CPS (Cam Profile Switching) vs VVTI vs DVVT

[D7zul]

why bother with high cam idling..?

get a VTEC / CPS / VVTLi / etc..

those engine comes with 2 cam... 1 small cam for low rpm & idling.. the other 1 hi cam for high rpm..

 

[GSR06]

You meant high cam will have unstable idling and it is normal? I haven't experienced it before and don't intend to actually

*well..regarding highcam a.k.a extreme performance cam....no amount of pulley adjustment or ecu tuning could do wonder and maintain proper idling...especially when power comes first in the tuning target......if mild cam or street cam it wasn't really big problem since the powerband and valve overlap not that much compared to full race/highcam/extreme cam.....

yep...FC would be sky high due to several reason:
1)high/unstable idling
2)injector working hard to keep the fuel amount accurate during that unstable idling
3)have to rev the engine a bit high to get the car first moving from stand still (traffic jams madness)

but city driving of car using highcam oso shiokkk what....




(u have to drive like mad revving and accelerating hard every possible moment...wakakakakkakaaka)

---------- Post added at 08:09 PM ---------- 6 hour anti-bump limit - Previous post was at 08:08 PM ----------

Some people just like to modify...just for the fun of it la ...

why bother with high cam idling..?

get a VTEC / CPS / VVTLi / etc..

those engine comes with 2 cam... 1 small cam for low rpm & idling.. the other 1 hi cam for high rpm..

 

[D7zul]

You meant high cam will have unstable idling and it is normal? I haven't experienced it before and don't intend to actually



---------- Post added at 08:09 PM ---------- 6 hour anti-bump limit - Previous post was at 08:08 PM ----------

Some people just like to modify...just for the fun of it la ...

hohoho.. boyz juz wanna have fun with their toyz..

 

[Veloc]

Just want to add...

VTEC, there is a 3 stage version also.
Mivec, they phased out the profiling and lift in later models and concentrate in variable valve timing.
iVtec, Huge range of hardware & settings for different car because honda doesn't change the badging. They just keep it simple as iVtec. Some have all of the above, some have timing only, some have timing on intake only, some on both camshaft, some incorporate lean burn like the honda stream.

 

[^pomen_GTR^]

You meant high cam will have unstable idling and it is normal? I haven't experienced it before and don't intend to actually


Some people just like to modify...just for the fun of it la ...

yep....most *highcam would have unstable idling or stable but very high idling..somewhere 1600rpm onwards untill 2500rpm....

or it would be like semput-semput...pum pum pum pum...during idling...due to high valve lift and big valve overlap duration....because at lower rpm the engine pumping efficiency was low (due to the cam profile)....

this was considered normal for cam that have *295degree and above.....if the duration was less than that,u might have a chance to reduce the idling problem..(also depends on the tuner capability and engine hardware ability)


thats why most ppl say if install highcam not good for daily/street use..especially on engine that doesn't have vvt/v-tec/mivec/cps function to switch cam profile/advance-retard the cam......


but that doesnt stop ppl using highcam on their street car.....well....u have to live from what u choose and what u ask for [power]....

 

[0382]

I thought for high cam, the rpm should not fluctuate so much and it might be related to throttle body faulty or something like that. Maybe, the 1.5k RPM setting for high cam is due to the adjustable cam pulley that is set at certain angle...need some experts to confirm this point as well la...any sifu can help to confirm this point or not...any engine type can be tuned to be high cam right?



---------- Post added at 07:56 PM ---------- 6 hour anti-bump limit - Previous post was at 07:54 PM ----------

Normally car only has 5 gears...I learnt that high cam is only syiok during highway drive and not city drive...and certainly, the FC will be sky high too.

yep....most *highcam would have unstable idling or stable but very high idling..somewhere 1600rpm onwards untill 2500rpm....

or it would be like semput-semput...pum pum pum pum...during idling...due to high valve lift and big valve overlap duration....because at lower rpm the engine pumping efficiency was low (due to the cam profile)....

this was considered normal for cam that have *295degree and above.....if the duration was less than that,u might have a chance to reduce the idling problem..(also depends on the tuner capability and engine hardware ability)


thats why most ppl say if install highcam not good for daily/street use..especially on engine that doesn't have vvt/v-tec/mivec/cps function to switch cam profile/advance-retard the cam......


but that doesnt stop ppl using highcam on their street car.....well....u have to live from what u choose and what u ask for [power]....

hehehe.... high cam,
i love the idling sound of overlapping valve, prump,prump,prump,prump,prump....
and put advance the intake cam, remap ecu for feul and advance timing, pranggggg....
J*J will ask : ada pakai high cam ke?

 

[GSR06]

The sky is the limit for car modifications.

hohoho.. boyz juz wanna have fun with their toyz..

