I know that I am probably going to get a lot of crap for this, but what is the diff between the 2 plenum spacers. I'm looking into buying one and wanted to know what fit, and what didn't. I have a 2003 touring. I know that they sometimes have the problem with the strut bar. Any help would be appreciated.

 

Assuming DE style hood (HR hood provides more clearance, so I'm not sure).

Should fit under strut bar:
5/16 Motordyne

Should fit under strut bar if you add washers under the strut bar:
3/8 Powerlab

Will not fit under strut bar:
1/2 Motordyne

Won't fit under strut bar & may even rub hood if you don't have engine damper:
5/8 Skunk2

 

http://www.motordyneengineering.com/...9efbd02174f6f7

 

I had an 06 350z and I bought the 3/8 spacer....and they gave me washers for strut bar spacers (looked very ghetto, 4 washers stacked for each bolt of the strut bar) and the hood hit my strut bar and wouldn't close right so it left a nasty gap in between my hood and fender! It looked like my car was in an accident and the body gaps were off or something. It was a worthless piece of junk! So I sold it to a g35 coupe owner who didn't have a strut bar, and he liked it. I then bought the 5/16 spacer and they gave me nice aluminum strut bar spacers with it, and hood clearance was perfect and the hood closed fine!

The 3/8 will give you more top end gains, the 5/16 more low end....but honestly I never revved up that high on a daily basis to notice a difference with a 3/8, and the hood hitting the strut bar threw me over the top. Go with the 5/16, you can't go wrong

 

Cannot believe this debate still exists in 2011.

 

Not sure that any of the spacers alone will give you any real world gains without a tune. Even if so, it's not anything you can notice in performance. You'll probably just notice a different sound to your intake/exhaust tone.

If you've also upgraded your intake, lower plenum (mrev2), cats, and exhaust, you may improve breathing overall to see some noticeable gains with a tune.

I've had the 5/16 and the 5/8 spacers, so I've seen both ends of the spectrum.

 

You need cams to take advantage of spacer like that. If you want to keep a strut bar and the hood, buy a crawford strut tower brace.

 

And, yes, the mrev2 has shown dyno gains on the non-revup DE engines like your 2003 and my 2004.

This post was a pre-emptive because I expect the usual "mrev is for revup" assumptions that many believe. Motordyne has plenty of real world dyno sheets that prove the difference that their porting/polishing does for our engines too.

Again, all of this assumes a tune.

 

Or the APS tall boy strut bar
Or the Stillen strut bar.
All will clear the bigger spacers

 

 

1/16

 

There are so many redundant spacer threads.



Mods, please lock this thread and advise OP to use the search function.

 

Some people are just afraid of the big bad monster hiding behind the search button.

 

When you all say "tune" what specifically are you referring to doing? Tuning the stock ECU, or something aftermarket?

What is the best way to tune once you are done with several "bolt on" upgrades?

 

www.uprev.com