Does Vtec really kick in?

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exar333

Diamond Member
Feb 7, 2004
8,518
8
91
Definitely kicked in on my old Prelude SH yo.

The Prelude SH handled beautifully! Nice car.

Just to keep in perspective, the prelude SH accelerated approx the same as a 2010 V6 Malibu (0-60 ~6.7sec). It drove great, but most VTEC motors are not all that great...
 

speedy2

Golden Member
Nov 30, 2008
1,294
0
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Umm so you're saying you'd rather have a more powerful engine???


Not just that, but look at that tq curve. It drops pretty good and then goes back up. A boost? Hardly. I would say, the VTEC, puts it where it should be.

LS1 - http://www.ericohlsen.com/FBODY/CamaroDyno.jpg

L67 V6 - http://www.azrockcrawler.com/_images/tech/2007/2-14-07l67/enginedyno.jpg

DOHC Northstar with NO variable valve timing - http://www.caddyinfo.com/northstardyno.htm

These are just 3 example of engines that are well over 10 years old. The amount of technology/complexity/etc just doesn't seem like that big of a deal to me.
 

zerocool84

Lifer
Nov 11, 2004
36,041
472
126
Lots of you guys are funny. Just because VTEC or variable valve timing is associated with Ricers, doesn't mean it's a bad thing. It's the wave of the future and great for vehicles in general. That's like saying well I don't like superchargers or turbos cus you need some fancy gadget to make up for the lack of power.
 

Evadman

Administrator Emeritus<br>Elite Member
Feb 18, 2001
30,990
5
81
Not just that, but look at that tq curve. It drops pretty good and then goes back up. A boost? Hardly. I would say, the VTEC, puts it where it should be.

A flat torque curve is infinitely better IMHO. Mmmm, the good old days.


Ram2500SC1.jpg
 

zerocool84

Lifer
Nov 11, 2004
36,041
472
126
Not just that, but look at that tq curve. It drops pretty good and then goes back up. A boost? Hardly. I would say, the VTEC, puts it where it should be.

LS1 - http://www.ericohlsen.com/FBODY/CamaroDyno.jpg

L67 V6 - http://www.azrockcrawler.com/_images/tech/2007/2-14-07l67/enginedyno.jpg

DOHC Northstar with NO variable valve timing - http://www.caddyinfo.com/northstardyno.htm

These are just 3 example of engines that are well over 10 years old. The amount of technology/complexity/etc just doesn't seem like that big of a deal to me.

Ok but what you said was that you'd take an engine with 300ft/lbs than one with 155ft/lbs. Umm duhh who wouldn't.
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
Lots of you guys are funny. Just because VTEC or variable valve timing is associated with Ricers, doesn't mean it's a bad thing. It's the wave of the future and great for vehicles in general. That's like saying well I don't like superchargers or turbos cus you need some fancy gadget to make up for the lack of power.

Screw that, how about valves that don't need no stinking cams! mmmm, infinitely variable lift and timing... :)
 

reallyscrued

Platinum Member
Jul 28, 2004
2,618
5
81
VTEC is very apparent on cars that have DOHC. VTEC on SOHC are a lot different, the torque curve in my 6th gen Accord is a lot flatter than my previous Civic Si (EM1) but both have VTEC. The EM1 had a definite crossover point where cams were switched (5900 RPM - 8250 RPM) and the Accord feels more like my 330ci (E46, Single VANOS, not Dual - Continuously different throughout the range, but total power topping out at less than 6 grand on the tach).

For those who say VTEC is a gimmicky thing: It's turned gimicky because of stupid ricer idiots and they way they perpetuate it. The fact of the matter is, The VTEC version of my Civic had 40 hp over the regular non-Si, definitely not a gimmick as it had actual power benefits.

For those who say you'd rather have a V8 torque curve: Why are you in this discussion?
 
