Hyundai Elantra GT banner
1 - 18 of 18 Posts

·
Registered
Joined
·
29 Posts
Hey, folks. I've already got over 12K on my 2020 GT N-Line (100+ miles per day). Here's what I've found...

Replaced OEM plugs and coil-overs with MSD coils and Bosch double iridium plugs. They really helped, but...

The tranny shifts into higher gears at or about 2.5K RPM, whether in Sport or normal mode. That means that just about the time the turbo spools up (c. 2K RPM) the stupid tranny shifts and you're back at 1.5K RPM, below the turbo actuation. Lags, spits, misfires.

So, the answer is leave it in manual mode and use the flappy paddles to shift at or above 3.5K RPM, the way God intended. That'll solve most of your problems.

Hope this helps.

-zed
 

·
Registered
Joined
·
29 Posts
Takeeon:

Not sure about the safety of narrower plug gaps. It is an aluminum block, after all... But, you may not be totally wrong either. After I pulled the OEM coil packs and NGK plugs, I saw evidence of arcing above the stem, a neat little burn just above where the plug meets the cylinder head on CYL #3.

For those with less inclination to mess with manufacturer's specs, at least try my driving setup, which yields nearly flawless results (I said 'nearly'):

1. Sport mode off, since you'll be shifting at whatever RPM you choose. Manual shifting in Sport mode has given undesirable results (misfires), for me.

2. ESC/TC on (cuz I gotta have cruise control and there's none with it turned off).

3. Shiftronic on (stick pulled to the left) and use either the shift lever to up- or down-shift (1st to 2nd gears on corners only, for me), or the flappy paddles (my preferred methodology).

4. And finally, never shift below 3.5K RPM, so you can stay in the turbo's power band! Personally, I never shift below 4K and frequently ~5K. I never redline the engine, cuz I want it to last awhile, y'know?

NOTE: Basically, what you're doing is 'dumbing down' the car by removing some crucial decisions the ECM and TCM are horribly, laughably mismanaging. If I weren't concerned about voiding my warranty (but I certainly am), I'd probably consider an actual custom tune (but, I'm not gonna cuzza the aforementioned) to make the danged thing work the way it oughtta.

As a final note: If you're in a low-leverage situation (e.g., residential driving, wide-open highways, etc.), the car's performance is perfectly acceptable in Sport mode (all it does is keep the revs up a little higher... kinda pointless, really, unless higher rev-sound equates to 'sporty' to you) and full-auto DCT mode... But, if you have to rapidly accelerate even moderately (1.5K cruise with sudden increase to 3.5 or 4K), you can expect a single- or multi-cylinder misfire and undriveable power loss that won't correct until you pull over, turn off the engine, open the door to discharge electrics and then restart like nothing ever happened. It's waaay stupid, and not in the good sense of the expression.

P.S.
My Fiesta ST was a banshee, but they don't sell 'em in the Americas anymore (all trucks and SUVs, gag/puke), so I got the GT N-Line with tech pkg as the nearest suitable replacement. It's a comfortable car, all the bells and whistles... but, it ain't comparable to the FiST for performance, by a long shot.

-zed
 

·
Registered
Joined
·
29 Posts
Takeeon:

My daddy always used to say, "If you drive like an old lady, you'll end up with an old lady's' car."

Now, granted, the low-end torque's alright... until you put your foot down, even a little. Then -- on my specific vehicle, at least -- the engine sputters, misfires and becomes virtually undriveable until I limp over to the shoulder and do a complete 'cold reboot', as outlined in my previous post.

For anyone who'll consider my findings:

1. Less drivetrain computerization is required, not more. There's a seat-of-the-pants sport car in this thing and imma find it, even if it hairlips the Governor!

I'm about 95% there, right now; I just can't trash 'muscle cars' the way I used to in my 2,400 lb. FiST, cuz Inertia is a Universal Law and responsiveness/'suddenness' is all about weight-to-power ratio. I doubt we'll see any Ed Block or Pros vs Joes videos featuring a GT N-Line.
(NB: I also doubt I'll ever be able to approach the FiST's performance in the GT, without significant and costly engineering-level mods. The HGTN-L just weighs too much at 3,500 lbs. -- see, 'Universal Law', above -- with the same HP and torque as the FiST, but no factory-standard 30-sec turbo overboost to 230 HP/210 ft-lb; but it's fast enough to do all the things I need it to do, given the right driver. Meaning, me.)

2. I'm not saying you should drive the car aggressively at all times. Rather, that it should driven as aggressively as is prudent for longevity in the vehicle, whenever you get the chance -- like, when entering a highway or making a passing/overtaking maneuver.

