ClioSport.net
Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
-
When you purchase through links on our site, we may earn an affiliate commission. Read more here.
ph1 172...a red one
its called VVT BUT it isn't the same as say TypeR...it comes on cam basically!!
ph1 172...a red one
lol...i'm right...
Pink & Blue 182, JDM DC2
From yesterday...
http://www.cliosport.net/forum/showthread.php?t=223506
Do a quick search and you'll see its been discussed trillions of times.
http://www.cliosport.net/forum/showthread.php?t=223506
Do a quick search and you'll see its been discussed trillions of times.
Tom
ClioSport Club Member
EV (s)
Both.
ph1 172...a red one
from BenR in THIS post
the vvt system in the 172/182 range is there simply to allow the renault engineers to run a wilder camshaft without any of the problems you would associate with larger overlap cams on a plenum with a classic speed density system.
The vvt system is a simple 1 step phasing operation which advances the inlet cam only by 16 degrees. In its resting (depahsed) status it sits with the valve events netting a zero overlap status. This gives a strong map signal and constant manifold vacuum at idle and low throttle angle, which makes smooth mapping at lower rpm and throttle angle easier, along with better emissions and economy.
As soon as you increase manifold pressure to 800mb+ and go above 1450rpm, the ecu will advance the cam. Its such a low rpm threshold because the cams are not that wild, but wild enough to cause problems at idle.
The kick at 5000rpm is simple the 'on cam' phenomenon where all operating parameters favourably meet and you get a sudden increase in volumetric efficiency.
the vvt system in the 172/182 range is there simply to allow the renault engineers to run a wilder camshaft without any of the problems you would associate with larger overlap cams on a plenum with a classic speed density system.
The vvt system is a simple 1 step phasing operation which advances the inlet cam only by 16 degrees. In its resting (depahsed) status it sits with the valve events netting a zero overlap status. This gives a strong map signal and constant manifold vacuum at idle and low throttle angle, which makes smooth mapping at lower rpm and throttle angle easier, along with better emissions and economy.
As soon as you increase manifold pressure to 800mb+ and go above 1450rpm, the ecu will advance the cam. Its such a low rpm threshold because the cams are not that wild, but wild enough to cause problems at idle.
The kick at 5000rpm is simple the 'on cam' phenomenon where all operating parameters favourably meet and you get a sudden increase in volumetric efficiency.
Civic Type R EK9
5k is cam, vvt runs from 1.6k to 5.5k
Civic Type R EK9
i do know i got that from fred ay yozzasport LOL
Civic Type R EK9
speak to fred he will tell you most accurate prices and yes you can
FredYozzasport IIRC
Without wanting to get shot down, isn't the confusion here about what is meant by "on cam"?
The F4R engine in the 172/182 (and various other renault's in a different form) has basic variable valve timing. As described before this simply changes the camshaft angle by 16 degrees so that the inlet valves open at a different point in the cycle. Between idle and about 1500rpm the system is on timing mode 1, then at about 1500rpm timing mode 2 is activated and the cam angle changes so that the inlet valves open sooner causing overlap with the outlet valves designed to give the engine a torque boost. Above about 5000 rpm, the system goes back to timing mode 1 to achieve maximum power.
I wouldn't really call this coming "on cam" in the Honda V-TEC way, which actually employs 2 sets of lobes on the camshaft, each which can have different timing, lift height and opening duration. Hence, when a V-TEC engine comes "on cam" it is actually moving from one set of lobes to the other.
I think the 197 has the same F4R engine but with a more sophisticated continuous variable valve timing system, i.e. the cam angle hasn't just got 2 positions but is constantly adjusted depending on engine speed.
The F4R engine in the 172/182 (and various other renault's in a different form) has basic variable valve timing. As described before this simply changes the camshaft angle by 16 degrees so that the inlet valves open at a different point in the cycle. Between idle and about 1500rpm the system is on timing mode 1, then at about 1500rpm timing mode 2 is activated and the cam angle changes so that the inlet valves open sooner causing overlap with the outlet valves designed to give the engine a torque boost. Above about 5000 rpm, the system goes back to timing mode 1 to achieve maximum power.
I wouldn't really call this coming "on cam" in the Honda V-TEC way, which actually employs 2 sets of lobes on the camshaft, each which can have different timing, lift height and opening duration. Hence, when a V-TEC engine comes "on cam" it is actually moving from one set of lobes to the other.
I think the 197 has the same F4R engine but with a more sophisticated continuous variable valve timing system, i.e. the cam angle hasn't just got 2 positions but is constantly adjusted depending on engine speed.
So has anyone in the Renault tuning business thought about how they could use the vvt hardware that's on the engine to get more horsepower?
No, its technically poinltess to do just a single stage kick since its of a set advance amount. By the time you run a cam thats wild enough to make use of a later phasing point, the stock management system would not be able to cope too well. And anybody should be running bodies and standalone by then.
Technically VTEC changes cam lobe, so is not really 'coming on cam' which is an old skool term to refer to the phenomenon where engine efficiency suddently takes a rise as port velocities increase.
If you ran on the high cam lobe on vtec only, then the point at where it all of a sudden came on song is the cam 'comming on cam'. The classical use of the term has no reference to any mechanical changes.
