BRZ/FR-S Vs. Civic SI

[Pakjk89]

More than the driving dynamics, I am thinking the engines were somewhat comparable. Besides the obvious (vtec vs NA) Power figures are almost spot on (last gen civic si). Anyone car to speculate if the engine will act similarly because of this?

[NESW20]

uhh, vtec is na...

[Pakjk89]

Originally Posted by NESW20

uhh, vtec is na...

Yeah but aren't their slight differences between vtec and a normal NA?

[serialk11r]

I don't think there's a such thing as a "normal" NA...VTEC is just a particular variable valve actuation system.
Anyways, the Civic is probably a bit stronger below 3000rpm because of VTEC, the FA20 has pretty crappy low end torque because it only has cam phasing, but the Civic weighs more and has FWD.

[TheBoogieBot]

Originally Posted by Pakjk89

Yeah but aren't their slight differences between vtec and a normal NA?

VTEC is just the way the valves work. Toyota and pretty much every auto maker these days makes their own version of VTEC. They do use VTEC on turbo cars also though.

As for your other question I'd say the Civic SI would be slightly slower then the FRS because the weight of the scion is less.

[NESW20]

different cam profile. not enough to warrant a new category of n/a.

back to topic, i think both cars will be a lot of fun and drive quite well. the civic is going to be more practical for carrying people (especially if you get the sedan) and the K20 responds very well to mods. IMO, you can't go wrong with either car.

[GT]

Originally Posted by Pakjk89

Yeah but aren't their slight differences between vtec and a normal NA?

vtec stands for Variable Valve Timing Engine Control. Its the timing for the cams of the engine which can can SOHC or DOHC (single or double).

EDIT: replied too late lol

[Dark]

Last generation Si has 197hp and 140lb.ft of torque, and it does 6.7sec about the same as FR-S/BRZ 0-62 in 6.9sec. The new generation is 200hp and 170lb.ft of torque. It's faster than the last gen and FR-S/BRZ straight-line( if that's all you care). It will probably be faster than FR-S at the track with summer tire package.

[serialk11r]

Dark I think you should hold off on that conclusion until independent tests are done, there are quite a few factors in the BRZ/FRS's favor such as ~6% less weight, RWD, not to mention that the gears seem too short to hit 60, which means the acceleration under 60 will actually feel stronger...The ft-lb number doesn't mean squat, what's important is that the Hondas don't have a torque dead zone below 3000 while the BRZ does, but a mild launch will take care of that disadvantage.

[tranzformer]

Originally Posted by NESW20

uhh, vtec is na...

"Yo VTEC just kicked in!"

[Dark]

Originally Posted by serialk11r

Dark I think you should hold off on that conclusion until independent tests are done, there are quite a few factors in the BRZ/FRS's favor such as ~6% less weight, RWD, not to mention that the gears seem too short to hit 60, which means the acceleration under 60 will actually feel stronger...The ft-lb number doesn't mean squat, what's important is that the Hondas don't have a torque dead zone below 3000 while the BRZ does, but a mild launch will take care of that disadvantage.

That's why I said "probably". However, this generation Si really produces more power than the old one. It has grown a bit though.

[serialk11r]

Oh snap I just realized the Si loses breath pretty fast at the top of its rev range (200hp at 7000...wtf?), so its off the line acceleration is very high. I guess it's probably a close call then.

[Maxim]

Based on the nearly 200lb weight difference between the cars, and the fact that the BRZ/FR-S is RWD and will actually put the power down in 1st gear, I'd say no contest. BRZ/FR-S will probably be marginally faster in every respect except maybe top-gear acceleration. It will certainly be faster on a track, especially if you put the same tires on both cars.

On a prepared drag-strip, they'll likely be very close, but in real world conditions, where traction is more limited and road conditions aren't perfect, the RWD layout is going to give a massive advantage to the BRZ/FR-S off the line. I've got a high-powered FWD car....launching it is a huge pain in the ass.

[Capt Canuck]

I guess we'll see in 2013 Lightning Laps how it does in comparison:
http://www.caranddriver.com/features...1-class-page-3

Obviously different weather and drivers skewer any real direct comparison, but be interesting to see nevertheless.

[Exage]

Originally Posted by serialk11r

Oh snap I just realized the Si loses breath pretty fast at the top of its rev range (200hp at 7000...wtf?), so its off the line acceleration is very high. I guess it's probably a close call then.

No not the K24Z7, the K20Z3. The K24 requires a light to tell you that it switched cams...