My goal when driving is to get to my cruising speed (speed limit plus 10%, e.g., 77 in a 70) as rapidly as possible and then make as few adjustments to speed as practicable thereafter. It keeps the car running right... or, as right as possible given the apparent computer problems this manufacturer has throughout their lineup. Why pay for and drive a titular sport car, if all you really need is a squirrel-in-a-cage, 86 hp/56 ft-lb FWT putter-buggy?

3. On my 108-mile roundtrip daily commute, I always accelerate up to </= 6K RPMs (sub-7K-redline), but fewer than 7 occurrences, for 30 seconds or less each time, in my total 2 hour drive (i,e., between 2 and 3 total minutes of 'hard acceleration' over a 2-hour timeframe). The rest of the roundtrip, I'm chillin' in cruise, Normal mode and full-auto DCT, letting the computer do most of the highway cornering, pulling about 2.5K RPM and making 35-37 MPG, depending primarily on headwind/tailwind factor. And I'm doing that on mid-grade 91 octane.

ADVICE: Dumb the car down, as described in previous post. ...It's already too smart for its own good...

Parenthetically
-zed
 

·
Registered
Joined
·
29 Posts
Upon further review:
Turning off Electronic Skid Control
does virtually eliminate uneven acceleration. So now, I only turn it on when at cruising speed on the highway and in low-leverage situations, as described above, so I can use cruise control. Kind of a PitA, given that my Fiesta ST would do cruise control regardless the status of ESC.

...and why in the name of all that's holy would the ESC be so stingy? I could see it if the GT N-L had the HP/torque of a Veloster N or i30 N. 'Granny' overkill and no Hyundai-based solutions likely forthcoming for this discontinued model. Meh.
 

·
Registered
Joined
·
29 Posts
Next thing to do is get Continental Extreme Contact all-season tires on it for about $1K, maybe lighter wheels too. Not keen on stock tires.
 

·
Registered
Joined
·
29 Posts
If anyone is still reading this:

I swear by Gumout products. I used them regularly with my Fiesta ST (FiST, to enthusiasts of the car, sadly discontinued in the Americas), about once every month and a half, or so.

I don't really know why it took me so long to use a bottle with my 2020 Elantra GT N-Line; but, I stuck in one of their complete fuel system treatments for GDI vehicles ($4.77 at Walmart) about 3 weeks ago, on an empty tank before fill-up and... Whoosh!

In Sport mode -- even in the plain-Jane, usually hiccup-y DCT -- the danged thing took off like its butt was on fire! And it's still running hell bent for leather,1.5K miles later.

Looking like my idea of a sport car, after all, wasting all those big-bore lead sleds when challenged... This is getting good!

-zed
 

·
Registered
Joined
·
29 Posts
What kind of fuel do you use? If you are not using top-tier, the owner's manual recommends a fuel additive every oil change. I use top-tier but I'm thinking of using your suggestion of Gumout anyway.
I fill up at Sam's twice a week, mid-tier (89 octane with ethanol). Try the Gumout. I guarantee you'll notice an almost immediate improvement in throttle response and just plain ol' giddyup.
-zed
 

·
Registered
Joined
·
29 Posts
Product page:
Regane® Complete Fuel System Cleaner – Gumout

gumout.com

Walmart sells it online for $4.44 USD:
https://www.walmart.com/ip/Gumout-Regane-Complete-Fuel-System-Cleaner-6oz-510014W/16888904
NOTE: The treatment packaging I use has GDI prominently displayed on the label; but the detail on Walmart's page says:

"CLEANS
GDI/direct and port/indirect fuel injectors, intake valves and ports, piston tops, cylinder heads, combustion chamber

CONDITIONS
Fuel to fight ethanol and water corrosion

PREVENTS
Future carbon buildup.

BEST FOR
Maximized performance and fuel economy in one fill-up, reduced emissions

DIRECTIONS
Oxygen sensor safe. Safe for use in turbocharged and supercharged vehicles. Will not void OEM/manufacturer’s warranty. Add entire bottle to nearly empty gasoline tank, then fill tank with up to 21 gallons of gasoline. For best results, do not refill tank until near empty. Use every 3,000 miles." (Emphases mine)

-zed
P.S.
I am not affiliated with, nor a paid promoter of Gumout. Their stuff just works.
 

