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Mountune Fiesta MRX Turbo

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Cockeysville
So, I actually just placed an order for this kit about a week ago, and am super excited :) I do have a quick question:

Is there any benefit to running an aux fuel unit in the future, or is the turbo pretty much maxed out with this setup? Basically, is the fuel system limiting the kit to ~300 whp, or would the snail need to be made bigger in the future? Also, with that in mind, will there be any future 'stage' packages available to move up to in the future? IE, "trade in towards stage 2 with a GTX2860R turbo!"? Just curious.

Awesome job with this kit guys - keep up the fantastic work! :)
 


Messages
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69
Location
Tucson
Does the oem manifold heat shield fit back on?
While I can't say for sure for the Mrx kit. It does not fit for my atp 2554r kit. Essentially the same type of turbo.


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OP
Brura22

Brura22

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Thread Starter #269
I feel like I'm taking crazy pills...

Does anyone else feel like peak tq at over 5000rpm is a bit high?
As in compared to the low end donkey kick of stock and hybrids?
I personally enjoy the linear power band


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OP
Brura22

Brura22

Active member
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Thread Starter #270
So, I actually just placed an order for this kit about a week ago, and am super excited :) I do have a quick question:

Is there any benefit to running an aux fuel unit in the future, or is the turbo pretty much maxed out with this setup? Basically, is the fuel system limiting the kit to ~300 whp, or would the snail need to be made bigger in the future? Also, with that in mind, will there be any future 'stage' packages available to move up to in the future? IE, "trade in towards stage 2 with a GTX2860R turbo!"? Just curious.

Awesome job with this kit guys - keep up the fantastic work! :)
No, I don't believe I'm at fuel limits yet.
Right now I'm on gas quality limit of 91 octane.

With fuel limits hitting around 315-330.. I doubt Mountune would step it up from here, seeing as they'd have to start selling aux fuel also.
But, I don't speak for them. Just my opinion. This seems like a really good long term big turbo kit that'll have a significant life span.
Once you start heading towards the 400 whp range you start cutting the lifespan of these motors lol


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Messages
389
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68
Location
Bethlehem
I feel like I'm taking crazy pills...

Does anyone else feel like peak tq at over 5000rpm is a bit high?
While that is kind of high, I don't want donkey punch torque down low. Still making more torque than stock around 3k.


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Messages
15
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7
Location
Cockeysville
I personally don't understand why everyone is skeptical about the torque flattening out up top - the curve from the posted logs looks extremely linear. To me, that just sounds like a good time. ;) Let's be real - we all bought a turbo'd car for the drama of the turbo lag, and the come-from-behind upset wins! I don't know about you, but a turbo that falls on it's face early is boring. To each their own I guess.
 


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Brura22

Brura22

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Thread Starter #275
Ofocurse he enjoys it since he owns the kit, but that sounds terrible.


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Lol correct you are. Even my x37 fell on its face up top. Compared to this kit that is..
 


WeTheNorth

1000 Post Club
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Lol correct you are. Even my x37 fell on its face up top. Compared to this kit that is..
Quite the fallacy your throwing around, the x37 does not fall on its face. As long as you're happy, that's what counts in the end. It's all preference in the end:)


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OP
Brura22

Brura22

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Thread Starter #277
Quite the fallacy your throwing around, the x37 does not fall on its face. As long as you're happy, that's what counts in the end. It's all preference in the end:)


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You don't read huh? I said when compared..
This was my 2nd revision MRX vs my final x37.
When compared, yeah x37 runs out of breath and the MRX keeps pulling
 


Messages
37
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9
Location
Hampton Roads
Quite the fallacy your throwing around, the x37 does not fall on its face. As long as you're happy, that's what counts in the end. It's all preference in the end:)


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It's no fallacy that turbine housing size affects a turbo's performance. Flow rate of compressible fluids is greatly affected by the cross sectional area of the conduit it is passing through. Smaller turbine housing means faster transient response (quicker to spool), but lower pressure ratio at higher engine speeds (resulting in the turbo "falling on its face" or running out of steam at high engine RPM). Larger turbine housing means lower transient response but higher pressure ratio at high engine speeds (more head room). Comparing the MRX (larger turbine housing) to the hybrid (stock KP39 turbine housing size) turbos, then yes, the hybrid options don't have the same affinity for maintaining power at higher engine speeds. They do however have the advantage for transient response.
 


Hijinx

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Watching the meta in this community has been interesting. For those unaware, I'm talking about the undercurrent/unseen driving force in people's decisions on power modifications. In order:

The torque meta
The "too much lag" meta
The powerband meta
The spool meta
The hybrid meta


And now we seem to be entering a "lag is ok" meta. We'll see another hybrid/powerband meta before the year is out.


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