Very respectable until the 60-80 mph range, then you can really see the wind resistance of an SUV slowing it down. Positively crawls from 80 on...
VVT vs VTEC interesting comparison.
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hardcore302 said:While I'm sure VTEC is great, all I can think of is some idiot kid in a SOCH 95 Civic with "VTECH" stickers everywhere revving his Folgers can exhaust at me. It's almost not worth the gas. Almost. [/quote]
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Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
Originally Posted By: Scott_Tucker
A patent was applied for in 1958, but it wasn't put into production. According to the Wikipedia article, Nissan was the first to use it in a production engine in 1987. The concept of variable valve timing is nothing new and I'm sure people have been building prototypes almost as long as the Otto engine has been around.
This is what Wiki says, and I know for a fact the date is correct for Alfa Romeo:
Alfa Romeo was the first manufacturer to use a variable valve timing system in production cars (US Patent 4,231,330).[3] The 1980 Alfa Romeo Spider 2.0 L had a mechanical VVT system in SPICA fuel-injected cars sold in the United States. Later this was also used in the 1983 Alfetta 2.0 Quadrifoglio Oro models as well as other cars. The system was engineered by Ing Giampaolo Garcea in the 1970s.[4]
I know this goes against the common wisdom that the Japanese invented the internal combustion engine and any advancements to it. But there you go.
Ed
A patent was applied for in 1958, but it wasn't put into production. According to the Wikipedia article, Nissan was the first to use it in a production engine in 1987. The concept of variable valve timing is nothing new and I'm sure people have been building prototypes almost as long as the Otto engine has been around.
This is what Wiki says, and I know for a fact the date is correct for Alfa Romeo:
Alfa Romeo was the first manufacturer to use a variable valve timing system in production cars (US Patent 4,231,330).[3] The 1980 Alfa Romeo Spider 2.0 L had a mechanical VVT system in SPICA fuel-injected cars sold in the United States. Later this was also used in the 1983 Alfetta 2.0 Quadrifoglio Oro models as well as other cars. The system was engineered by Ing Giampaolo Garcea in the 1970s.[4]
I know this goes against the common wisdom that the Japanese invented the internal combustion engine and any advancements to it. But there you go.
Ed
I just went into Wikipedia and changed the article to reflect Lada having the first VVT system in 1895.
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
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Originally Posted By: LeakySeals
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
Indeed.
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
Indeed.
Originally Posted By: LeakySeals
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
How so? VVT-i doesn't include any changes to valve lift, and that's a key component to VTEC. Some VTEC implementations are also using cam phasing now, but all still manage valve lift, at least to my knowledge.
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
How so? VVT-i doesn't include any changes to valve lift, and that's a key component to VTEC. Some VTEC implementations are also using cam phasing now, but all still manage valve lift, at least to my knowledge.
just think the plymouth/dodge SS/AH goes so fast with out VVT.
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Originally Posted By: morris
just think the plymouth/dodge SS/AH goes so fast with out VVT.
How does it do in MPG and low speed putting around town?
That's the advantage of these kinds of systems. You can get boring drivability and great MPG while still making oodles of power.
just think the plymouth/dodge SS/AH goes so fast with out VVT.
How does it do in MPG and low speed putting around town?
That's the advantage of these kinds of systems. You can get boring drivability and great MPG while still making oodles of power.
Originally Posted By: Hokiefyd
Originally Posted By: LeakySeals
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
How so? VVT-i doesn't include any changes to valve lift, and that's a key component to VTEC. Some VTEC implementations are also using cam phasing now, but all still manage valve lift, at least to my knowledge.
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
Originally Posted By: LeakySeals
Originally Posted By: OVERK1LL
Originally Posted By: HTSS_TR
I can actually feel the VTEC engagement at 6000 RPM on the S2000, the engine power seems to be much more than at 5500 RPM, but the 8000 redline comes so quick. I wish the AP2 retains redline at 9000 as of AP1.
