I did the JBWeld VIAS fix yesterday. My car feels like a new car, it pulls hard after 5k rpm now and the engine seems to be a little more responsive and smooth at all engine RPMs.

Here is a good writeup I saw on how to do this:

http://www.cardomain.com/memberpage/763858/5

Passing and merging on the freeway is effortless now. I had such a bad powerdrop off after 5k that I usually used 4th gear rather than 3rd as a passing gear. I saw no reason to take it to the redline because there was less power there. The butt dyno tells me I gained more than 30hp. I prolly gained (or recovered) 1-2 sec. in the quarter mile.

If you haven't done this do it! It only took me about 30min and $3.99 to do. I had a hardon to get a 5.5gen or a 6th gen, but now don't see much of a reason to. I drove a stock 5 speed 3.5 Altima yesterday and it didn't feel any faster than my 00 Max with the VIAS fix, intake, and exhaust. Maybe a little more torque on the low end for the Altima, but didn't feel any faster.

 

More than 30HP??? C'mon man, are you sure? Take it to the dyno and let us know for sure.

 

30 crank hp... without VIAS we are just another 4th gen vq30de. But then again... nissan likes to make HP numbers like magic!

 

i have 32k miles on my maxima 5spd, can i still fiddle around with that and get some extra hp??? i believe that could help cause nissan does make hp outta magic... haha. where did that spring pop out of on the last pic of your car domain foobaca??

 

That's not my car domain. As far as I know, most of the difference between the 4th gen and the 5th gen 3.0 can be attributed to the VIAS which is 32hp, which is not throughout the RPM band, just 5k-6.5k.

 

No, I'm not sure. That's why I mentioned "butt dyno." 0-5k, there wasn't much of a difference, if any. But the dfference from 5k-6.5k was like night and day.

 

I have 86k miles and my vias was completely non-functional. Your vias may be degrading even with only 32k miles. I suggest you fix yours too. Rememeber, you're not gaining HP above that of stock, but you are regaining what you had lost.

There's a few dynos on this thread:
http://forums.maxima.org/showthread....2&page=1&pp=30

SR20DEN dyno'ed it before and after:

before: whp 177.54 trq: 196.85
after: whp: 201.8 trq: 186.0

Not sure why the torque would be lower so much lower with the vias working. but notice how torque takes a noisedive after 4.7k rpm with the non-functional vias. The HP with a non-functional vias peaks also at about 4.7k rpm.

24hp at the wheels is good for ~30hp at the crank.

 

irvine78 put down 204hp and 201ft-lbs all motor on the stillen dyno with the vias working

 

vias? tands for what? and what exactly does it do? sorry for this but i dont know

 

Glad you approve!

On another interesting note: I received a spare intake manifold from another org member who was parting out a blown engine, right... Anyway, I swapped the VIAS control box from it to mine. Its metal cup was unbroken! Anyway, it's been about 4 months driving on this thing, and the cup is STILL not broken. Weird, maybe some of them were defective and some weren't?
The only difference here is that my power valve rod is shortened by a tiny bit, along with the spring being shortened to reduce tension (that was done for my original box's JB weld fix, which did break)...

Maybe that's the key? Shorten the spring and rod a little to reduce tension on the metal cup?

 

i have 108k miles on my car and checked it the other day. my cup was perfect. yeah, i think it depends on the car. btw, i drive it past 5k many times.

 

duh. i just found it

 

damn i wanna try that out but i think it's a little advance for me. im worried i might f*ck up

 

you dont really need the torque that late in the power band, you need torque early to get the car moving and hp later to make it go faster. the VIAS system starts to replace torque with hp by opening the butterfly valves, if they stay closed, you can make more torque, but lose hp. thats the reason behind valved mufflers, they close the valve at low rpms to create backpressure and increase torque, then open later to flow better and create hp.

 

With the VIAS broken, torque is very likely hampered all across the powerband, from low-end to high-end. This is because when the metal cup breaks, it never fully opens the power valve, BUT never fully CLOSES it either, causing a leak from the surge tank even at lower RPMs.

Fixing the VIAS cup, even if it does eventually break again, should give you a modest torque boost all over the place.