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speedy2

Golden Member
Nov 30, 2008
1,294
0
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VTEC did not add the 40HP. It might have brought the peak up maybe 10HP. Look at that chart posted on the first page. The line stays in a 20 lb ft range, but not before dropping a good 20 lb ft. Even still, how many people are really going to use a 10-20HP increase at over 6000rpm? A flat curve from 1500-4000 is a lot more practical.
 

speedy2

Golden Member
Nov 30, 2008
1,294
0
71
That wouldn't be much different than a V8. I wasn't talking about peak numbers. But, the flatness of the curve itself.
 

poopaskoopa

Diamond Member
Sep 12, 2000
4,836
1
81
It definitely sounded like it was going harder and I could feel it, but nothing like a big turbo kicking in. 2000 Prelude.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
50,419
8
81
I can feel VTEC kick in on my Insight at about 3,000RPM(low compares to most of Honda's VTEC implementations).
 

overst33r

Diamond Member
Oct 3, 2004
5,761
12
81
Good question. Personally, I would rather have a V10's torque curve.

Barring any huge differences other than cylinder count, V8 vs V10cyl isn't going to result in a drastically different torque curve.

Plus there's different V10s... A V10 from a Viper will certainly have a different shape than that of a Carrera GT. The Viper will have low and mid range grunt and will lose torque up high, while a CGT will make 80-90% of it at redline. Though the Viper will definitely be more tractable and usable due to the sheer amount of it.

So with that said, do you prefer high revving motors or high displacement motors?
 

Evadman

Administrator Emeritus<br>Elite Member
Feb 18, 2001
30,990
5
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The Viper will have low and mid range grunt and will lose torque up high, while a CGT will make 80-90&#37; of it at redline. Though the Viper will definitely be more tractable and usable due to the sheer amount of it.

I should probably point out the chart I posted is from a gas V10 in a truck.

Do you prefer high revving motors or high displacement motors?

I prefer gobs of torque, preferably off idle. That means high displacement. When stomp on the accelerator, I want there to be a nearly constant acceleration from 2000 RPM to redline, not higher acceleration as redline approaches. Otherwize, you end up shifting a bunch (and losing time) to keep the engine in a very narrow powerband.
 

KIAman

Diamond Member
Mar 7, 2001
3,342
23
81
Personally, I'd take torque curve of a 6.75L TT V-8 found in the 2008 Bently Brooklands Coupe

The Brooklands is powered by a 6.75 litre Rolls-Royce twin-turbocharged V8 engine,[3] producing 530 horsepower (395 kW)[3] and 1,050 newton metres (774 ft·lbf), the highest torque ever developed by a production V8 engine. It featured on Top Gear in series 11 by Jeremy Clarkson, but due to the car having so much torque, one of the car's tyres blew out during a powerslide.
 

jtvang125

Diamond Member
Nov 10, 2004
5,399
51
91
VTEC did not add the 40HP. It might have brought the peak up maybe 10HP. Look at that chart posted on the first page. The line stays in a 20 lb ft range, but not before dropping a good 20 lb ft. Even still, how many people are really going to use a 10-20HP increase at over 6000rpm? A flat curve from 1500-4000 is a lot more practical.

Not many I'll agree but taking that little engine to redline in each gear with the vtec screaming definitely puts a smile on your face sometimes.
 

ayabe

Diamond Member
Aug 10, 2005
7,449
0
0
Having owned a VTEC-Yo mobile I'll have to chime in here. Yes 170 HP or even 200HP out of a 4 cylinder is nothing special, and laughable in anything but a super light performance car.

But the truth is the Prelude and Integra were two of the best performance cars produced in the late 80's and throughout the 90's. In terms of cheap performance there wasn't much better out there.

You could buy a POS DSM Eclipse with a turbo and it would be faster in a straight line, Mustang GT's were faster but a few mods here and there and it could get very close.

Back then, the GT's only made ~225hp and weighed ~3200lbs. Compared to 170/~2700 for the GSR.
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
A flat torque curve is infinitely better IMHO. Mmmm, the good old days.


Ram2500SC1.jpg

okay, someone's going to have to explain that one to me. The legend is saying that blue is torque and red is power. However the math says that if that were the case the red line should be below the blue until 5252RPM and then be above. Not above it the whole time. Should the key read blue=before supercharger, red=with supercharger?