I think VTEC is much more sophisticate than VVT, without it the S2000 can not achieve 240 HP from a 2 liters engine (in the AP1)
Take a look at any of the cam phaser setups on a modern VVT equipped vehicle, and then tell me traditional VTEC is more "complicated". It is far more simple.
The "race" lobes and free breathing head, intake....etc. Is what allowed the S2000 to achieve the power it did.
No different than BMW's 5.0L V10 making 550HP with VANOS.
The modern vtec has become more like a vvt-i
How so? VVT-i doesn't include any changes to valve lift, and that's a key component to VTEC. Some VTEC implementations are also using cam phasing now, but all still manage valve lift, at least to my knowledge.
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
welllllll, the hemi does have a draw back or two. i was just being silly. every system has good points and may be some not so good points. iam not really trying to judge those systems. i do not have the know how to judge that system. i did enjoy reading about it.
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Originally Posted By: LeakySeals
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
I believe I understood you correctly. You were saying that VTEC has become more like VVT-i.
Yes, VTEC with VTC is now called i-VTEC. The VTEC mechanism still hasn't changed; it's still a valve lift controlling technology. Honda has now added VTC (which is pretty much what VVT-i is) to supplement VTEC in some engines. None of the V-6 engines have VTC. I don't believe the L-series engine has VTC either. Only the K-series and R-series have it to my knowledge, which is why I said that only some of the VTEC implementations have been supplemented with VTC.
For VTEC to become more like VVT-i, Honda would have to take away the valve lift controlling mechanism (basically, the second cam profile), because VVT-i doesn't alter valve lift. Instead, Honda is going in the opposite direction with their Advanced VTEC, or a-VTEC, as you alluded to, and furthering their valve lift management technology:
http://www.vtec.net/news/news-item?news_item_id=659664
The way I see it, Honda is moving further away from VVT-i, but it's probably simply a difference in perspective or semantics.
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
I believe I understood you correctly. You were saying that VTEC has become more like VVT-i.
Yes, VTEC with VTC is now called i-VTEC. The VTEC mechanism still hasn't changed; it's still a valve lift controlling technology. Honda has now added VTC (which is pretty much what VVT-i is) to supplement VTEC in some engines. None of the V-6 engines have VTC. I don't believe the L-series engine has VTC either. Only the K-series and R-series have it to my knowledge, which is why I said that only some of the VTEC implementations have been supplemented with VTC.
For VTEC to become more like VVT-i, Honda would have to take away the valve lift controlling mechanism (basically, the second cam profile), because VVT-i doesn't alter valve lift. Instead, Honda is going in the opposite direction with their Advanced VTEC, or a-VTEC, as you alluded to, and furthering their valve lift management technology:
http://www.vtec.net/news/news-item?news_item_id=659664
The way I see it, Honda is moving further away from VVT-i, but it's probably simply a difference in perspective or semantics.
Many ways to skin the same cat.
IMO the advantage goes to cam moving VVT setups as they are smooth and progressive and do not have that "on-off" feel to them.
IMO the advantage goes to cam moving VVT setups as they are smooth and progressive and do not have that "on-off" feel to them.
Originally Posted By: lexus114
hardcore302 said:While I'm sure VTEC is great, all I can think of is some idiot kid in a SOCH 95 Civic with "VTECH" stickers everywhere revving his Folgers can exhaust at me. It's almost not worth the gas. Almost. [/quote]
And why anyone wants to sound like their going down the road with a bad case of gas is way beyond me. They all sound like a big phart to me. Do these kids actually think that this sound is cool?? At least we had the nice rumble of V-8`s when I was their age. And those cars DIDNT sound like a bad case of gas either.
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Originally Posted By: Hokiefyd
Originally Posted By: LeakySeals
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
I believe I understood you correctly. You were saying that VTEC has become more like VVT-i.
Yes, VTEC with VTC is now called i-VTEC. The VTEC mechanism still hasn't changed; it's still a valve lift controlling technology. Honda has now added VTC (which is pretty much what VVT-i is) to supplement VTEC in some engines. None of the V-6 engines have VTC. I don't believe the L-series engine has VTC either. Only the K-series and R-series have it to my knowledge, which is why I said that only some of the VTEC implementations have been supplemented with VTC.
