6 MS6s have bad choke point in TMIC cold tube

[dale_gribble]

This is probably common knowledge but I literally had no idea after years of ownership. I have been investigating opening up my OEM intercooler cold pipe because the taper down from the intercooler flange visually looks like a choke point. I attached some pics I found of the neck inlet compared to the outlet.

I was getting ready to have my cold pipe cut and welded out to open that neck up like this guy in the pic I posted below. Then my buddy brought me an 07+ cold pipe and the thing was WAY more opened up in the neck area. You can see that here.



I found some measurements online of the 06 pipe vs. the 07 pipe.

The 06 pipe is 5.28 sq inch at the intercooler gasket area and drops to 2.51 sq inch at the pinch area and 4.91 sq inch at the throttle body end of the pipe.

The 07 pipe is 5.28 sq inch at the intercooler gasket area and drops to 3.11 sq inch at the pinch area and 4.91 sq inch at the throttle body end of the pipe.

The 07 pipe has 20% larger area in that pinch area and the pipe is generally opened up quite a bit more throughout. I am guessing that Mazda knew the 06 cold pipe flowed like crap but didn't have time to revise it before early shipments and revised it as soon as possible. It's one thing to have the aftermarket fix a problem, but you know its a big deal when the OEM revised a part bigger. This tells me I'm onto something.

I don't know how this extra flow will impact performance on a k04, but I am willing to bet it's going to make a good difference on my bnr, especially considering how opened up everything else is on my intake/exhaust. Wouldn't it be crazy if this stupid cold pipe has been holding my car back all along?

I am using my buddies 07 cold pipe, I ordered some JBR cold tubes and a Snow meth tap for the silicone tube so I can swap the setup in place of my 06 cold pipe. I will definitely post up before/afters, but my gut says there will be gains above the noise floor.

I don't know how many others with older 6 speed 6's knew this. I sure as shit didn't.

[Hargarbl]

That's a good find. I wonder how hard it would be to get rid on the stock cast outlet and for someone to make an aluminum mandrel bent peice instead. I think that would help improve the flow coming out of the intercooler and would also eliminate that bottle neck.

[dale_gribble]

Its not that easy with the stock intercooler flange, I.e. welding flange to mandrel pipe. The pipe hugs right up against the intake runners on the back side. There is room towards the front of the engine though to expand out.

Corksport did experiment with a big cold pipe years ago but insisted their tmic was the bottleneck and that the pipe didn't matter; they didn't build it. I didn't think that spoke much for their tmic.

There is room for something creative, I'm just not sure you can do tubing right off the flange without clearance issues. .

[Hargarbl]

I did some searching and found out trz made a tmic, looks like they had the right idea for the cold side

[Fully6mps]

Never knew that Mazda themselves revised the part, but think autoexe had an aftermarket version? Called it an air charger or similar. Keen to see what changes the switch will make, have a 2005 mps here in Aus so assume have the same bottleneck.

[Hargarbl]

Originally Posted by Fully6mps Never knew that Mazda themselves revised the part, but think autoexe had an aftermarket version? Called it an air charger or similar. Keen to see what changes the switch will make, have a 2005 mps here in Aus so assume have the same bottleneck.

I think I found what you are talking about, this is the best picture I could find right now.


Edit: found it
http://www.nengun.com/autoexe/turbo-suction-kit

[scubasteve711]

Will be interested to see what kind of difference it makes! I remember working on one of the NATOR guys cars here in CT and at the time didn't realize there was a difference there!

[neganox]

meth nozzle hole pre-drilled is a nice touch too.

[Spec]

@SparkySparks;

[SparkySparks]

I was actually working on opening up a 06 MS6 coldpipe that came with the TMIC I just picked up and noticed it was slightly smaller as I was having a hard time getting it all smoothed out. I also noticed that the opening in the flange both on the TMIC and the coldpipe are smaller then the gasket's opening so I ported the openings to match the gasket and smoothed out as much as I could. Not sure if this is going to help much if any but figured it shouldn't hurt either and it is a free mod.

