I switched to the S2000, and here is what I think (video)

[mokinbird87]

Originally Posted by NoHaveMSG

You talk at the 1:34 and 4:18 mark about how you can't design a car with such a low hoodline anymore but post in this forum?

Oversquare engines are a design favored for high RPM's since it lowers piston speeds. The same size engine that is undersquare, would have a higher piston speed at the same RPM since it has to cover a longer stroke in the same amount of time.

Half a Ferrari V8 by adding ITB's?

86 twins hide the height restrictions pretty well due to having the wheel arch poke over the hood line a bit, but in reality it's still sits much higher than the S2000 hood line. It's got to do a lot with the amount of room you have between the hood and the engine, and in this case the boxer motor really helps.

As for the Ferrari comparison, yes it's a stretch but, they're Normally oversquare, very similar firing order (per four cylinders) and with something like a Toda ITBs, it really does remind me of something more exotic.

[serialk11r]

Originally Posted by Yoshoobaroo

The main reason NA engines are dying is the average CO2 rule in the European regulations, and that can’t be fixed with emissions equipment or better combustion control. That can only be reduced by making engines smaller and reducing revs.

Who said the engine has to run at high revs?

Cooled EGR and modern combustion chamber design allow very high EGR dilution ratios for drastically higher efficiency at low load. If you haven't noticed, Toyota's new engines are almost all NA with the exception of the V35, and the fuel economy is great. 90s engines have similar efficiency to new engines running at half the load thanks to high volume EGR and high tumble ports. Combine that with strategically picked gear ratios and passing the NEDC is a piece of cake.

The F20C and F22C were produced in the 2000s but they're a 90s design; no cam phasers, no EGR => poor low load efficiency, poor fuel economy. The only saving grace is the sort of high compression ratio. Combine that with short gearing and horrible aerodynamics and you get abysmal fuel economy for how much power it has.

There are plenty of underpowered NA cars that get great fuel economy. A high revving short stroke engine loses a few % efficiency compared to a long stroke low rev limit economy engine, but it's not a big difference. The F20C stroke isn't even that short at 84mm (contrast with Porsche, which had a 72mm stroke on its 2.7L H6).

In fact I would argue that the hypothetical modern S2000 almost exists in the ND2 Miata. It's NA, and could rev higher if Mazda felt like spending more money on the engine. It only needs 700 more rpm to match the F22C rev limit. Thanks to slightly wider gear spacing than what (IMO silly) Honda and Toyota used in the past, it takes off quickly enough in 1st gear for modern expectations, and gets good fuel economy at higher speeds. The only reason I haven't bought one and spent tons of money on custom engine parts is because I rented one on Turo and could not tolerate the cramped cabin.

[serialk11r]

Originally Posted by mokinbird87

As for the Ferrari comparison, yes it's a stretch but, they're Normally oversquare, very similar firing order (per four cylinders) and with something like a Toda ITBs, it really does remind me of something more exotic.

IIRC most recent Ferraris never had ITBs, they came with dual plenums and dual throttle bodies. A dry sumped Honda engine with ITBs would be better than half a Ferrari V8

[86MLR]

So....how good are these new hybrids

[mokinbird87]

Originally Posted by serialk11r

Who said the engine has to run at high revs?

Cooled EGR and modern combustion chamber design allow very high EGR dilution ratios for drastically higher efficiency at low load. If you haven't noticed, Toyota's new engines are almost all NA with the exception of the V35, and the fuel economy is great. 90s engines have similar efficiency to new engines running at half the load thanks to high volume EGR and high tumble ports. Combine that with strategically picked gear ratios and passing the NEDC is a piece of cake.

The F20C and F22C were produced in the 2000s but they're a 90s design; no cam phasers, no EGR => poor low load efficiency, poor fuel economy. The only saving grace is the sort of high compression ratio. Combine that with short gearing and horrible aerodynamics and you get abysmal fuel economy for how much power it has.

There are plenty of underpowered NA cars that get great fuel economy. A high revving short stroke engine loses a few % efficiency compared to a long stroke low rev limit economy engine, but it's not a big difference. The F20C stroke isn't even that short at 84mm (contrast with Porsche, which had a 72mm stroke on its 2.7L H6).

In fact I would argue that the hypothetical modern S2000 almost exists in the ND2 Miata. It's NA, and could rev higher if Mazda felt like spending more money on the engine. It only needs 700 more rpm to match the F22C rev limit. Thanks to slightly wider gear spacing than what (IMO silly) Honda and Toyota used in the past, it takes off quickly enough in 1st gear for modern expectations, and gets good fuel economy at higher speeds. The only reason I haven't bought one and spent tons of money on custom engine parts is because I rented one on Turo and could not tolerate the cramped cabin.

Thanks for the insight. Aero does seem to be an achilles heel on the S2000, especially compared to the 86 twins. I think the new bumper and some other parts from the S2000 they showed recently seems to try and revise some of those things.

I rly wanted the Miata to work as they're really reasonable in terms of price and aftermarket support, but even the biggest one (NC) I cannot fit in comfortably after strapping on supercharger kits and all on the BRZ, I rly didn't feel like modding the engine for more power, so I ended up with the S2000.

[mn_ca]

Originally Posted by Rampage

Yeah, I love how I fit in the twins. In fact, I love just about everything about them other than the sound of the engine, If I did not have the 2ZZ Spyder then I would buy one in a heartbeat. I would still buy one for my wife but she is not a fan of how low they sit so we just keep her more upright sedan.

I just cannot buy a car that I cannot get comfortable in and that is why I passed on both the s2000 and all the MX-5 models. The ND MX-5 came the closest of the two-seaters but the headroom was tight and the cabin is kind of narrow.

Sorry to thread jack but...