For VTEC to become more like VVT-i, Honda would have to take away the valve lift controlling mechanism (basically, the second cam profile), because VVT-i doesn't alter valve lift. Instead, Honda is going in the opposite direction with their Advanced VTEC, or a-VTEC, as you alluded to, and furthering their valve lift management technology:
http://www.vtec.net/news/news-item?news_item_id=659664
The way I see it, Honda is moving further away from VVT-i, but it's probably simply a difference in perspective or semantics.
Why the focus on lift? A cam lobe is more than just its peak lift #. Duration and ramp rates are more important factors here. In my mind the advantage of having the 2nd set of lobes is that they can be far more aggressive in all ways than their economy-oriented siblings, and this includes faster ramps and more duration.
Originally Posted By: LeakySeals
Your reading my reply backwards. I did not say VVT-i has become more like the VTEC, I said the VTEC has become more like VVT-i. Honda made VTEC even better with VTC (variable timing control). Thats what VVT-i is (Variable Valve Timing with intelligence). Honda even put an "i" (for intelligent) on VTEC, calling it i-VTEC. just like Toyota has been doing for many years. Also, its more than "some" using i-VTEC, its most new ones. The a-VTEC, which is too long a story to explain this time of night is either delayed, or dead.
I believe I understood you correctly. You were saying that VTEC has become more like VVT-i.
Yes, VTEC with VTC is now called i-VTEC. The VTEC mechanism still hasn't changed; it's still a valve lift controlling technology. Honda has now added VTC (which is pretty much what VVT-i is) to supplement VTEC in some engines. None of the V-6 engines have VTC. I don't believe the L-series engine has VTC either. Only the K-series and R-series have it to my knowledge, which is why I said that only some of the VTEC implementations have been supplemented with VTC.
For VTEC to become more like VVT-i, Honda would have to take away the valve lift controlling mechanism (basically, the second cam profile), because VVT-i doesn't alter valve lift. Instead, Honda is going in the opposite direction with their Advanced VTEC, or a-VTEC, as you alluded to, and furthering their valve lift management technology:
http://www.vtec.net/news/news-item?news_item_id=659664
The way I see it, Honda is moving further away from VVT-i, but it's probably simply a difference in perspective or semantics.
Why the focus on lift? A cam lobe is more than just its peak lift #. Duration and ramp rates are more important factors here. In my mind the advantage of having the 2nd set of lobes is that they can be far more aggressive in all ways than their economy-oriented siblings, and this includes faster ramps and more duration.
Originally Posted By: OVERK1LL
Why the focus on lift? A cam lobe is more than just its peak lift #. Duration and ramp rates are more important factors here. In my mind the advantage of having the 2nd set of lobes is that they can be far more aggressive in all ways than their economy-oriented siblings, and this includes faster ramps and more duration.
You are absolutely correct. The entire cam profile is different, including lift, valve timing, duration, overlap, etc. Valve lift is just one aspect of it, but the one that most are likely familiar with so that's the particular aspect that I used to highlight the distinction between a system with multiple cam profiles like VTEC, and a cam phasing system like VVT-i.
I didn't intend to fully describe the system as that information can be found elsewhere, but you are correct that there are other factors besides lift, and those factors may be even more important than total lift.
Why the focus on lift? A cam lobe is more than just its peak lift #. Duration and ramp rates are more important factors here. In my mind the advantage of having the 2nd set of lobes is that they can be far more aggressive in all ways than their economy-oriented siblings, and this includes faster ramps and more duration.
You are absolutely correct. The entire cam profile is different, including lift, valve timing, duration, overlap, etc. Valve lift is just one aspect of it, but the one that most are likely familiar with so that's the particular aspect that I used to highlight the distinction between a system with multiple cam profiles like VTEC, and a cam phasing system like VVT-i.
I didn't intend to fully describe the system as that information can be found elsewhere, but you are correct that there are other factors besides lift, and those factors may be even more important than total lift.
