Mountune Fiesta MRX Turbo

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

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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

View attachment 17315

Good stuff Pete. Put your smoothing at 3, you'll have more accurate estimates. I think the MRX is advertised as around 275 on pump gas so anything past that would be beyond fantastic. Good luck and thanks for posting.

BTW are you getting a real dyno test done when it's all over?

Thanks! Honestly I dont worry too much what the actual dyno numbers are as long as they are in the right range for the kit. I dont want to stress out the axles and such nor do I want to do 110+ on a dyno in 4th. VDyno is usually close within 4% so if I'm getting 280-290 on there, I'm a happy camper. I did switch the smoothing and looks pretty similar, just a few hp less per run. Thx for the tip.

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Very cool. So how is the spool with this new thing. I have heard its later, which sounds good I am hoping for just a bit, as stock is so fast that with a tune its spinning on third gear pulls on the dyno. If its at 3500 or so I am game. Really curious on the details of how it drives. Tho I should ask once its all done haha. How was the install???

Only 269 ft lbs? Why does that seem low for an upgraded turbo.

The turbo is honestly the biggest I would ever consider for the car. Spool is just where I would want it, around 3500-4000 which is much easier on the rods and allows you to get moving and try to put the tires down. It spools quite fast too despite being higher in the RPMs, wouldnt want it lower frankly or too much higher. Feels like you have a BMW 4 Liter V8 in the car, nice midrange punch but really opens up 4k+ and just keeps going and going and going. Install took about 8.5hrs to be honest with a lift. Some snafus we ran into below that I sent to Mountune, nothing we couldnt fix but a few

1. The wastegate actuator bracket was touching the back of the engine which made lining up the turbo on the vband essentially impossible. We had to cut the wastegate actuator bracket back a bit for it to fit properly. My friend who installed an ATP GT2554R had the exact same issue. Bracket is now still supported on both sides, just was trimmed a bit.

2. The stock oil drain line was too long to re-use since the vband adapter effectively lowered the turbo a little ways. We ended up cutting the drain and putting in an oil-safe rubber hose there and clamping it up (1/2" diameter opening hose needed). This is a low pressure drain so PVC hose works fine.

3. The fitment of the OEM turbo inlet pipe on the reducer in the silicone elbow is so tight it was extremely difficult to get it on, even with a bit of lube on the elbow side. Not sure if it is a hair too big but we got it on after about 30 min of working it. It didnt work to install it beforehand as the angle of the pipe wasnt right without fitting the turbo inlet pipe after the elbow was on the cold side inlet.

4. We were short the two bolts and two nuts needed for the downpipe to catback flange. I went through everything carefully and they are listed on the instructions but were not in the package fyi. We used some others we had at the shop though.

5. Install would likely be a lot easier with the passenger side axle removed but it was not 100% necessary, if worth noting in the instructions.

6. Be sure to install the inside water line (block side) on the turbo and also attach the wastegate actuator vacuum line BEFORE mounting the turbo or you will change your religion doing it on the backend as someone told me rightly so.

7. Manifold did NOT have to come off, we didnt want to start breaking studs. I would advise you not touch it. The manifold heat shield went back on with some trimming but I just used DEI Titanium Heat Wrap on the downpipe, works great (smokes for a sec then hardens) vs messing with that heat shield.

Great info. Thanks for the tips. This will surely come in handy when it comes time to do the job, whether it be this turbo or not. I want as close to 300whp as I can but on something reliable and not 5k bucks. This is right in the wheel house, and Mountune makes good parts. Plus I have already tuned with Randy on the stocker. Just kind of makes sense. The real issue is our 91 fuel is the best we can get and its absolute trash. Might as well be 89. That and elevation. Im at 2800 ft. Nothing terrible but not doing me favors either haha. Since all of this matters its leaving me trying to figure out exactly what I want to do.

Find a station with some E85 and use a ethanol content calculator to blend to E15-E16. It will get you a bit more octane. 0.75 gallons of 104 octane E85 and 7.5 gallons of 91 octane should come to around 92.2, about E17 in content. Randy can tune for it, or hell just blend to E30 and tune for it.

http://www.georgebelton.com/E85Calculator.php

Only 21.5 psi at the moment, 5.5-6 more to go. Should be a nice 290-295whp and similar torque. Frankly, it has enough as is at 21.5, any more down low and you're not going anywhere really lol

Updated MRX Vdyno, smoothing 3, corrected for actual barometric pressure. 22.2psi vs 23.96psi peak in the charts. Only 57% Wastegate Duty Cycle on the non-billet WGA currently.

DataZap Log

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After a lot of assessment of different turbo kits and comparison to the hybrid kits, how is the MRX / Garrett on the bottom end? The info says that it's present through the entire RPM band.

Mountune MRX Turbo, 3rd gear pull, ATP 3" Downpipe, Mountune Catback and Intake, CP-e Intercooler, Turbosmart BOV. Vdyno posted here too from same day, same gear. Testing in Mexico.

Vid: https://youtu.be/lf3RDxGcBiI

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