CPS (Cam Profile Switching) vs VVTI vs DVVT

[Newbienissan]

but even pro oso crash sometimes la. for the engine types, frankly regardless what engine they are, na or turbo, vtec or whatever, the most important is the powerband should kick in at the right time, and the rev range must not overheat during the whole course. and the car chassis n handling can take the maximum speed n maximum braking range.

so by just judging the power the engine produces, it doesnt mean the car will be fastest uphill. I believe thats why the wira gsr trying to chase me franticly as i was juz driving a stock satria neo. and also i have been driving genting roads for quite some time i know every corner and its limits, but the wira gsr was a newbie to genting i guess. it has a high gt-wing, the rear of the wheel is tonggek up so high, if pushing that car to maximum it will lose control. im just surprised that the owner doesnt know how to tune a car properly.

---------- Post added at 11:47 AM ---------- 6 hour anti-bump limit - Previous post was at 11:42 AM ----------

All in all, the driver matters the most....so my prediction is correct huh...mad driver with a Kancil L2 will win afterall

kancil L2 still faces a problem, near the tokong all the way up to genting first world hotel, it is VERY steep, and L2 tends to overheat at that part of the course. but i have not tried with modified L2 like 850turbo or 960turbo. but if play genting sempah, L2 is just nice, nimble and ez to drive in the hairpins

 

[GSR06]

I just wish the wira owner could tell us what happened on that day :P Anyway, you are a regular on that uphill course and you have the upper hand though. Knowing the twist and turn of the course earlier has already won 50% of the race. With high GT wing, it should be giving a high downforce and should provide more traction during high speed cornering.

If you had tested with L2 using SNeo CPS, it will be more interesting...like WRC, the size of the rally cars are like already downsized...see the C4 and ford focus for example. No VTEC or VVTI, there is no problem...

 

[Newbienissan]

rally cars are 4wd, rollcaged, interior stripped, and so much more. it is heaven n hell to compare a wrc car with a wira gsr

 

[GSR06]

..hehe...I wasn't comparing WRC cars with Wira...I was just saying the size of the rally cars had reduced tremendously if compared to the cars in early 2000. Afterall, it might be due better handling and easier to drive

There is also S Neo participating in rally right now but I believe it is a 2.0L engine...not CPS I guess...

 

[Newbienissan]

hehe, what I felt is satria neo cps beat a gsr is so hard to believe for you......you should come n drive genting when u have the opportunity urself n understand why small hatches is so important for to play genting

 

[GSR06]

Well, whether to believe or not, it depends on the individual la. For the GSR vs SNeo CPS debate, we could ask others for more opinion and I totally understand what you were trying to explain all this while. Basically, if I don't know the course well, I won't push my car to the limit.

 

[EGNINE]

in the wira & neo case, 1stly that was not even a mutual race..how do we know the other driver push the car or not... normally people make assumption that the other party were racing with us...may be his fuel level too low to push the car, maybe he has faulty absorber, maybe he has leaked boost, plus tonggek car on touge? no chance lerr...

but i do agree that neo really got good handling to tackle corner

 

[max327]

Pity on u Mr.GSR06...May I help u with my little bit xprience n opinion....
CPS compared to VVTi or DVVT...:-
A) Performance ...
* Pick-up
1) DVVT
2) VVTi
3) CPS
* Long
1) CPS
2) VVTi
3) DVVT

B) Fuel Efficiency ...
1) DVVT
2) VVTi
3) CPS

C) Advantegeos/Disadvantegoes ...
1) DVVT
Advan --> hardly R&D by TOYOTA & DAIHATSU plus with PERODUA..(3 R&D made) ..this tech is base from VVTi
Disadvan > some politic involved in this 3 car manufacturer will effect others fact such like every R&D not 100% shared with themself..
2) VVTi
Advan --> hardly R&D by TOYOTA, founder of Variable Valve Timing using rocker arm system..
Disadvan > high cost to maintain, moderate finding spare parts.
3) CPS
Advan --> R&D influenced by europe technology, easy spare parts, by Malaysian
Disadvan > not very suitable with Malaysian culture (driving culture + environment fact ex..wheather, road)..middle range R&D...

Well, statement above is influent by different car weight, gear transmition ratio, combusion engine design, aerodynamic fact, engine capacity ..n etc... that mean... all 3 technology seemly similiar on about performance, fuel, n others if apply these technologies into 1 single engine system... Just the diff is the design..These technology, car is made to fullfill market requirement n needed...example...'If want to buy a car..hav to ask self demand n interest..' This mean...these car's R&D is diff & unique...But.., I can say all these tech is GOOD...!!

think there is some confusion here.
1) DVVT and VVTi are the same thing, eg
myvi, kembara - K3-VE DVVT
avanza - K3-VE VVTi

2) VVTi does't have rocker arm. most DOHC engine doesn't have rocker arm, except VTEC and MIVEC which use rocker arm to achieve cam lobe/profile changing.

