They have outstanding results on 4 cylinders. Why do engineers not use them on larger engines? The equation seems to be 100 Horses per liter. On a 4 liter 6 cyl that would be 400Hp. That is a fantastic result.
Actually, VVTI doesn’t create the power in those engines…VVTI smoothes out the engine at lower speeds. The engines themselves are built to produce that output, however without VVTI they would idle so roughly and suck so much gas that no one would want them.
So without having VVTi those engines would not run correctly therefore not producing efficient power ergo VVTi enables the power. Thanks for explaining that.
Now, why do they not mass produce larger engines using the VVTi technology?
actually, VVTI enables them to run smoothly at low RPMS. If you could take a VVTI engine, and “disable” it, the result would be that the engine would still produce the same power at high RPMS, but at low RPMs it would stutter, run poorly, and have poor gas mileage.
Perhaps one reason is that VVTI is a need on engines that produce power at very high RPMS…6 cyl. and 8 cyl. engines do not like high revs.
Or, history shows that American car companies prefer to produce performance engines that get power from their sheer size. Japanese manufacturers have produced lightweight, smaller engines that get their power from having the ability to rev high, so you see VVTI on Toyotas and Hondas(called V-Tec).
VVTI doesn’t give you any power, it just allows your high-revving 4cyl. engine to be efficient at lower RPMs as well.
ahh the olde “there is a replacement for displacement” arguement. I disagree. I could get more HP and torque from my big american V-8 than any four or six.I work my azz off for it ,political correctness be damned… 
:eek: 
Yes but the trade off is in handling/weight distribution/braking.
Smaller engine=less weight in front=neutral handling.
I saw a test last year, a Mustang GT(V8) vs. an Integra Type R(V4)
The mustang was a tick faster in 1/4mile times, but the Integra would beat it around any track they raced on. It just depends on what kind of race car you want to build. If you want to build a drag 1/4 mile car, go for a bigger engine. If you want a rally type car, go for a higher-revving lighter car.
I’m most familiar with the Supra(I’ve done alot of research into this particular model), and will be purchasing one as fast as I can pay off my Jeep. Supra engine will dyno at over 400HP with a $2000 basic performance upgrade(exhaust, boost controller, etc.)
I hate the whole import peformance vs. American muscle car argument. I appreciate a 68 camaro that runs a 10.0 in a 1/4 mile. I also appreciate a 4cyl. car that runs it in 13.5 and runs circles around everything at a track.
Am I correct in understanding that VVTi is Toyota’s own term for variable valve timing? If so, then the Audi A8 (V8) and the BMW M3 (I6) both use variable valve timing, and I’d imagine there are probably others as well, in the high-end, high-performance category. Whether one considers cars in the $50,000 - $70,000 (and up) range “mass produced” or not, these are certainly not exotic one-off models.
SCCA standings (from SCCA SF region)
1 11 # T1 NATHAN CHESMORE(287555), ROCKLIN NCD ENTERPRISES INC SF 02 CHEV 8 2:03.162
2 4 T1 RICK BOYSAL(280949), DANVILLE PROSTAFFINGCORP.COM SF 01 CORVETT 10 2:04.106
3 78 ITE MARSHALL DONIG(190656), SAN RAFAEL CALIF DRIVING ADVEN SF 84 NISSAN 8 2:05.410
4 51 ITE DAVID C SMITH(191438), SACRAMENTO MCGEE MOTORSPORTS SF 95 BMW 9 2:06.669
5 14 ITE DAVID ALLEN(221726), CUPERTINO MOTORSPORTS DYNAMICS SF 86 MAZDA 7 2:08.614