Originally Posted by TheBoogieBot

VTEC is just the way the valves work. Toyota and pretty much every auto maker these days makes their own version of VTEC. They do use VTEC on turbo cars also though.

Not really. VTEC in the tradition sense is a cam-switching system. VVT is a cam-phasing system.

To put it very simply; VVT was widely adopted by the automotive industry. Engines produced today without a intelligent VVT system are stone age basically (I don't know if there are any). An intelligent VVT system is included with VTEC engines as current i-VTEC.

Most VTEC cam switching was not as widely adopted. Toyotas' 2ZZ-GE is the only Toyota engine to mimic the VTEC system with the single cam swap VVTL-i. Many manufactures are looking into variable that control valve lift variably rather than a cam switch. And many didn't even explore a cam switch system in it's prime.

[serialk11r]

Originally Posted by Exage

No not the K24Z7, the K20Z3. The K24 requires a light to tell you that it switched cams...

I assumed he was talking about the K24 Civic, because it's most fair to compare new cars afterall...the old Civic would get smoked as it does not have as great of a low end torque advantage. Well not exactly, it'd still be close.

[Mitch]

Originally Posted by Exage

No not the K24Z7, the K20Z3. The K24 requires a light to tell you that it switched cams...

The k20z3 vtec isn't that great either. They downtuned the engine just prior to the cam switchover so that it would have an artificial "kick". The sound it makes when it switches over is nice though.

[Rampage]

Originally Posted by Maxim

Based on the nearly 200lb weight difference between the cars, and the fact that the BRZ/FR-S is RWD and will actually put the power down in 1st gear, I'd say no contest. BRZ/FR-S will probably be marginally faster in every respect except maybe top-gear acceleration. It will certainly be faster on a track, especially if you put the same tires on both cars.

On a prepared drag-strip, they'll likely be very close, but in real world conditions, where traction is more limited and road conditions aren't perfect, the RWD layout is going to give a massive advantage to the BRZ/FR-S off the line. I've got a high-powered FWD car....launching it is a huge pain in the ass.

If by "track" you mean Drag Strip, Auto X or Drifting then you are right. The BRZ.FR-S will have a RWD advantage. However, for everyday driving and/or Road race track use or time trials there will be no such advantage. For realitively low horsepower cars (under approximately 300HP) FWD is just as viable as RWD. As evidence I offer World GT racing, Continental Tire racing, British Touring Car Championship and Grand AM ST racing. In each case FWD won their respective Championships.

For everyday driving, for the average or slightly above average driver, FWD is superior due to better all weather traction.

I grew up and learned to drive in a time when the only front wheel drive cars were "Elder"ados. Toronados and some "quirky" foreign cars. I had nothing but contempt for FWD "performance" cars through much of my life. That changed when I drove a Scirroco and owned a Integra GSR. I still prefer RWD in my sporty cars but there is no arguing that FWD makes more sense for a street car than RWD above the snowbelt. Can you get through a winter with RWD? Sure. I did it for over 30 years. But it is easier if you own a FWD for those really bad days.

The Civic is a solid, direct competitior to the FT86 models for most American drivers IMO. Even the ones that want a "sporty" car.

[SkullWorks]

Originally Posted by Exage

No not the K24Z7, the K20Z3. The K24 requires a light to tell you that it switched cams...



Not really. VTEC in the tradition sense is a cam-switching system. VVT is a cam-phasing system.

To put it very simply; VVT was widely adopted by the automotive industry. Engines produced today without a intelligent VVT system are stone age basically (I don't know if there are any). An intelligent VVT system is included with VTEC engines as current i-VTEC.

Most VTEC cam switching was not as widely adopted. Toyotas' 2ZZ-GE is the only Toyota engine to mimic the VTEC system with the single cam swap VVTL-i. Many manufactures are looking into variable that control valve lift variably rather than a cam switch. And many didn't even explore a cam switch system in it's prime.

I think you missed some of the systems that came out that weren't as widely used as Vtec, for instance the nissan NEO-VVL (Nissan Ecology Oriented Variable Valve Lift) Subaru had some dual pattern cam system that opened one valve before the other then locked both together...i-AVLS maybe.....I'm too lazy to look.

