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Mountune Fiesta MRX Turbo

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*disclaimer* this is NOT the final revision.

Two shown.

One at sea level.
One at 4,300 ft in altitude. (clearly the lower one)

Shitty New Mexico 91 octane gas.



Need a graph with stock turbo to compare to. On the mountune site it shows the mrx matching power numbers until the stock turbo starts dying off. Then the mrx just keeps building to redline.

I'm completely fine with having stock levels at and below 2500ish and then building all the way up to 300hp at the top end on 91 octane. Is that what you are describing?
 


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XLR8 said:
The stock turbo hits full boost before 2500rpm. It's not going to happen with the MRX.

I think something worth remembering is we run a 1.6l with a very light rotating assembly. If things start to get lively at above 3k rpm then getting there isn't going to take long.

Furthermore, 3k and above is more than acceptable to me and it mimics virtually every other turbo car I have built/driven. We are spoiled by the immediate kick in the pants of the stock turbo. Like the synthetic V8 Fiesta but then it falls on its face, as we know.

Well, it's just... how much time do I spend at 4000rpm+? Not trying to be that guy that is constantly revving it out to redline between each stop light. Usually I'm just cruising at like 2,500. I also don't want it to feel like a NA Fiesta below 3,000rpm.

Stock power up to 3ish, and then building up from there would be my perfect scenario. But I also don't trust any of the hybrid options. [?|]




Edit: I went back and looked at Mountune's graph. Looks like they show it matching stock power from 3000-3600 at which point it starts to pull away. They show the stock turbo isn't even hitting peak torque until like 4000rpm. By which point the MRX is already a good 30 lb-ft stronger. Based on Mountune's graph it appears to be doing what I want. Unless I am reading this wrong.



 


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Well, it's just... how much time do I spend at 4000rpm+? Not trying to be that guy that is constantly revving it out to redline between each stop light. Usually I'm just cruising at like 2,500. I also don't want it to feel like a NA Fiesta below 3,000rpm.

Stock power up to 3ish, and then building up from there would be my perfect scenario. But I also don't trust any of the hybrid options. [?|]




Edit: I went back and looked at Mountune's graph. Looks like they show it matching stock power from 3000-3600 at which point it starts to pull away. They show the stock turbo isn't even hitting peak torque until like 4000rpm. By which point the MRX is already a good 30 lb-ft stronger. Based on Mountune's graph it appears to be doing what I want. Unless I am reading this wrong.



That's what I am seeing and I'm in the same boat as you. I'd love to have the stock feel from 3k and below and the top end really open up on the days I really wanna get on it.

This graph may have just sold me on this turbo.


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XLR8

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Spend some time in the V-dyno and Dyno threads. Stock turbo's are well over 200ftlbs at 2.5k rpm. Stage 1-3 cars are hitting 260-270ftlbs by then. As I said before, the MRX just isn't going to do it. Unfortunately graphs are deceptive with measuring spool and how well the power comes on. Spool is a direct result of load and load can be controlled. For example, I could dyno 2 different turbos like a big GTX2860r and a stock turbo but use the same progressive pedal pressure as the pull proceeds. The smaller turbo may be capable of increased spool but because the load is slowed by the progressive throttle input it makes the graphs align. Now once the little turbo runs out of steam, the bigger plot would show it continuing to pull. Now drop them on top of each other and it "looks" like they have the same characteristics until the big guy pulls away. Am I saying Mountune did this, no. But it's hard to get that extra data over the internet. At what point in the plots did the user initiate WOT or max load? Vdyno adds extra variables as well.

Me personally, I have come to accept that my goal of 300whp will likely not happen with stock spool. No worries, but I also don't want slow spool either. I need balance. I need things to turn on around 3k rpm. I have been looking at DHM's GTX360r kit for some time so it has been the kit I am comparing this to. Many people have given the feedback on this kit that spool is quick and progressive with nothing but praise. Considering it costs more than TWICE as the MRX, it's worth examining the data for the MRX as it comes up. No knock on DHM either, they have a FULL kit here with a stainless manifold and proper wastegate use. They are also using a bigger turbo with a much higher ceiling than my 300whp goal. The DHM kit is just getting warmed up at 300whp. The good thing is that there is plenty of dyno/vdyno plots out there for this kit. I have attached 2 plots from the Vdyno section. Lets compare.


