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'17 Forte5 SX 6M
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Discussion Starter · #1 ·
Hello fellow Forte enthusiasts,

I have a 2017 Forte5 SX (1.6T, 6M) with about 85k miles, and I've owned it for a little over a year and about 20k miles. For the most part, it's a fine little car, especially for what I paid (Thanks previous owner for taking the depreciation 馃槈). One of my main complaints about it, though, is how short the gearing is, especially in 6th. I do a lot of highway driving, and 3k rpm at 70mph gets old pretty quick. Thankfully the stock exhaust and interior do a pretty good job of masking the noise, but I only average about 32mpg, which for a little car with a little engine, especially with it being only 4 years old, is not grand. I'm also not thrilled about driving for hours on end at an RPM I rarely see on the street (yes, I granny shift the heck out of it).
So naturally, when I found out that it's Hyundai sedan contemporary, the Elantra Sport, has longer gears from 3rd-6th, it piqued my interest. And when I saw that I can purchase one of many used transmissions on eBay for $400-500, that comes with a (short, but free) warranty and return period, and that came out of wrecked cars with half or less-than-half the mileage on my car, I became very, very intrigued as to whether or not I could swap my transmission for one from an Elantra Sport for some better mpgs, less highway NVH, and less engine wear.
I'm wondering if anyone here has any information at all about anything that might keep me from being able to do this, i.e. if the mounts are too different to work, different electronics, different axles, etc. If not, I might find myself with an extra transmission once I notice my clutch beginning to give way, and test fit the Hyundai trans in my Forte while it's trans is out to see if it's potentially possible.

P.S. This is my first time ever posting in a forum, so if there's something I did wrong or can improve upon, feel free to leave constructive criticism in the comments. Thanks!
 

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'21 Forte FE 6-Speed
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I have no idea, but it鈥檚 an interesting idea. I do know the FE and GT six speed manuals are the same transmission case with different gearing and clutch assemblies, so it鈥檚 always possible. I鈥檓 not sure though. Let of know how it goes if you end up doing it!
 
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2021 Forte GT w/GT2, Currant Red, Wagner-Tuning Intercooler, Evilla Exhaust, Takeda S1 Intake
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I think it is possible to swap out manual transmissions in cars that originally came with manuals, However I think you'll need the ability to upgrade the car's computer controls - Most likely you'll get irritating warnings and set driveline codes because information won't match up (Rpm Vs MPH, speedometer inaccuracies, and such). You would have to research compatibility, such as the axles - might be lucky if they are the same between transmissions with different ratios, for example

In Auto equipped cars the ECM "talks" to the TCM and BCM so I expect this to be somewhat the case with manual transmissions too - but I honestly have no experience with modern Kias and manual transmissions to know if it is the same. I've been trying to find out if manual equipped Fortes have a TCM or not.
 

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'17 Forte5 SX 6M
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Discussion Starter · #4 ·
Most likely you'll get irritating warnings and set driveline codes because information won't match up (Rpm Vs MPH, speedometer inaccuracies, and such).
...
I've been trying to find out if manual equipped Fortes have a TCM or not.
That's something I'm worried about, and should probably check and see where the speed sensor gets its reading on these cars and what all the car uses it for. My car has a "shift indicator," but I think it only uses gear position (obviously), load, and RPM, not speed.
I don't believe the manual cars have a TCM, since there's really nothing it can control. All the inputs and gear changes and such are mechanical or hydraulic. I'm sure there are plenty of sensors, but I think they communicate with the ECM and BCM, and not its own TCM.
 

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'17 Forte5 SX 6M
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Discussion Starter · #5 ·
I was wrong. The car uses vehicle speed and engine speed together to recognize what gear the car is in (so the shift indicator does use speed), and is a major input to the ECM. @ForteGT2 you were totally right when you were concerned about the RPM/speed info not matching up. Total bummer. 馃槚馃槚 I've enjoyed all the newer technology in this as opposed to what's in my 25+ year old Volvo or Nissan, but now I've to get used to how prohibitive the electronics are in newer cars. Thanks, guys, for the support regardless!! Sorry I can't give you anything to look forward to.
 

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Before you even start working on this project - ask yourself a question how much you want to spend on it.
Can you justify spending range of 5k on it? Maybe more... maybe less...

Anything can be done. The question is - how much it will cost.

As harsh at it will sound, I would say - swap the car or learn how to live with that.

I had 2015 F5 SX, MT. Yes, I disliked 70 [email protected] or [email protected] rpm.
The AT version was 2650 and 2800 rpm respectively.

The DCT version should be at around 2100 rpm at 70 mph. Maybe swap the cars instead?
 
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'17 Forte5 SX 6M
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Discussion Starter · #9 ·
@PLP I was initially hoping that they would be similar enough to be a relatively straightforward swap, but was wrong. I'm used to older cars haha. The DCT has its advantages, but I do enjoy driving a stick shift much more than an automatic, even with the shift paddles. Maybe I'll just start saving up (a lot) for a new Civic Si or Integra :)
 

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maybe reviving a old thread here but you are more then able to swap transmissions out for the elantra. as long as everything matches up and bolts up you dont need to change any computers or anything. as the only thing your changing is gear ratio and your computer has nothing to do with that at all. ive done a couple 6 speed swaps from a 5 speed and never changed any computers o anything and never got a warning light or fault code. again as long as it matches up and bolts up and uses all exsisting wiring and such your fine to swap
 
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