I ask this question for all but quoting your post since you mentioned it. What, if any, disadvantages do leaks at the slip points create?

Chris is not ready for all this!

The proximity of the slip joints to the heater boxes makes me concerned about exhaust fumes entering the cabin when the heat is on. I do get occasional exhaust smells inside the car with the heat on, especially during boost, although I'm not 100% sure the fumes are sourced from the slip joint leaks vs. other modifications that have been done to my car.

Here's a pic from Brian's website. This is not my car but I have the same headers. Notice the location of the slip joints and heat boxes.

http://forums.pelicanparts.com/uploa...1523302265.jpg

That's an old Gen I picture, design has changed many times sense then. We will be updating the website soon to reflect the current offerings.

Asian 304 is just that, Chinese grade 304 stainless. It's garbage which is why it often cracks in short order even in N/A applications. Pictures of that all over the internet.

It would be extremely simple to build short tube headers like everyone else but there is an advantage to equal length primaries and secondaries for street applications. The sound alone lets you know something good is going on. We weren't the first to use this design, many of the old school big names such as Mode had their versions. Chris knows this and has used our headers on a few of his builds just as I have used some of his products which fit the application on a few of our builds. All of our headers are split plenum with the twin waste gate versions isolating the banks. Bolt on a split volute turbo and you have a true split system. Lots of options to build what you want.


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Do you have any pics of your current design that you can share with us here on the forum? Both with and without heat boxes installed?

Do you have upgrades/trade-in options available for us early customers of your 930 headers?

Possibly depending on which Generation you have. Shoot me an email and we'll see what can be done. We are finalizing the heater boxes on the latest version. They will likely not be a simple retrofit for the older headers but we may be able to upgrade older headers to the new design. I will continue to keep boxes in stock for the older model as the racers do replace them periodically when damaged.

I think he meant to say thick b*lled Asians from the 404 that are running twin scroll 321 stainless TK setups...



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Atlanta’s nice this time of the year- I see what you did there. That’s funny as hell. ;-)

This is Brian’s latest design. These are ceramic coated with the heat boxes on. The header is bare inside the box. The idea is to retain the heat as best as possible and improve the heater output.

As you can see the guy takes pride in his work. These welds are perfect.
And as for the whole waste of tubing and distance for a tuned header. I don’t think it applies here. I’ve seen the old school snake pit to get equal length and disagree too. These are no bigger than my hand! Why not make them tuned?

And I am not saying Chris doesn’t make quality products or take pride in his work. I have spent twice as much with him. I’m just showing what Brian’s latest header looks like.

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Sent from my iPhone while Driving

That's some nice pipe you got there...Haha

Sent from my SM-N950U using Tapatalk

^^^

Wipe yer chin, Kevin! :eek:

Yo Deez, is that a slip joint(s) where the merge collector meets the head pipes, or is it welded? If slip, is it double walled (much better for preventing exhaust gas leakage - different than your leakage, which nothing can prevent! :eek:)? Regardless of double or single walled, if a slip joint, I'm surprised that there are no tension springs there (such as is a common practice with motorcycle exhaust systems).

Derrick,

Here's a little friendly disagreement for you.

As pointed out in an earlier post, Brian's heater box gaps and sheet metal screws are a little worrisome from a sealing and durability perspective - even when coated in ceramic. From a construction point of view, it would probably be better to fully weld the heater box seams. This would make the heater boxes more rigid and also less susceptible to carbon monoxide leakage into the cabin.

There is a lot of discussion about the benefit of equal length primary tubes. Brian says in an earlier post that "The sound alone lets you know something good is going on." The known tradeoffs of the longer equal length primary tubes include loss of exhaust gas velocity from more complex curves with more thermal loss from the longer tubing length. For the turbo application, preservation of exhaust gas velocity is likely the single most important parameter since that is what provides the energy to spin up the turbo. In this case, shorter but unequal length primaries may be better as long as the exhaust pulses don't interfere - which is why spool up is better with a twin scroll turbo with a dual wastegate configuration.

The only way to really see the difference is to test both and see the dynos. Equal length but longer and more tortuous vs. nonequal length but shorter with fewer curves. Who wins? It would be fun to definitively find out.

I'm going to step in here and say THANK YOU to Tonger for keeping the tone positive, in contrast to the thread-closing yelling we saw earlier this week (not by Tonger, in case it sounded like that).

Civil disagreement and discussion -- it's a win-win for all.

A 930 header argument would not be complete without giving some credit to the GODFATHER Bob Holcombe. I believe he was the first one to bring a true equal length header to the market for these cars, surely he had a reason?!

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Unfortunately when I was in the market I could not afford (or find) a set so I am happily rocking a set of Brian's headers as they are almost identical!

