00VI VIAS Delete
#41
If the 5speed has other supporting mods, then you may see more gains from deleting the VIAS. I'm not stating that the block off provides more power than keeping the VIAS. It just shifts the power band to the top end, which a 5speed with supporting mods can greatly benefit from.
When it comes down to it, everyone is different. There is no 100% proof that doing the VIAS block of is better than an RPM switch. It's all based on personal preference, your car and your mods to support it.
When it comes down to it, everyone is different. There is no 100% proof that doing the VIAS block of is better than an RPM switch. It's all based on personal preference, your car and your mods to support it.
I want my cake and to eat it too. I want to keep the VQs great low end TQ and get a better top end. I don't need 7200 rpms redline, just keep making TQ all the way to 6500 or so.
00VI with fucntioning VIAS > USIM down low and all the way to redline. And with that, I am good.
DW
#42
The long runners are for low end torque. Short run with plenum open are for high rpm.
A basic way to think about it is the engines piston going down creates a vacuum. A long runner allows it to 'suck' the air in the runner at low rpm (good air velocity). At higher rpm the long runner would be a restriction after it used up the volume of air in the runner and would be getting the air from the plenum. it would be basically winded. The shorter runner have a shorter distance for the air to travel at high rpm but at lower rpm it would have lower velocitys because it would drawing its air from the plenum.
A basic way to think about it is the engines piston going down creates a vacuum. A long runner allows it to 'suck' the air in the runner at low rpm (good air velocity). At higher rpm the long runner would be a restriction after it used up the volume of air in the runner and would be getting the air from the plenum. it would be basically winded. The shorter runner have a shorter distance for the air to travel at high rpm but at lower rpm it would have lower velocitys because it would drawing its air from the plenum.
#43
So by research and experience, you've personally removed the VIAS/power rod and blocked it off completely, then ran the car on a dyno? Then you did a comparison run with the power rod and VIAS back on the manifold? Can you provide dyno sheets to compare the results?
I ask simply because that's the only way to prove which is better. Even so, there is still 10 or so different ways to install the 00VI on the 4th gen and it's all relative to your set up and other mods you might have on your car. Do you have headers/ypipe? Are they Equal length longtube? Do you have a piggy back ECU for tuning, Are you using the 5th gen LIM with larger injectors? Are you 5speed or Auto?
Pretty much all these things determine whether or not you'll see good gains from blocking off the VIAS. I personally want to block it off because my car has a significant amount of low end, but practically zero top end. Last time I ran my car on a Dyno the peak power was 191 torque between 3400RPM and 4400RPM. The rest of the power band pretty much fell on It's face after 4800RPM. You can feel the lack of top end power when you drive my car. I Just posted a video of me racing a 7th gen, see for yourself. After about the 1/8 mile the 7th gen just blows past me. This is because of my serious lack of top end power. What I'm getting at is I'd rather lose some low/mid end power to gain a significant amount of top end power.
The shorter intake runners are for lower speed to improve velocity to increase the blend of air and fuel. The longer runners are for the higher speed. There is a door that looks like a throttle or choke. It closes off the short set and opens the longer set or visa versa. In a nut shell that's all the VIAS and choke doors on the 5th gen LIM are for.
Essentially by removing the Choke doors on the LIM and the power rod on the UIM, you are using a full open long runner with no air obstructions. Increasing air flow at full throttle and giving you a better top end power band as the engine revs past the 5000rpm range.
I ask simply because that's the only way to prove which is better. Even so, there is still 10 or so different ways to install the 00VI on the 4th gen and it's all relative to your set up and other mods you might have on your car. Do you have headers/ypipe? Are they Equal length longtube? Do you have a piggy back ECU for tuning, Are you using the 5th gen LIM with larger injectors? Are you 5speed or Auto?
Pretty much all these things determine whether or not you'll see good gains from blocking off the VIAS. I personally want to block it off because my car has a significant amount of low end, but practically zero top end. Last time I ran my car on a Dyno the peak power was 191 torque between 3400RPM and 4400RPM. The rest of the power band pretty much fell on It's face after 4800RPM. You can feel the lack of top end power when you drive my car. I Just posted a video of me racing a 7th gen, see for yourself. After about the 1/8 mile the 7th gen just blows past me. This is because of my serious lack of top end power. What I'm getting at is I'd rather lose some low/mid end power to gain a significant amount of top end power.
The shorter intake runners are for lower speed to improve velocity to increase the blend of air and fuel. The longer runners are for the higher speed. There is a door that looks like a throttle or choke. It closes off the short set and opens the longer set or visa versa. In a nut shell that's all the VIAS and choke doors on the 5th gen LIM are for.
Essentially by removing the Choke doors on the LIM and the power rod on the UIM, you are using a full open long runner with no air obstructions. Increasing air flow at full throttle and giving you a better top end power band as the engine revs past the 5000rpm range.
So i get that without it you get the full potential of the longer runner but since the rod is removed, doesn't that mean that the lower speed runner is also always open?
I have 00vi setup #7. I have 5th gen air box, y pipe, 2.5" catback exhaust, auto and vlsd. My rpm switch is set to 4800 rpm which I found worked best from a seat of the pants. It as pretty obvious were to set it, I wanted to get into the high rpm mode as soon as possible but even with it set to 4600 rpm I could feel it bog for a sec when switching. I ran my car for three weeks before I got around to installing rpm switch so I did do plenty of rod disconnected and rod tied open to see the difference. I have no dyno's and I no interest in doing any dyno's. This is my daily driver and I have another fun vehicle that I play with. I have not gone to the track with my set up. I raced a good friend and found I gained 4 cars in the 1/4 with my y pipe and 00vi. If i happen to be at track meet i would race the car again I was going to tune it but it seems like every time I turn around I have another repair.
