VRIS

[Shady469]

I was reading on Vaughn Niroshima's (sorry if i killed the spelling) Page about how we have a VRIS (Mazdas version of the VTEC). It sounded like this was to help in improving low end torque which is great and all but due to the lack of any kind of top end tq. theres no pull in the higher rpms. Then, it seems to me, when i shift into the next gear im half way through the VRIS's control and before long the acceleration has gone to a crawl.<BR>I just want to know what we can do to make it(the duration of the VRIS) last longer or happen later in the power band. I was even thinkin would a feild VTEC controller work if our ECU's had a pin for the VRIC.<BR>also, i accelerate pretty fast to about 3,800-4000 then it seems to slow way down then accelerate again (still kind of slow) around 4,500 untill red line. what is this all about?<BR>thanx in advance for any input.<p>[ March 19, 2002: Message edited by: Shady469 ]

[white fish]

do you meen VRIS and if so I thought it was the V6 only but then again I know very little about the I4

[Shady469]

yeah VRIS sounds more like it... <BR>and u were correct in that it is just in the V6 (from the thing i read anyway).<BR>so i guess that makes me look like a bit of a gooder but you V6 can lead the way on this discussion......<p>[ March 19, 2002: Message edited by: Shady469 ]

[Brainless]

Can you post a link, I can't find it on the page?

[pelado]

Just in case you guys don't know there is a online shop manual for the MX-3 on mx-3.com. You know, that site that hosts this bulletin board?<P>VRIS stands for Variable Resonance Induction System. It isn't used on the 4 cyl and it is nothing like the VTEC in Hondas. VRIS controls two butterfly valves in the intakes of the V-6s to take advantage of resonance in the pressure waves to make the most torque possible. Check out the shop manual, look under engines, specifically the K8, then look for VRIS.<P>Honda's VTEC consists of a multiple rocker arms actuated by different cam lobes with different profiles on the same camshaft. There is one cam profile for normal driving and another for high horsepower. At a specific RPM (~4500, I think) a solenoid operates using oil pressure to position the second set of rocker arms, actuated by the wilder cam, so they are now operating the valves vs. the mild cam. This allows one to have a decent idle, decent mileage, and low emissions while still having a cam profile for high horsepower romps. The VTEC setup is just dead weight for racing however, and the serious racers dump it for a regular cam setup.<P>Honda isn't the only maker to use this system, the Porsche Variocam setup on the 968 was similar, Suzuki even used a similar system on a special version of the home market Bandit, and there are lots of variable timing systems in usage today.

[Brainless]

Don't forget Tayota's VVT-I. I think nissan and subaru also has their version of this technology.

[mrprecidia]

mazda also has this variable valve timeing technology on ther newer engines.

[pelado]

Like I said, Honda isn't the only one and wasn't the first.

[justin h]

By the way Mazda was the first car company to use the variable valve timing. It was used on the Eunos Cosmos.

[Coolzombi]

even PORSCHE have this system for a while...<BR>...i think its call VARIOCAMS...<P>(hmmm... porsche)

[pelado]

Is there an echo in here?