V-6 engines begin long fade into history

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TehMac

Diamond Member
Aug 18, 2006
9,976
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I think this thread title should be renamed: V10s and V12s are on their way out.

V8s are nice because turbocharged they can render the same gains as V10s and even V12 engines. V6s are nice because turbocharged they can render the same gains as V8s. And so forth.

I'm just looking for the day when i4s can produce as much hp and torque as a V8 engine. Then we will know we have reached driving nirvana--oh wait, the STi has a turbo i4 engine.

hrmm...
 

DivideBYZero

Lifer
May 18, 2001
24,117
2
0
I think this thread title should be renamed: V10s and V12s are on their way out.

V8s are nice because turbocharged they can render the same gains as V10s and even V12 engines. V6s are nice because turbocharged they can render the same gains as V8s. And so forth.

I'm just looking for the day when i4s can produce as much hp and torque as a V8 engine. Then we will know we have reached driving nirvana--oh wait, the STi has a turbo i4 engine.

hrmm...

*cough* H4 *cough*
():)
 

DietDrThunder

Platinum Member
Apr 6, 2001
2,262
326
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I've driven in Texas (Houston & Austin area, my company is based there) & Florida and took a trip from Miami to Orlando by car. I could have done it all in the 2006 Renault Clio 1.4ltr i4 we used to have.

I've driven from Istanbul to Antalya along the Turkish west coast. I've driven from the south coast of England to Glasgow. I'm quite well aware what long distance driving is. I find Americans often think that Europe is just a collection of twee little villages connected by dirt tracks and cute little Inns. This is the modern reality:

m6_m6_toll.jpg


If you want to drive 1800 miles, good for you, but in reality you would be better off flying. You'd only drive it non-stop as a test or because you hated yourself. Doing 75Mph in an i4 is no big deal, trust me, I've done it most of my life, 23 hours or otherwise.

And finally, the speeds are higher in Europe and your link bears that out, that's all I'm saying. Some were inferring that we all run around in i4's doing 42Mph "because that's all an i4 can do". Which is an incorrect assumption.

The i4 is a fine configuration. The issue is in the public's head. For example, the 3800 engine used in the Impala. I had a rental Impala with this motor. It produced 180Hp and a similar amount of torque( cannot find a number, so I'm assuming no more than 200lb/ft) and could barely pull skin off milk, let alone move the barge it had been shoe-horned into. Fast forward to our i4 Diesel and that has 180Hp and 260ft/lb torque. Far outstripping a V6 in performance with respect to its cylinder capacity, 1995cc vs 3800cc, yet producing the same amount of power and vastly more torque. So, in this case, which is better? The V6 or i4?

I never said you couldn't drive it in an I4. In my earlier posts I agreed with you that for the majority of people, an I4 is good enough. I can also one up you on your I4 driving in houston/austin. This is my daily driver that I use for my commute in D/FW traffic (75 to 80mph).

IMG_1256.jpg

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2.7 liter 102hp air cooled six banger :D

As far as flying vs. driving, I fly for business and drive for leasure/vacation. I've always felt you miss seeing so much of our beautiful country by flying.

As the song goes: "See the USA, in your Chevrolet, America is asking you call. Drive the USA, in your Chevrolet, America is the greatest land of all. So take a break today, and see the USA, and see it in your Chevrolet!" Or whatever else you want to drive. ;)
 

DietDrThunder

Platinum Member
Apr 6, 2001
2,262
326
126
But..BUT IT'S A SIX!!!!
The Clio had 102hp, too, but out of 1.4 litres! ;)

Not apples to apples. The Clio is mid to late 1980's technology, the Chevrolet is 1958 development, and 1960's production, with optional 150 hp factory turbo, 140 hp 4 carb, and in 1965 180 hp factory turbo.

corsa_turbo2.jpg


Corsa_turbo.jpg


fourcarb.jpg
 
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TehMac

Diamond Member
Aug 18, 2006
9,976
3
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It'd be awesome to take a Corvair and perform a restomod on it.

