Turbo Manifolds Explained.

[BlackMount]

Can some one explain the Pros + Cons of a Tubular Manifold instead of typical Cast Manifold, or VS versa

which is better?

what does the purpose of each serve?


Whats the difference between a typical tubular manifold, Top Mount Turbo Manifold, and a RAM Horn Manifold? what are the benefits and disadvantages of each?

What makes a aftermarket Turbo Manifold a Good one?

I want very specific Details.

 

[black_gst]

TUBULAR

 

[gstbobby]

Tubular are designed to be equal length but strength and durability is given up when using one of these manifolds because they are made out of stainless steel and they like to crack, I personally would just go with a cast iron manifold.

 

[BlackMount]

TUBULAR

Tubular are designed to be equal length but strength and durability is given up when using one of these manifolds because they are made out of stainless steel and they like to crack, I personally would just go with a cast iron manifold.

ok you answered .00001% of what I was asking.


Why Ram Horn?

Why Top Mount?

Why not have Equal Runners but they are each 4 feet long? (not being serious but trying to point out the lack properly answered questions)

 

[ThomasG-1b]

Your engine firers a different cyl. every stroke. Which makes exhaust "pulses" that go into the exhuast stream. Start your car and go put your hand by the exhaust tip you will feel each "pulse." This is fine from the factory but we all know its no good to us. So when you make equal leagth tubes from the head to the turbo you can get exhaust scavenging to work for you. Which makes the turbo spool up just a little faster.

When you say "Top Mount Turbo Manifold" are your meaning the intercooler? Cause if so the factory uses them so they dont get damaged like fmic's. Yes heat does soak into them more but that was for the averge person.

 

[pboglio]

FP Race manifold is a very good "header" style cast exhaust manifold. Its not equal length but more importantly it does offer a "ram horn" style collector which minimizes exhaust reversion caused by runners that face directly towards each other. Being cast, its much less likely to crack and hold the heat in a little better.

Very few after market headers are equal length, and if they are they aren't even the correct tuned length for your setup anyways. Its been mentioned in literature that non-equal length can be more beneficial in N/A street applications since the tuned rpm is spread out thru the rpm range, unlike equal length which focuses the tuned rpm in a narrow rpm band.

Burns stainless will provide you the correct tuned header runner length and runner diameter if you give them your exact cam, intake manifold, and engine specs. Though they didn't feel there was much gains in header tuning on a turbo car, their exact words.

 

[DWR-DSM]

Top mount meaning the turbo is on top of the exhaust manifold instead of under.

 

[ThomasG-1b]

FP Race manifold is a very good "header" style cast exhaust manifold.

If I were to buy one this is the manifold I would get. The equal leagth ones are more for huge power or drag only kinda deals.

 

[gorf]

Surprised no one has said this yet - what's your goals?
Or why do you want "all specifics"

an Evo 3 cast manifold has larger runners and collector. a good choice for most people.

I have heard/read nothing but good stuff about the the FP cast manifold. It incorporates one of the biggest advantages of tubular manifold, all runners turn down and point into the collector. 1g 2g and evo all have diverter plates to direct the gas downwards, with the FP and tubular manifolds diverters are not required.

If you have a big turbo, smim and 280 cams go for a good tubular, otherwise get the FP.
Opinion only......

 

[BlackMount]

Surprised no one has said this yet - what's your goals?
Or why do you want "all specifics"

an Evo 3 cast manifold has larger runners and collector. a good choice for most people.

I have heard/read nothing but good stuff about the the FP cast manifold. It incorporates one of the biggest advantages of tubular manifold, all runners turn down and point into the collector. 1g 2g and evo all have diverter plates to direct the gas downwards, with the FP and tubular manifolds diverters are not required.

If you have a big turbo, smim and 280 cams go for a good tubular, otherwise get the FP.
Opinion only......

No Goals, My car @ 15 PSI with a 2G manifold, and I'm set. I'm building a Off Road DSM (for Rallying of course!) I don't need much more power then I already have!

I asked out of pure hunger for the knowledge.

 

[1gDSM4g63]

Top-mount manifold are generically used for massive T4 turbos that have issues with going the other way another.

Tubular are designed to be equal length but strength and durability is given up when using one of these manifolds because they are made out of stainless steel and they like to crack, I personally would just go with a cast iron manifold.

No true, tubular are not designed for equal lengths, cast iron are more is an equal length and are more stronger.


If you're staying with a 50 trim or small turbo and not dealing with high boost I wouldn't even consider going to the tubular manifold. Staying for cast iron will do the job and will have faster spool rates due to shorter and more equal length.

 

[jrohner]

If you don't get the header heat coated, or come up with some other way to hold the heat in, you'll probably lose performance with the big increase of under-hood temperature.

 

[Calan]

If you don't get the header heat coated, or come up with some other way to hold the heat in, you'll probably lose performance with the big increase of under-hood temperature.

