To VVT or not to VVT

[blink172]

Popped into the local dealers to chat about the passenger side rubbing sound on my car, got speaking and he tells me that he just bought his boy a 182. He mentioned that a difference between the two was that the 182 had VVT and the 172 didnt, is this right? I thought we poor cousins in the 172s had vvt too, and that the changes we purely the exhausts and some other cosmetic things. Is he just talking out of his hoop as usual?

 

[Chad]

talking out of his hoop as usual

 

[McBunny]

hoop lol 172 has vvt but not like the vetec stuff just aids low speeds makes it a bit smoother

 

[wackojacko]

Does it really suprises you that you well being told total horse crap. You were in a Renault garage.

That one of the most ignorant things i heard them say. Who was this?? The service manager??

 

[KDF]

He will be telling you next you dont need to service your car till 18,000 miles

 

[Yugguy]

Yeah, my little renault dealer that I bought mine from, very nice but convinced that the 172 service intervals were 18k and also that if I did an oil change in the meantime Id trip the ECU error event and it would have to go back to the dealers for resetting.



Hmmm.

 

[Mondial172]

Thought they all had VVT? MK1,2,cup and 182

 

[Frosty]

The MK1 & MK2 172s and the Cup all have VVT on the inlet camshaft. Renault may have altered how the VVT works for the 182, but the fact remains the each of the aforementioned cars have VVT.

The V6 MK 1 doesnt have it - not sure about the MK2s though!

 

[jonnyboy]

They make you laugh. My handover monkey when I picked my 172 up said that hes written off a 172, and also that driving with the ESP on (its on by default) reduces MPG by half!! I was laughing at him!

 

[JAY172]

all 172/182 f4r engines have vvt.i think the mk2 v6 has vvt as well.looked into the vvt after many discussions and found the following

F4R in laguna 2 and megane works between 1450 and 4500 rpm,at a coolant temp above 80c and at full throttle only.

F4R in clio 172 works between 1450 and 6500 rpm,at a coolant temp above 80c and at full throttle only.

 

[Neil82]

How long would it take to reach 80c Jay? Also when at that temp would it be possible fo the coolant to fall below 80c after sensible driving?? (that may be a stupid question)

 

[JAY172]

depends on outside temp and how hard you drive it.the early rev limiter is active until you are above 80c coolant temp so as soon as the engine will rev past 6500 you are above 80c.sometimes when its quite cold mine takes a while to fully warm up.its the coolant temp the computer moniters not the oil temp.once its fully warmed up the coolant temp should stay around there until the engine is turned off.

 

[Frosty]

Im pretty sure the early limiter is driven by oil temperature.

You can warm the car up so the water temp needle sits where it normally does (normal running temp) and the early limiter still kicks in. Its usually about 5 mins after the coolant has warmed up that the limiter is raised.

 

[BenR]

Quote: Originally posted by JAY172 on 10 March 2004


all 172/182 f4r engines have vvt.i think the mk2 v6 has vvt as well.looked into the vvt after many discussions and found the following

F4R in laguna 2 and megane works between 1450 and 4500 rpm,at a coolant temp above 80c and at full throttle only.

F4R in clio 172 works between 1450 and 6500 rpm,at a coolant temp above 80c and at full throttle only.

can i say told u so lol.

I knew it didnt kick off at 4500 rpm like as per discussed a while ago.

 

[KDF]

So the VVT only works if your at WOT ?

 

[TheCake]

Sounds like it _KDF.... interesting since as dogmaul said above: hoop lol 172 has vvt but not like the vetec stuff just aids low speeds makes it a bit smoother

Surely if you driving at lower speeds, your not WOT?

Confuzzled Si.

 

[Tom]

I thought it came on at 1450 regardless of throttle postion?

 

[JAY172]

Quote: Originally posted by BenR on 11 March 2004

Quote: Originally posted by JAY172 on 10 March 2004


all 172/182 f4r engines have vvt.i think the mk2 v6 has vvt as well.looked into the vvt after many discussions and found the following

F4R in laguna 2 and megane works between 1450 and 4500 rpm,at a coolant temp above 80c and at full throttle only.

F4R in clio 172 works between 1450 and 6500 rpm,at a coolant temp above 80c and at full throttle only.

can i say told u so lol.

I knew it didnt kick off at 4500 rpm like as per discussed a while ago.

it does in all other vehicles the f4r is put in.it took me ages to find a manual that gave the other figure for the 172.nobodys perfect.

 

[JAY172]

Quote: Originally posted by Si172 on 11 March 2004


Sounds like it _KDF.... interesting since as dogmaul said above: hoop lol 172 has vvt but not like the vetec stuff just aids low speeds makes it a bit smoother

Surely if you driving at lower speeds, your not WOT?

Confuzzled Si.

the vetec has an additional cam and valves that cut in when required the 172 just uses a dephasor on the original inlet cam to advance valve timing on that cam only by 16degrees.it only works at full throttle or near enough full throttle(850mbar+ inlet manifold pressure which is near enough full throttle as full throttle is atmospheric or a 1000mbars)

 

[JAY172]

Quote: Originally posted by Tomclio182 on 11 March 2004

I thought it came on at 1450 regardless of throttle postion?

full throttle/near enough full throttle is when it kicks in(when the ecu reads 850+ inlet manifold pressue)

 

[JAY172]

why has my writing got really big even though i turn the size down

 

[JAY172]

Quote: Originally posted by Frosty on 10 March 2004


Im pretty sure the early limiter is driven by oil temperature.

You can warm the car up so the water temp needle sits where it normally does (normal running temp) and the early limiter still kicks in. Its usually about 5 mins after the coolant has warmed up that the limiter is raised.

coolant temp 80c and above.there isnt an oil temp sensor.

 

[McBunny]

lesbians and nipple clamps

 

[JAY172]

off topic but more interesting,more details for us perverted members please!

 

[BenR]

Quote: Originally posted by JAY172 on 11 March 2004

Quote: Originally posted by BenR on 11 March 2004

Quote: Originally posted by JAY172 on 10 March 2004


all 172/182 f4r engines have vvt.i think the mk2 v6 has vvt as well.looked into the vvt after many discussions and found the following

F4R in laguna 2 and megane works between 1450 and 4500 rpm,at a coolant temp above 80c and at full throttle only.

F4R in clio 172 works between 1450 and 6500 rpm,at a coolant temp above 80c and at full throttle only.

can i say told u so lol.

I knew it didnt kick off at 4500 rpm like as per discussed a while ago.

it does in all other vehicles the f4r is put in.it took me ages to find a manual that gave the other figure for the 172.nobodys perfect.

Nah, dun worry mate, you should see how much i get wrong, jsut glad i got that one thing right lol.

 

[BenR]

Quote: Originally posted by JAY172 on 11 March 2004

Quote: Originally posted by Si172 on 11 March 2004


Sounds like it _KDF.... interesting since as dogmaul said above: hoop lol 172 has vvt but not like the vetec stuff just aids low speeds makes it a bit smoother

Surely if you driving at lower speeds, your not WOT?

Confuzzled Si.

the vetec has an additional cam and valves that cut in when required the 172 just uses a dephasor on the original inlet cam to advance valve timing on that cam only by 16degrees.it only works at full throttle or near enough full throttle(850mbar+ inlet manifold pressure which is near enough full throttle as full throttle is atmospheric or a 1000mbars)

The newer i-vtec is 3 stage with 3 cam lobes and 3 follwers. And like Jay says its doesnt just phase a cam to advance or r****d a static cam profile, it actually changes the cam to one with me lift, duration and different cam timing. Lovely system.