I'm fairly certain if you took a flat six blueprint, forged it and bored it out and then bi turbo'd it, it be a pretty awesome machine.
 

DietDrThunder

Platinum Member
Apr 6, 2001
2,262
326
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It'd be awesome to take a Corvair and perform a restomod on it.

I'm fairly certain if you took a flat six blueprint, forged it and bored it out and then bi turbo'd it, it be a pretty awesome machine.

We've got guys in our club that have bumped them up to 3.6 liter, and with turbo charging 300hp on the dyno. HP = $$$
 

TehMac

Diamond Member
Aug 18, 2006
9,976
3
71
We've got guys in our club that have bumped them up to 3.6 liter, and with turbo charging 300hp on the dyno. HP = $$$

Yes...yes it does cost money, I know :(


That's all they're able to get out of it...300? Is that rwhp?
 

DietDrThunder

Platinum Member
Apr 6, 2001
2,262
326
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Yes, rwhp. Which is pretty good considering the vehicle weighs 2200 lbs. They could push it more, but you have to remember that these are air cooled engines, and turbo charging produces a lot of heat. If you want more than 300, you'll have to do water jacketing of the cylinders, or massive oil cooling like Porsche (I believe 16 quarts of oil in the Porsche oil cooling system). I've seen 250 hp out of air cooled 4 cylinder VW engines, but there is a larger after market for VW's vs. Corvairs, so more R&D.
 

DivideBYZero

Lifer
May 18, 2001
24,117
2
0
Not apples to apples. The Clio is mid to late 1980's technology, the Chevrolet is 1958 development, and 1960's production, with optional 150 hp factory turbo, 140 hp 4 carb, and in 1965 180 hp factory turbo.

I know, I was using it to show how I4 technology has moved on, and ours was a 2006 model that is sold today, so a little more up to date than 1980's. That and it also comes in a 200hp normally aspirated version (also I4)!
 

TehMac

Diamond Member
Aug 18, 2006
9,976
3
71
Yes, rwhp. Which is pretty good considering the vehicle weighs 2200 lbs. They could push it more, but you have to remember that these are air cooled engines, and turbo charging produces a lot of heat. If you want more than 300, you'll have to do water jacketing of the cylinders, or massive oil cooling like Porsche (I believe 16 quarts of oil in the Porsche oil cooling system). I've seen 250 hp out of air cooled 4 cylinder VW engines, but there is a larger after market for VW's vs. Corvairs, so more R&D.

300 rwhp is plenty for a car that weighs 2200 lbs. Thats very impressive. Assuming an 11% loss in power if he's using a modern transmission, he's producing around 340 bhp. Which is impressive.

What are 0-60 times?
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
44
91
massive oil cooling like Porsche (I believe 16 quarts of oil in the Porsche oil cooling system).

Close. 12.1 quart system capacity with a typical oil change cycling about 9.5 quarts for the non-turbo cars. I could imagine modified 911 Turbos having enough extra plumbing to bring them to around 16 quarts though.

ZV
 

exdeath

Lifer
Jan 29, 2004
13,679
10
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I think this thread title should be renamed: V10s and V12s are on their way out.

V8s are nice because turbocharged they can render the same gains as V10s and even V12 engines. V6s are nice because turbocharged they can render the same gains as V8s. And so forth.

I'm just looking for the day when i4s can produce as much hp and torque as a V8 engine. Then we will know we have reached driving nirvana--oh wait, the STi has a turbo i4 engine.

hrmm...

V12s are used for their smoothness when an engine with more displacement than is practical in a I6 is called for. Not because of power. They aren't typically any more powerful or larger displacement than a V8 from the same manufacturer.

And I4s will never produce as much HP and torque as a V8, unless there is a 10+ year discrepancy between the two. A 4 cyl in 2010 will have the torque and power of a V8 from 1990 sure, but not a V8 also from 2010. The technology used to make a powerful 4 cyl doesn't magically only work on a 4 cyl and hit a brick wall on everything else; that same technology is applied across the board, and the relative differences between a small and large engine of the same era remain pretty much constant.