+1 ^^^.

Not to mention you'll get tired of trying to remove the melted plastic from around your fans and wiring.

IMHO, getting ceramic (or even better...ceramic/titanium ) coating on all the hot parts is one of the best long-term mods you can do, and should be high up on the "must do" list.

 

[tkelly27]

A standard tubular manifold will be something like this DNP setup
http://www.cimotorsports.net/images/T/dnp60_f.jpg
The runners are as close to equal length as possible and it has a collector. You can see here
http://www.dsmparts.com/customer/image.php?id=15&type=D
the collector can be short, and have sharp bends leading into it. The advantage is that it can be compact, and quickly assembled for custom projects. You can also stuff a 1-4 2-3 twin scroll setup in one of these. Otherwise I don't see it offering too much of an advantage over a cast piece.

http://www.synapseturbo.com/gallery/cache/1a88735315b75646b075a4ca8f6550bbde3be49d_800.jpg
A ram horn manifold is also a compact design, but it seems the central focus is on a true collector and nearly even length. These are a pain in the ass to make, but seem to be popular for looks and they do make power.

http://www.speedfactoryracing.net/store/images/topmount.jpg
That is a top mount. The turbo mounts on top of the manifold. While nearly all top mounts are equal length, have a nice collector, and can incorporate the twin scroll design if you choose for them to be so, the main purpose of this manifold is to mount a big f*ing turbo. When you are running a turbo this size you run into clearance issues with your radiator, engine mount, oil filter, oil pan, and or any of the other pieces that get in the way when the turbo is under the manifold. I had tacked one together that fit perfectly bottom mount but realized there was no way the drain was going to fit so it had to be top mount.

Then there are specialty long tube headers like Shep or some big FWD race teams have setup.
http://www.loxlee-loves-engines.com/blog/wp-content/uploads/2009/08/massive-turbo-fwd.jpeg
I'm not really sure on the design of these, but I'm sure they serve a purpose the others do not fill. Perhaps it is facing the turbo forward and getting a giant one to fit? It could also be the tube length helps with power. Although if you look at a turbo F1 setup,
http://www.race-cars.com/engsales/other/1195563771/1195563771pa.jpg
http://upload.wikimedia.org/wikipedia/commons/8/82/Honda_RA168E_engine_Honda_Collection_Hall.jpg
some times they are long, and some times they are short and rarely are they as long as the fwd dragster.

Some other places to look can be found here
exhaust collector design - Google Search
From everything I've read, the length of the piping is less crucial than the exhaust making a smooth transition from tubing to turbine. That is at least until every hp is mission critical.

http://store.forcedperformance.net/...reen=PROD&Store_Code=FP&Product_Code=EMFPRace
I would run a FP manifold in a heartbeat, but that's not really what I consider a true collector when you compare it to the ram horn design or the top mount which has something more like this inside it
http://www.bo-port.com/images/uploads/turbocollectortackedinside.jpg
It's also most definitely NOT equal length.
http://store.forcedperformance.net/merchant2/graphics/00000001/tiny/EMFPRace6.jpg
compare cylinder 1 with cylinder 3.

As far as cracking, tubular SS manifolds go on airplanes. I've been working with someone who is FAA certified to weld them. I don't imagine they crack any more or less than cast manifolds. A cast manifold will crack with enough time, heat, and stress. If you haven't seen one, then you probably haven't seen more than 2 or 3 1g manifolds. Many tubular manifolds don't get the proper bracing for turbo and down pipe, nor do people properly isolate the rest of the exhaust from the down pipe. Also, I imagine most people welding car manifolds never get them x-rayed, and if they dip the tungsten in the pool nobody is ever the wiser.

 

[GRNDSM]

The bottom line is that it doesn't really matter... Many people come from the NT world and jump on the exhaust manifold as one of the sources for extra power, because that is what they do in NT world. But this is a lot less important on a turbo application.

What is important is that you do not have exhaust leaks before the turbo. Everything else is hype.

Personally, I prefer to run ported EVO3 or even 2G OEM manifolds. Yes, they crack with time, but they still tend to last longer than tubular headers.

Naturally, this only applies to Mitsu housing, smallish turbos. Big turbos usually require tubular, headers because of packaging concerns.

 

[pboglio]

Stainless headers are notorious for cracking on street cars. The high coefficient of thermal expansion fatigue stresses the hell out of the brittle weld joint due to the rigid flange mounting to the head. Cast iron is much more thermally stable. The lack of downpipe bracing doesn't help but it isn't the prime cause of failure.

I agree a true collector might be beneficial. Not making a 90* turn right before the turbine inlet is going to present a higher drive pressure to the turbine wheel. This is why the "true" merge collectors have a long straight run before the collector opening. It also requires a shit load of vertical space which is probably easier inverting the merge and coming up from the bottom like a topmount turbo.