These are essentially both stage 3 GTX360R cars running 93 pump only (which is what I plan to do).
ihx0YjV.jpg r34GsJA.jpg

Now look at the MRX (not final on 91).
MRX.jpg

Some VERY interesting stuff here. The GTX360R is at a huge advantage sporting a tubular manifold. Look at the torque from 3k - 4k rpm on all 3 graphs. Then look at the total numbers. The MRX is ON PAR with DHM's kit! Again, remembering these are 91 numbers on the MRX. 93 will spool a tad quicker as timing can be bumped during tip in. The MRX is also making more torque at 3k rpm than either! The 360R is even hitting 20psi 200rpm earlier when comparing the plot that maps boost. BUT the torque 3k-4k still favoring the MRX!! This could be due to the 2554's custom compressor and turbine sizing. We don't have access to compressor maps of both but it's safe to say the 2554 MRX is coming into it's efficiency at a lower boost level.

3k to 4k comparison
MRX - 175tq to 275tq
GTX360R(A) - 160tq to 280tq
GTX360R(B) - 170tq to 260tq

This is really a win to me.
 


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Brura22

Brura22

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Thread Starter #205
I always knew a GTX style 2554 would be great [emoji1303]


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I just have MP215 right now. Debating whether to go all out and get a kit like this, or to give "stage 3" a try first.
 


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This is some good stuff!

My biggest question for these upgraded turbos is what supporting mods are required, and what is recommended? I assume standard full bolt ons (intake, downpipe, catback, intercooler) is recommended, but would the stock intake be suitable? Or would it not provide enough air...is a just a drop-in suitable then, or is a full intake upgrade needed? In a month or two I will have a full turboback and intercooler and would love to upgrade the turbo soon after, but it will be delayed if I have to get an intake first. If that is the case then so be it, I just haven't been able to find an answer and am curious. TIA!
 


A7xogg

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This is some good stuff!

My biggest question for these upgraded turbos is what supporting mods are required, and what is recommended? I assume standard full bolt ons (intake, downpipe, catback, intercooler) is recommended, but would the stock intake be suitable? Or would it not provide enough air...is a just a drop-in suitable then, or is a full intake upgrade needed? In a month or two I will have a full turboback and intercooler and would love to upgrade the turbo soon after, but it will be delayed if I have to get an intake first. If that is the case then so be it, I just haven't been able to find an answer and am curious. TIA!
I would have to say def fbo intake dp intercooler charge pipes mount or mounts.
 


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I just have MP215 right now. Debating whether to go all out and get a kit like this, or to give "stage 3" a try first.
MP215 to MR230 within first three weeks of my FiST ownership. (Power corrupts, ABSOLUTELY!)

Interesting to see mountune's MRx vs stock curve crosses at 3600 rpm. At 3600 the [MENTION=4388]Brura22[/MENTION] 's sea-level MRx surpasses the MR230's 240 lb-ft.
 


koozy

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Spend some time in the V-dyno and Dyno threads. Stock turbo's are well over 200ftlbs at 2.5k rpm. Stage 1-3 cars are hitting 260-270ftlbs by then. As I said before, the MRX just isn't going to do it. Unfortunately graphs are deceptive with measuring spool and how well the power comes on. Spool is a direct result of load and load can be controlled. For example, I could dyno 2 different turbos like a big GTX2860r and a stock turbo but use the same progressive pedal pressure as the pull proceeds. The smaller turbo may be capable of increased spool but because the load is slowed by the progressive throttle input it makes the graphs align. Now once the little turbo runs out of steam, the bigger plot would show it continuing to pull. Now drop them on top of each other and it "looks" like they have the same characteristics until the big guy pulls away. Am I saying Mountune did this, no. But it's hard to get that extra data over the internet. At what point in the plots did the user initiate WOT or max load? Vdyno adds extra variables as well.

Me personally, I have come to accept that my goal of 300whp will likely not happen with stock spool. No worries, but I also don't want slow spool either. I need balance. I need things to turn on around 3k rpm. I have been looking at DHM's GTX360r kit for some time so it has been the kit I am comparing this to. Many people have given the feedback on this kit that spool is quick and progressive with nothing but praise. Considering it costs more than TWICE as the MRX, it's worth examining the data for the MRX as it comes up. No knock on DHM either, they have a FULL kit here with a stainless manifold and proper wastegate use. They are also using a bigger turbo with a much higher ceiling than my 300whp goal. The DHM kit is just getting warmed up at 300whp. The good thing is that there is plenty of dyno/vdyno plots out there for this kit. I have attached 2 plots from the Vdyno section. Lets compare.


