Why the V8 is not that much faster than the V6

[Lonny 53]

A lot of people who have driven both the V6 and the V8 were quick to point out that the V8 is not really that much quicker. And Hyundai themselves said that it is only a 1/2 second quicker. If you look at the spec sheet, you will find the answer: the final drive ratio for the V6 is 3.909:1 and for the V8 it is 3.133:1. That, coupled with the extra "heft" in the V8 probably explains why the V8 is not quicker. My M45 had a 335 hp engine and consistently hit 60 in the mid five second range. One would expect a 375 hp sedan to hit 60 in less than 5.2 seconds. I am sure that the higher gearing Hyundai chose as a compromise between being quicker and getting better mileage.

 

[GenesisBlog]

A lot of people who have driven both the V6 and the V8 were quick to point out that the V8 is not really that much quicker. And Hyundai themselves said that it is only a 1/2 second quicker. If you look at the spec sheet, you will find the answer: the final drive ratio for the V6 is 3.909:1 and for the V8 it is 3.133:1. That, coupled with the extra "heft" in the V8 probably explains why the V8 is not quicker. My M45 had a 335 hp engine and consistently hit 60 in the mid five second range. One would expect a 375 hp sedan to hit 60 in less than 5.2 seconds. I am sure that the higher gearing Hyundai chose as a compromise between being quicker and getting better mileage.

Uhhhh... there is a VAST difference between 6.3 and 5.5 seconds.... If you look at the Boxter race which was a much thinner margin, it was car lengthS. A street or drag strip race is won in hundreds of second. You either win or you don't. But a street race with this much margin is a true-in-the-blue ass whoopin'.

There is also much more room to get faster in the V8 than the 6 if one wished to. Most likely there will be a 5.0 motor in the production car, not the 4.6, either from the first shipments to possibly the second shipments.

An air filter and cat-back on this 8 will produce much more of a result than if one did so on this 6. By a 6 I am not referring to turbo or super charged, nor direct injection motors, which ar a whole different ball game.

But a race of 6.3 and 5.5 means that a terrible driver could confidently race for pink slips against a great driver in the 6. Period.
Link to Tested time: http://www.motortrend.com/roadtests/sedans/112_0810_2009_hyundai_genesis_first_test/full_specs_chart.html

 

[GenesisBlog]

By the way, MT's observed 22.1 mpg is pretty damned excellent in my book.

You can bet your lunch that these guys were not gentle in their driving either.

 

[GenesisBlog]

Not to trash you further bud, but I re-read your other comment about you're 335hp M motor.

My 07' 335i sedan Step (not the stick) consistently got 4.9 seconds with a "mere" 300hp. By you're math I shouldn't get better than 5.9 0-60.

The Step automatic has already established times totally stock with stock tires of 4.8 and 4.9, in time or beating the stick versions.

Math doesn't always pan out as one thinks it should.

 

[Duaine]

I guess if Hyundai doesn't ever get the V-8's to us the world may never know!!!

 

[jwaters943]

Uhhhh... there is a VAST difference between 6.3 and 5.5 seconds.... If you look at the Boxter race which was a much thinner margin, it was car lengthS. A street or drag strip race is won in hundreds of second. You either win or you don't. But a street race with this much margin is a true-in-the-blue ass whoopin'.

There is also much more room to get faster in the V8 than the 6 if one wished to. Most likely there will be a 5.0 motor in the production car, not the 4.6, either from the first shipments to possibly the second shipments.

An air filter and cat-back on this 8 will produce much more of a result than if one did so on this 6. By a 6 I am not referring to turbo or super charged, nor direct injection motors, which ar a whole different ball game.

But a race of 6.3 and 5.5 means that a terrible driver could confidently race for pink slips against a great driver in the 6. Period.
Link to Tested time: http://www.motortrend.com/roadtests/sedans/112_0810_2009_hyundai_genesis_first_test/full_specs_chart.html

To be fair, very few testers have managed 5.5 seconds 0-60 w/ the V8 Genesis. Edmunds managed 5.9, Car & Driver got 6.0, and Automobile Mag got 6.3.

 

[Jerrad]

I wonder how much of the difference in 0-60 times from all these magazine articles might have something to do with the time they have had the car before testing them. I wonder if they are driving them hard for several hundred miles (stop and go with full throttle) to let the computer learn your driving habits and adjust for better response time.