Can you compare your 2zz mr2 to the s2000? That's something I've been pondering about. Been searching a 2zz swapped mr2 spyder. Looking for possibly a project.

[serialk11r]

Originally Posted by mokinbird87

I rly wanted the Miata to work as they're really reasonable in terms of price and aftermarket support, but even the biggest one (NC) I cannot fit in comfortably

You said in the video you're 6'1", is that more torso or leg? I'm a hair shorter but it's mostly in the legs so I don't feel cramped in most cars. I am planning on buying an AP1 and waiting to see how the next gen Lotus cars turn out.

For Miatas, the aftermarket support is so awesome and the cars are really well thought out, so I really really wanted to accept a lot of the shortcomings. After spending a few days in one, I just couldn't get over the windshield being right up next to my forehead. I really loved that car and would've been willing to dump money into titanium valves and custom pistons.

[Yoshoobaroo]

Originally Posted by serialk11r

You said in the video you're 6'1", is that more torso or leg? I'm a hair shorter but it's mostly in the legs so I don't feel cramped in most cars. I am planning on buying an AP1 and waiting to see how the next gen Lotus cars turn out.

I’m the same height as you but I’m all torso. I don’t fit in shit. I *just* fit in a 1 series. A Miata/S2K is fine, with the top down. I can’t sit straight in an RX8. The BRZ is a godsend with the seat lumbar mod.

[serialk11r]

Originally Posted by Yoshoobaroo

I’m the same height as you but I’m all torso. I don’t fit in shit. I *just* fit in a 1 series. A Miata/S2K is fine, with the top down. I can’t sit straight in an RX8. The BRZ is a godsend with the seat lumbar mod.

Oh man, that really sucks. I had a problem with legroom in the Miata, needed to set the seat almost all the way back putting the seat back at a pretty straight angle. That then put my face right into the windshield. Aside from being worried about cracking my skull, I managed to feel sort of comfortable while driving it.

When I had my MR2 Spyder with stock seats, there was just the right amount of room to feel comfortable, though the seats themselves were horrendously uncomfortable. A bucket seat with no sliders was perfect, knee just barely missed the steering wheel, an inch to spare behind the seat, head far from the roof.

My FR-S was really comfortable and I loved the driving position, it just didn't really get me excited. If you need the headroom and want something more exciting, a 981 would be good. For me, modern Porsches are a little too roomy and long, I need just a little bit of claustrophobia

[NoHaveMSG]

Originally Posted by mokinbird87

86 twins hide the height restrictions pretty well due to having the wheel arch poke over the hood line a bit, but in reality it's still sits much higher than the S2000 hood line. It's got to do a lot with the amount of room you have between the hood and the engine, and in this case the boxer motor really helps.

As for the Ferrari comparison, yes it's a stretch but, they're Normally oversquare, very similar firing order (per four cylinders) and with something like a Toda ITBs, it really does remind me of something more exotic.

Fair enough on the hoodline.

I'd say you could make the case on any of the well designed inline 4's with that comparison. Like I said, oversquare doesn't really mean anything other then it was designed to handle high RPM's. High RPM's aren't everything, there is a whole host of problems associated with it.

[serialk11r]

Originally Posted by NoHaveMSG

High RPM's aren't everything, there is a whole host of problems associated with it.

I guess it depends on your definition of high rpms, but it's not difficult to get any cheap DOHC engine to run at 8000rpm. Toyota and Honda engines that redline below 7000 are supposed to survive to 7500-8000. Lighter pistons and 20% uprated valve springs will get you there reliably, and you don't need crazy cams that can't idle properly.

9000 takes more work but people like Papadakis think engines like the lowly 2AR are basically ready for it (with upgraded reciprocating parts of course). Past 9000 is where auto manufacturers haven't dared to go for the most part.

[NoHaveMSG]

Originally Posted by serialk11r

I guess it depends on your definition of high rpms, but it's not difficult to get any cheap DOHC engine to run at 8000rpm. Toyota and Honda engines that redline below 7000 are supposed to survive to 7500-8000. Lighter pistons and 20% uprated valve springs will get you there reliably, and you don't need crazy cams that can't idle properly.

9000 takes more work but people like Papadakis think engines like the lowly 2AR are basically ready for it (with upgraded reciprocating parts of course). Past 9000 is where auto manufacturers haven't dared to go for the most part.

I think it goes without saying that you can modify an engine to operate outside of OEM specs.

My comments come from the OP's video talking along the lines of over square engine for throttle response.

[serialk11r]

Originally Posted by NoHaveMSG

I think it goes without saying that you can modify an engine to operate outside of OEM specs.

My comments come from the OP's video talking along the lines of over square engine for throttle response.

Oh what I was trying to get at is OEMs don't always use long rods or short stroke or fancy valvetrains for high rpm engines. Many components do a simple job and aren't under a lot of stress.

But yea oversquare doesn't give better throttle response, that comes from throttle body size, plenum volume, and to some extent the actuation speed of VVT and other components.

[NoHaveMSG]

Originally Posted by serialk11r

Oh what I was trying to get at is OEMs don't always use long rods or short stroke or fancy valvetrains for high rpm engines. Many components do a simple job and aren't under a lot of stress.

But yea oversquare doesn't give better throttle response, that comes from throttle body size, plenum volume, and to some extent the actuation speed of VVT and other components.

Yeah there are exceptions. I was mostly just generalizing since it is typically cheaper to design an over square high RPM engine so they tend to be more common. Even the F22 in the AP2 is under square with an 8200rpm rev limit which is pretty good. Something, something you take the engineered load capability of a rotating assembly and determine what speeds would exceed that load capability and either set a limit that doesn't exceed that, or increase the load capability of the assembly. Or something like that.