I was at my engine builders shop shooting the shit and saw a aluminum downpipe flange on the counter. We got into discussion and they told me that I could run an aluminum exhaust if I went with 11ga tubing. This would offer a great weight savings over my current 5" 304SS exhaust system so it naturally caught my attention.

I find it hard to believe that an aluminum downpipe pipe would survive on a street car, but they assured me that they have seen it done before.

I'd like to get a second opinion, Can anyone confirm this?


Thanks

 

There are some guys making aluminum 4 and 5 inch exhausts on Honda-Tech.com

 

For racing maybe but for the street it would probably die. IMHO

 

Run steel or s/s out of the turbo 18-36 inches.
Or the first couple of bends and then alum there back.
Depends on how you hot side is running.

Race set-up this is great.

 

just curious as to why

 

I think I will keep the SS 90 comming directly off of the turbo there. I will then run aluminum from there back. There is a lot of weight there that I can knock off by going with aluminum.

 

I bet some ceramic coating would help out a lot for longevity..

 

i wonder what the weight difference is between 11ga. (.120) aluminum and 18ga (.040) steel?

 

Can you get 18 ga .040 SS in 3" or larger bends?

 

I believe woolf aircraft will literally make you anything you want, of course most of the time cost is a factor, and custom stuff is VERY expensive usually

 

I have seen this done on race applications, so it can be done... Even with the heavy gauge stuff, there are weight savings to be had, but for a daily driven street car, it's not going to make enough difference, to justify the cost.

 

Aluminum will work for a race car, or a very rarely driven "street car" I sell aluminum bends and tubing for aluminum exhaust and intercooler tubing. My customers are using .065" wall and some are using .083 and .120 wall right from the turbo, then running .065 wall a few feet back.

 

The 16ga 5" SS bends I got from Woolf were very expensive, and are still very heavy. The 11 and 14ga 5" aluminum bends that I have are WAY lighter than the SS. I am sure I could knock 25-30lbs off of the car going with an aluminum exhaust.

 

I don't see any reason why you couldn't make an entire exhaust out of aluminum. After all, we have heads and pistons made out of aluminum. The question would be whether or not you could get away with it being thing enough to actually have a weight saving without it breaking or failing in some way. I'm certain it is possible.

 

Yeah, but the heads are water cooled, and the pistons have oil to cool them off. I really don't see the point in making a whole exhaust system out of aluminum on a street car. If your turbo is large enough to run a 4 or 5 inch dp, then you should be making way more power than you can manage on the street and shouldn't be worried about a few extra pounds.

 

If you saw the car, you would realize there was a lot of effort put into things with minimal benefit, where the major things got skimped on. It's humorous at best.

I'd work on fixing the cluster fuck of a header setup long before I worried about droping a couple pounds from changing the down pipe.

 

Whose car are you talking about?

 

DynoDaddy's Viper