I went to tech school in 2000 and 2001 with a kid that had a new at the time Civic SI. He had a full DC Sports exhaust from the header back and a AEM cold air intake. I went for a ride in it and loved it. VTEC kicked in around 5,000rpms or so and I thought it was the coolest thing at the time. The whole sound of the engine changed and you could feel that extra boost of power. I got tired of the "ricer" crowd though and eventually gravitated towards VW's, it seemed like a much more mature crowd at the time, although that seems to be changing as well. No better sounding engine than a VR6 screaming its lungs out
Except maybe a V8 with a lumpy cam in it. But that kids SI was the first time I was introduced to VTECH and I credit it with getting me into modern cars ( was a muscle car guy before), the technology fascinated me. I now have a Scion XB with a VVTI engine, and while its nothing earth shattering power wise, it sure beats my 08 Wrangler that I had. My only worry is having problems with the cam phasers, as I've heard of some issues with them on the 2.5's and some ford products. VTECH just seems like a more reliable system to me.
Except maybe a V8 with a lumpy cam in it. But that kids SI was the first time I was introduced to VTECH and I credit it with getting me into modern cars ( was a muscle car guy before), the technology fascinated me. I now have a Scion XB with a VVTI engine, and while its nothing earth shattering power wise, it sure beats my 08 Wrangler that I had. My only worry is having problems with the cam phasers, as I've heard of some issues with them on the 2.5's and some ford products. VTECH just seems like a more reliable system to me.
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I'm sure I've bored you all with this before, but this is a video I took of our MDX shortly after we first got it. The transition isn't all that easy to hear under normal circumstances if you're not aware that it's there, so I fitted a cone air filter I had in the garage and went for a ride to hear the transition.
With an exposed filter, the transition point is very apparent (4,400 rpm always, regardless of load). I wouldn't say that you can feel a "boost" in power, and you really can't feel the transition in the back of the seat. But the engine simply doesn't stop pulling to redline. The first half or so of the video is at very light throttle held in 2nd gear, just to hear the transition. The last run is WOT to about 70 mph. This is a 3.5L V-6 in a 4,500 pound SUV from 2005.
I don't have a video of it, but our CR-V is clearly different. It has an economy version of VTEC where one valve is essentially closed at lower engine speeds. At what most resources claim is 2,200 rpm, the VTEC system locks the two rocker arms together and both valves operate on the "normal" cam. This engine has good mid range, but you can tell it starts to loose its breath when it approaches 6,000 rpm and beyond. I can contrast it directly with my in-laws' 2011 CR-V. That version of the engine has "real" 3-lobe VTEC and 15 more claimed horsepower. Below 5,000 rpm, the engines feel nearly identical. But at 5,000 rpm, that engine transitions to the "big" cam and it keeps pulling strong to about 6,800 rpm. Essentially no loss in low and mid range power, but better top end power.
With an exposed filter, the transition point is very apparent (4,400 rpm always, regardless of load). I wouldn't say that you can feel a "boost" in power, and you really can't feel the transition in the back of the seat. But the engine simply doesn't stop pulling to redline. The first half or so of the video is at very light throttle held in 2nd gear, just to hear the transition. The last run is WOT to about 70 mph. This is a 3.5L V-6 in a 4,500 pound SUV from 2005.
I don't have a video of it, but our CR-V is clearly different. It has an economy version of VTEC where one valve is essentially closed at lower engine speeds. At what most resources claim is 2,200 rpm, the VTEC system locks the two rocker arms together and both valves operate on the "normal" cam. This engine has good mid range, but you can tell it starts to loose its breath when it approaches 6,000 rpm and beyond. I can contrast it directly with my in-laws' 2011 CR-V. That version of the engine has "real" 3-lobe VTEC and 15 more claimed horsepower. Below 5,000 rpm, the engines feel nearly identical. But at 5,000 rpm, that engine transitions to the "big" cam and it keeps pulling strong to about 6,800 rpm. Essentially no loss in low and mid range power, but better top end power.
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