If you think engines like EcoBoost are impressive, just imagine a EcoBoost twin turbo 5.0L V8.
 
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TehMac

Diamond Member
Aug 18, 2006
9,976
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And I4s will never produce as much HP and torque as a V8, unless there is a 10+ year discrepancy between the two. A 4 cyl in 2010 will have the torque and power of a V8 from 1990 sure, but not a V8 also from 2010. The technology used to make a powerful 4 cyl doesn't magically only work on a 4 cyl and hit a brick wall on everything else; that same technology is applied across the board, and the relative differences between a small and large engine of the same era remain pretty much constant.

No no I agree with you, I meant like, a 4 cyl getting say BMW 4.0L performance with say 27 mpg.

I doubt we'll see that for a while.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
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No no I agree with you, I meant like, a 4 cyl getting say BMW 4.0L performance with say 27 mpg.

I doubt we'll see that for a while.

If ever. Power still requires energy regardless how many cylinders you have. An STI gets what 19 mpg? Same or worse than a Mustang GT V8 making the same numbers.

Look at the fuel economy of some of the higher performance I4s. They are often no better than a V6 or V8 of similar power levels. An I4 with a fast spooling turbo and the torque and power of a V8 is going to have the fuel economy of a V8. Slightly better if it doesn't have a broad flat torque curve and the low end of the RPM is optimized for fuel economy and your power is focused in only 20% of the power band provided you stay in that 80% below it (most won't, and will still think they are getting 45 mpg).

When people talk about turbo I4's being adequate to replace a V8, they want big flat torque curves. But the whole "two engines in one" concept employing things like large turbos or VTEC to give fuel economy when cruising and only deliver power up top when you need it is the exact opposite. The mileage on the SHO for example is pretty poor; 18/22 or something like that, no better than a 390 HP supercharged DOHC V8. Sure it has the power of a V8, but it certainly doesn't have the thirst of a V6 as the commercial claims.

The laws of physics surrounding energy and power are clear cut. Can't have your cake and eat it too.

Those who think they can have 400 HP and still get 35 mpg because it's a 4 cyl are misguided or deceived, it doesn't work like that. 400 HP still requires 400 HP worth of fuel, and it doesn't matter if it comes from a 2 cyl or a V16. The 1-2 MPG improvement you might see from 200 lbs less weight or less internal friction is negligible in the grand scheme of things, and serves little more than an excuse for greenies to pat themselves on the back for doing nothing (eg: the out of sight out of mind hybrid car mentality).

Also again, see what I said about about engines from the same era. A 4cyl in 2010 might have more power and better mileage than a V8 from 1990, but then, so will a V8 also made in 2010. Conversely the V8 from 2010 would get better mileage than a 4 cyl with half the power from 1990. Technology is a double edged sword, thus nothing really ever changes relatively.
 
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secretanchitman

Diamond Member
Apr 11, 2001
9,352
23
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turbo I-6's are where its at (335i)! :p

i agree that SOME V6's are going away but not all of them. i would give it few years before we really start to see them disappearing.
 

Fenixgoon

Lifer
Jun 30, 2003
33,291
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turbo I-6's are where its at (335i)! :p

i agree that SOME V6's are going away but not all of them. i would give it few years before we really start to see them disappearing.

Audi's supercharged V6 in the S4 makes the 335i's turbo I6 look silly :p

the new S4 is almost as quick as the old RS4!
 

secretanchitman

Diamond Member
Apr 11, 2001
9,352
23
91
Audi's supercharged V6 in the S4 makes the 335i's turbo I6 look silly :p

the new S4 is almost as quick as the old RS4!

true that! totally agreed. what do you think of the 335is/z4 sdrive35is? i think they just released it has a mid-cycle refresh to compete with the S4. :)
 

DivideBYZero

Lifer
May 18, 2001
24,117
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Audi's supercharged V6 in the S4 makes the 335i's turbo I6 look silly :p

the new S4 is almost as quick as the old RS4!

