FT-86 / FR-S size dimensions compared to Genesis, Civic, Sction tC, etc

[70NYD]

VVTL-i = vtec = mivec = nvcs
depending on how economical they are trying to make this car will result in how much power it will actually make. but it will most likely be able to make more than 100bhp/L properly tuned

[Snaps]

Yep, just read up on vtec vs vvt-i. Seems in that case vtec is generally better, but as soon as you go to vvtL-i you basically have the same systems.

Which begs the question, will Toyota use dual-vvt-i, or dual vvtL-i? (Is the dual thing still right? I'm sure I read that somewhere). If they use vvtL-i, I would expect the power to be quite a lot higher than the predicted 200hp, more like 210-220, which should be more than doable.

[70NYD]

Originally Posted by Snaps

Yep, just read up on vtec vs vvt-i. Seems in that case vtec is generally better, but as soon as you go to vvtL-i you basically have the same systems.

Which begs the question, will Toyota use dual-vvt-i, or dual vvtL-i? (Is the dual thing still right? I'm sure I read that somewhere). If they use vvtL-i, I would expect the power to be quite a lot higher than the predicted 200hp, more like 210-220, which should be more than doable.

it could even be 190 with kick arse fuel economy thats just a tune away from awesome power :p
i dont remember exactly on the specifics of any of those systems ay.. i cant reember which one but one of them only controlls the intake cam. and im not sure if vtec also changes the came phase angle like vvtl-i does (basicaly vvt-i does just came phase angle and not lift)

[Snaps]

vvt-i used to only control the intake cam, because it generally made very little difference when added to the exhaust cam (I believe as exhaust valves/ports are generally larger anyway). Maybe they've found a way for it to make a larger difference, which is why they'll be adding vvti to the exhaust cam on the FT86 too?

From what I've made sense of, vtec uses a camshaft with two different lobe sets for each cylinder, and the used lobe set is changed at a certain rpm, where vvt-i uses a camshaft with a single lobe set for each cylinder, but instead uses a variable gear to change the gearing on the camshaft to essentially lengthen the timing, allowing more flow.

That's only if I've got the concept right though.

[stevens8]

I'm very interested to see what cam lift will produce on a flat four motor. I don't believe it's ever been done before, has it? I've heard the flat four gives less friction on on the pistons, cylinder walls, and crank shaft due to them being sideways. If that's the case I would think with a high flowing head, this motor should rev very high and be able to make power that high too.

[Dimman]

Originally Posted by Snaps

vvt-i used to only control the intake cam, because it generally made very little difference when added to the exhaust cam (I believe as exhaust valves/ports are generally larger anyway). Maybe they've found a way for it to make a larger difference, which is why they'll be adding vvti to the exhaust cam on the FT86 too?

From what I've made sense of, vtec uses a camshaft with two different lobe sets for each cylinder, and the used lobe set is changed at a certain rpm, where vvt-i uses a camshaft with a single lobe set for each cylinder, but instead uses a variable gear to change the gearing on the camshaft to essentially lengthen the timing, allowing more flow.

That's only if I've got the concept right though.

VVTL-i is closer to Honda's iVTEC not the old VTEC due to the cam phasing (old VTEC was just lift/profile changing). I think the newer Toyotas are VVT-i on both intake and exhaust (Intake valves are typically larger than exhaust valves) but there is something called 'Valvematic' I think it is, that is Toyota's next-gen cam/valve control tech.

I haven't really heard of VVTL-i in anything other than the 2ZZGE. Can anyone clarify for me?

The Lexus LFA I believe only used VVT-i on intake and exhaust.

[Snaps]

Reading up again, seems it's like this:

- VVT-I - variable cam gear timing (like adjustable cam gears, changes timing but not lift)
- V-TEC - variable cam lobes (two sets of lobes, changes between them to change lift + duration)
- VVTL-I - variable cam timing, with variable cam lobes like vtec (changes between two sets of lobes, while at the same time adjusts the cam gear timing for a fine tune)
- I-VTEC - same as vvtl-i (uses two sets of cam lobes to change lift and duration, with electronically controlled cam gear to fine tune)

Edit: To add a few more in here:
-VVT-Ie - variable cam gear timing , with electronic control (uses electric motor that spins at the speed of the camshaft, adjusts it's speed to adjust timing. This is instead of using an adjustable gear controlled by hydraulics)
-Valvematic - Edit: Found it, the difference is that valvematic continuosly adjusts lift, it doens't just switch from one cam to another.

