VVT Varible Valve timing

oh.. ok.. so it'* kinda like V-tec and all the other variable timing kinda stuff.. thanx..

Sort of......VTEC controls lift (by way of a camshaft with 2 sets of lobes that slides longways at a certain RPM) as well as cam timing.

VVT usually has a centrifugally actuated pulley on the cam gear(*) that alters cam timing by up to 30 degrees (IIRC).

KEWL.. didn't know that either.. thanx for all this new info.

Yes the VTEC engineering is really neat. there are Cams that have 2 sets of lobes and VTEC kicks in at about 4,000 RPM. the engine has a totally different sound to it and alot more power

Yeah, one set is used for lower revs that has short duration and less valve lift to keep the cylinders full and thus, help out low end torque.

Above the switch-over point, the other set comes in. These lobes are a higher lift and longer duration that help top end breathing.

VTEC comes in a couple of flavors......one just works on the intake valves that helps boost fuel economy and emissions (usually on Civics) and the other acts on both intake and exhaust valves and is solely for performance (used on the ricers that we all know and love.....the Type R'* etc.)

Yep, these two "flavours" are SOHC and DOHC VTEC, respectively. Something like SOHC VTEC boosts power across the entire rev range.


Toyota VVT-i/VVTL-i, Nissan CVTC, and so on are different systems from Honda, likely more like that of the Caddy.

L67 > all v6 engines ( well except the GN turbo 3.8 )[/quote]

What about the Syclone/Typhoon 4.3?

Also, GM has the motors to keep up with the Hemi......they just don't use them where they should. The LS2 is only slightly larger than the Hemi (6.0L vs.5.7) but has much more power (400HP vs. 345) and is no where near being fully developed (next-gen Z06 being the example). With the 5.3 being in the new GP GXP, they could easily put the 6.0L version in (the motors are the same size externally) which makes 345/380 in its best form, which matches the Hemi in HP, and bests it in torque by 10.[/quote]

I agree GM has the engines to keep up with the Hemi and they don't use them, but I think they do need to a little more work to the LS2. The 300C SRT-8 is going to have a 6.1L 425hp Hemi in it. However, the new Z06 with 500hp will have no problem stomping the **** out of it, however the Z06 is a 7.1L or something like that IIRC, so its obvious advantage is displacement. It supposed to do mid 11'* in the 1/4 though!

Shawn

[quote="dbtk2I agree GM has the engines to keep up with the Hemi and they don't use them, but I think they do need to a little more work to the LS2. The 300C SRT-8 is going to have a 6.1L 425hp Hemi in it. However, the new Z06 with 500hp will have no problem stomping the ***^ out of it, however the Z06 is a 7.1L or something like that IIRC, so its obvious advantage is displacement. It supposed to do mid 11'* in the 1/4 though!
[/quote]

True, but remember when the LS1 came out, it was rated at 345HP in 1997. In 1999 the LS6 came out and was rated at 385HP, and the LS1 got bumped up to 350HP (though torque went from 350 lb/ft to 370). In 2000 the LS6 got bumped to 405HP, so I think there is more room left in the LS2. (I may have got the dates messed up on the LS6)

As for the C6 Z06, it has a 7.0L (427 cu in) based on the LS2, rated at 500HP. This isn't a new thing, for Lingenfelter has been building the 427 for a couple of years ( www.lingenfelter.com ). It is basically the C5R block bored and stroked....so technically it is a 427 small block.....weird huh? Plus, they have a LS2 6.0L setup that has 480HP.

For a total rush, check out the 427 twin turbo setup....there is a link of a Vette with this motor running high 8'* at over 150MPH in the 1/4. (click on the media section)



EDIT:

Here is the skinny on the Z06 and the STS-V

http://www.autoextremist.com/firstlook.shtml

When I wrote that, I didn't have my many many pages of literature on that car in front of me, I've been keeping track of it for a while and couldn't remember the liters displacement exactly, I knew the C.I. displacement was 427.6 c.i., technically making it a 428 not a 427.

Ligenfelter had the 427 available for the LS1/LS6 a long time ago. Pretty sweet IMO, but definately been out for a while. However, that was as big as they could punch out the block safely. The LS7 has a new block though with a few revisions, so it takes the displacement safely, and it probably leaves room for even more displacement. But its not just the old block with a bigger crank and punched out a little. Lingenfelters TT 427 is pretty insane, I've seen videos and read articles on it before, but it just reminds me of all the other 8 second race-cars I've seen.

I'm sure the LS2 probably does have more in it, but as for the LS7, I'm not sure what it does have left in it. Yeah, with different headers and exhaust and intake there is a small gain to be had, and obviously the normal cam and head swaps, but it already has 11:1 compression, has .591" valve lift, titanium valves 2.2" intake/1.81" exhaust, factory headers, and 3" Dual Exhaust. I don't know how much you really do to it. You could definately stretch that power number out, but its pretty close to its limits stock. But, what do you really need a faster car than that for?

Car & Driver says 3.8 seconds to 60, 7.7 to 100mph, and 11.7 @ 127 in the quarter. Not bad for a mid $60k car. Top speed in excess of 190mph.

Shawn