Guess I will be selling the MS6 cold pipe and using my Gen2 pipe.

[SparkySparks]

Oh and just encase anyone was wondering, the choke point on both versions is still smaller then 2.5"(4.9088"^2) piping used for most FMICs, even 2"(3.1416"^2) piping is slightly better then the revised cold pipe.

[someguy]

Originally Posted by SparkySparks I was actually working on opening up a 06 MS6 coldpipe that came with the TMIC I just picked up and noticed it was slightly smaller as I was having a hard time getting it all smoothed out. I also noticed that the opening in the flange both on the TMIC and the coldpipe are smaller then the gasket's opening so I ported the openings to match the gasket and smoothed out as much as I could. Not sure if this is going to help much if any but figured it shouldn't hurt either and it is a free mod. Guess I will be selling the MS6 cold pipe and using my Gen2 pipe.

I did the same on the my cpe TMIC. The actual cold pipe was pretty close to gasket size though.

[5LOWMS6]

Originally Posted by Hargarbl I did some searching and found out trz made a tmic, looks like they had the right idea for the cold side

is that still available? I would've definitely bought that instead of the cpe.

fuck the 06 cold pipe. I knew it was a restriction just like that pos stock tip, but the cold end flange itself on all of the aftermarket tmic's would be the next issue as mentioned above if you only upgrade the cold pipe to ones like the autoexe. so what's the point?

I don't think the cold pipe itself will make any difference unless on a BT, and the gains will still be negligible.

[SparkySparks]

Originally Posted by someguy I did the same on the my cpe TMIC. The actual cold pipe was pretty close to gasket size though.

Yes, the cold pipe was only off by about a sharpie width while the CP-E TMIC was off by a bit more. The casting was also not all that great (smooth) on the inside of either end tank.

[SparkySparks]

@kashbringer; I wonder if this was a possible limitation with how much you were pushing the K04.

[dale_gribble]

Guys, just an update, this went nowhere after comparing before/after tests of 06 cold pipe vs. 07 cold pipe. No gains were had with the 07 cold tube FML. Kind of shocked, but it is what it is. It is a choke point, but as @CorkSport; previously reported on their cold tube research, the intercooler is a greater choke point so the cold tube isn't an issue. Definitely a case of mind/physics playing tricks on me.

[5LOWMS6]

I wonder if the width of a tmic will make a difference in the case of it being less of a choke point since the air will go through less space. The problem is there isn't a way to test that.

[Easter Bunny]

is the 07 MS6 the same as the cold pipe used on all the MS3's could the later PU's also have a revision?

[Lex]

When you are pressurizing air choke points such as these have less of an effect. If you go too big on the piping you actually lose response.

Good find and testing.

On that TRZ TMIC, I would not get something that doesn't seal to the OEM shroud. The MS6 already has the hardest time (compared to an MS3) channelling air to the TMIC and cooling it.

[SNOW_QN]

Originally Posted by Hargarbl I think I found what you are talking about, this is the best picture I could find right now. Edit: found it http://www.nengun.com/autoexe/turbo-suction-kit

Thread revival!

Was thinking about this today since it seems to be a major restrictive point. Has any tried this aftermarket elbow?

I know that you @dale_gribble; have done the 06 vs 07 comparison but they seem too similar to possibly have any significant differences. It seems like the autoexe would be much smoother, and have a noticeable difference.

Anyone have any data on this?

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[Omega]

Subbed for interest, I really doubt there will be any gains, if the 06 cold pipe with the smallest surface area wasn't choking going to an even bigger flange still wouldn't make an impact (there's no choke to "fix").

Maybe if you're on a turbo that's quite a bit bigger but unless it's a GTX30xx I don't think it would make any difference and the difference would probably be negligible.

