake, and these tend to take up space.

Generally, I'd just think it was complete system packaging and trying to keep the CoG as low as possible. But that's just my 2 cents http://fsae.com/groupee_common/emoticons/icon_smile.gif

[R/TErnie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Ever try hanging out a 10 pound mass from a silicon hose? It doesn't stay there for long. The simple answer is that you really can't hang the turbo from the compressor housing, it's just not designed to do that.

-Kirk </div></BLOCKQUOTE>

I've fabricated several systems relocating the turbocharger (T4/60-1's to GT4202R's) 60" from the head flange with NO BRACING. This includes the external wastegate, dumptube, and the 3-4" downpipe.

[John Stimpson]

Not to be rude, but hanging a turbo off a manifold (even if its NOT 60" away from the head) with no other support is bad engineering and shows a lack of consideration to thermal management.

I would give a passing grade to a compact cast or thick "weld el" manifold supporting the turbo itself, but barely.

Never forget that turbo bracing must account for turbo movement as well. As mentioned, manifolds and exhaust conduits grow a LOT as they get hot - particularly stainless! keep this in mind in your designs, guys.

[drivetrainUW-Platt]

Igonore him, he will disappear and drive his Neon some more

[flavorPacket]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by R/TErnie:
I've fabricated several systems relocating the turbocharger (T4/60-1's to GT4202R's) 60" from the head flange with NO BRACING. This includes the external wastegate, dumptube, and the 3-4" downpipe. </div></BLOCKQUOTE>

I've put rod ends in bending, but you don't see me bragging about it...

[Pete M]

I guess our exhaust is poorly designed then. Our turbo mounts off our manifold and nothing else. We've been doing this since 2004 and have never had a single problem. And yes, they glow, a bright yellow-orange colour sometimes.

60" unsupported is a bit much though, our headers are basically as short as possible.

[R/TErnie]

I wasn't implying it was a good idea...just that its been done with out incident.

A GT42R weighs quite a bit more than a GT12.

[ad]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by R/TErnie:
I wasn't implying it was a good idea...just that its been done with out incident.

A GT42R weighs quite a bit more than a GT12. </div></BLOCKQUOTE>

or a GT15v

[flavorPacket]

well, we cracked our manifold (using a K03)after a bit of dyno time. Our competition manifold now has supports, and we haven't had any issues.

[R/TErnie]

If you use Inco or 321SS instead of 304SS You'll be less prone to cracking due to heat fatigue.

[flavorPacket]

if you buy inco, i'll use it.

our manifold was 316 btw

[R/TErnie]

I used to get inco scraps from Casey@Burns Stainless. He left Burns a while ago to work for the Mazda World Challenge Team.

Try backpurging as well...it will produce a 100% penetration weld...that is much stronger.

http://www.full-race.com/personal/Javier/teh_recirculator/cut_tube_inside_view_01.jpg

[John Stimpson]

Ti makes a nice header too... Cheaper than inc, particularly if you buy OEM bike headers that some dumbass has replaced with a stainless one that is louder and makes less power.

[R/TErnie]

good call http://fsae.com/groupee_common/emoticons/icon_smile.gif