It has ~30hp more, not exactly making the tt I6 look 'silly' as the 335i is a regular model, whereas the S series is the halo model. Not only that, but bumping the 35 motor to 330hp is not only possible with the current production motor, but would be simple for BMW to produce. They don't simply by the virtue that it would cannibalise M3 sales.

In regard to Exdeath's comments about i4s and big turbos, you are right, to a degree. The benefit of a V8 or any car that produces big power is that it is there when you want it. You don't spend 90% of your time in these cars with you foot in it so deep that your are producing peak power. A turbo will only produce extra puff, and therefore use more fuel, when you ask for it. e.g., 3.5l 300hp V6 running at 2500 RPM on the highway at a constant speed will use more fuel than an 2.0l 300hp i4 at 2500 RPM doing the same. When you drop the hammer on both, they use similar amounts of fuel, but the average usage over time will be lower on the i4, unless you drive like a hooligan every time you get in the car.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
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A turbo will only produce extra puff, and therefore use more fuel, when you ask for it. e.g., 3.5l 300hp V6 running at 2500 RPM on the highway at a constant speed will use more fuel than an 2.0l 300hp i4 at 2500 RPM doing the same. When you drop the hammer on both, they use similar amounts of fuel, but the average usage over time will be lower on the i4, unless you drive like a hooligan every time you get in the car.

It's not that simple.

To move a car at about 65 mph on a flat surface takes ~25 hp. That's it. So no matter what RPM the engine is at or what configuration it's in, if you're cruising at 65 mph and maintaining a constant speed, the engine is producing ~25 hp. The power requirement is constant and while a turbo I4 does enjoy a slight efficiency advantage over a V8, it's not a very large one and it still takes roughly the same amount of fuel to produce that 25 hp regardless of the engine configuration.

Now, where both a turbo I4 and a V8 have an advantage is that their wide torque curves allow a tall top gear and therefore can cruise in a low RPM, large throttle opening condition which is more efficient than the high RPM, small throttle opening condition necessitated by engines with less low-end torque.

ZV
 

PricklyPete

Lifer
Sep 17, 2002
14,582
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It has ~30hp more, not exactly making the tt I6 look 'silly' as the 335i is a regular model, whereas the S series is the halo model. Not only that, but bumping the 35 motor to 330hp is not only possible with the current production motor, but would be simple for BMW to produce. They don't simply by the virtue that it would cannibalise M3 sales.

BMW is coming out with a "sports" model that bumps the horsepower up accordingly for some extra cheddar...so you are correct.

I wouldn't say the S4 is the "halo" car that it used to be...at least it is not marketed here in the USA that way anymore. It is priced much closer to the regular 335i. The way Audi is marketing the cars in the US seems to be:

328i/328xi -> A4
335i/335xi -> S4
M3 -> Upcoming RS4

Looking at price and performance here in the states...this just makes sense. The "S" moniker for the "4" series car in the US is not the pinnacle that it used to be...that is now reserved for "RS"...and that is what matches up with the M3 (in price and performance).
 

DivideBYZero

Lifer
May 18, 2001
24,117
2
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BMW is coming out with a "sports" model that bumps the horsepower up accordingly for some extra cheddar...so you are correct.

I wouldn't say the S4 is the "halo" car that it used to be...at least it is not marketed here in the USA that way anymore. It is priced much closer to the regular 335i. The way Audi is marketing the cars in the US seems to be:

328i/328xi -> A4
335i/335xi -> S4
M3 -> Upcoming RS4

Looking at price and performance here in the states...this just makes sense. The "S" moniker for the "4" series car in the US is not the pinnacle that it used to be...that is now reserved for "RS"...and that is what matches up with the M3 (in price and performance).