Coming from a person that likes speed and drives a car (SRT-4) that is gear limited to very fast speeds (160+ tested on the Autobahn by SRT owners stationed overseas), I am choosing the V8 over the V6 not only for the 0-60 but also for the top end speed. I would have been keener to the V6 if it had not been limited to 130.

To me, there is nothing more annoying then playfully testing your speed against another car and your speed limiter shutting down your car at a certain speed while the other car inches by you .

I need to mentally know I can hang with the big boys that this car was intended to compete with in top end speed as well as quality (whether or not I intend to take the car to that speed). Since most of the cars that the Genesis was compared to can exceed the 130 MPH mark I only wished the Genesis V6 would have not be limited or I may have considered the V6 over the V8.

If I were not into 0-60 or top speed the V6 by all means is the best bang for the buck of these two cars. But since I still have that “Need for Speed” in my daily routine the V8 would be my choice as best value overall for Top Speed & 0-60 over the V6.

People say a half second is not that much but in the game of racing a loss is a loss whether it is by 1/100th of a second or 3 seconds.

This is my opinion and reflects my thoughts, experiences, and my driving habits.

 

[John M]

Speed limiters are usually decided by what tires the manufacturer decides to equip the car with. If H-rated 130 mph tires save them money over Z-rated tires, that's what they'll put on the car. They'll limit the car to that speed to avoid lawsuits. Around 1993-1994, the Firebird was available with the LT1 and wimpy tires, limiting it to ~ 115 mph on cars without the "performance" package that allowed 150+. The speedometer in those cars even stopped at that speed.

Has anybody looked at the driveshaft to see if it is one piece or two? A single shaft can have resonance issues that also dictate the top speed of the car. For example, most Crown Vic's have a driveshaft that'll self-destruct somewhere around 130 mph. Two-piece shafts move that problem well past speeds most people will ever experience. Hyundai allows the Sonata and Azera to reach past 145 mph so maybe it's a physical limitation.

And finally, 0-60 times are very driver dependent. The balance of launch vs. wheelspin will make or break the results. The testing surface and even tire pressure can make a few tenths difference either way. Some magazines are willing to powerbrake while others just nail the throttle from idle.

 

[Michael_S]

Not to trash you further bud, but I re-read your other comment about you're 335hp M motor.

My 07' 335i sedan Step (not the stick) consistently got 4.9 seconds with a "mere" 300hp. By you're math I shouldn't get better than 5.9 0-60.

The Step automatic has already established times totally stock with stock tires of 4.8 and 4.9, in time or beating the stick versions.

Math doesn't always pan out as one thinks it should.

Your 335i is 400 pounds lighter than the Genesis and uses twin turbochargers to get the full 300 foot pound of torque on tap at 1500 RPMs (or, if my math is right, about 7 mph). V8s make good torque at low RPMs, but I doubt the Genesis V8 or most of its competitors can match 300 pound feet at 1500 RPMs. Does anyone have a dynometer graph on the Genesis engine?

I would have been keener to the V6 if it had not been limited to 130.

To me, there is nothing more annoying then playfully testing your speed against another car and your speed limiter shutting down your car at a certain speed while the other car inches by you .

Jerrad, 130 mph is 191 feet per second.

If you and a competitor were driving that fast on a public road, the both of you are idiots.

If someone who doesn't realize how fast you are moving pulls out into traffic in front of you or changes lanes, you will travel 70 feet before your foot even starts to lay off the gas and your hands start to turn the wheel. You will run into their car with more force than driving off the side of a five story building.

If a deer jumps out in front of you, it will hit your car harder than if someone fired it out of a cannon.

There's a damn good reason street racing is illegal. I don't care if you have reflexes like Superman, you cannot possibly drive safely on public roads at that speeds.

Grow up. Rent time at a track.

[EDIT] In the post below Jerrad clarifies that he doesn't street race. My angry statements were misplaced, and I apologize.

 

[Jerrad]

I would never go that fast if there was traffic on the highway, and I do not go that fast on public streets.

I do race my car at a track here in San Diego when they have a setup on weekends that allows people to race 1/4 mile provided you have a helmet.

