Latest Project - Headers

[RarlyL8]

The cars using these slip joints don't have springs so this is an added feature. The point is to allow the pipes grow and contract which relieves pressures that cause cracking.
How many times have you seen or heard of cracking? It is common. Anything that will add length to the life of these systems is a plus. At 1.0bar boost and typical back pressure you don't even need springs. It is a non-issue.

[beepbeep]

I've seen slip-ons on cars with zoomies and other highly strung N/A engines with zero back-pressure and very thin-gauge material (Iconel etc). But I've never seen them on turbo headers (which can be pressurized to over 2 bar when on boost).

It will be interesting to see if slip-ons can withstand heat-cycling, high EGT and exhaust pressure without leaks...

[911st]

My old B&B's had a slip joint between the half's with no springs and there was no leakage there.

Slip-on's not only allow for expansion but make the install better. They also are not as likely to induce stresses at the joints do to production variations or changes in material properties with numerous heat cycles.

I suspect that with this design it is not only the springs that holds things together. I suspect that if one assembled the system without the springs, I drought any joint could be manually shifted to any significant degree. Remember the turbo is hard mounted and that and the surface area of the slip joints would probably be enough to hold things together under boost.

If the slip joints are double walled on the female side (recomeded), even the better.

I am not an expert but I do not see that as a potential weakness but if it is it sould be immediately apparent in testing.

[RarlyL8]

All it takes is a few 1000th of an inch movement to cause a crack in a welded joint. The springs do not hold the pipes together. These slip joints are over an inch long each and so tight you have difficulty rotating the pipe in the barrel. It is a precision fit. We added the springs simply to provide tension during heat cycles. Once the system has heat cycled a few times the tubes will relax relieving the stress that would occur if the joint was welded.
These types of joints are found on many brands of aftermarket turbo headers, typically without springs. If you don't like the springs then simply remove them. They are not critical.

[mb911]

again I use them on my 993 setup and also all of the ssi setups that I built for Brian are slipped as well. there a at least 4 regular forum vistors that can chime in that use the same basic setup.


I agree though this is out of the norm an example of thinking outside the box . Though it will show up in testing and if need be we would weld them just not the goal and we have suggested to Brian for this project that he retain the springs versus welding for all the above mentioned reasons.

[msucro]

Add me to the already long list of potential buyers!

[RarlyL8]

Production run is being coordinated right now. I'll send you an e-mail and get your spot reserved. Thanks!

[RarlyL8]

Been furiously busy lately. Engine is still not back in the car.

Good news is the 1 5/8" tooling is finished and production for that size has begun.
Will do another run of 1 1/2" primaries after that.
More good news we were able to retain the design for the secondary y-assembly without adding cost.
Bad news is my engine is still not back in my car. Clients come first.
I am pecking away at it though and have the engine/tranny ready to go and now the car is ready as well. Had to delete a few "while you are in there" items from the list. Must get this thing back on the road by this weekend so we can do some dyno testing.

Here is the revised Y-assembly and a pic of my engine and tranny waiting in the wings.

[Miguel Antonett]

Looking better and better!

Good luck and let us know the numbers you get from the dyno.

You've got to have that car ready for the minipalooza in early Nov - right?

Stay focused!!!

[RarlyL8]

Thanks Miguel but the car needs to be ready waaay before November. This weekend would be good.
Everything is with the shop now so I've got to do some catching up on other neglected projects. The 911 headers are finished as well and will roll out soon. I'll post pictures of everything as it comes. Very excited about the different sizes which will give folks more choices to better match their engines/builds.

[patkeefe]

Originally Posted by RarlyL8

Ever question the use of the turbo bracket? Take a look at the second picture and you'll see that the turbo is the ONLY thing left of the exhaust system. The bracket held it perfectly during removal of the exhaust system - it did not budge.
The reason for this is that I will build the secondary around the stock position of the turbo. THIS IS CRITICAL TO FITMENT. I tell everyone who is installing exhaust components that the turbo must be in the proper spot, if not nothing will fit right. My turbo is fitted perfectly through the tin so we have a great reference point. Also you can see how the bracket will relieve any stress on the headers which should reduce opportunities for stress cracking over time.

Brian:
I was looking for the picture like the one above, and ended up reading this entire thread. This is a major accomplishment on your part, really excellent work, well thought out, great job!!

I was looking for the stock location for the 3LDZ/K27, for my retrofit. Bad thing about converting an SC without having a 930 around to use as a guide, is that I reinvent everything. I was wondering how to get the inlet pipe down to the compressor, but now I can see it. If only someone has hard dimensions. And there's a bracket to hold the turbo? Porsche thought of everything.

Once again, beautiful work!
Pat

[RarlyL8]

Thank you Pat!
One thing that will help you is to locate a 930 console and stock turbo bracket. Those items are unique to the 930 and will line everything up for you.
I have on my future product list a K27 turbo bracket. This will once and for all solve the coversion fitment issues so common. Not everyone can cut and weld and slotting means you no longer can use the upper bolt mount so this will help.

[RarlyL8]

Finally putting the engine back in the car. Got caught up in while-you-are-in-there-itis which made this a lot more time consuming than it should have been. All that is left is to fill it with oil and then check all the systems. Once she is back on the road I will schedule some dyno time and see what we have. Will post my initial drive impressions as well.

[RarlyL8]

Well good news, bad news, good news.

Good news - the engine has fired and runs/sounds great. All looks good.

Bad news - the transmission I had rebuilt a year ago containing special gears is making a god-awful noise in gears 1-4. Sounds like marbles in a can.

Good news - I have the original tranny I can put in for now. Not really fired up for another engine pull however. It is what it is. Crap.

[gsmith660]

Sorry to hear about the tranny ouch

[RarlyL8]

Mike with MB Engineering posted some pictures of what is wrong with my tranny. Looks simple to fix so that is better news. Now to figure out just how I can fit another engine drop into my zero tolerance schedule. Unfortunately sleep is not over rated.

[wjfk32]

Brian

As for start-up/sound is there a slight or big diff. in sound as to stock 930 headers or other systems u came across with? I know my wrench's setup with b&b headers and muffler is unbearable inside the cabin when driving on hwy(headache). Is there vibration on your set-up??

Thnxs

Walt

[RarlyL8]

No vibration that I can tell. Most ressonance comes from chambered mufflers which mine is not.
The sound is different. Don't know exactly how to describe it but at idle it has a different tone than before. Not bad, just different, a little higher tone. I won't know anything else until I can actually drive the car. AHHHR!

[wjfk32]

Brian

Waiting for your testing results and driving impressions. Good luck with the transmission!!
Hopefully, u can get some kind of video or audio..That would be great!!

Walt

[stup]

Personally know Mike at MB engineering and he is a very nice guy with a vast knowledge of our engines and transmissions,,hope he helped you in some kind of way and good luck with the fix!