 

[max327]

back on the topic of CPS vs VVTI vs DVVT

VVTI = DVVT changing the valve timing (but not the duration, lift) CONTINOUSLY
just like changing to a Adjustable Cam Pully, but VVTi/DVVT do it on the fly when the engine is running.

CPS (comparable to VTEC, MIVEC, NEO VVL) changing CAM PROFILE/LOBE in STAGES altering valve TIMING, DURATION, LIFT all in one go. just like changing to High Lift cam shaft, but on the fly

technologically speaking, CPS is got more potential and flexibility than VVTi, also more sophisticated but more difficult to implement. (changing to ACP vs changing to High CAM, which one more gain? which one more difficult?)

then, there is iVTEC and VVTL-i = changing to ACP and also High CAM. best of both world.

---------- Post added at 02:44 PM ---------- 6 hour anti-bump limit - Previous post was at 02:21 PM ----------

if compare CPS (mechanism) to VTEC, MIVEC, NEO VVL, CPS got even more flexibility, cause each individual valve got their own set of high/low lift cam lobe.
for CPS, each cylinder is service by 4 different cam lobe while VTEC/VVL and newer MIVEC have 3 (different low lift cam for each valve, the high lift cam are shared), older MIVEC only has 2(as in G92)
(note, i mean CPS got 4 intake lobe per cylinder, 2 high, 2 low. and thanks artworkz for correction, newer MIVEC is not cam changing anymore, become CVVT instead)

of course, the credit should goes to LOTUS, not PROTON.

and each valve in the CPS have their own sliding pin mechanism (in the tappet) to engage the high cam.

by adding an extra sliding pin mechanism, hydraulic channel and V-tec solenoid HONDA is able to create a 3-stage VTEC which have a "12 valve mode" to enhance fuel economy.
search for "3 stages vtec autozine" in google

so MY IDEA for the CPS is, since each valve already had their own set of high/low cam and sliding pin mechanism; by adding an extra hydraulic passage and hydraulic controller, the valve lift of each valve in the same cylinder can be control independently, and a "4 stages CPS" can be achieve.

eg,
left valve got lift 0, 3
right valve got lift 2, 4
(bigger number = higher lift, longer duration)

stage 1: left 0, right 2
stage 2: left 0, right 4
stage 3: left 3, right 2
stage 4: left 3, right 4

 

[artworkz]

back on the topic of cps vs vvti vs dvvt

vvti = dvvt changing the valve timing (but not the duration, lift) continously
just like changing to a adjustable cam pully, but vvti/dvvt do it on the fly when the engine is running.

Cps (comparable to vtec, mivec, neo vvl) changing cam profile/lobe in stages altering valve timing, duration, lift all in one go. Just like changing to high lift cam shaft, but on the fly

technologically speaking, cps is got more potential and flexibility than vvti, also more sophisticated but more difficult to implement. (changing to acp vs changing to high cam, which one more gain? Which one more difficult?)

then, there is ivtec and vvtl-i = changing to acp and also high cam. Best of both world. bmw valtronic use variable valve timing and variable lift

---------- post added at 02:44 pm ---------- 6 hour anti-bump limit - previous post was at 02:21 pm ----------

if compare cps (mechanism) to vtec, mivec, neo vvl, cps got even more flexibility, cause each individual valve got their own set of high/low lift cam lobe.
For cps, each cylinder is service by 4 different cam lobe while vtec/vvl and newer mivec have 3 (different low lift cam for each valve, the high lift cam are shared), older mivec only has 2(as in g92)

of course, the credit should goes to lotus, not proton.

And each valve in the cps have their own sliding pin mechanism (in the tappet) to engage the high cam.

By adding an extra sliding pin mechanism, hydraulic channel and v-tec solenoid honda is able to create a 3-stage vtec which have a "12 valve mode" to enhance fuel economy.
Search for "3 stages vtec autozine" in google

so my idea for the cps is, since each valve already had their own set of high/low cam and sliding pin mechanism; by adding an extra hydraulic passage and hydraulic controller, the valve lift of each valve in the same cylinder can be control independently, and a "4 stages cps" can be achieve.

Eg,
left valve got lift 0, 3
right valve got lift 2, 4
(bigger number = higher lift, longer duration)

stage 1: Left 0, right 2
stage 2: Left 0, right 4
stage 3: Left 3, right 2
stage 4: Left 3, right 4

did u really understand what is cps??? Cps control valve profile, by `off` use low lobe, and `on` use high lobe.
What u r talking is u misunderstanding mechanism of cps.

---------- Post added at 03:05 PM ---------- 6 hour anti-bump limit - Previous post was at 03:00 PM ----------

newer mivec is run variable timing oni, no run high/low cam anymore.

 

[Newbienissan]

*eat popcorns reading*

to me, the results more important. may i say, vvti for fuel saving, and cps for performance ?

 

[max327]

did u really understand what is cps??? Cps control valve profile, by `off` use low lobe, and `on` use high lobe.
What u r talking is u misunderstanding mechanism of cps.

