Where Did the High Revving Four Cylinders Go?

"LongbowMkII" (longbowmkii) 06/16/2015 at 17:14 • Filed to: None

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My theory from another discussion:

I could be wrong, but generally in order to get a lot of power at high rpms the efficiency and cleanliness suffers at low rpms. Instead of having to spin that 2.0 at 8k to make ~200hp (and have slightly dirtier tests) you can spin a 2.4 at 7k and meet standards more inexpensively.

Seriously, where did they go? A Honda Civic Si with all its VTAKS and DOHCS is only redlining at 7000rpm(the same as a base Corolla). The Toyobaru ups it a bit to 7400. Maybe all the criticism that motor receives explains the lack of interest in low displacement screamers (not that 7400 is particularly screaming). You can rework an economy motor to 100hp/l and people will whine about a lack of low end torque. Maybe the Alfa can top them all. How could I overlook the most famous builders of a revvy 4 cylinders. Well the 4C tops out at..... 6500rpm. ugh. Am I overlooking a car? This is the future damnit! I want super fast spinning motors!

MultiplaOrgasms > LongbowMkII 06/16/2015 at 17:16

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Arch Duke Maxyenko, Shit Talk Extraordinaire > LongbowMkII 06/16/2015 at 17:17

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Euro/EPA Emissions done killed them all.

Kanaric > LongbowMkII 06/16/2015 at 17:17

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Cars got too fat for the lower torque.

KamikazePigeon > LongbowMkII 06/16/2015 at 17:17

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Someone may correct me if I’m wrong.

I feel as if it may be due to the swing to turbocharging. Could it be that super high revving engines do not like turbochargers too much?

Or is it purely coincidence?

LongbowMkII > MultiplaOrgasms 06/16/2015 at 17:18

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There’s no reason you can’t build a high revving turbo motor. Except for Renault... they don’t quite get it apparently.

But you’re right :(

LongbowMkII > Arch Duke Maxyenko, Shit Talk Extraordinaire 06/16/2015 at 17:19

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:( I want to be wrong!

LongbowMkII > KamikazePigeon 06/16/2015 at 17:20

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There’s nothing that says you can’t have a high revving turbo motor, but it’s much easier to retune for more boost than re-engineer the motor for an extra 400rpm.

MultiplaOrgasms > LongbowMkII 06/16/2015 at 17:22

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You can, but there is no point in doing so for a road car.

ttyymmnn > LongbowMkII 06/16/2015 at 17:26

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Be patient. We’ll probably be seeing 4-cyls in F1 soon.

/serious not serious

dogisbadob > LongbowMkII 06/16/2015 at 17:27

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red valve cover adds 30 hp, but why didn;t they paint the spark plug cover part red too? :(

Opposite Locksmith > LongbowMkII 06/16/2015 at 17:27

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Short stroke = lower piston speeds = ability to rev = less leverage on the crank=less efficient = less torque

SnapUndersteer, Italian Spiderman > LongbowMkII 06/16/2015 at 17:27

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Can you believe it’s not butter?

dogisbadob > LongbowMkII 06/16/2015 at 17:28

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For one, turbos.

And two, a lot of people don’t like them, so tha stupid haterz ruined them :(

Just like digital dashes. Aweso,me as fuck, but the stupid car magazine tards had to talk shit about them. Luckily Jalopnik is here now to make those magazines obsolete :p

I don’t think emissions standards killed them in and of itself. For example, ferrari had the 9500 rpm 458, and Lambo’s V12 can still pass 8k. If 8-12 cylinders of high rpm can meet the standards, then a cute lil 4-banger certainly can, too.

PS9 > LongbowMkII 06/16/2015 at 17:30

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An engine is an air pump. More revvs = more air = more fuel = more emissions. Stoiciometry.

If revvs keep an engine from passing an emissions test (and they do, that’s why they went away) then a turbo will exacerbate this problem.

LongbowMkII > MultiplaOrgasms 06/16/2015 at 17:37

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stahp crushing my dreams.

BoxerFanatic, troublesome iconoclast. > LongbowMkII 06/16/2015 at 17:38

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Most high RPM screamers are dogs lower in the RPM band, and you have to drive them like you stole them to get them to even respond to your right foot.

While fun occasionally... it is less fun to have to drive like that constantly.

It actually becomes frustrating to have to drive angry all the time.

And it isn’t particularly kindly treated by the EPA mileage rating cycle, so the EPA fuel economy numbers suffer, and the CAFE regulations on the car manufacturers start to pinch if they sell a lot of them... it lowers their fleet average fuel economy... and if the regs get stricter, or the fleet average gets too low, the government fines the car manufacturer for not meeting the CAFE fleet standards for passenger cars.

It becomes more affordable to platform share and slightly up-tune an economy engine than develop a stand-alone screamer of an engine, including the federalization costs before the car even gets to the lot.

