So why does the 3.8 coupe get 348 h.p.?

[Billbert]

I'm a brand new owner of the Genesis 3.8 with a long history of never being able to leave a good thing alone. While in the dealership this week, I'm reading the brochure on the coupe. It appears it shares the same engine as the sedan but packs substantially more horsepower. I'm guessing some of it is exhaust system but I'm hoping that there may be a bootleg engine management software upgrade that tweaks the sedan up bit.

Anybody know the differences between the two motors?

Sorry if this has already been flogged on the site. I haven't learned to use the search function yet.

 

[powerslide]

I couldn't tell you for sure, but the 1G 3.8 sedan was rated at 333 HP. The 2G was retuned for improved torque and mid band and that brought the max HP down to 311. I suspect the coupe is a much lighter vehicle and as a result can get by with less torque. This allows them to squeeze out a few additional HP at the expense of torque.

 

[GenesisCaptain]

It looks like they tuned the engine to delay the delivery of the torque a little to keep it from falling off as much at the higher RPM limit. In other words, they did tune the engine a little, but it was to just play tricks with the math. Check out the engine's rated output (from autos.msn):
Sedan = 311 @ 6,000 RPM and 293 @ 5,000 RPM
Coupe = 348 @ 6,400 RPM and 295 @ 5,100 RPM

Torque is just slightly higher and 100 RPM later. However, peak RPM comes 400 RPM later. Since HP is just a math formula that is a function of torque and RPM, one trick to raising HP is to just test at a higher RPM. (It is not quite this simple, but really, it is.)

HP = ( Torque * RPM ) / 5252

The sedan engine's torque falls off from its peak at 293 to 256 at 6,000 RPM.
The coup's engine torque dropped from 295 peak to 286 ft-lb at 6,400.

So, the trick is that they did something to keep the torque delivery a little flatter at the top end of the RPM range. It is more HP, but it is more phantom than real performance-changing improvements.

My guess is that you do not want this "improvement." It is only for show to attract potential Coupe buyers. The sedan probably delivers more torque at lower RPM, and that translates to better acceleration and real-life performance.

 

[Billbert]

Nice analysis, Captain. You doug a little deeper than I did. I'd still guess the deltas are due to exhaust systems and a little engine management (injection, ignition timing) rather than say, different cams.

Guess I'll wait for the turbo motor. My lease is up in 35 months and it should be well sorted by then.

Billbert

 

[carlosfernandez]

It looks like they tuned the engine to delay the delivery of the torque a little to keep it from falling off as much at the higher RPM limit. In other words, they did tune the engine a little, but it was to just play tricks with the math. Check out the engine's rated output (from autos.msn):
Sedan = 311 @ 6,000 RPM and 293 @ 5,000 RPM
Coupe = 348 @ 6,400 RPM and 295 @ 5,100 RPM

Torque is just slightly higher and 100 RPM later. However, peak RPM comes 400 RPM later. Since HP is just a math formula that is a function of torque and RPM, one trick to raising HP is to just test at a higher RPM. (It is not quite this simple, but really, it is.)

HP = ( Torque * RPM ) / 5252

The sedan engine's torque falls off from its peak at 293 to 256 at 6,000 RPM.
The coup's engine torque dropped from 295 peak to 286 ft-lb at 6,400.

So, the trick is that they did something to keep the torque delivery a little flatter at the top end of the RPM range. It is more HP, but it is more phantom than real performance-changing improvements.

My guess is that you do not want this "improvement." It is only for show to attract potential Coupe buyers. The sedan probably delivers more torque at lower RPM, and that translates to better acceleration and real-life performance.

Excellent explication !!!

 

[15GenesisAWD]

It looks like they tuned the engine to delay the delivery of the torque a little to keep it from falling off as much at the higher RPM limit. In other words, they did tune the engine a little, but it was to just play tricks with the math. Check out the engine's rated output (from autos.msn):
Sedan = 311 @ 6,000 RPM and 293 @ 5,000 RPM
Coupe = 348 @ 6,400 RPM and 295 @ 5,100 RPM

Torque is just slightly higher and 100 RPM later. However, peak RPM comes 400 RPM later. Since HP is just a math formula that is a function of torque and RPM, one trick to raising HP is to just test at a higher RPM. (It is not quite this simple, but really, it is.)

HP = ( Torque * RPM ) / 5252

The sedan engine's torque falls off from its peak at 293 to 256 at 6,000 RPM.
The coup's engine torque dropped from 295 peak to 286 ft-lb at 6,400.

So, the trick is that they did something to keep the torque delivery a little flatter at the top end of the RPM range. It is more HP, but it is more phantom than real performance-changing improvements.

My guess is that you do not want this "improvement." It is only for show to attract potential Coupe buyers. The sedan probably delivers more torque at lower RPM, and that translates to better acceleration and real-life performance.

Did you actually look at their power graphs?
Isn't it possible that,

Sedan = 311 @ 6,000 RPM and 293 @ 5,000 RPM
Coupe = 348 @ 6,400 RPM and 295 @ 5,100 RPM

Coupe could be delivering around 311@ 6000 rpm and 293 @ 5000 rpm?
But it has mods or software upgrade to keep breathing harder at higher RPM to produce even more power at top?

Isn't it possible Hyundai offering 10 yrs power train warranty has something to do with it? Lessen the power on global market car to be safer? Just saying.

 

[GenesisCaptain]

Coupe could be delivering around 311@ 6000 rpm and 293 @ 5000 rpm? But it has mods or software upgrade to keep breathing harder at higher RPM to produce even more power at top?

It is possible that the Coupe engine could be producing 311 HP at 6,000 RPM, but it is unlikely. It is more likely producing 330 HP at 6,000 RPM.

I have not found a current HP/torque chart for the new Coupe engine. However, torque curves tend to be somewhat linear with respect to RPM. Therefore, if the torque at 5,100 RPM is 295 and the torque at 6,400 is 286, the it is likely that the torque at 6,000 RPM is 289 (using simple linear regression). So, that means that the HP at 6,000 with a torque of 289 is 330 HP.

If the HP was 311 at 6,000 RPM, then the torque would have to be 272 ft-lb. The torque probably does not dip down from 295 to 272 and then back up to 286.

 

[amartz]

It is possible that the Coupe engine could be producing 311 HP at 6,000 RPM, but it is unlikely. It is more likely producing 330 HP at 6,000 RPM.

Since my motor is supposed to be rated at 333hp, that sounds about right.
Art