I tried utilizing the search function for this but couldn't find much on this topic. I am thinking about buying a MD 5/16 copper isothermal plenum spacer since I heard great things about it. I was wondering if this mod lowers the engine life of the car or any sort of other side effects. Also, is the power improved noticeably? I know its not day and night, but I wanted to hear peoples thoughts. BTW, I have a Stillen CAI box with a z tube. I don't know if that helps the plenum spacer do more of its thing. I appreciate your responses.

 

Ice, what MotorDynes spacer does is correct a Nissan design flaw. The plenum is too narrow at the front to allow equeal volume to all ports, the spacer corrects this. It changes nothing about how long your engine will last. Stillens CAI/Z-Tube combo with the spacer compliment each other, good choice!
Gary

 

If it's really a design flaw, then why hasn't Nissan ever bothered to fix it?

The VQ35DE engine is used in so many models for the past 10yrs... but yet no engine revision... other than simply tweaking settings for different models.

 

They have changed it for the new 3.7 liter motors. Most cars are built and tuned pretty conservatively out of the box, so I wouldn't call it a design flaw more than just a built in restriction.

 

if they built it perfect, what would you spend your money on?!

 

Its all about business. Automobiles aren't made to last like they used to be.

 

Technically, professional race car teams change their motors as much as people running NASA or other sporting events change their tires. Cars nowadays are built conservative from the factory so they do last longer without needing as much maintenance like most true performance cars.

So technically, you're right... things have to change when the market demands more power, more performance in a reliable car that requires little maintenance at a low cost. But a small change like the plenum spacer isn't going to make that big of a change on reliability.