[SNOW_QN]

I agree that a larger turbo would magnify any flow enhancement from the autoexe unit, but it seems like it should do something even on a smaller turbo setup. The design is much different than the difference between an oem elbow.

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[SNOW_QN]

@Dat8687; do you still have this piece?

[speedfreak44]

Corksport designed a bigger one that had no impact on flow. The intercooler was more of a restriction even upgraded

[SNOW_QN]

You're crushing my dreams man. I'm hoping to find a way to avoid going fmic in the future, and was hoping this might help a little.

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[speedfreak44]

No dreams crushed. Let me break this down simple and sweet;

Tr6 or 8: Rpm sale comes to about $210
Underoute piping (bnr does it) on sale $470

Tmic cpe $360
Boost tubes $60
Hood scoop for better cooling $250

They break down to being almost exactly the same cost and fmic is way more efficient

[RalliartRsX]

The pressurized, "high" velocity air (as being pumped from the compressor) that is flowing at or below Mach 0.3-0.4 is not entirely sensitive to minor increases/decreases in flow area as opposed to air flowing with at 1 atmosphere (standard atmospheric pressure).

Simply put, don't waste your money.

Source: I am an Aerospace Engineer.

[SNOW_QN]

Originally Posted by speedfreak44 No dreams crushed. Let me break this down simple and sweet; Tr6 or 8: Rpm sale comes to about $210 Underoute piping (bnr does it) on sale $470 Tmic cpe $360 Boost tubes $60 Hood scoop for better cooling $250 They break down to being almost exactly the same cost and fmic is way more efficient

I really don't want to go through the hassle of hacking up my crash bar to accommodate a fmic. I'm sure the tr6 could be fit without cutting the bar, but is that any better than the having the cpe tmic that I already have?

Lol thanks @RalliartRsX; I'm convinced now that beating the dead horse is going to continue resulting in the same thing.

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[speedfreak44]

Did not see the cpe in your sig. I would stay with it and get the Cs hood scoop.

[MS3Shadow]

But @SNOW_QN; has a MS6..

sent from my HTC One M9

[speedfreak44]

Gah stop throwing me curve balls! Yea that's kinda hard to install on an ms6 lol. Fmic ftw

[MS3Shadow]

Unless you can make the Gen 2 hood fit on a MS6. It'll work awesome.

Hood scoop is awesome for the TMIC.
I also don't want to cut up my crash bar either.

sent from my HTC One M9

[speedfreak44]

Tr6 flows 400whp. That's all our fueling does anyway and nobody really shoots past that anymore with supplemental fueling. I say go tr6 and call it a day. Treadstone shit is top notch

[SNOW_QN]

Hood scoop would certainly help, but it would be out of place on the subtle sedan.

I'll look more into the tr6. When the time comes to upgrade, maybe there will be another option or two out there. (Don't ruin my wishful thinking. I need something to hope for)

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[Dat8687]

Originally Posted by SNOW_QN @Dat8687; do you still have this piece?

I actually had 2.. One on my 6 and one on my speed 3 which Im selling on the car.

you can get it from around 375-450 from RHD japan



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What it all comes with





This was it on my speed 6 several years ago

[macdiesel]

That's one stout cold pipe. Notice any gains?

[Dat8687]

Originally Posted by macdiesel That's one stout cold pipe. Notice any gains?

I think its more about improving response and consistent pressure at the TB.. Meh maybe lol. The throttle did feel like it responded better

[Federighi]

Anyone know where to find the Autoexe TMIC cold charge pipe kit? Specifically looking for the elbow. New or used, any info is greatly appreciated. Thanks!

[Vansquish]

Originally Posted by Federighi Anyone know where to find the Autoexe TMIC cold charge pipe kit? Specifically looking for the elbow. New or used, any info is greatly appreciated. Thanks!

Dude...5 years late to the party, and still can't use Google.

[Federighi]

Better late than never!

If anyone has a used Autoexe turbo suction kit or knows where to find one, please let me know.

Thanks in advance!