My buddy and are looking to manufacture and sell aluminum lightwieght split DP For RX-7's and other cars. This DP will create better airflow because it will eliminate the turbulance created from the changes in diameter of a single opening DP this will also create a divorced waste-gated turbo which acts like more like an external waste-gate. We have the plans and are currently working on a prototype for my RX-7. My question to you guys is: Would any of you be interested? If so, what is a reasonable price range? Free is not an option. lol

 

its the aluminum part that I have the question about. how are you going to get it to handel the heat ? the exhuast is way to hot for it. isnt the max temp for alumn well below 800 deg? rotary exhaust well above 800.

 

theres a reson youve never seen an aluminum downpipe/headers, it would melt before the engine got the tempture.

-Daniel

 

I too suspect you are going to see too much turbo outlet heat.

It might work with a thick wall heat sinking design with cooling fins in the first 12".

Another potential issue is how to keep the flange bolts from working loose..

 

not intrested in a aluminum DP. To hot

 

make a steel one may be ?

 

we were melting aluminum cans in a camp fire once for fun, so i wouldnt want an exhaust componet to be made of the stuff.

 

yeah....well, it seems that Aluminum melts at around 1228 degrees Farenheit and the Exhaust temperatures are around 800 Degrees BUT that is only under low throttle, when WOT the exhaust temperatures can exceed 1400 degrees. We will now work with Steel which has a melting point at 2500 Degrees Farenheit. Thanks alot for pointing this out... Glad you guys had good input, and we had not started the building process yet. I'll keep you posted on any new developments.

 

Cool I was about to say the melting point for aluminum but you got it. Get pics for us as soon as you get an example of what we are going to be looking at.


Santiago



EDIT I just thought about turbo manifolds. DI you guys think you could make a manifold for a TO4 for less than the HKS collected manifold? Or less than the XS and other divided manifold?

 

If you want it to be quality the answer is no not really. Those manifolds are very reasonably priced. If you don't care about equal length etc then a cast manifold is probably better for durability reasons. If you do care about the actual design then you need tubular and making it for less than the $250 HKS manifold isn't going to happen.


EDIT: I"m not really sure what you are trying to accomplish with your DP? Are you saying that it will just be divided immediately from the turbo?

 

yes the DP will be divided from the turbo. Itt will have two pipes , one for the turbine and the other for the waste-gate. This will allow for better airflow because, as I said earlier, it will eliminate the air turbulence created by the mixture of the two airflows ( turbine and waste-gate) As soon as we have a working prototype I will post it here. We will be making these for S4 and S5 turbos. So far we are going with Stainless steel instead of aluminum due to high exhaust Temps.Feel free to voice any concerns because we are at the early stages and your input is very valuable.
Thanks,
Hassell

 

How are you separating the flow from the WG on a stock turbo?

FWIW, 304 is usually the stainless of choice for these projects.

 

You might be able to get away with aluminum if and ONLY if you had it ceramic coated inside and out...and they had best not miss anywhere. We burned out our aluminum headers on our SAE car cuz the coaters didn't do the entire inside....doh.

 

we are using 304 stainless steel, and we will have a prototype soon so you can see how we are going to separate the airflow. Thanks alot you guys.

 

It is a very good design to seperate the turbine flow from WG flow in the downpipe.

Helps relieve boost creep AND adds more power.

Generally one does it by making the downpipe(s) flange incorporate a new turbo backing plate. This plate has a divider (stainless pipe radius) that matches up w/ the radius around the turbine exit.

I used a separate iron block machined to fit well between the turbine exhaust and WG exh. sandwiched between the stock turbo housing and stock backing plate. Then I cut a 2 1/4" hole in the backing plate for the WG exhaust. I ran 2 downpipes and open air vented the WG flow one. The stock flapper WG leaks at idle so I had a little muffler on it.

I now use the same divider and a new stainless backplate w/ a 60mm external WG on it so I could remove the WG flapper and hog the WG holes larger than the turbo runners.

It would be great if someone would offer this divided downpipe design for our cars since boost creep is such a common problem!

 

Glad to be of assistance . A finished product will be coming your way in 2 to 3 weeks.

 

Somebody already did this to their stock turbo to cut down on creep. Search around. You will find it. I know I posted to it. Maybe you could use my name to find it?

James