Mountune Fiesta MRX Turbo

[Bretley]

The rev limit is set to 6850 on my mrx kit, wonder why yours is set lower to 6600? I don't even have the upgraded WG... It's probably pushing the fuel limits past that rpm with the upgraded WG. Yours is making about 35-40 more hp and tq than mine. (Using vdyno with all parameters inputted) so probably even more in real world settings.

 

[molten16st]

7000rpm isn't sh*t for these engines. If anything, they NEED more cam/spring and RPM. Look at the geometries, they're really good! Spin that thing out, you still have lots of power to make without putting it on the ragged edge.

This is a garrett gt2554r turbo with a different compressor wheel. I'm making significantly more power than the turbo was designed for. Its still a small turbo. If the turbo was bigger and flowing more air then revving it higher makes sense. My tuner said power was falling off and he was fighting the ecu with knock corrections at a higher rpm. Here is some info

https://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Product_Code=GRT-TBO-001Dual Ball Bearing Garrett GT2554R (aka GT25R) Turbo. Excellent responding turbo for 4 cylinder applications. The Garrett GT2554R has a flow capacity of approximately 240HP.

From garrett-GT2554R Turbocharger https://www.turbobygarrett.com/turbobygarrett/turbochargers/gt2554r
Horsepower:
170 - 270
Displacement:
1.4L - 2.2L

 

[Quisp]

http://dsportmag.com/the-tech/ford-ecoboost-1-6l-analysis-turbocharged-direct-injection-ccvtc/

Start comparing them newfangled geo met trees to some other high strung engines and you'll see this thing can handle WAY more "stress" than what the factory gave them. The cam specs are super puny, almost hilariously small. A camshaft and spring upgrade, in my opinion, should be the next step after a tune/intercooler/ turbo upgrade. Spinning 7000rpm on all factory components is nothing. Not worth it with the baby OEM turbo, but even something slightly larger can take advantage of the additional RPM, if sized properly.

Smallest rod bolts they'd ever seen.

 

[Dazzle]

The particular engine in question is begging for more RPM to keep making power.

I'm sure everyone on this forum would be happy for you to show us with your engine
Please post a link to your thread as I'm very interested in what you find

 

[koozy]

My rev limit is set to 7,500rpms on the DHM turbo kit tuned by Russ. To my knowledge so are the majority of others running DHM turbo kits tuned by Russ. The stock motor handles it fine. There are plenty of graphs showcasing this http://www.fiestastforum.com/forum/threads/11970-The-ULTIMATE-Dyno-V-Dyno-Thread

 

[Dazzle]

Thanks Koozy, I appreciate you taking the time to show us your graph.
It's really good to see it hold boost and power all the way to the limit as well, impressive

As a nu be, It's taking me all of my time to even read through a few of these threads so forgive me if I'm a bit behind. I am trying to catch up

 

[Bretley]

The issue with stock fuel system guys is that we tap out at a certain HP, no matter what you rev to. The engine may definately be able to spin up to those rpm's like Koozy's very nice graph shows, but not on the stock fuel system alone. This is why im so anxious for stratifieds new aux fuel system. Pricey, but worth it in every way.

 

[M-Sport fan]

The issue with stock fuel system guys is that we tap out at a certain HP, no matter what you rev to. The engine may definately be able to spin up to those rpm's like Koozy's very nice graph shows, but not on the stock fuel system alone. This is why im so anxious for stratifieds new aux fuel system. Pricey, but worth it in every way.

Plus, you get the bonus of cleaner intake valves as well!

 

[STAZ15]

The issue with stock fuel system guys is that we tap out at a certain HP, no matter what you rev to. The engine may definately be able to spin up to those rpm's like Koozy's very nice graph shows, but not on the stock fuel system alone. This is why im so anxious for stratifieds new aux fuel system. Pricey, but worth it in every way.

I’ll bet we see someone break 500 hp with that stratified kit and an engine build. I have been toying with buying a block and slowly doing a build.