---------- Post added at 09:09 PM ---------- 6 hour anti-bump limit - Previous post was at 09:08 PM ----------

You are driving one?

hehehe.... high cam,
i love the idling sound of overlapping valve, prump,prump,prump,prump,prump....
and put advance the intake cam, remap ecu for feul and advance timing, pranggggg....
J*J will ask : ada pakai high cam ke?

---------- Post added at 09:19 PM ---------- 6 hour anti-bump limit - Previous post was at 09:09 PM ----------

I really can't imagine the idling rpm is at 2.5k Need to buy a petrol station later

Any heavily modified high cam (N/A) can beat a turbocharged or supercharged car or not? Based on history, which engine technology can be modified easily with high cam huh? I am sure high cam sound can be differentiated easily.

One will do anything just for the power syiok..

yep....most *highcam would have unstable idling or stable but very high idling..somewhere 1600rpm onwards untill 2500rpm....

or it would be like semput-semput...pum pum pum pum...during idling...due to high valve lift and big valve overlap duration....because at lower rpm the engine pumping efficiency was low (due to the cam profile)....

this was considered normal for cam that have *295degree and above.....if the duration was less than that,u might have a chance to reduce the idling problem..(also depends on the tuner capability and engine hardware ability)


thats why most ppl say if install highcam not good for daily/street use..especially on engine that doesn't have vvt/v-tec/mivec/cps function to switch cam profile/advance-retard the cam......


but that doesnt stop ppl using highcam on their street car.....well....u have to live from what u choose and what u ask for [power]....

 

[^pomen_GTR^]

The sky is the limit for car modifications.


I really can't imagine the idling rpm is at 2.5k Need to buy a petrol station later

Any heavily modified high cam (N/A) can beat a turbocharged or supercharged car or not? Based on history, which engine technology can be modified easily with high cam huh? I am sure high cam sound can be differentiated easily.

One will do anything just for the power syiok..

its not really stay at 2.5k......its like crazy idle....playing down from 800rpm to 2.5k rpm later goes down back up-down-up-down......

heavily modded n/a can surely beat some turbo engine (provided that turbo engine was stock) but turbo always got fat torque graph curve advantage in acceleration.....

another perfect example of super high cam in N/A engine is F1 engine....that one idling was exactly at 2.5k rpm.....

 

[D7zul]

NA can beat Turbo?

in a straight line (drag race) NOT A CHANCE..

on track with lots of corners.. any engine can win..

it all depends on 'how much fuel u burn'..

the more fuel u burn.. the more power u make.. cause power comes from fuel.. duh..

---------------------

most manufacturer like to turbocharge their engine because it can save fuel when idling..

imagine a 5liter NA engine in a traffic jam.. how much fuel they burn?

then imagine a 2.5 liter Turbo engine in a traffic jam.. much less fuel burn, doesnt it?

both of that engine produce roughly the same power..

 

[^pomen_GTR^]

zul..i said some turbo...not all turbo can get beaten by heavily modded n/a car...


guess u already heard and maybe saw some illegal/legal drag where n/a ride beat turbo ride....well....world of mods is huge....so many factor played their role....


but highcam idling was like ectassy.....u'll carried away by it even tough the power not really that high (especially on n/a engine)

 

[EGNINE]

zul..i said some turbo...not all turbo can get beaten by heavily modded n/a car...


guess u already heard and maybe saw some illegal/legal drag where n/a ride beat turbo ride....well....world of mods is huge....so many factor played their role....


but highcam idling was like ectassy.....u'll carried away by it even tough the power not really that high (especially on n/a engine)

yup agree with you...saw few time already na car beat turbocharge car...usually the turbo car which beaten by NA car is langsi type or just convert to turbo car...always wanted to ram ram at other NA car or make SQV sound next to NA car...when they were beaten by NA car straight away they drive slowly after that haha...seldom see Monster turbo do that kind of thing huhu ...

 

[0382]

yup agree with you...saw few time already na car beat turbocharge car...usually the turbo car which beaten by NA car is langsi type or just convert to turbo car...always wanted to ram ram at other NA car or make SQV sound next to NA car...when they were beaten by NA car straight away they drive slowly after that haha...seldom see Monster turbo do that kind of thing huhu ...

i had seen 1.6 NA modded proton car beat 1.8 mitsu-proton turbocharge on hiway espacially when exit corner, NA do not have lag ma...

GSR06 yup, it was before but now no more la, sudah 40an hati sudah ada goyang and not hati kering lagi la :proud:

 

[GSR06]

If the idling sensor is faulty, you also have similar crazy idling...anyway, I am not going for high cam setting though after listening to your comments

Yes..Heavily modded N/A can beat turbo engine and like I said, the sky is the limit in terms of car modifications. I also heard a heavily modified kancil (N/A) can beat a GSR...this happened in KL though.

