I've been researching the VIAS block plate for the 3.5L. It's an inexpensive, and simple bolt-on. And the NWP polished plate is a very attractive hunk of metal.

From what I can gather, on a modded 3.5 the butterfly valve in the VIAS flutters at the high end because air turbulence is compromising the vacuum actuator. Personally, I'm thinking the valve mechanism itself is compromising the air flow when wide open; (I mean, how wide open can you be when there's something in the way?)

Comments about HP gains in the high-end seem all across the board regarding the effective RPM range. I'd like to get a better handle on that. Although one of the more consistent opinions is that the low-end loss is virtually imperceptible (on a modded 3.5).

Some other questions: did you buy a new VIAS gasket, or were you content to reuse the original? Did anyone with a 3.5L run the dyno numbers before/after to prove out the theory? Did you use penetrating oil on the original plate bolts, or is that not advisable for some reason?

I know it's an inexpensive, DIY mod that can be easily reverted to stock... but I'd like to read some experienced opinions beforehand.

Thanks, guys!

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[edit] Finally deleted the VIAS, June 2010.

I'm with you on the gain coming from removing the blockage but either way it's a good mod.

Modding is all about getting more air to flow through the engine so the more you're modded the better this should be. Peoples experiences may be varying based on their mods and expectations. This is a subtle mod that makes a difference but still a small one. The only way to know if you like it is to try it.

The original gasket is fine to reuse. It's not a crush gasket that deforms under pressure. You'll see what iI mean when you take it out.

You can use lube in the bolts if you want.

Ha, you still have a typo in the title.

I used Permatex grey on mine w/ no gasket.

just an fyi-... those oem 3 bolts are soft.. so make sure the wrench is on them pretty solid..

and it def give you alot more pull on the upper end.. but you feel the zippy tq drop...its kinda give and take.. your low end pull will be slightly less..but your high end will be noticeably better... on a privately owned closed to the public road, i ran with a alti 3.5 where my mods were intake/nwp plate.. and his were intake/catback(not sure if any more).. and i put a solid car length on him from 2 second gear on..

i re-used the oem gasket...

oem gasket or rtv sealant or aluminum flange sealant should be fine.

i have it and personally it is one of my favorite mods IDK y... I personally cant say i felt a difference in performance with the addition of new mods but i can tell you that there was no loss... i really dont know what to even look for as far as dyno goes, but its just a mod that i love

Good to know you don't feel any low-end loss, but I don't understand the rest. I mean, I'm happy that you're happy, but if you didn't feel a change in engine behavior, why is the block plate one of your favorite mods?

I respect your opinion, it's just that I don't understand it.

Thanks for the details on the gasket design, and the go-ahead on penetrating oil. That's good feedback on the installation process.


That's also good advice on the installation process. If I pursue this, I'll make sure to have a perfect fit socket on the wrench and to crank without twisting. Thank you.

I wonder if I'll feel the low end loss, seeing as I've got spacers and a light crank pulley? What RPM range are you considering low-end and high-end?

have it on mine, didnt notice a damn thing. To me its eye candy and makes the engine look a bit nicer. As far as gains, I didnt feel anything.

Well... yeah, but you said the same about phenolic spacers.

Don't take that wrong, it just is what it is. If you didn't notice the efficiency gains of the spacers (which are fantastic), it's kind of a given you wouldn't feel any differences with the block off plate, either low-end loss or high-end gain.

"eye candy" -- most definitely. His hand-polished plate with the raised logo is downright pretty. I wouldn't mind seeing that under the hood.

I dont know about that. People say adding a test pipe (straight pipe by removing the cat) wont result in any gain that you can feel b/c the stock cat is very free flowing. However with my test pipe I felt a difference in the way the car revved up and I even told myself not to expect anything from it.

BUT, the block off plate is cheap so you dont lose much either way.

I think the fact that I have so many other bigger power adders makes it hard to feel how much gain other small mods may give.

Nice! You're quick on your feet tonight, pbn85.

I try, sir

Go for the block off plate though.

Actually, I plan on hitting the dyno next week to get my current #s. The latest editions were spacers and the block off plate. So I should be able to let everyone know how much extra of a gain both give. I think that should be interesting.

I have the plate and it is a very easy install. You don't need to use anything on the bolts if you have any meager strength in your arms its not hard. lol.... the gasket is fine to reuse.

The plate is definitely worth the money. I felt no loss but a slight high end power gain. As for eye candy, this thing looks hot!

Install plate= profit

http://forums.maxima.org/all-motor/5...o-comparo.html

there ya go...


i just got my 5.5 gen (came from a 98) and i think this will be my first performance mod. looks like it makes good gains.

What is "high end"? Seriously, if the gains are all slightly south of 6000 RPM, then there's not much of a point to it... unless you race.

If, however, "high end" is slightly north of 4000 RPM, then yeah, that would be sweet.

^^^ This is the most important question for me.

IIRC the plate is open to 3800, then close until 5200 then open again at 5200. So I would consider high end would be 5200 where the plate opens up again and then starts to close about 5400 or so because of the turbulence.

like i said, i dont really kno why i like it so much... maybe its the way it looks and i rather not have the butterfly... but i may have done good... before the plate i never really drove the car pass 110mph so idk what the car acts like without the block plate at high speeds... but to me its a mind thing it just feels better in my head lol... nismology is the best person to give you info on this mod

Thanks, man! I wasn't looking in the "all motor" section. Nice find. There were some good posts there, as well as this great post in Nissanclub:

http://www.nissanclub.com/forums/eng...-vs-stock.html

In particular, I like this collection of comments from the OP there:

I appreciate these posts, guys. Thank you.