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[WeTheNorth]

Actually, you probably need a hug. I feel sorry for you. You must be filling some void in your life by being an internet tough guy.

I know there is a diaphragm and spring inside. You are correct. I don't have a tension gauge. I should have just said I had to use a little force to install the wastegate rod onto the flapper pin. (I don't know all the technical terms) I'm sure you do though. Either way if I have to make the rod length shorter I would be preloading the spring since the rod wont just fall onto the pin. I had to pull on the rod which I believe is compressing the spring.

If your head hurts from reading on this forum then don't come on here. You will probably be back to insult me some more though.

Lmao, this guy is not tough, you could sit him down with one hand. He’s another nerdy married internet thug. Where I’m from this guy wouldnt even look up, let alone say anything in person.


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[molten16st]

Lmao, this guy is not tough, you could sit him down with one hand. He’s another nerdy married internet thug. Where I’m from this guy wouldnt even look up, let alone say anything in person.


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Lol, that figures. One of those guys. Thanks for the info. 😁

 

[WeTheNorth]

Lol, that figures. One of those guys. Thanks for the info. [emoji16]

Good vibes only[emoji680]🤙🏼


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[M-Sport fan]

I’ll bet we see someone break 500 hp with that stratified kit and an engine build.

Yes, but the critical trick will be to get usable/tractable power under the curve, while hitting that 500 WHP peak.
(And then GOOD LUCK in putting it into the pavement without a full-on drag race suspension setup. )

 

[blurred]

Yes, but the critical trick will be to get usable/tractable power under the curve, while hitting that 500 WHP peak.
(And then GOOD LUCK in putting it into the pavement without a full-on drag race suspension setup. )

It isn't that difficult. "Power under the curve" is not a metric to be used for Turbo cars, or at least not as important as in an NA car. If you are building a high hp fwd car you want high rpm, a flat torque curve and take careful consideration on making the powerband as far to the right as possible while maintaining as much off-boost torque as possible for normal driving. For this car keeping peak torque at 350 or less and carrying that to 8000rpm would be ideal for a 500whp goal. A turbo large enough to flow for 350wtq at 8000rpm would also have the benefit of not making peak torque in 1st or 2nd gear anyways so driving in the lower gears wouldn't be useless.

Ideally you would make 350wtq flat from 6000-8000. traction would only be a minor issue and it would put down the power just fine. The higher you rev and build the setup to rev the lower the torque requirement to make the power which makes traction less of an issue and allows narrower tires, less aggressive clutches, less breakage etc.... It also allows you to remain in a lower gear for longer which makes it much faster overall.

 

[M-Sport fan]

^^^That all sounds GREAT, but, WHY then are so many on here only in the high 13s in the quarter mile (NOT that I give two shits about drag racing FWD cars, but what good is the power IF it cannot be used to accelerate?), despite; sticky tires, maybe even an LSD, well prepped tracks/launch pads, and 350+ peak WHP/great mid range torque in a 2600 lb. (or less) car, IF it is not the weight transferring off of the powered wheels slowing them down?!?

By comparison; my 3200 lb.+, manual, ~330 WHP/325 lb. ft. of torque LS1 Z28 did mid 12s @ 115 MPH, EVEN WITH; full size fronts, large aftermarket front sway bar still attached, and a 60' KILLING road race type suspension, and low profile, stiff side walled road race type (Nitto 555R2s) wheel hop/spinning prone tires on it.

There has to be a point where the weight transfer NEGATES all of the power gains (without a FWD drag race type suspension, slicks on the front/skinnies on the back setup, which is USELESS on the street, let alone a road course) for standing start acceleration.
Of course, with a good limited slip diff, it is more useful, especially coming on high up in the power band as you describe above, when already MOVING at speed, on a road course.

