The plenum spacer for the 350z seems to be the best mod going for the cost, what are the down sides to this mod and why did nissan not just make the plenum a better design from the factory if there is such a big improvment when the plenum spacer is fitted??

Thanks for the reply Tim.

 

with 25k on my 5/16 MD, I have not found any downsides. The kit is so complete and fit and finish so good, it all seems factory when its installed. I have no idea why Nissan did not just make the plenum a little taller, they certainly have corrected it now in the HR motor.

Chris

 

Only downside is that you have to use spacers on your strut brace. This might cause clearance issues on aftermarket hoods.

Other than that, really no downside to it...

 

you have to go to the trouble of installing it - that's it... just do it - particularly if you have a non revup motor (287 hp). Otherwise for rev up, consider the mrev2.

 

+1 and make sure you install it correctly because leaks can happen easy if you **** it up

 

Nissan has other considerations besides horsepower: reliability, cost, fuel efficiency.

Put the upper and lower plenum together, and you have two contact surfaces for potential vacuum leaks. Add a spacer in the middle, and you now have four.

 

IF you use a spacer, if they made it bigger in the first place you'd still have two.

 

Hi David,

I actually adressed that issue a while back with the new design.

In the early days yes, it was a stock gasket beneath the spacer and a stock gasket above the spacer. So yes, it had twice the chance for a leak (albeit very small)

But now, the spacer comes with custom gaskets bonded to the upper and lower surface of the spacer. So now the spacer itself becomes sandwiched in as part of the gasket. Its essentially now a 5/16" thick gasket all by itself.

So its no longer 4 surfaces to seal, its 2. Just like stock.

The gaskets applied to the spacer are also very thick and compliant so they actually seal better than the thin stock metal gaskets.
Assuming the spacer is installed correctly, I guarantee this new design will never leak.

 

no downside, easy install, nice performance gain, stealth mod

 

get it, great mod and good power for the money

 

downside, bad gas mileage because you would try to hear the car or feel the performance.

 

I assume this voids any warranty.....Am I correct?

 

Only if they know what to look for? It looks very OEM.

 

The only downside is more horsepower, which causes you to be more generous on the throttle with your right foot, causing lower MPG. LOL

 

Funny but 120% truth.

 

Not necessarily.

http://www.sema.org/main/semaorghome.aspx?ID=50096

 

haha, probably wont void warranty, but i brought my car in for an oil change at my dealership, and when i got the car back with the reciept, it noted that i had a plenum spacer.... totall ignored the fujitsubo exhaust with 4 in tips. but noticed a plenum spacer

 

I love my MD 1/2" spacer, I havent run the STB in forever so its not a big deal, I could also run my Crawford STB but I dont like that thing. Only downside is it rubs my hood, it has ruined 2 small areas of my powdercoated plenum and rubbed the intake pipe of my Greddy kit since install

 

How is handling w/o the strutbar?

 

For the most part, its unaffected. For daily driving and drag racing it won't really make a difference.

But if you do road course racing, I would defenitly keep the strut bar on.