When I was traveling at those speeds I do so on open highway usually on the way to Vegas where the nearest town is hours away and if I happen to see a car off in the distance I slow down way before I get to that car.

Even though there is no such thing as being safe while driving fast I try to be as safe as possible and not when other vehicles are around when I go to Vegas or when the track is open.

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[GenesisBlog]

To be fair, very few testers have managed 5.5 seconds 0-60 w/ the V8 Genesis. Edmunds managed 5.9, Car & Driver got 6.0, and Automobile Mag got 6.3.

Very few testers? Motortrend's numbers are considered the most accurate in the industry. The plain fact is if one or two testers get 5.5, than that car is capable of doing 5.5.

I have looked over and over on Automobile Mags site and cannot find any reference to 0-60 except what they reference as Hyundai's proposed specs.

Edmunds? Who listens to Edmunds for performance specs? This is an internt magazine akin to Consumer Reports. While they do commendable tests, no one looks to them for performance specs or track shoot-outs.

Autoblog also got 5.7 http://www.autoblog.com/2008/06/27/first-drive-2009-hyundai-genesis/

Here is the Proof on a second platter. A car either can or can't do 5.5 - 5.6. Its not a grey area.
[ame="http://www.youtube.com/watch?v=oHcBJe13rb8"]http://www.youtube.com/watch?v=oHcBJe13rb8[/ame]

 

[Michael_S]

I would never go that fast if there was traffic on the highway, and I do not go that fast on public streets.

I do race my car at a track here in San Diego when they have a setup on weekends that allows people to race 1/4 mile provided you have a helmet.

When I was traveling at those speeds I do so on open highway usually on the way to Vegas where the nearest town is hours away and if I happen to see a car off in the distance I slow down way before I get to that car.

Even though there is no such thing as being safe while driving fast I try to be as safe as possible and not when other vehicles are around when I go to Vegas or when the track is open.

I withdraw my criticism then.

I apologize for jumping all over you. On other forums, I read about young guys bragging about how fast they drive, and it drives me crazy. People get killed.

 

[YEH]

Keep in mind that Lexus reported the SAME 0-60 time of 5.7 seconds for the GS 430 and the GS350.

The 2008 GS460 w/ an 8 speed tranny does it in 5.4 seconds, not much quicker than the V-6 GS.

 

[Michael_S]

YEH,
On the other hand, the GS460 is 3950 pounds and rated for 342 peak horsepower.

So going by power-to-weight ratio, the GS460 should be slower than the Genesis and not the other way around.

 

[YEH]

MS - my post was to just illustrate that there often isn't much difference (about half a second) btwn the V6 and V8 versions of the same model.

As for a comparison btwn the Genesis and the GS - I'll bet the Genesis would be just as fast (if not faster) if Hyundai retuned it where fuel economy wasn't such a big consideration and included a 8-speed tranny.

 

[YEH]

MS - my post was to just illustrate that there often isn't much difference (about half a second) btwn the V6 and V8 versions of the same model.

As for a comparison btwn the Genesis and the GS - I'll bet the Genesis would be just as fast (if not faster) if Hyundai retuned it whereby fuel economy wasn't such a big consideration and included a 8-speed tranny.

 

[Michael_S]

MS - my post was to just illustrate that there often isn't much difference (about half a second) btwn the V6 and V8 versions of the same model.

As for a comparison btwn the Genesis and the GS - I'll bet the Genesis would be just as fast (if not faster) if Hyundai retuned it whereby fuel economy wasn't such a big consideration and included a 8-speed tranny.

You're right.

I'm certainly no expert on this kind of thing. I remember reading a long discussion between some guys who seemed (?) to know what they were talking about, and they were saying that with a manual transmission car and a driver that doesn't give a hoot about wearing out the transmission in a hurry, horsepower-to-weight is all that matters. The driver can simply rev the car up to peak horsepower at a dead stop with the car in neutral, shift into gear, and dump the clutch ( known as a clutch drop ) to start moving. I've never seen it done. If you do that, gearing is almost irrelevant because you're starting with 100% of maximum power.

That's how a car like the Mazda RX-8 with 232 peak horsepower and extremely poor low-end torque can manage a 6.2 second 0-60 mph time. The driver spins the engine to 8500 RPMs and then dumps the clutch. From a rolling start, when it's impossible to do that, the RX-8 is dog slow.