Plus, the dwindling discretionary spending of the general population makes sports cars and other non-essential big-ticket items harder to sell in as many numbers, possibly dropping below the quantity of sales to remain profitable.

LongbowMkII > dogisbadob 06/16/2015 at 17:40

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Well I think the profit margins justify the higher expense of engineering a cleaner high revving motor. plus they probably have different standards sinc there are hundreds of ferrari v12’s as opposed to tens of thousands of high revving I4’s

TheHondaBro > MultiplaOrgasms 06/16/2015 at 17:46

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^

davedave1111 > LongbowMkII 06/16/2015 at 17:46

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One thing that hasn’t been mentioned here is that the high-revving 4 cylinders mostly sold in Europe, and thanks to tax stuff we’ve had a hell of a lot of diesels filling that kind of role over the last few years.

Plus, as others have said, high-revving engines with a narrow power band do absolutely dreadfully on standard fuel economy tests.

RightFootDown > LongbowMkII 06/16/2015 at 17:47

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This 2.0 goes to 8k RPM and makes good power. ;)

BoxerFanatic, troublesome iconoclast. > KamikazePigeon 06/16/2015 at 17:56

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Turbochargers have a range of impeller efficiency that takes into account input pressure (hot exhaust stacking up in front of the impeller, compared to lower pressure and temperature behind the impeller, creating a differential, and the rush to equalize spins the impeller wheel faster. It also takes into account the volume that can flow through the turbocharger impeller.

Low volume creates input pressure earlier with lower exhaust volume from the engine, thus it spins up with that pressure differential at lower engine RPMs, with less or imperceptible lag, and paired to a properly sized compressor stage, increases intake pressure into the engine sooner, at lower RPMs.

Most new turbos are going that way for low-lag, high efficiency turbocharging, with small turbochargers.

BIG turbochargers flow much more volume, but the pressure doesn’t build until the exhaust volume increases out of the engine, and builds up at the entry to the impeller, which is LAG, but when the turbo has both high volume, and a good pressure differential across the impeller, it can drive a similarly high-volume and high pressure compressor on the intake side of the engine, to make bigger PSI numbers, and much more power in the engine... but they lag, and the high-volume, high pressure intake charge requires a LOT of fuel in the engine, so it isn’t as fuel efficient, either.

A Turbocharger can’t usually do both truly well, although Variable Nozzle Turbochargers, or Variable Vane impeller entry gates try to approximate both behaviors in the same turbo, it isn’t a fix-all, and a high-RPM screamer of an I4 has a wide range of exhaust volume between idle and redline. The Turbo usually doesn’t have that wide of an efficiency band, and so it either lags, then really BOOSTS, or if it has a small turbo, it boosts in the mid-range with not much lag, but then falls flat at higher RPMS, as the turbocharger can’t physically flow the additional exhaust volume, or run the compressor any faster.

dual turbocharging with asymmetrical turbos (a small stage 1 turbo, and a big stage 2 turbo) makes for a much more complex system to build, manage, or maintain, and was tried on FD-3S RX7, which has even MORE variability on exhaust volume and pressure between idle and 3 firing pulses per rotor, per revolution at an 8-10,000RPM redline.

Most of the new turbocharged engines are not high-boost engines, they are low-lag systems, with consistent, but modest intake pressure, no lag, and little risk of pre-detonation, as well as gasoline direct injection for more precise fuel metering, for a wider torque curve that emulates a larger-displacement atmospheric engine. (turbo-4 instead of an atmo-V6, for instance.) not a big-power high-horsepower, fire-breathing turbocharged engine, with throttle-response lag that can be timed with a stop-watch.

Decay buys too many beaters > LongbowMkII 06/16/2015 at 17:59

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Step 1, Get a bike

Step 2, Enjoy some of the best high revving 4 cylinders in history, and they are being made right now!

LongbowMkII > Decay buys too many beaters 06/16/2015 at 18:01

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point. but cagelyfe.

HFV has no HFV. But somehow has 2 motorcycles > MultiplaOrgasms 06/16/2015 at 18:10

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Yup turbos make low end torque which is better for MPGs, and most people, especially Americans love low end torque. Most people don’t like having to rev out a motor. My wife used to scream at me for going above 5000RPM in my Civic, until she drove it and kinda understood that you have to go there. she was used to her cavalier which has a bigger engine(1.7 vs 2.2), and hates revving higher than 4500RPM.

Decay buys too many beaters > LongbowMkII 06/16/2015 at 18:38

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it’s just a smaller cage :)

asindhidude > ttyymmnn 06/16/2015 at 20:24

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#scaredthatserious

Smallbear wants a modern Syclone, local Maple Leafs spammer > LongbowMkII 06/22/2015 at 15:23

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They grew up, got married, and became LS7’s.