·
Registered
Joined
·
29 Posts
Will_p:

GDIs are known to carbon up. Also, they don't much like ethanol, which is pretty much ubiquitous in gasolines today. Gumout Complete Fuel System treatment purports to address both those issues. I'm not a petrochemist. I just know it works, it ain't snake oil; but, I wouldn't use it beyond the manufacturer's recommendation: once every 3,000 miles. As to breaking down your cylinder heads or over-gapping your plugs -- as others are doing -- I just wouldn't. I'm pretty sure that would void my warranty and possibly ruin my engine. I've swapped out the OEM plugs and coil packs; but, I'm not otherwise gonna alter the car mechanically, for the same reason.

I can say that Gumout has made a significant improvement in my 2020 GT N-line and that I will use it religiously henceforth, as I did with my previous 2 Fiesta STs.

Happy motoring!

-zed
P.S.
I'm 63 years old and my daddy taught me to drive at the age of 8 in his sky blue Ford Falcon station wagon (3-speed satellite-shift manual, 'three on the tree') on an abandoned section of The Old Galveston Highway. When I was 13, I taught my mom how to drive... So, I've been around the block a couple times.
 

·
Registered
Joined
·
29 Posts
Try one of these:

I got one before I figured out the car needed new plugs, coil-overs and Gumout (e.g., not the turbo's fault) and the tuner box really didn't do much with the car still in stock condition. Those easy upgrades improved the car so much I forgot to put it back on for a while. It's a 5-minute install, so I thought, why not try it again?

I did and now I'm completely fixed. Just absolutely trashing turboed lead sleds, trucks, SUVs... everything but motorcycles. Very sudden, hiccup free acceleration to over 100 MPH...

Closest I got to busting a knuckle was swapping out trash NGKs for Bosch iridiums. Closest I got to reprogramming my ECM was resetting code-trips with my phone via BT to OBDII. So simple, a girl could do it.

My car is now everything I hoped it might be when I bought it 4 mo/16K miles ago. Sometimes, less work is the more effective solution.

-zed
 

·
Registered
Joined
·
29 Posts
To those who might be interested in TDI's box, some notes:

  1. It ships from Chelmsford, England, UK (The World, The Solar System, The Universe). I got it within a week, shipped free via DHL.
  2. Follow instructions carefully. For the GT-NL, it's only two bypass connectors. You will want to remove your filter box to reach one of the connectors (10mm socket x 4 bolts).
  3. 50 mile burn-in (or 1 leg of trip to work for me). After that, it has 'learned' your ECM/turbo data and gains set in. If you get impatient and start switching program modes before that, you're only going to disappoint yourself. Show a little restraint and you will be rewarded.
  4. Reverse the install before taking it for service (another 5 minutes) to avoid stink-eye, at the minimum. After service, when you get back home, let the engine cool down and reinstall tuner box.
  5. It's so simple to do, I don't even have to read the little instruction sheet anymore, after having installed and de-installed twice for dealership service.

Just remember to swap plugs and boots for premium grade ones and run at least 1 bottle of Gumout ($1.44 at Walmart), or you won't really see much alleviation of hiccupping throttle and limp-mode.

With all that done properly, the little car even roars a bit now, so you can shift by pitch rather than eyeballing the tach. ...Just the way I like it!

I've said my piece and I'm out.
-zed
 

·
Registered
Joined
·
29 Posts
bigmoderness:

"...MSD coils and Bosch double iridium plugs...". I got mine from Summit Racing website. That has smoothed out my acceleration curve.

The tuning box makes the car quick, sudden... which I value above 'fast'.
 

·
Registered
Joined
·
29 Posts

It will run great until the electrode breaks off and toasts the engine.
Probably improperly installed -- as Bosch determined in the Hyundai Kona owners' forum thread, from which full posting the excerpted repost above comes -- or ill-advisedly over-gapped as previously discussed in this thread...

Searched 100's of reviews before posting this. Europeans (Germans, in particular) love them and have nothing bad to say about them. They are even using them in i30s. NOTE: Most are '0 reviews' or 'has not been reviewed'. Still, if they were defectively manufactured, I should've found something negative and detailed. I did not.

I do, however, invite others to share any findings they may have, beyond the 1 Kona driver with 1 failed and 3 bad plugs. I'm mildly concerned over even 1 bad report.

According to NGK's 'fit your vehicle' for a 2020 Elantra GT N Line (mine precisely), the NGK Laser Iridium Spark Plug 97080 is OEM compatible.
Website: https://www.ngk.com/ngk-97080-silzkr8e8g-laser-iridium-spark-plug (sells for $12.69 USD from NGK's website)

According to Bosch manufacturer's website's 'fit your vehicle' for my car, the Bosch Double Iridium Spark Plug YR6NI332S is certified as "
OE Replacement: meets or exceeds manufacturer design requirements for modern gasoline engines to provide OE fit, form and function."
Website: Double Iridium Spark Plugs | Bosch Auto Parts (sells for $11.99 USD each at Autozone, local or web)

Looks like stock reach is 26.4922mm (e.g., "26.5mm") or 1.043in. Both of these plugs are 26.5mm reach and have identical other physical dimensions. If they've been properly installed, either should perform admirably and provide a cost-effective improvement over stock plugs..

