That's a very interesting concept on the exhaust port inserts, wonder how well they would work if made for street ported engine with that insert milled the same size as the street ported exhaust port. Hope u understood what I meant. I took it that those r milled the same size as stock.

 

Actually they are the same size as stock. I have done a ported set on a different car but that guy didn't listen to turbo size recommendations and killed his motor. Didn't break it in or anything. Just broke it. Then got pissed off at me.

They look nothing like the Cosmo sleeves. Mine make sense.

 

Oh yeah missed a question. The BOV is in front of the throttle plate but ON the throttle body. Only 1/4 inch off the plate. This way when I let off the gas, the air doesn't have to reverse through the intake instead it keeps flowing forward but just goes out. Seems to make sense in theory and looks damn cool. I'll post pics of the TB and BOV here tomorrow.

 

How in the hell do you remove the stock sleeves? I couldn't get a good grip to pull the roll pins, and every drill bit I hoisted from my toolbox got dulled fairly quickly while barely making a mark.

A better question is, what exactly are the sleeves made of? Stainless, mild steel, or ?. I'm half tempted to just cut a hole in each side of the sleeve, drive the rollpins all the way through, and weld the holes shut & grind the scabbing away.

 

Since I threw away my original sleeves I didn't care what I did to them. I ground them from the inside with a die grinder using a carbide bit and hammered the pins out from the inside. Took about 5 minutes a housing. I've only gotten one sleeve out the hard way and I can't even remember how long it took or how I did it. I do remember getting really pissed off! I have no idea what material they are made of. I don't even know what my new ones are made of. Whatever Marcus used, they are even harder than the factory ones! Why do you want to remove them and put them back in? Too difficult. Leave them in and port it or pull them out and replace them.

 

did he buy the adaptor by itself or in a greddy kit, from what ive found greddy doesnt want to sell them by themselves.

 

Very interesting.

I wonder how much louder having those new exhaust sleeves would make a straight pipe n/a
Your neighbors would really hate you, infact I don't even want to think about how loud it would be

Say goodbye to Rotaryproof catalytic convertors

Have you ever measured an increase in performance by dyno? A p-port engine would be a great way to test them.
Before and after dyno. Maybe even do it to a stock port highly modified n/a.

Marcus: get back to us about those exhaust sleeves! We want more information

 

I dunno about that. I wouldn't say "nothing like". The shape of yours is a rounded edge low rectangle on the sleeve.


The Cosmo one is also a low rectangle on the sleeve.



Your sleeve is similar in shape with the exception you brought the rectangle shape all the way out to the edge, without opening up to a larger more turbulent flow. Also yours has slightly rounded edges.

I still think the actual size and shape is similar, but yours definately is an improvement over stock.

Based on all the theories posted here:
1) Your sleeves
2) Cosmo's
3) FD's

 

Remove them, reshape them (possibly welding material in as well), and then reinstall them.

 

From the Yawpower site:

----

The real improvement lies inside of this initial straight run from the port. Inside the pipe is a laser cut "wing" which extends into the port, reducing the turbulence at the roof of the port. This wing increases the flow through the exhaust port by 28%.

When I first started working with this insert on running engines, it made the exhaust note very sharp and metallic sounding, as well as making the overall exhaust noise louder.

To combat this, the collector is designed with a rapid expansion which effectively dampens the pressure waves, and makes the exhaust note more pleasant. This actually worked much better than expected. The test engine was tuned with Racing Beat road race headers. This consisted of 100+" primaries feeding a merge collector which gradually expanded to a single 3" outlet, and then into a straight through muffler exiting the rear of the car. After bolting on my headers with the same 3" muffler dumping straight down towards the ground before the rear axle, the exhaust was slightly quieter in comparison, with a much smoother sound. I guess we all get lucky once in a while!

----


The cat problem isn't really from the exhaust pressure, it's from the exhaust HEAT, and the fact that complete combustion is so hard to achieve with a rotary. The converter gets very hot burning (converting) the remaining free HC and O2 into CO2 and H2O, not to mention the fact that rotary exhaust is so hot to begin with.

 

here are the sleeves that peejay was talking about

 

 

those are a lot easier than swapping sleeves...

mike

 

Yep those are the compromise inserts Paul made for some 12A headers. It is much easier than swapping sleeves and much cheaper but doesn't flow quite as much as a new sleeve does. It does offer a significant improvement though over stock. Just be sure your header pipes at the flange are exactly the same shape and size and that you don't use any existing header or manifold with it.

 

Has anybody actually used these better exhaust sleeves on a turbocharged car?

 

What kind of turbo do you have to run with these sleeves though.... Won't the extra heat really chew up a standard turbine quickly?

/me imagines BB T66 with these sleeves on a road race car...

 

you would have to have a inconel turbine wheel i would expect, i don't know what else.
what about the manifold? would the heat be too much.

 

They have really only been used in turbo cars as far as I know. Boost response is incredible. Plan on an exhaust housing a/r of about 1.72 with a Q-trim turbine wheel!!! Definitely need an inconel turbine wheel. Exhaust manifold has to be entirely custom made from 321 stainless (including flanges) or even beter use inconel. Very expensive but the results are awesome.

 

Do you know of anyone who has actually used this? I would like to know kind of materials and whatnot were used.

Also those yaw power inserts are for a N/A 12A.

 

the only difference between the 12a an 13b exhaust flanges is the distance between them

mike

 

So? I meant it was for a 12a N/A because it had matching headers. And he said he had only heard of it being used on turbocharged rotaries













Silver Polish

 

The picture of the machined sleeves are mine. That is my engine. The inserts are a 12A that Paul built for his road race headers. My friend Marcus has used a few sets with great success. I have built two engines using them, my own and a 3rd gen. The 3rd gen had ported exhaust with sleeves. PITA to do with sleeves. As far as I know all of the machined ones have been done to single turbo 3rd gens. except mine which is a single turbo 2nd gen. Paul has done n/a 12A's and a 13B turbo airplane engine. Knowing him he has probably done several others but he is hard to get a hold of so I don't know. They have always worked great.

The 12A inserts would not work in the 13B since the factory exhaust sleeves are a different size and shape. Also the 13B sleeves from pre 1986 are different from the later ones n/a turbo or otherwise.

 

Thanks for the info

 

sorry for not getting back to y'all sooner, i have been busy with the race car (check out the avatar!!) . ok, the inserts were made of a36 steel and CNC machined to be slightly smaller than the stock port so that they could be ported to match by hand. i did burn out a few turbine wheels when i first tried it and finally ended up using a clipped 'p' trim with a 1.3 on center housing and it worked excellent ang gave phenomenal boost responce and spool up and yes the car have a sharper exhaust note. tuning wise it seemed to work better on the rich side ( around 11.6). EGT's typically ran higher no matter what you did. header wise the best one was 1.75 primaries but it was REAL hard on turbine wheels so i ended up going to 2" and the response was only slightly slower. the best all around turbo that i came up with was the garret T-64 with a 1.03 on center housing and a 15 degree clip on a 'p' trim. i use on center housing because they allow you to use longer header primaries. 'q' trim wheels do not typically last as long and are expensive, you can get the same flow with the clipped 'p' trim.

MWW

 

oh yeah. i used standard 304 SS materials for the header but braced the comp. housing to elimnate resonance. i would imagine that Ceramic coated steel woudl work just fine.

MWW