Yes, in fact I had some marketing fluff in the mail the other day regarding BMW Performance pack for the 35i motor on the 1 and 3 series, bumping it up to just shy of 320Hp IIRC. Also, the F01 has a few more ponies and a different torque output in its version of the 35i motor. This engine will be quite important in future models, I think.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
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It has ~30hp more, not exactly making the tt I6 look 'silly' as the 335i is a regular model, whereas the S series is the halo model. Not only that, but bumping the 35 motor to 330hp is not only possible with the current production motor, but would be simple for BMW to produce. They don't simply by the virtue that it would cannibalise M3 sales.

In regard to Exdeath's comments about i4s and big turbos, you are right, to a degree. The benefit of a V8 or any car that produces big power is that it is there when you want it. You don't spend 90% of your time in these cars with you foot in it so deep that your are producing peak power. A turbo will only produce extra puff, and therefore use more fuel, when you ask for it. e.g., 3.5l 300hp V6 running at 2500 RPM on the highway at a constant speed will use more fuel than an 2.0l 300hp i4 at 2500 RPM doing the same. When you drop the hammer on both, they use similar amounts of fuel, but the average usage over time will be lower on the i4, unless you drive like a hooligan every time you get in the car.

My point was that a turbo I4 with a good flat torque curve and instant throttle response is going to spool quickly and see boost with the slightest bit of throttle movement, so it's not only going to be there "when you need it", it's going to be there all the time because the design goal of the engine and turbo sizing was to make it feel like a V6 or V8 all the time.

Look at the mileage of some torquey (is that even a word? it is now) turbo I4s like the STI; no better mileage than a V6 or V8 making the same power. x power requires x energy, regardless of the package. There is much more to engine performance than identical peak numbers. The only way a turbo I4 in your example is going to get better mileage than the V6 of the same power is if it's average torque curve is under the V6's torque curve except for the last 100 RPM. And in that case, it's a moot argument because we are supposed to be talking substitute engines that deliver exactly the same driving experience. (eg: identical torque and power curves). You can make a turbo I4 with a big fat torque curve that matches a V6 perfectly, but it's going to get the same mileage as that V6. If you are getting better mileage, you are giving something up somewhere.

You might see some efficiency gains with a oversized turbo and and peaky engine with no low end or middle range with all it's power at the top, because you don't spend all that much time in the top 20% of the powerband just putting around town. But the flat torque curve engines people are talking about here that are suitable replacements for V8s are not going to be designed that way. They are going to have small fast spooling turbos that build boost at the slightest hint of throttle and are going to eat just as much fuel just as fast as a V8 making the same power because they designed and marketed to feel like a V8. The whole point is that you are not supposed to even know you are driving a turbo 4 banger, and that's not going to give you 40 mpg, or even 30.

Look at the Ecoboost 3.5L V6. 17 MPG vs the GT500 5.4L V8 14 MPG, and that 3 MPG difference can be explained simply by the fact the GT500 has 175 more HP. Bump the boost up on the V6 to get 175 HP more or detune the GT500 and gut 175 HP out of it and you have two cars of similar weights with the same power and same mileage with two drastically different engines.

But some people just buy it up because it says "Eco" on it. Props to Ford's marketing department.
 
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EightySix Four

Diamond Member
Jul 17, 2004
5,122
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And I4s will never produce as much HP and torque as a V8, unless there is a 10+ year discrepancy between the two. A 4 cyl in 2010 will have the torque and power of a V8 from 1990 sure, but not a V8 also from 2010. The technology used to make a powerful 4 cyl doesn't magically only work on a 4 cyl and hit a brick wall on everything else; that same technology is applied across the board, and the relative differences between a small and large engine of the same era remain pretty much constant.

I have to disagree with this part. Many modern turbo I4's are quite a bit more advanced than their V8 counterparts from the same company. For example, the Ecotec LNF (GM) has a forged crankshaft and rods, variable valve timing, sodium filled valves, a twin scroll turbo, oil squirters, and direct injection. It's been out since 2007 and no GM V8 on the market has comparable tech behind it.

I can also argue with the fuel efficiency portion, but I'd be comparing a tuned turbo I4 to a stock v8 and that wouldn't necessarily be fair.
 
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