danielm3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turboteener &raquo;</TD></TR><TR><TD CLASS="quote">On one of the RX7 GTUs that I work with we use a 96in primary. The collector is right under the rear axle. This is for a peripheral port 13B engine, so it will be a little different. The other best option for that engine is a very short 16in Primary. According to Downing that is one of the best setups. Bigger is better.

Your final setup needs to be made of heavy wall stainless tubing. Rotaries have VERY high egts. They will burn out mild steel in short order.


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Thank you, stuff like this helps a lot!

I only make stuff out of 16g 304 SS, I don't have the tooling to bend mild.

They had my header on there for about 30 40 min, at around 1600/1700 degrees, the whole thing was glowing orange.. I had no idea they get so hot.

Top Ramen

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by danielm3 &raquo;</TD></TR><TR><TD CLASS="quote">I had no idea they get so hot. </TD></TR></TABLE>

Yeah, the exhaust temps on those things are crazy.

Johnny_Rocket

I remember on my FC I installed a header and complete 3" exaust and that damn "exaust temp" light and buzzer would go off when I ran her hard on a hot day for a while. I just kept beating it though. I figured the faster I went the cooler it would get. lol

clayne

Also, check out this dude's (tyson):



From this thread:

http://www.nopistons.com/forum...eader


And here's another guy's custom work:





http://www.nopistons.com/forum...eader

danielm3

I want to start working on the second design already, stupid orders are keeping me too busy. I hope to get some free time on Friday to make another one.

Thanks a lot guys for posting all this info. Posts like this really makes our brain work over time.

danielm3

Ok here is my second idea which will be dynoed again shortly. (the middle on out of the 3).





I decided to not go with the "intake manifold" looking design and went with this instead. The runners are all 2" and instead of merging all 3 in to 1, I decided to break it up have the 2 outside ones merge in to a 2.5" than run the middle one and merge it to the 2.5" in to 3". What do you guys think?

143MYVTECEF

Whats the theory running the seperate collectors? Running the two into one and the the third one by it self?

drumking15

looks good...like it better than the 1st design...only thing id change is that on the middle port you cheat the cut a lil bit...id make it staright out the port and adjust w/ bends for the offset

wantboost

iTrader: (2)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 143MYVTECEF &raquo;</TD></TR><TR><TD CLASS="quote">Whats the theory running the seperate collectors? Running the two into one and the the third one by it self? </TD></TR></TABLE>

the 2 outer fire at the same time.. the middle fires by itself, the reason is for equal exhaust pulses, and scavenging id imagine

143MYVTECEF

Oh i see makes sense. im a noob to /_\

danielm3

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

the 2 outer fire at the same time.. the middle fires by itself, the reason is for equal exhaust pulses, and scavenging id imagine</TD></TR></TABLE>

Yeah the outer too are for each rotor, the middle one both rotors share, so in a sense its like have 4 ports.. that's why I was thinking it would make more sense to make it 4 to 2 to 1 instead of merging all 3 in to one. Need to wait for the dyno to see the out come.

3minburnout

any dyno # yet?

danielm3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 3minburnout &raquo;</TD></TR><TR><TD CLASS="quote">any dyno # yet?</TD></TR></TABLE>

Nothing yet. Sometime this month it should be done.