---------- Post added at 03:05 PM ---------- 6 hour anti-bump limit - Previous post was at 03:00 PM ----------

newer mivec is run variable timing oni, no run high/low cam anymore.

first i had to emphasis the "4 stages CPS" is just my wild idea.

fully understood.
so how is the CPS "off" and "on" being accomplish?
CPS use hydraulic tappet to do it. the inner tappet is always in-sync with the valve stem, but only in-sync with the low lobe when off
when "on" the inner and out tappet will be lock together by the hydraulic actuated sliding pin. since the outer tappet is in-sync with the outer tappet, the valve will be operated by the high lobe.

what kind of high/low profile (which includes timing,duration,lift) the lobes have is up to the manufacturer (proton, porsche, land rover), or even after market parts manufacturer.

thanks for reminding me of the valvetronic, but it's in the league of it's own, CONTINUOUS valve lifting (vs stages in VTEC/CPS...)

thanks for correcting, the latest MIVEC no longer provide variable valve lift.

 

[max327]

while my previous post explain the difference of CPS (which uses the tappet) vs other cam lifting techno, take note most other techno use rocker arms (VTEC, VVL, MIVEC) to make the cam shifting.

CPS as use in campro cps is similar to porsche variocam plus, just that porsche also have the VVT (like i-vtec)

the middle picture shows "high lift", the little green part in the tappet is engaged, locking the outer and inner tappet. low cam not touching the inner tappet.

picture on the right shows "low lift", the inner tappet seems "protrude" out to touch the low cam in the middle. actually is the high lift cam on the outside pushing the outer tappet down without acting on the valve.

below is a bigger picture showing the "low lift". sliding pin in red not engaging.

the inner tappet ALWAYS contact with the valve.

 

[max327]

knowing that CPS is comparable to VTEC, MIVEC, most people immediately compare CAMPRO CPS to B16A and 4G92 MIVEC. then draw conclusion that CPS is inferior to VTEC, MIVEC.

this is not fair, cause in B16A and 4G92 MIVEC the variable valve lift is being employed on both intake and exhaust. while Campro CPS only have it on the intake.

another fact that had never been mentioned in this tread is the BORE and STROKE.

campro CPS 76 x 88 mm (small bore, long stroke)

B16A 81 x 77.4 mm
4G92 (mivec or non-mivec DOHC) 81 x 77.5 mm
big bore, short stroke, OVER SQUARE, HIGH revving.

so, base on the bore and stroke design, CAMPRO CPS was never design to be a high revving engine.

power = torque x RPM/k (k is a constant)

so loosing the high RPM capability also means loosing on HP

---------- Post added at 08:33 PM ---------- 6 hour anti-bump limit - Previous post was at 07:46 PM ----------

so, it will be more fair to compare the CAMPRO CPS to a current generation engine which comply with the current emission regulation and with variable lift on intake only.

take the honda civic FD2's K20Z2 DOHC i-VTEC with the variable valve lift on intake cam (and advantage of variable timing control)
1998cc
86x86mm (square)
155 hp @ 6000 rpm
188 N·m @ 4500 rpm
specific horsepower 77.6hp/liter

CAMPRO CPS, DOHC, variable valve lift on intake
1598cc
76 x 88 mm
125 bhp (93 kW; 127 PS) at 6,500 rpm
150 N·m (110 ft·lbf) of torque at 4,500 rpm
specific horsepower 78.2hp/liter

now, you shall see that the CAMPRO CPS got pretty comparable performance to a current generation engine with singe variable vale lift (and also VTC).
isn't that pretty impressive?at least on paper.

wait till the CPS being implement on both side. then we shall see.

 

[artworkz]

evo x 4b11 oni have variable timing and dun have variable valve lift.

 

[max327]

evo x 4b11 oni have variable timing and dun have variable valve lift.

thanks again for correction. misread when checking on wikipedia

 

[boyzone]

Let's me clearify again.

Latest i-Vtec, Mivec are establish to acheive Euro 4 emission control.
Thus, all the technologies are apply on intake cam only.
So, cannot compare with those 90s v-tec and mivec, which is no emission control.

Today, if no emission control on CPS engine, output for this engine should be capable to achieve 145ps.

 

[GSR06]

What about the latest Vios with Dual VVT-I and the 7-speed Super CVT-I ? It sounds great and CVT-I is equivalent to Mitsubishi's INVEC III gearbox?

Boyzone, congrats. for being a Sr Member in ZTH and when is my turn to become one :P Yes, we hear you about the Euro 4 emission control...

 

[boyzone]

What about the latest Vios with Dual VVT-I and the 7-speed Super CVT-I ? It sounds great and CVT-I is equivalent to Mitsubishi's INVEC III gearbox?

Boyzone, congrats. for being a Sr Member in ZTH and when is my turn to become one :P Yes, we hear you about the Euro 4 emission control...

Thx bro..

5 yrs ++ in ZTH
Time passing so fast.
Actually, Toyota is put a lot of technologies interm of fuel efficiency.
Their road map is from FC.

 

[Newbienissan]

yes, put a vvti vs ivtec vs cps, vvti will win hands down on best fc