VRIS POINTS.....OPEN OR NOT

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » March 3rd, 2006, 2:21 am

Well the thing is i got a big race comming up against a crx (b16) i beat him before but i just want to run at my best...... those of you who have ran with them (VRIS) tied open can tell me....does it help to tie them open or not.

XxantwawnxX · Post by **XxantwawnxX** » March 3rd, 2006, 2:33 am

Keep them the way there made to be. UNless maybe you have the wrong ecu for ur manifold.

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » March 3rd, 2006, 3:06 am

KL-31 ECU

ccreech · Post by **ccreech** » March 3rd, 2006, 8:17 am

XxantwawnxX wrote:Keep them the way there made to be. UNless maybe you have the wrong ecu for ur manifold.

Word! Mazda wouldn't have made the VRIS system open and close if there wasn't a reason for it to. It would have been much easier for them to have a less complex intake manifold with the passages open all the time if the car ran better that way. Since there is some engineering behind the VRIS system I trust it a lot more than someone who used a shoelace and thought their performance improved. I agree that having the wrong ECU could screw with your VRIS points and MIGHT make a small difference for the half second that it takes from when it should open up to when it does. But I am not convinced that it helps any even in this situation. Where I think it MIGHT help is when someones car is timed improperly (advanced) and they require more air because they are running pig rich.

I may be wrong but I think that when the VRIS is closed you will get more bottom end torque. This is because there is a shorter path between the outside air and the combusiton chamber. The VRIS opens up to lengthen this path and thus produce more Horse Power in the Higher Revs.

I would love to hear the Old Schoolers weigh in on this and put it to rest once and for all. I am getting tired of hearing "Just tie open the VRIS. It will pull much harder."

hppwdn · Post by **hppwdn** » March 3rd, 2006, 9:31 am

There's a lot more to VRIS than what ccreech said. In general tying them open is only a temporary solution to regain the top end you lose when swapping IMs at the expense of low end power.

When it comes to aftermarket control and stock control that's where the differences show up. On a stock ECU the VRIS are activated by a combination of load sensing (throttle position) and RPMs. This was done in an effort to improve fuel efficiency. Unless the throttle is at 85% or greater the VRIS do not function (at least on a probe ecu, assuming the same for all K-Series ecus).

With aftermarket control such as window switches, megasquirt, VRTuner (no longer around) the load sensing requirement is eliminated. The result is more on demand power in the lower RPMs.

I had all of the three methods of controlling VRIS above. The VRTuner had a potentiometer hooked up to your TPS that actually allowed you to control load sensing. Since 99% of people tuning VRIS do it for performance that feature is fairly useless.

The Window Switches were a great, easy to install option. Very easy to play with on a dyno. And with the new digital versions there's no need to buy those $5 a piece rpm pills.

Megasquirt is a superior option to the window switches, but only a viable option if you are going to run it as a stand alone. Installing a megasquirt just for VRIS control is a waste of time. I currently use megasquirt for my VRIS and sometimes I even change the settings at street lights if my laptop is on.

In my personal opinion the VRIS are nothing more than a pain when you start attempting to make more power. As I see it the VRIS don't help you gain any power, they real only serve as a way to lose power you already had by having incorrect points. And once you start modding your engine the optimal points will start floating all over the place.

ccreech · Post by **ccreech** » March 3rd, 2006, 9:38 am

There's a lot more to VRIS than what ccreech said

Yeah, I am sure that there is, I don't claim to know much about VRIS...but do you agree with what I did say?

hgallegos915 · Post by **hgallegos915** » March 3rd, 2006, 11:23 am

megasquirt it

!!

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » March 3rd, 2006, 11:32 am

-hec NO squirting

max kl · Post by **max kl** » March 3rd, 2006, 12:10 pm

ccreech wrote:
There's a lot more to VRIS than what ccreech said
Yeah, I am sure that there is, I don't claim to know much about VRIS...but do you agree with what I did say?

no you got it backwards short runners loose torqe and gain high endpower
long runners help low end torque and hurt top end power

XxantwawnxX · Post by **XxantwawnxX** » March 3rd, 2006, 1:16 pm

As far as i know, if u have the right ecu for the right vris points then haveing the vris points tied open will hurt ur low end(there meant to be closed at lower rpm full throttle) I have the k8 ecu and the Millinia manifold and my vris points work pretty good, when i tied them open it got slower. Now thats not to say someone elses diff set up might not benifit from it...but im stil skepticle.

ccreech · Post by **ccreech** » March 3rd, 2006, 2:47 pm

These last 2 posts seem contradictory. Opening up the VRIS solenoid would lengthen the run of the air in the intake. So I was thinking like XxantwawnxX posted that opening these up would take away from your lower end. max kl says that it is just the oposite. Now I am more confused than I was before.

DavidOS · Post by **DavidOS** » March 3rd, 2006, 3:01 pm

just leave them and buy a 50 shot of nitrous

XxantwawnxX · Post by **XxantwawnxX** » March 3rd, 2006, 3:35 pm

DavidOS wrote:just leave them and buy a 50 shot of nitrous

yes! end of story.

wepeo · Post by **wepeo** » March 6th, 2006, 4:45 pm

babyblueMX3 · Post by **babyblueMX3** » March 7th, 2006, 8:41 am

to answer the questions that was first asked. Tying both vris WILL GET YOU SLOWER. It's close on lower rpms to give you more torque down there and open at higher rpms for better power up there. Though they close at around 6300 (around that don't quote me on the number) and it is better that way because it makes more power CLOSED at those rpms. It is just the way it works.

leave them alone end of story