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Mountune Fiesta MRX Turbo

Messages
188
Likes
83
Location
Baton Rouge
Better options out there. The kit just doesnt produce the numbers that are stated. Believe me, I went around and around with this turbo.
Eh, I knew what I was getting with this turbo and picked up the upgraded wastegate, and cranked it up to ~4mm of preload a few weeks ago when I installed it.

100% stock intake and filter with a catalytic converter installed, it spools with peak torque at around 3.4-3.7k (depends on the gear)...still flows ~29.xx lbs/min with 90F-100F charge air temps. It has been pretty hot here for February. When a cold front comes through, it goes over 30 lbs/min. I am surprised the stock intake/filter can even flow that much. Still early in the tuning process, haven't seen cold weather since the boost was upped. Very safe so far with the "OK" quality 93 in my area.

I rolled the dice and it worked out for me. I have a preference for saving my rods from that brutal low end torque, and I have seen very few Garrett core failures in motorsports. I trust Garret and Borg Warner to make good turbo cores. The bored-out, stock-turbo based hybrids just don't last as long. They will blow sooner than later, those tiny wheels are just spinning too fast. I'm planning to keep my car for quite a few years, so these things matter to me.

Edit: Saw a pumaspeed turbo in the "for sale" section with a snapped exhaust turbine with less than 10k miles. Reconfirming my already very heavy bias, I don't think those turbos are reliable with 29-30 lbs/min flow going through them. Sure, they might do it...but for how long? Bet they are very safe at ~260 whp, though.
 


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Messages
90
Likes
31
Location
Corpus Christi
Yeah I have the full MR230 kit with the MRX turbo and at 6800 rpm I'm moving 31.50 lb/min. Randy at Mountune said the fuel injectors have nothing left to give at this point. You cant really complain about the turbo set up when it moves enough air to make the fuel injectors void. On the track this thing is an absolute joy too, and you get the motorsports pedigree of Mountune as piece of mind. Looking forward to getting it back on the dyno now that the tuning process is all done.
 


CarGuy

1000 Post Club
Messages
1,057
Likes
661
Location
Daytona Beach, FL, USA
Yeah I have the full MR230 kit with the MRX turbo and at 6800 rpm I'm moving 31.50 lb/min. Randy at Mountune said the fuel injectors have nothing left to give at this point. You cant really complain about the turbo set up when it moves enough air to make the fuel injectors void. On the track this thing is an absolute joy too, and you get the motorsports pedigree of Mountune as piece of mind. Looking forward to getting it back on the dyno now that the tuning process is all done.
I'm waiting for my MR230 kits pieces to all come in. I'll be curious to know what it'll do on the dyna pre and after the MRX.

Sent from my SM-N950U using Tapatalk
 


Messages
48
Likes
10
Location
Sykesville
Yeah I have the full MR230 kit with the MRX turbo and at 6800 rpm I'm moving 31.50 lb/min. Randy at Mountune said the fuel injectors have nothing left to give at this point. You cant really complain about the turbo set up when it moves enough air to make the fuel injectors void. On the track this thing is an absolute joy too, and you get the motorsports pedigree of Mountune as piece of mind. Looking forward to getting it back on the dyno now that the tuning process is all done.
Is this on 93 or E blend?
 


Messages
37
Likes
8
Location
Cincinnati
I hate to ask as I am unsure if it has been stated already within these 145 pages, but, can anyone attest to the reliability of the MRX over 10k miles? 20k miles? I am not looking for over 270hp, looking for fun and reliable. I scoured these pages and from what I have read I am seeing mixed reviews and looks like no one has had issues other than fun factor down low.
I have 14k miles on mine with zero issues.
 


DaveG99

Active member
Messages
747
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214
Location
Dallas
If you google "MRX fiesta 1/4 mile" one of the first links has this in the descritpion.....

Fiesta ST MRX Turbocharger Upgrade is engineered around a genuine Garrett GT2554R core that features a custom engineered 11-blade billet compressor wheel and .... 1/4 Mile Time: 11.739@119.8mph
Where is this run? What are the details? Is there a video of it? 119mph is really good but I dont see any information about this anywhere.
 


Messages
48
Likes
10
Location
Sykesville
If you google "MRX fiesta 1/4 mile" one of the first links has this in the descritpion.....



Where is this run? What are the details? Is there a video of it? 119mph is really good but I dont see any information about this anywhere.
Pretty sure that's the time run from the 2867 car. 119 is 380+HP for a Fiesta.

Sent from my XT1650 using Tapatalk
 


Messages
181
Likes
100
Location
Baton Rouge
If you google "MRX fiesta 1/4 mile" one of the first links has this in the descritpion.....



Where is this run? What are the details? Is there a video of it? 119mph is really good but I dont see any information about this anywhere.
User FearTheSnail has that time in his signature and happened to reply to the first page of this thread.

You'll have to spend a little time looking through his posts to see what mods he has to his car.
 


DaveG99

Active member
Messages
747
Likes
214
Location
Dallas
User FearTheSnail has that time in his signature and happened to reply to the first page of this thread.

You'll have to spend a little time looking through his posts to see what mods he has to his car.
Oh OK. I was geting really excited and thought WTF is this!

Im familiar with his car.
 


Messages
19
Likes
1
Location
Metro Detroit
I am sure its been asked but maybe I missed it. Is anyone running the MRX with the BCP/ebay/etc. manifold? Bonus question, anyone using a ported stock manifold?
 


Messages
13
Likes
5
Location
Middletown
Had my car up on a lift today to fix the exhaust hitting the underbody and noticed coolant leak on the turbo. Small drops of coolant sitting on the hard lines underneath. I put a wrench on the blue nut and it was tight as I could get it. Resevoir is on the low side but ok, I’ll have to add soon...anyone else experience a coolant leak?
 


Messages
143
Likes
43
Location
Hela
Tuning underway at Mountune, MRX VDynos, log data below also. 93 with a little extra E85 (E15ish) at ~15psi on 2nd map test. Randy is slowing upping the boost and re-checking.

3.png

2nd MRX Data Log Graph.png

2.jpg
 


Messages
143
Likes
43
Location
Hela
Solid catch. Its the one thing I didnt look at. Curious if its a skew, or if the car actually went on a mega diet.
Hey folks. Car is indeed 2580lbs, you read it right. Trunk materials and back seat removed (115lbs less), removed washer fluid reservoir (5lbs), OZ Ultraleggera 17x7's w/Eagle F1 Tires (36lbs less total), Tarox 6pot 300mm Two Piece BBK (10lbs less), Braille Lightweight Battery (15lbs less). Puts me at 2539 down from 2720 factory, now add back in 20 lbs for the heavier CPE intercooler and the braces on the car are another 15-20lbs total, so right around 2580. Add the 175lbs for me to the car as done in VDyno and there you go. :) If I raised the weight it would actually bloat the dyno results higher since I'd be going the same speed with more weight...

Updates on VDynos and logs below. Shooting for 290-295 end point right now at 27psi, right where I was looking to be. I went back and made sure the baro pressure was as close as possible (sea level baro for my area then adjusted for elevation at 940 feet above, using Weather Underground historical data), forgot to do that last time I posted them all (altitude correction). Weather is much colder today so that's helping a bit on the latest run.

- Red line is 11.5psi, wastegate pressure only, 0% WGDC (non-billet WGA)
- Blue line is 15.5psi
- Green line is 21.5psi

Comparison Dyno - MRX 11.5psi, 15.5psi, 21.5psi.png
 




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