Would this be a good idea? I am building a CRX drag car and trying to get a little more edge.
What would be the good and bad about this?
It will not see a lot of daily driving but maybe some.

 

It is definitely feasable. Most people are doing downpipe-back in aluminum and stainless for the front (this is how I'm doing it on my car as well) but while at E-town this past weekend I saw two twin turbo mustangs with GT42r's that had aluminum right off the turbo. I'm hearing about a few other people doing this too, although these are strictly drag cars.

 

cooler after-turbo exhaust temp and less weight.

 

this is what I was thinking so cool, I am not doing a turbo on this car but I am just getting as my wight off as I can with out ripping the car apart. I'll be running this all they way back, I guess it would weigh like next to nothing.

 

Ti titanium would be a better solution for weight because it will not crack like the aluminum is going to on a street car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GeeGee &raquo;</TD></TR><TR><TD CLASS="quote">cooler after-turbo exhaust temp and less weight.</TD></TR></TABLE>

why would you want your exhaust temps to cool that quickly after the turbo? I see no advantage

 

I think he's saying that you can't have an aluminum exhaust before the turbo because of the high heat, but after it is fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16hybridsol &raquo;</TD></TR><TR><TD CLASS="quote">

why would you want your exhaust temps to cool that quickly after the turbo? I see no advantage</TD></TR></TABLE>

I know you want it to expand as much as possible.. I'm not sure about the cooling part... I'll try to research that tonight... I'm sure tony1 or somebody would know this though..

 

The whole point of an engine is to get air "in" as fast as possible and exhaust "out" as fast as possible.

Since hot exhaust moves faster, the goal should be to keep the exhaust as hot as possible.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shepherd &raquo;</TD></TR><TR><TD CLASS="quote">The whole point of an engine is to get air "in" as fast as possible and exhaust "out" as fast as possible.

Since hot exhaust moves faster, the goal should be to keep the exhaust as hot as possible.</TD></TR></TABLE>

that is true on a N/A car... but the turbo changes this

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dmoto &raquo;</TD></TR><TR><TD CLASS="quote">

that is true on a N/A car... but the turbo changes this</TD></TR></TABLE>

In what sense?!

An engine is an engine. It wants air in, exhaust out. Just because a turbo consumes a portion of the exhaust's thermal energy doesn't mean you want the exhaust to cool as it exits the turbine.

Bottom line, colder exhaust is slower. If you have a turbo-back exhaust system made out of aluminum, the gas is going to cool and slow down as it heads for the tailpipe. That means the hotter/faster exhaust pulses coming out of the turbo are going to push into the slower moving gases up ahead.

Perhaps the backpressure caused by such a circumstance is negligible, but it's certainly not beneficial.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shepherd &raquo;</TD></TR><TR><TD CLASS="quote">

In what sense?!

An engine is an engine. It wants air in, exhaust out. Just because a turbo consumes a portion of the exhaust's thermal energy doesn't mean you want the exhaust to cool as it exits the turbine.

Bottom line, colder exhaust is slower. If you have a turbo-back exhaust system made out of aluminum, the gas is going to cool and slow down as it heads for the tailpipe. That means the hotter/faster exhaust pulses coming out of the turbo are going to push into the slower moving gases up ahead.

Perhaps the backpressure caused by such a circumstance is negligible, but it's certainly not beneficial.</TD></TR></TABLE>

Maybe for a dyno queen. In real life there's this thing called weight, it makes cars slower.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dmoto &raquo;</TD></TR><TR><TD CLASS="quote">

I know you want it to expand as much as possible.. I'm not sure about the cooling part... I'll try to research that tonight... I'm sure tony1 or somebody would know this though.. </TD></TR></TABLE>

thats what i was thinking.

 

You want the greatest pressure and temperature differential across the turbine. A big aluminum downpipe does that better than a big steel one. Is the power difference even measureable? I don't know, but in theory, the aluminum is better, and it's damn sure lighter.

 

the cooler the exhaust gases are the easier they are to push out the exhaust. keep in mind when exhaust gases expand they expand in all directions including against the tube walls and back towards the head. this is beneficial for headers, both NA and long tube turbo because each cylinder is helping the next with a properly designed collector of course. but after the turbo you want the least back pressure possible so letting as much heat as possible escape through dissipation is what the aluminum is good for.

at least this is how it was explained to me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trickeng &raquo;</TD></TR><TR><TD CLASS="quote">the cooler the exhaust gases are the easier they are to push out the exhaust. keep in mind when exhaust gases expand they expand in all directions including against the tube walls and back towards the head. this is beneficial for headers, both NA and long tube turbo because each cylinder is helping the next with a properly designed collector of course. but after the turbo you want the least back pressure possible so letting as much heat as possible escape through dissipation is what the aluminum is good for.

at least this is how it was explained to me.
</TD></TR></TABLE>

But as already stated the heat/pressure of the exhaust gases is going to make the exhaust expand making it a bigger diameter (as suttle as it may be)

 

Some pics from the past weekend of those Mustangs.

 

James/John from Mazworx run a full aluminum exhaust on their EG. It's sexy and I can pick it up with one hand.

I'll most likely be doing a full alum exhaust on my EK as well. The only thing that sucks about Ti is the cost.

 

that rustangs set up is the sickness

 

Your car is at JM Fab now isnt it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by srt4thatazz &raquo;</TD></TR><TR><TD CLASS="quote">Your car is at JM Fab now isnt it?</TD></TR></TABLE>
Maybe........

 

Wow guys thanks for all the info, I thought for sure I was going to get a "search you ***"

I know the coast will be high, but hell I am only going to have to do it one time.

 

search you ***

 

LOL how did I know that was coming? lol