These are essentially both stage 3 GTX360R cars running 93 pump only (which is what I plan to do).
View attachment 14718 View attachment 14719

Now look at the MRX (not final on 91).
View attachment 14720

Some VERY interesting stuff here. The GTX360R is at a huge advantage sporting a tubular manifold. Look at the torque from 3k - 4k rpm on all 3 graphs. Then look at the total numbers. The MRX is ON PAR with DHM's kit! Again, remembering these are 91 numbers on the MRX. 93 will spool a tad quicker as timing can be bumped during tip in. The MRX is also making more torque at 3k rpm than either! The 360R is even hitting 20psi 200rpm earlier when comparing the plot that maps boost. BUT the torque 3k-4k still favoring the MRX!! This could be due to the 2554's custom compressor and turbine sizing. We don't have access to compressor maps of both but it's safe to say the 2554 MRX is coming into it's efficiency at a lower boost level.

3k to 4k comparison
MRX - 175tq to 275tq
GTX360R(A) - 160tq to 280tq
GTX360R(B) - 170tq to 260tq

This is really a win to me.
here's my 91 octane DHM360R BASE Tune.
 


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Brura22

Brura22

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Thread Starter #213
Seems like he may be pointing out spool and not overall power. Or he posted the wrong one
Looks like he hit peak tq in the 3000's. And it says peak hp in the 5000's.
Is it dropping off after that?? Why not show it all lol

The log file literally says Protune 9..


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koozy

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the log file shows 9 because it got cut off due to character limits with VD, the complete log is labelled 'LOG_DHM GTX360r ProTune 91oct base 2-2'.

my post was to show how quick things happen.
 


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Brura22

Brura22

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Thread Starter #216
the log file shows 9 because it got cut off due to character limits with VD, the complete log is labelled 'LOG_DHM GTX360r ProTune 91oct base 2-2'.

my post was to show how quick things happen.
Awesome [emoji1303]


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I'm looking at $5,600-6500 for the 360R kit (depending if Xtra fuel or not). But $3,000 total for the MRX kit (with downpipe, accessport, and BOV). Not a chance in hell I could convince my wife to let me spend 6k on this Fiesta. 1/3rd the cost of a brand new FiST in a turbo kit lol. Yes yes I know, amazing kit. But that's too much money for me.

Plus everything else in my car up to now is Mountune brand. Might as well stick with the theme right?

From what I'm seeing so far, when factoring in cost, I'm leaning towards simply pro tuning the stock turbo. I can pro tune, and if I feel I need more - then think about something else. I need an Accessport and downpipe anyway.

I foresee lots of issues keeping traction with a protuned stock turbo though. idk. ¯\_(ツ)_/¯
 


XLR8

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I'm looking at $5,600-6500 for the 360R kit (depending if Xtra fuel or not). But $3,000 total for the MRX kit (with downpipe, accessport, and BOV). Not a chance in hell I could convince my wife to let me spend 6k on this Fiesta. 1/3rd the cost of a brand new FiST in a turbo kit lol. Yes yes I know, amazing kit. But that's too much money for me.

Plus everything else in my car up to now is Mountune brand. Might as well stick with the theme right?

From what I'm seeing so far, when factoring in cost, I'm leaning towards simply pro tuning the stock turbo. I can pro tune, and if I feel I need more - then think about something else. I need an Accessport and downpipe anyway.

I foresee lots of issues keeping traction with a protuned stock turbo though. idk. ¯\_(ツ)_/¯
Kind of in the same boat. I could muscle the wife into letting me, but not sure I want to see the savings take such a hit. Looking forward to seeing CpE's manifold release as well. It's definitely going to be the MRX or Tune+'s upcoming hybrid. But like Brura22 said, the longevity of a Garrett core is some solid piece of mind.
 


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Kind of in the same boat. I could muscle the wife into letting me, but not sure I want to see the savings take such a hit. Looking forward to seeing CpE's manifold release as well. It's definitely going to be the MRX or Tune+'s upcoming hybrid. But like Brura22 said, the longevity of a Garrett core is some solid piece of mind.
Bingo, and on the track longevity and reliability definitely matter. Its all good to make 350 hp if youre just gonna hot rod it around town or drag race it occasionally. This MRX kit seems to be one of the better ways to get competitive power on stock internals, and have the car remain reliable (though I guess we'll see for sure over time). The power being on the top end is fine too since you rarely spend time under 4000 rpm on the track anyhow.
 




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