Let's not allow scare tactics to rule everything in our lives, okay?

-zed

P.S.
Mine runs like a beast, now, with the 3 changes I've made: MSD Ignition 826943 - MSD Blaster OEM Replacement Coils (c. $150 free-shipped from Summit), Bosch Double Iridium Spark Plugs (c.$50 locally), and 5-minute install/removal TDI turbo tuner with Bluetooth, cuz I like changing the map on-the-fly from my phone (c. $375 free-shipped) . Y'all be careful with your hit-or-miss tinkering...

P.P.S
Here's the TDI website again, for those who might have missed it (NB: It ain't just a 'chip' and for our GTs it only tunes the turbo, not fuel supply/mixture, and leaves no trace in diagnostic logs. It's straight up magic.)
 

·
Registered
Joined
·
29 Posts
The bosch are 2 heat ranges warmer than the OEM NGK and the plug clearly overheated. Do what you like im not risking it.
Pulled my plugs to inspect. Clean as a whistle. Don't know what y'all are doing wrong. You could always try the NGK Iridiums I listed above... or not, you know. Just stick with crappy stock NGKs and complain your car is balky and slower than it's got any right to be.
 

·
Registered
Joined
·
29 Posts
That's correct a warmer heat range plug will keep clean easier because it gets warmer faster but will also cause detonation if it gets too hot. Just because a plug is stock doesn't make it cheap.
...No, it's when a plug (or other part) degrades the vehicle's designed performance that it becomes cheap and worthless. That's what this thread is about: sub-standard performance from a superiorly designed automotive platform...

...And it's because of cheap-ass, sub-standard plugs and coil packs. Quick search on i30n OEM standard plugs reveals "NGK 97080 SILZKR8E8G Laser Iridium Spark Plug" heat range 8, as I listed above. The only time they go cooler is on remap.

You may be over-thinking this.
 

·
Registered
Joined
·
29 Posts
My NGK plugs look exactly like line 1, "Carbon fouled", in this image:
Product Orange Font Advertising Screenshot


NGK's fix, according to their chart, is to replace the "too cold a plug" with the correct (e.g. hotter) heat range. All the other charts I Googled for heat range show that "6,7" of the Bosch is actually the next hottest plug, not 2 hotter...

Rebuttals?

-zed
 

·
Registered
Joined
·
29 Posts
Final note:
Because I'm not unappreciative of the inputs of others, I changed the plugs back to stock NGK SILZKR8E8G plugs. With the MSD coils, TDI turbo tuner and Gumout, the car still performs as I had originally hoped, though perhaps not quite as spirited as with the Bosch plugs -- by a mere touch -- gauged by the seat of my pants only.

Happy motoring!

-zed
 

·
Registered
Joined
·
29 Posts
Midenginedriver:
Yeah, that "flat spot" kinda stays there... unless you go into the DCT's manual shift mode (pull the gear selector lever toward the driver's side) and then keep the revs above 4,500 RPM in a shift. You'll feel it kick really nicely around 5K, then upshift at 6k RPM (redline is 7K RPM, btw). That'll smooth that flat response out nicely, when you're trying to go really fast -- say, around all those unconscious slowpokes driving in herds and clogging up your freeway.

For the most part, though, I just stay in full-auto and punch it, after using the paddles to downshift a couple-three gears to get the revs up into the 4K's. With my setup, that takes care of most of the run-of-the-mill weenies. The fine-control manual method I reserve for on-ramps and muscle car drivers that don't understand the principle of inertia (big-bore, twin-turbo diesel pickup trucks are especially hilarious, cuz of all the engine-roar rapidly fading away into my six o'clock).

And yes, the little black square caps sitting 4 in a row atop the engine are the coil packs. I had all kinds of problems with misfires and limp-mode -- even when driving like an aged grandma -- until I replaced them with proper MSD (manufacturer) coil-overs from Summit Racing. You simply unscrew the retaining bolt on the old ones and then pull them out approximately 4 inches. To put new ones in, just reverse the process. Simple and effective.

The TDI turbo tuner, OTOH, has literally turned my 2020 GT N-Line into an I30 N. It's so fast, it can honestly be a little scary... but, I LIKE that.

Hope this helps.

-zed
 
1 - 18 of 18 Posts
Top