F1 is a totally different beast...I heard they plan to change to inline 4 with turbocharged engine in the near future. If they can put turbocharged VTEC/CPS/VVTI or anything in F1...lagi best.

its not really stay at 2.5k......its like crazy idle....playing down from 800rpm to 2.5k rpm later goes down back up-down-up-down......

heavily modded n/a can surely beat some turbo engine (provided that turbo engine was stock) but turbo always got fat torque graph curve advantage in acceleration.....

another perfect example of super high cam in N/A engine is F1 engine....that one idling was exactly at 2.5k rpm.....

---------- Post added at 09:49 PM ---------- 6 hour anti-bump limit - Previous post was at 09:46 PM ----------

Passion doesn't die easily la...if you love car modifications, the age is not the limit. Anyway, have to be careful lor.

Usually, a normal car can't beat a turbocharged car unless it is heavily modified.

i had seen 1.6 NA modded proton car beat 1.8 mitsu-proton turbocharge on hiway espacially when exit corner, NA do not have lag ma...

GSR06 yup, it was before but now no more la, sudah 40an hati sudah ada goyang and not hati kering lagi la :proud:

---------- Post added at 09:51 PM ---------- 6 hour anti-bump limit - Previous post was at 09:49 PM ----------

Kesian the owners with turbocharged engine...usually, turbo car will always kena cucuk from the back one eventhough the car is in joyride mode at least, this is what I usually experience ma.

yup agree with you...saw few time already na car beat turbocharge car...usually the turbo car which beaten by NA car is langsi type or just convert to turbo car...always wanted to ram ram at other NA car or make SQV sound next to NA car...when they were beaten by NA car straight away they drive slowly after that haha...seldom see Monster turbo do that kind of thing huhu ...

 

[mines998]

Yesterday I saw a CPS dyno chart it seem the power band only been lift up around 5000 to 5500 rpm it kinda slow compare with VTEC. Just wondering does the CPS really significant?

 

[^pomen_GTR^]

cps inly activate at intake side cam....


not both side like old mivec and v-tec...

and they focus on better low rpm powerband instead of high power..(also to cope with EU emission std "maybe")

 

[GSR06]

Wait for the CPS Turbo to be available soon...then, it might be significant. Not many people talk about normal CPS though.

Yesterday I saw a CPS dyno chart it seem the power band only been lift up around 5000 to 5500 rpm it kinda slow compare with VTEC. Just wondering does the CPS really significant?

---------- Post added at 08:42 AM ---------- 6 hour anti-bump limit - Previous post was at 08:31 AM ----------

Old MIVEC is good. MIVEC, as with other similar systems, varies the timing of the intake and exhaust camshafts which increases the power and torque output over a broad engine speed range while also being able to help spool a turbocharger more quickly.

Not sure about VTEC. SOHC VTEC and DOHC VTEC have differences though. I don't think current I-VTEC controls both intake and exhaust camshafts. Kindly confirm.

cps inly activate at intake side cam....


not both side like old mivec and v-tec...

and they focus on better low rpm powerband instead of high power..(also to cope with EU emission std "maybe")

 

[mines998]

Ya...the after market forge piston & con rod already available happy boosting.

 

[GSR06]

I just love the sound of VTEC when it kicked in @5000 rpm.. whoever loves VTEC, maybe this is the reason though.

YouTube - b20 Vtec turbo 318whp

---------- Post added at 07:57 PM ---------- 6 hour anti-bump limit - Previous post was at 07:52 PM ----------

Yaris' top speed...

YouTube - Yaris T-Sport Top Speed - 202,7km/h

---------- Post added at 08:03 PM ---------- 6 hour anti-bump limit - Previous post was at 07:57 PM ----------

No end la...

Ya...the after market forge piston & con rod already available happy boosting.

 

[^pomen_GTR^]

yaris-T use same engine as yrv-t rite??? K3-vet (with vvt) am i correct???

 

[GSR06]

Toyota Yaris T Sport is a B Segment car. It has a 1.5L engine (1NZ-FE) with VVT-I. It also develops 106 DIN hp (78kW) of power at 6,000rpm and has maximum torque of 145Nm at 4,200rpm.

Daihatsu YRV-T uses a 1.3L engine with DVVT technology. Maximum power is 129 PS at 6,400 rpm & its torque is rated to be 125.4 lb.ft

Engine wise should be different then. I might be wrong though. YRV-T is faster from 0-100kmh (8.1s vs 9.0s for Yaris T Sport).

yaris-T use same engine as yrv-t rite??? K3-vet (with vvt) am i correct???