 

[TyphoonFiST]

^^^That all sounds GREAT, but, WHY then are so many on here only in the high 13s in the quarter mile (NOT that I give two shits about drag racing FWD cars, but what good is the power IF it cannot be used to accelerate?), despite; sticky tires, maybe even an LSD, well prepped tracks/launch pads, and 350+ peak WHP/great mid range torque in a 2600 lb. (or less) car, IF it is not the weight transferring off of the powered wheels slowing them down?!?

My thoughts also...

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[apex1]

I’ll bet we see someone break 500 hp with that stratified kit and an engine build. I have been toying with buying a block and slowly doing a build.


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In one of the several FiST videos done by Matt Farah on his YouTube channel, he drove a built big turbo FiST that made big power. According to the car owner, however, he was on his third gearbox. It makes me wonder if the gearbox might end up being a limiting factor.

 

[STAZ15]

This is true! Our transmissions can handle only so much


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[STAZ15]

Yes, but the critical trick will be to get usable/tractable power under the curve, while hitting that 500 WHP peak.
(And then GOOD LUCK in putting it into the pavement without a full-on drag race suspension setup. )

I think the person or people that try and break those numbers will be drag racing it. So a full drag suspension would be the idea. Dhm was working on a 9 second Fiesta I believe.



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[blurred]

^^^That all sounds GREAT, but, WHY then are so many on here only in the high 13s in the quarter mile (NOT that I give two shits about drag racing FWD cars, but what good is the power IF it cannot be used to accelerate?), despite; sticky tires, maybe even an LSD, well prepped tracks/launch pads, and 350+ peak WHP/great mid range torque in a 2600 lb. (or less) car, IF it is not the weight transferring off of the powered wheels slowing them down?!?

By comparison; my 3200 lb.+, manual, ~330 WHP/325 lb. ft. of torque LS1 Z28 did mid 12s @ 115 MPH, EVEN WITH; full size fronts, large aftermarket front sway bar still attached, and a 60' KILLING road race type suspension, and low profile, stiff side walled road race type (Nitto 555R2s) wheel hop/spinning prone tires on it.

There has to be a point where the weight transfer NEGATES all of the power gains (without a FWD drag race type suspension, slicks on the front/skinnies on the back setup, which is USELESS on the street, let alone a road course) for standing start acceleration.
Of course, with a good limited slip diff, it is more useful, especially coming on high up in the power band as you describe above, on a road course.

I know nothing about drag racing, nor care about drag racing to be honest. All we build here are high hp street cars so they need to work everywhere and on stiff suspensions and r-compound tires with low profiles, have to have huge cornering grip, great braking and be able to do a decent street launch, but be able to hook a maximum amount of power always, but more keyed to normal street driving and higher speed races where a full on drag launch is never used.

Powerband is all that matters, as well as keeping a torque level that can be handled. the cars you are referring to that are "slow" are just making too much midrange power in too low a gear to have traction, then too low a redline so they can't utilize that torque to make any hp. If that car is only making 350whp from 350wtq it is wasting its potential. The only time you need all of that power is while racing, so it means that you only need full power in the last 1000-1500rpm. If a car is making "square" power it means that it has a low redline and power is falling so when you are racing you are accelerating a diminishing powerband. So that car is only accelerating like an average 300whp. The byproduct of a torque curve that is dropping is that acceleration g's are also falling the higher it revs which means the rate of acceleration is slowing.

I have some friends with high hp fwd cars that are very driveable, hook the power decently, and make between 600-1150whp on a few different platforms. The key is 8500-10,000rpm redline, flat torque curves, in some cases boost by gear if the turbo is small enough to make full torque in the lower gears, and tuning to allow the cars to be very responsive so that wheelspin can be managed. As in running a peak of 700+wtq through 225 width tires and being able to out-launch gtr's, r8's, gallardos, etc... So it's all possible, but requires the right decisions, making the right compromises, and having a tuner and builder that fully understands it.

Typically the higher rpm car is always faster anyways, so especially with a traction limited setup this should always be a build goal.