Since we are talking about headers, I'd like to throw out there that my equal length, FULLY welded Protomotive headers have never had any cracks and are over a decade old.

There is always talk how about how slip-fit joints are needed and required. Mine have zero, zilch, nada. It is one piece from 1 bank to the other.

Not sure of the alloy of stainless steel, though.

Tonger,

I agree the heater boxes are not nearly as nice as everyone else's. That is the one area that they look lesser quality. But they are designed to be removable and light weight. They do the job.

As for equal verses non. I too would love for someone with the disposable cash to do a comparison. As I mentioned these are not a snake pit. There are no unnecessary sharp U-turns, IMO. Maybe the sweeping U-turn design does slow the pulse down enough to matter. It would be fun to find out. But what do you think the HP difference would be? I'm thinking you would be splitting hares at less than 20HP?? Chris? Brian? Opinions?


And if Brian's headers looked like this I would be on the non-equal length design side here.

http://forums.pelicanparts.com/uploa...1523626651.jpg

I spent some time on the phone with the guy from CMS who supplies header parts because i plan on making my own. He told me that they dont recomend slip flanges for turbo headers beacuse they tend to leak. He was willing to sell me set of double slip collectors but said he didnt recoment it for a turbo.

The distinction needs to be made between custom headers (built on a car or engine) and commercial headers with options that are built in a fixture.
The latitude you have in the build is wide open when the engine is sitting in front of you. All the obstacles are there. This luxury does not exist when someone 1000 miles away calls up wanting a split system using a v-band turbo that is twice the size of a 3LDZ with nothing in the stock location. This is one reason for the slip joints, to give some freedom of adjustment. Even something as minor as a crooked turbo bracket becomes impassable if the headers are welded up rigid as one piece (ever try to ship something like that?).
I gave credit to Mode as one of the old school builders who used the tuned system in their design. Also give credit to Chris/TK who do fantastic custom systems. They are not the purveyors of cheap short tube Chinese 304 systems.
As for the advantages of a tuned system, this was hashed out here on this forum a decade ago when I introduced my system. I have posted a dyno comparison that I did using a Euro spec 3.3L engine and asked that folks do their own unbiased testing as well. Pay attention to what happens not only on boost but OFF boost, where you do most of your driving.
All of our systems are divided at the turbo flange. Optional twin waste gates complete the division of the two banks. T3, T4, and V-band flanges are all options as well as double slip joints. Adjustability allows you to move the location of the turbo slightly from stock if needed.



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The black coated system pictured above (thank you for that!) is the Gen III system. Our Gen IV headers will be released soon. One of the new features will be welded primaries which has required us to change the design of the heater boxes. The secondaries will remain adjustable to ease installation and accommodate the various turbo flanges. I'll be posting pictures of these soon and asking for feedback from the racers and the street guys.


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Dyno Shootout and Header Prep Suggestion
 

Derrick,

One of the considerations for the dyno shootout would be not only what the max HP but more importantly what the shape of the torque curve is. Long tube headers may help off boost torque and may help or hinder the boost threshold. I chose to go with a ball bearing turbo and a divided system with twin scroll and dual wastegates in an attempt to get the boost threshold as low as possible. As it is, I've got a full 1.1 (edit - should have read 1.1 instead of 1.2) bar of boost under 3100 rpm using the GT35R which is a good fit for the progressive drivability that I was looking for.

What matters more to me is what the boost and torque curves look like in the rpm range where I spend most of my time (midrange). In this case, a low boost threshold using a ball bearing turbo was my priority. The accessibility of partial and progressive boost was a determining factor for me and the big peak hp number was just the icing on the cake.

Like JakobM on page 2, I am fine with other people choosing other products. Don't get me wrong, I think it is great for us to have more choices. I just think that we have to make intellectually honest arguments when discussing the relative merits of design - "Chinese crap" arguments not withstanding. Perhaps Bob Holcombe's beautiful double slip-jointed headers were equal length because he only used a single wastegate and the left and right sides were joined in the wastegate plumbing making accurate pulse separation more important in his otherwise split design? Maybe he used slip joints because he didn't have to worry about adjacent heater boxes? I have no idea but I'd love to hear it from him...

One suggestion that I have for you is to look inside the secondary of the header you've shown and dress/grind off the areas that I've marked with the yellow arrows on the annotated photo. I would hate for either piece (especially the one at 8 o'clock) to come loose and go through your turbo after being heat cycled a few times.

http://forums.pelicanparts.com/uploa...1523629544.jpg

I tried doing the calcs for a tuned system with unequal lengths for the primaries and found that at different rpm's the harmonic nodes were in different places. So I'm thinking thats why they need to be equal lengths to work at all rpms and power ranges. I wanted to make them unequal so that the volume would be smaller even with the larger tubes hence less lag.