At least that's what I can manage to pull from the information I've found.

[Dimman]

Originally Posted by Snaps

Reading up again, seems it's like this:

- vvti - variable cam gear timing (like adjustable cam gears, changes duration but not lift...?)
- vtec - variable cam lobes (two sets of lobes, changes between them to change lift + duration)
- vvtl-i - variable cam timing, with variable cam lobes like vtec (changes between two sets of lobes, while at the same time adjusts the cam gear timing for a fine tune)
- i-vtec - same as vvtl-i (uses two sets of cam lobes to change lift and duration, with electronically controlled cam gear to fine tune)

At least that's what I can manage to pull from the information I've found.

It doesn't change duration, that's in the grind of the cam profile (in regular VTEC the description is correct, though). How the timing affects overlap or lobe separation angles are probably better description of what changes. But yes it's like an adjustable cam gear continuously and infinitely controlled while the engine runs, by the ECU, to the range limit of the pulley (for example it may have 15 degrees of adjustment range, but it can be anywhere within the range).

[Snaps]

Haha, I was getting confused. I've got it now, duration is how 'wide' the lobe is on the cam, whereas timing is where the lobe is introduced in the intake stroke. If that makes sense?

[70NYD]

yeah that makes sense
timing is where the lobe is introduced in the cycle (720 degrees cus of the 2 revolutuions per 1 power stroke) and duration is how long it is opened, lift is how far it opens. you want it to open as far as posible without smacking in to the piston many people regrind cams by doing so they change the base circle that by shimming the valves you get effectively longer/higher lobes so more lift and by changing how wide the lobe is (by wide i mean if you are looking at the profile of the lobe down the axis of rotation, where the lobe profile stops/starts to push the valve open) you can get different duration. cam gears effect the timing.
valve-matic is awesome

[u2b]RHNXbGGvOdc[/u2b]

its a more simple solution to the vtec as u dont need 2 cams per intace/exhaust, nor do you need 3 lobes per intake/exhaust on a single cam. there is more mass but less rotating mass, and in effect its just like SOHC with rockers, they are just adjustible. but with 2 cams you can still individually adjust timing. however if they make the cam followers (little rollers) adjustible as well (like in and out) then you can get away with one cam, too complicated but

[Snaps]

What a great video lol, explains it perfectly... I now say Toyota put dual valvematic (if it will make any difference adding it to the exhaust cam too) to the FT86, should easily be able to reach 220hp IMO. Should also give it great economy!

[70NYD]

with direct injection it will give it awesome economy and power.. just think of the boost you could run without knock

[Want.FR-S]

Originally Posted by Snaps

Guys, there seems to be some discrepencies between the actual height of the FT-86... Some people are saying 49.6", the beginning of this thread (and the 'FT86 info thread') states 48.1. What is it really?

I've done a little photoshop too, should clearly show the size difference. Both the cars are aligned to the right side of the picture, and aligned to the bottom.

Edit: The bottom of both cars is clearly not right, this is because of my shoddy selecting. Don't use the 'wheels' as a reference, just the body.

Edit: Also note, this is using the height of 48.1", not 49.6... These were done by cropping the pictures I used to the edges of the car, then changing the width + height to 10x the car's height (in inches) in pixels, so should be pretty much completely accurate.

Actually, I would scale the image only based on one direction rather than both. You either scale it based on length or height, but not both. If you do that, given that the numbers could be mistaken, the picture would then be distorted on the direction with wrong numbers.

I scale the images based on length rather than height since the height can be changed depends on the source image that you have. (people redue ride height sometimes..) However, if there is no aftermarket on the front/rear bumper, it can be said that the length should be accurate. Therefore, you scale based on length and see how the height compares.

I would also like to stress the significance of aligning the images to the front wheel. If you want to see which car is longer, you can see that simply based on the reported numbers. There is no need to do this work. However, if you align to the front wheels, you can compare the wheel base, along with the possible engine placement to gussestimate the possible weight distribution, and also the overhangs on each car. That is something that you cannot see if you align the pictures to the front or the back of the cars.

My $0.02.

[Snaps]

Those are some good points... I'll make sure I use them in my next comparison