You mention about having plenty of torque and giving away low/mid for high end. You don't have to give away low end torque with an 00vi, that is the beauty of the intake. I found the torque went away with rod in high rpm mode. I have read on the all motor section about 00vi pulling the rod high and barely running much quicker than stock. With rod in low rpm the power band really dies after 5000rpm even more so than the usim. That is just my experience.
You mention about having plenty of torque and giving away low/mid for high end. You don't have to give away low end torque with an 00vi, that is the beauty of the intake. I found the torque went away with rod in high rpm mode. I have read on the all motor section about 00vi pulling the rod high and barely running much quicker than stock. With rod in low rpm the power band really dies after 5000rpm even more so than the usim. That is just my experience.
it wouldn't benefit you either since you have an auto. those 4 gears are super spaced out and you fall out of the 5k+ rpm range much farther than a 5 spd. even more so if you run the stock rev limit. so the top end gained will probably be negated by the boggy acceleration leading to 5krpm.
I have a 5spd so my gear ratios are closer right off the bat. having an extra gear with same top speed as the auto allows every gear to get to redline a bit quicker than the 4spd, even if the 4spd was manual. on top of that i have a jwt ecu allowing 7200rpm. if i shift at 7100 the next gear comes in at 4800 which makes this juuust right
and there are 2 runner lengths... dunno why you said there aren't
like infinimax said, not only is there plenty of torque, and its available at a fairly low rpm so losing/shifting peak torque to a higher rpm doesn't hurt that much. if you think about it, for 5spds it would make it awesome... not only are we increasing top end power by doing this but it could (key word here) also shift the torque curve to the right without losing torque. this could give the torque needed to get the engine up to 5k quicker.
#44
The long runners are for low end torque. Short run with plenum open are for high rpm.
A basic way to think about it is the engines piston going down creates a vacuum. A long runner allows it to 'suck' the air in the runner at low rpm (good air velocity). At higher rpm the long runner would be a restriction after it used up the volume of air in the runner and would be getting the air from the plenum. it would be basically winded. The shorter runner have a shorter distance for the air to travel at high rpm but at lower rpm it would have lower velocitys because it would drawing its air from the plenum.
A basic way to think about it is the engines piston going down creates a vacuum. A long runner allows it to 'suck' the air in the runner at low rpm (good air velocity). At higher rpm the long runner would be a restriction after it used up the volume of air in the runner and would be getting the air from the plenum. it would be basically winded. The shorter runner have a shorter distance for the air to travel at high rpm but at lower rpm it would have lower velocitys because it would drawing its air from the plenum.
but you're right about the runner lengths, i had it backwards (short for low rpm)
http://www.cdxetextbook.com/images/variablemanifold.jpg
#45
so first you tell me there aren't 2 runners and now you're talking about there being 2 runners
but you're right about the runner lengths, i had it backwards (short for low rpm)
http://www.cdxetextbook.com/images/variablemanifold.jpg
but you're right about the runner lengths, i had it backwards (short for low rpm)
http://www.cdxetextbook.com/images/variablemanifold.jpg
#46
still don't get how removing it won't allow flow from both length runners. if there is no vias rod http://i19.photobucket.com/albums/b1...S/DSC00211.jpg blocking either runner, aren't both gonna be used?
#47
This is best example i can think of. Take a straw cut a hole in the middle large enough so that it matches the cross sectional area of the straw. Put the straw in your mouth and put the other end in the a liquid, but don't the straw in so far that it would cover the hole. You won't be able to draw any liquid into the straw when you place a vacuum at the other end. Basically the long portion of intake becomes part of the plenum volume.
#48
it wouldn't benefit you either since you have an auto. those 4 gears are super spaced out and you fall out of the 5k+ rpm range much farther than a 5 spd. even more so if you run the stock rev limit. so the top end gained will probably be negated by the boggy acceleration leading to 5krpm.
I have a 5spd so my gear ratios are closer right off the bat. having an extra gear with same top speed as the auto allows every gear to get to redline a bit quicker than the 4spd, even if the 4spd was manual. on top of that i have a jwt ecu allowing 7200rpm. if i shift at 7100 the next gear comes in at 4800 which makes this juuust right
#49
http://www.nissanclub.com/forums/eng...-vs-stock.html
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
#50
http://www.nissanclub.com/forums/eng...-vs-stock.html
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
DW
#51
http://www.nissanclub.com/forums/eng...-vs-stock.html
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
stock im w/vias, stock IM w/vias delete, SSIM
Dyno results^^
#52
#54
Bumping an old thread, I'm deleting my VIAS as soon as I can get those pesky bolts off!! lol but in addition to that, I'm going turbo (parts already ordered), so I'll have all the power I need up top with good tune. Since I'm going turbo I'd rather have less power low end so I don't spin TOO much.
#56
#60
#61
Question: some 00vi have only one ViAS solenoid, and some have two ViAS solenoids. My 00vi has only one black solenoid, and inside the other solenoid space is a fake plug solenoid. Then other 00vi have a black and brown solenoid working together it seems. Is this the better one is it less prone to failure? maybe the other solenoid acts like a back-up?
#64
My 2k fed spec 5 speed has them. When I took it apart it was pretty apparent I was the first to do so as well.
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