I'm going to keep researching and taking my time, but here's my plan. (OK, well, here's tonight's plan) --

Enjoy the spacers for a few months and lay low this winter, saving for struts/rotors/pads/tires when winter is over. After blowing my wad on that somewhat expensive collection of maintenance/mods, treat myself to a new replacement Apexi filter and the NWP VIAS Block Plate in the Spring.

Zelinsky would probably disagree with this, but I've found it's best to walk slowly into new mods, one at a time.

Yeah. But you really wont know which helped more, the spacers or the plate..

I know this thread hasn't been touched in 5 days...but I just installed the VIAS plate today when I got home from work. I gotta say for the price and simplicity of the install its definitely something worth trying! I ordered it along with the nwp spacers (which aren't instaled yet). I put it the block plate in and it took me about 10 minutes to do on a hot engine. The removal was self explanatory and with the right tools shouldn't be difficult. I reused the oem gasket btw. After the install and getting gas I decided to try it out. Bc I have a 4AT I didn't notice that much of a loss on the lower end but definitely felt a different and somewhat stronger pull. I feel like it was stronger from appx 4000 or 4500 rpm and upward. It also felt like it wanted to keep pulling as the revs got higher. I forgot to mention the only mods I have on the car are suspension and an injen intake.

Take it how you want. After I'm done 'playing' with it, I wanna see how it affects fuel economy. My belief is that even tho you're removing a restriction which improves high velocity airflow, low engine speed cruise will have a less "tuned" airflow due to the higher volume without the blocking from the butterfly valve.

Anyway hope that helps you some with your decision!

the op has no hlsd and is sad..so no one cares

Great info Rochester.

Absolutely. There was some good feedback and research that came out of this, yours included. I'm going to play with this mod in Spring 2010, after Winter winds down.

OK, Hotshot. In a straight line, on dry pavement, HLSD is just extra weight. But if it makes you feel like you've got some edge, then more power to you, man. Perception is 90% reality anyway.

Thanks. That's nice of you. Like I said, some good opinions gathered on this. And that's all I was looking for... opinions and advice.

This forum is (mostly) awesome. I wish I'd participated years ago.

yeeeeeeeeeeeeaaa!!! i kinda never fell into that HLSD, VLSD thing neither.. but hey why am i even commenting on this im auto...

Well I for one wish to say thank you Rochester for the great question and result topic ... this is a mod that i may never have though of or considered but after reading the great posting dialog (thanks to all that offered some in) I too will most likely pick up the vias blocking plate when I order my spacers ... should work out to be a great combination

Very cool, Ghost. I know you're going to plotz over the spacers.

You know, it would be neat if you did that installation in stages. Run the spacers for a few weeks, and then install the block plate and see where you're thoughts are on the shift in HP.

I agree on doing mod's one at a time and gauge the improvements if any, not to mention it gives you something still to look forward to doing ... great discussion thread I have enjoyed the reading.

haha auto ftw! I'm right there with ya unfortunately

Exactly! I always have something in the queue, whether it's hundreds of dollars like the spacers, or something as simple as $4 LED's... but there's always something going on to keep me interested and entertained.

You should see my spreadsheet! LOL

It's the hobby that keeps me from buying a new G37S. The longer I can stay happy with my ride, the better off I am in the long run.

Gotta agree with ya on that one..except I bought my car used and I'm still paying it off lol. But I've learned its cheaper to love the car you have..and much more fun!

i have the block plate layin around sumwhere hear..and i have the TS ecu. anyone kno how the power gains are with this set-up? because i went to the track and i actually had slower times then i did w.o it..just want to find some info out. thanks

See post #16

You're not going to see much out of that block plate if it's just "layin around sumwhere hear" (sic)

hmmm strange... u did the SSIM mod?

I'll make you one Jim, unless you really want the bling factor

Go for it, Ghost. If the plate is a keeper, you can always swap it for the pretty NWP product down the road.

And either way you go, I'm interested in reading your opinions afterward.

I would say 4500-5000+ is what I am saying by high end. I do 1/4 mile racing so it makes a nice difference for me. Although I havent been able to hit the track since I installed my block plate and obx headers...

No I definitely agree with you on that one. I may be moving quickly on my mods but mostly because I thought our race track was getting shut down by the city this year (now we're good for 5 more years ).

I did extensive research on all my mods because at my old job I spent most of my day reading on these forums and others. I have to say I did move a little too hastily because now I am backtracking to fix my SES and AF ratio that are screwed up from my amateur header install (DIY) lol

But for something like this NWP plate it is pretty much a no brainer. There are no drawbacks or worries about screwing anything up. It is very simple install and inexpensive. A monkey could put that thing on if he was drunk and high and still have no problems

Put it on today, and it is well worth the money. Car feels more responsive. NWP Intake Spacers combined with the VIAS Block Plate feels real nice. NO power loss noticed.


The GAB sounds very healthy. I would love to see a dyno with the spacers and vais block plate!