 

Can anyone post better pictures for those of us that are worried about messing things up so we know exactly what we are doing, nothing like going from step 1 to step 10 and missing things. Thanks

 

cant wait to do this! if the cups not broken does that mean the VIAS was good all along? I have no power anywhere, cant merge very well at all. and i've been beat many times by a 4th gen and honda's !

 

I do not recomend what I did to my VIAS- removing the power rod. This kills the low end and midrange considerably. My new VIAS will be installed under warranty sometime next week- just in time to drive down to TX.

 

You think you could test my theory--cut the spring at the end of the power valve (from the new, warranty-installed manifold) a little short, maybe down to 2/3rds of what it is... to see if the lessened tension helps prolong its life?

 

The spring in my manifold thats currently on the car didn't have much tension. I could fully compress it holding it with my fingers. I don't know how long it will take for the new one to fail, or even if it does fail. I heard Nissan redesigned the VIAS box due to alot of problems with them failing- I have been waiting for my VIAS for almost 3 months due to a backorder on them ! I will take mine apart when it comes in and see what it looks like. My old VIAS got eatten by my engine- the metal behind the cup got all chewed up and wasn't even there. Engine runs great with no problems, I have noticed the VIAS stopped working some 40K miles ago, and was getting weird noises from the engine- pinging like noise but not detonation. I think it was the intake manifold chunks getting sucked in.

 

I am not educated in this at all, but is this only for 00-01's?

 

On this pic.. where should I put the JB weld...I want to this...or at least check mine out....

 

It didn't feel any faster because you didn't want it to.

 

Hmm, interesting BlackBIRDVQ. Hopefully this redesign works out for you.

 

you see where the brass cup is inside of that hole on the right? the gray matter is JB Weld setting. Make sure that about every hour you move the rod after you put jbweld in the cup to ensure that it doesnt stick.

 

that is correct. you dont have the same internals as the composite manifold. i have seen conflicting info on which flows better but it is obvious which is built to last.

 

when i dynoed my max i got 183 hp and 196 tq in a 3rd gear dpull. does that sound right? i checked my vias and the actuator opened. could it still be busted?

 

Sounds like it might be. Any other mods?
I dyno'd around that w/ my '98 USIM... I/Y/E mods

 

i have i/ y/ pulley/ grounding

 

I am so lost. Is this a DIY mod to increase power?

 

It's a DIY mod to reclaim a significant amount of power that you may have lost since the vehicle was brand new.

 

How long for a entire JB-quik weld Fix including taking everything off and putting it back together and drying time?

 

over 4 hrs just taking off the vias for me. suggestion, use a VICE GRIP!!!! I am still having prob with the 7 o'clock screw. I havent taken off as much as SPIRILIS in his pics but i have NO clearance to take off with vice grips. I have this god bent rod seriously in the way. WHAT TO DO!!!!?

 

Is there away to keep the vias open all the time. Kind of like having a vtec controller and setting it to engage at a really low rpm

 

you would not want to engage it very low rps and it cause too much turbulence. the result would be a power loss. you could use a vafc2 and be able to tune and adjust the vi switchover. if you want it like its open all the time then you pull the power rod out but that is advised against like blackbird said because of low end loss. i have heard if you dont have headers then 4800 was close to a optimal switchover and 5000 if you did have headers. that was from the all motor forum.

 

You don't have the dyno run pic ? Its eassy to tell just from looking at the dyno if the VIAS is not working. Dumping those 17" OEM wheels is good for 10WHP.

 

Actually, that was my dyno and SR20DEN posted if for me. The runs were done with the valve broken at first, and then with the valve totally removed. Since then I have done the JB weld fix and it has broken again.So I have taken the valve out completely now and have plans to make it work to my advantage. Don't get me wrong, a fixed or undamaged VIAS is far superior to removing the valve altogether with a stock or near stock max, I just got tired of f!ucking with it. SR20DEN is going to be the brains behind all of this, but, with time, we're looking to totally do away with the whole valve and make the car faster in the long run.

 

it turned out it was broken, ive already jb weld'edededed it in palce and jus awaiting it to dry. pix comin...

 

i also took the time to re-spray the black spacers that runs into the im with high temp cermic paint, i did thie due to nissans crappy paint that was peeling and fallin into the im.

 

lets hope it works tomorrow