Since you can't do something like a clutch drop with an automatic transmission, gearing matters.

So, if I understood the discussion accurately and if I'm describing it accurately, that's why the Genesis has a fast but not brutally fast 0-60 mph but may still make the official listed 375 horsepower.

 

[gentau]

You're right.

I'm certainly no expert on this kind of thing. I remember reading a long discussion between some guys who seemed (?) to know what they were talking about, and they were saying that with a manual transmission car and a driver that doesn't give a hoot about wearing out the transmission in a hurry, horsepower-to-weight is all that matters. The driver can simply rev the car up to peak horsepower at a dead stop with the car in neutral, shift into gear, and dump the clutch ( known as a clutch drop ) to start moving. I've never seen it done. If you do that, gearing is almost irrelevant because you're starting with 100% of maximum power.

That's how a car like the Mazda RX-8 with 232 peak horsepower and extremely poor low-end torque can manage a 6.2 second 0-60 mph time. The driver spins the engine to 8500 RPMs and then dumps the clutch. From a rolling start, when it's impossible to do that, the RX-8 is dog slow.

Since you can't do something like a clutch drop with an automatic transmission, gearing matters.

So, if I understood the discussion accurately and if I'm describing it accurately, that's why the Genesis has a fast but not brutally fast 0-60 mph but may still make the official listed 375 horsepower.

If only it were that simple things would be much easier in this drag racing world in which I live. In the real world, the laws of physics make that scenario very unlikely. First of all, the driven wheels are likely to go up in smoke. Wheel spin, while impressive to some, is something that drag racers spend a great deal of money to prevent. Assuming that the track is properly prepared and you have sticky tires, the next thing that can be over-powered is the clutch. Neither wheel spin nor a slipping clutch are conducive to faster acceleration times.

Now, let's assume that, after a significant cash outlay, we have tires that will grip and a clutch that will hold without slipping. If the car doesn't make enough power to overcome the forces of inertia to get the car moving, the engine will fall flat on it's face (bogging); and the car will stumble away from the line. Again, a condition that isn't conducive to lower acceleration times.

Finally, in a worst case scenario, there is the very real possibility that the sudden shock of dropping the clutch can twist a drive shaft and/or shear the teeth off the ring gear in the rear end. Interestingly, when this happens, the car tends not to accelerate at all.

I have been involved in the drag racing game since the early fifties; and I cannot think of any instance where a full throttle clutch drop was used successfully. Launching a car from a dead stop is a delicate art. Ideally, the driver must apply as much power as possible while still staying within physical limitations to avoid loss of traction or parts breakage.

Serious drag racers of street cars have grudgingly come to recognize that a well prepared automatic transmission car will usually win out over a manual transmission car. Notice that I limited this statement to drag racing. The statement is, obviously, not true for other types of racing. It's all about having the right tool for a specific job.

Oh, just for the record...it is also possible to overpower the rear wheels with an automatic transmission. See my avatar for proof.

 

[John M]

I'd love to see a v8 Genesis with a higher stall torque converter and stickier tires. It'd probably lop off almost a full second off its 1/4 mile times. In these days of computer nannies it's harder to do that than before; if you try it on a Lexus it'll trigger a CEL for excessive trans slippage.

It is true that cars like the RX8, or even worse, the Honda S2000, require high rpm launches for any useful acceleration. Testers reported a 0-60 time of over 10 seconds when the S2000 is launched anywhere below 6k rpm - redline is 9k though.

I've been launching turbo AWD cars for over 15 years. A quick slip from 4500 rpm, not a dump, and you'll nail a perfect launch. Too much and you'll fry the clutch or snap an axle. Too little and it'll bog. The #1 truth in drag racing is that for whatever you improve (traction, tires, clutch, axles), the next weakest item in the chain will be what breaks.

My last car weighed 4050lbs with me in it and with bolt-ons ran 12.5 @ 109 - yay for the v6 (with the stock pair of turbos). My current Subaru sedan is under the knife right now and will end up with over 400 hp to the wheels on 93 octane. There's no such thing as too much power

 

[Jerrad]

There's no such thing as too much power

I agree with you!