i was told that the newer supras ie. mkiv have something called V.V.T, is there such a thing and if so what is it? the guy didnt seem to know anything about cars but i was just wondering
someone told me something i have never heard today...
- Thread starter fohead
- Start date
http://en.wikipedia.org/wiki/VVT-i
read
The 3.0 L (2997 cc) 2JZ has been produced since 1991 (first released in the 1991 Toyota Aristo). Cylinder bore was 86 mm (3.39 in) and stroke was 86 mm (3.39 in). VVT-i variable valve timing was added later in 1997 for the 1998 model year.
read
The 3.0 L (2997 cc) 2JZ has been produced since 1991 (first released in the 1991 Toyota Aristo). Cylinder bore was 86 mm (3.39 in) and stroke was 86 mm (3.39 in). VVT-i variable valve timing was added later in 1997 for the 1998 model year.
o ok well i guess he did know what he was talking about. he asked me about it and i had no info to give him now i can elaborate to him thanks
actually vvti was first intro duced in 98 with the mk4 supra. the 2jz reg. 2jz was introduced far before that.
Its rare the VVTI engines are better internally.
For example the 3SGE Altezza B.E.A.M.S. Haves dual VVTI and could be built up to 275HP or more on stock internals no problem.
But the !UZ JZ engines usually use thinner rods to make the engines more efficient and can not handle upgrades.
Also a lot of the older VVTI systems have issues with oil control and thats why DENSO have now developed an electronic VVTI actuating system.
Source: http://www.denso-europe.com/Electric-Variable-Cam-Timing--1014030000000001.aspx
In theory having an intake and exhaust cam adjust while the engine runs would give you the best of low end & highend performance even allow you to spool a larger turbo sooner by controlling adv ret of cams.
Using that and an advanced engine managment system could yeild less lag better economy better prefomance.
The problem is most peope dont know how to tune it.
For example the 3SGE Altezza B.E.A.M.S. Haves dual VVTI and could be built up to 275HP or more on stock internals no problem.
But the !UZ JZ engines usually use thinner rods to make the engines more efficient and can not handle upgrades.
Also a lot of the older VVTI systems have issues with oil control and thats why DENSO have now developed an electronic VVTI actuating system.
Source: http://www.denso-europe.com/Electric-Variable-Cam-Timing--1014030000000001.aspx
In theory having an intake and exhaust cam adjust while the engine runs would give you the best of low end & highend performance even allow you to spool a larger turbo sooner by controlling adv ret of cams.
Using that and an advanced engine managment system could yeild less lag better economy better prefomance.
The problem is most peope dont know how to tune it.
Are you positive that the 2jzgte vvti motor uses "thinner" rods than the reg motor? Vvti only controls the intake cam, there for i do not see why they would use "thinner" rods.
According to the title I thought he was going to say something along the lines of pregnancy. I'm really not sure why.
-Mike
-Mike
so let me see it i got this right... its kind of like toyotas version of vtec? or is it something completely different?
It's almost the default now, my xB has it on it's mighty 1.5L I4, cranking out a thundering 110 hp...
On the right thinking track, different technology. Vtech uses a whole extra cam lobe (iirc)
And yes, the 2jz engines in any flavor can handle 600whp reliably on stock internals. Just make sure the bearing, oiling, and supporting mods are good!
And yes, the 2jz engines in any flavor can handle 600whp reliably on stock internals. Just make sure the bearing, oiling, and supporting mods are good!
ok so is this a rarre thing or is it as common as say vtec? and has any1 ever thought of designing somthing similar to this for say the 7m series or 1j series?
ok so basically there is no such thing for 7m's? i am trying to figure this out so i know what people are talking about when they say it to me
Its a design of the head, you can't just "add" it...
1jz VVT-i's are single turbo as well, just a heads-up...
1jz VVT-i's are single turbo as well, just a heads-up...
VTEC is more like the VVT(L)I system where lift is changed.
VVTI is way more advanced also since nissan uses DESNO parts they share the same technology with VVTI.
Think of VVTI as being like those $200+ variable mechanical cam gears except instead of degreeing your cams so you get power in just one spot of the power band the VVTI cam gear shifts while the engine runs.
As far as having thinner rods all of the 1UZ vvti engines have thinner rods.
http://www.supramania.com/forums/showthread.php?t=65382
As far as JZ engines people have taken them apart and shown photos of VVTI engines having thinner rods.
But I am not 100% on it people say for sure the 1JZs vvti & non have the same rods.
But a lot of people say NA & GTE rods are the same with 2JZs but around 1998 some of the VVTIs in 2JZ came out with thinner rods.
I dont know it would have to be proven by part numbers and compairing JDM with US to be sure also.
Technicaly yes & no
http://www.nengun.com/hks/v-cam-system-step-1-a-b
They discontinued this system I dont know why but it was possible to add I am sure with some machining you maybe able to add the new denso electronic ones to the intake and exhaust cam sometime in the future.
VVTI is way more advanced also since nissan uses DESNO parts they share the same technology with VVTI.
Think of VVTI as being like those $200+ variable mechanical cam gears except instead of degreeing your cams so you get power in just one spot of the power band the VVTI cam gear shifts while the engine runs.
As far as having thinner rods all of the 1UZ vvti engines have thinner rods.
http://www.supramania.com/forums/showthread.php?t=65382
As far as JZ engines people have taken them apart and shown photos of VVTI engines having thinner rods.
But I am not 100% on it people say for sure the 1JZs vvti & non have the same rods.
But a lot of people say NA & GTE rods are the same with 2JZs but around 1998 some of the VVTIs in 2JZ came out with thinner rods.
I dont know it would have to be proven by part numbers and compairing JDM with US to be sure also.
RazoE;1524124 said:
Technicaly yes & no
http://www.nengun.com/hks/v-cam-system-step-1-a-b
They discontinued this system I dont know why but it was possible to add I am sure with some machining you maybe able to add the new denso electronic ones to the intake and exhaust cam sometime in the future.
Nghty89;1524016 said:
Correct. VTEC = Variable Timing and lift Electronic Controler Each pair of valves have their individual lobes with a vtec lobe in between them. When vtec is engaged a solenoid engages an additional rocker placing both valves under the control of the shared vtec lobe. Essentially it allows the car to have two cam profiles, one for low end/mid range enconomy driving and another for high end performance. Newer models come with i-VTEC and despite common misconception it has nothing to do with apple or iTunes (that was a joke) The "i" stands for intelligent and is the addition of a VTC (variable timing controller) which allows the computer to advance or retard cam timing. VTEC was originally developed in the C30 NSX engine and released in 90 stateside. I believe it was 89 in japan but dont quote me on that.
Honda essentially started this trend which was resultant of systems such as the aforementioned VVTi and MIVEC systems. Many other systems have been researched such as 3 dimensional lobe profiles on a hollow camshaft on a splined core that would allow the cam to actuate throughtout the rpm range. Ferrari had tested this concept and abandoned it. As we move into the future we will likely see valves that would be controlled by precision linear actuators controlled by the engine computer. This will not only enable the ability for infinite adjustment of valve timing and lift but also completely eliminate timing chains cams and all that good stuff.