Did you know there was an 8 injector 1.6l four cylinder from nissan that was knocking on the door to 9K rpm and made 200 HP? they out Vtec'd honda bro

NOW throttle bodies are becoming obsolete in the wake of cams that are so variable in lift duration and LSA that they are throttle controlled and the TB is only used for IDLE air control and engine deceleration...BMW, Nissan, Toyota, not to mention Ferrari, have variable height and duration systems (i'm sure there are others these are the only ones i've looked at enough to know for sure what is going on as far as valve event)

[xrs]

Originally Posted by Exage

No not the K24Z7, the K20Z3. The K24 requires a light to tell you that it switched cams...



Not really. VTEC in the tradition sense is a cam-switching system. VVT is a cam-phasing system.

To put it very simply; VVT was widely adopted by the automotive industry. Engines produced today without a intelligent VVT system are stone age basically (I don't know if there are any). An intelligent VVT system is included with VTEC engines as current i-VTEC.

Most VTEC cam switching was not as widely adopted. Toyotas' 2ZZ-GE is the only Toyota engine to mimic the VTEC system with the single cam swap VVTL-i. Many manufactures are looking into variable that control valve lift variably rather than a cam switch. And many didn't even explore a cam switch system in it's prime.

Originally Posted by SkullWorks

I think you missed some of the systems that came out that weren't as widely used as Vtec, for instance the nissan NEO-VVL (Nissan Ecology Oriented Variable Valve Lift) Subaru had some dual pattern cam system that opened one valve before the other then locked both together...i-AVLS maybe.....I'm too lazy to look.

Did you know there was an 8 injector 1.6l four cylinder from nissan that was knocking on the door to 9K rpm and made 200 HP? they out Vtec'd honda bro

NOW throttle bodies are becoming obsolete in the wake of cams that are so variable in lift duration and LSA that they are throttle controlled and the TB is only used for IDLE air control and engine deceleration...BMW, Nissan, Toyota, not to mention Ferrari, have variable height and duration systems (i'm sure there are others these are the only ones i've looked at enough to know for sure what is going on as far as valve event)

As always, mitsubishi's MIVEC system is always forgotten. The earlier MIVEC systems were pretty much a direct clone of the vtech system. Never made it to the U.S. of course and woulda given Honda a run for their money. They axed it before it made any global headway in favor of TURBO!!!

[serialk11r]

Originally Posted by SkullWorks

NOW throttle bodies are becoming obsolete in the wake of cams that are so variable in lift duration and LSA that they are throttle controlled and the TB is only used for IDLE air control and engine deceleration...BMW, Nissan, Toyota, not to mention Ferrari, have variable height and duration systems (i'm sure there are others these are the only ones i've looked at enough to know for sure what is going on as far as valve event)

True, but cost/reliability will delay the adoption of these systems in favor of easier ways to improve economy. Toyota didn't want to use variable lift on the LFA for example.

[Exage]

Originally Posted by SkullWorks

I think you missed some of the systems that came out that weren't as widely used as Vtec

I kept it basic and brief; for the sake of posting without

A) Confusing members, easy to distinguish what is VTEC and VVT. Verses something like MIVEC and Double-VANOS.

or

B) a length of off-topic discussion

You are correct. i-AVLS is similar to VTEC-E, in which number of valves actuated is decreased at low rpm. While the system is similar, its application to engine performance [fuel economy/drivability] is on a much different note.

Originally Posted by serialk11r

I assumed he was talking about the K24 Civic, because it's most fair to compare new cars afterall...the old Civic would get smoked as it does not have as great of a low end torque advantage. Well not exactly, it'd still be close.

Well you can look at it two ways. It makes sense considering sale period. When comparing engine/drivetrain I tend to to make leeway on this in favour of something more precise [Displacement, Gear Ratios etc].

I got into pissing match once that engine for engine the 2ZZ-GE shouldn't be compared to a B18C1 or B18C5, but rather a K20A2. [SarcasticClap]

Originally Posted by Mitch

The k20z3 vtec isn't that great either. They downtuned the engine just prior to the cam switchover so that it would have an artificial "kick". The sound it makes when it switches over is nice though.

It's actually better to have the switch point lower, the consequence is less kick. Power is accessible towards the end of the midrange. So I respect your opinion Mitch that it's detuned (with you owning a 8th Gen Si), however I believe it's just less abrupt then the past non cam-phasing Honda engines (B series).

I don't land on my high cam even with redline shifts because it's set [stock] at a silly 6700rpm. The tuners that use the Apexi-PFC always decrease it to 5800-6200rpm on this engine, trading the "kick" for better performance and land on upshift. It gives a hell of jolt and noise in 1st and 2nd stock though.

________________

And that's all the off topic from me today...