I'm looking to get a spacer or new intake manifold. Which one should I get or can I do both?

 

Welcome. This subject goes back to 2004. Read the Sport Z magazine Plenum vs plenum spacer results.

 

There is no universal answer to your question. It really depends on your application (NA, stock block FI, or built motor FI), power goals, and budget. Whichever you choose, stay away from the Kinetix SSV intake manifold. Don't believe the marketing hype about it. It's crap for NA applications and I'm not convinced of its worth for FI applications either. I'm one of many guys who lost power with that intake manifold.

If I were to choose a spacer, I'd get the PowerLab 3/8" spacer. (which I currently have)

If I were to choose an intake manifold, especially for a built motor FI application, I'd get the CJM intake manifold. (which I plan on getting)

My

 

Another option to consider...

https://my350z.com/forum/intake-exha...e-motor-8.html

 

I'm looking to spend around $400-500 motor is stock. Do I have to do any modifications with the 3/8 spacer?

 

No modifications needed with a 3/8" spacer.

http://intensepower.com/pobi3plspvq.html

 

I chose a plenum cover because I figured a spacer is just giving another possible place to leak. My 3 cents right der

 

Show me a bunch of threads and documented incidents where properly installed spacers leaked (especially the PowerLab spacer which I recommended to the OP) to support your comment. Spacers have a good and reliable history on this platform including FI applications to 1000+whp. Plenum spacer leaks are not a common or widespread problem, especially if they are installed correctly.

 

What is the difference in gains between the 5/16 and 3/8 spacer?

 

1.352866 awhp

 

The differences are negligible ...except the quality of materials used and the price. The PowerLab spacer is one piece CNC billet and is cheaper.

 

I have the MD 5/16 iso spacer. I've had no problems with it. After my new tune, I felt a big performance gain.

 

without knowing the year of the car, it's impossible to answer

 

Will I have to retune the car after I install the spacer? The car is a 05 35th anniversary

 

an 05 anniversary is a revup engine...a spacer alone is pointless and will not net you any gains

a spacer + older collector (from an 03-04, or any non Anniversary/non track 05) + spacer will give a nice bump in power. Ideally, retuning would be beneficial as further gains can be realized, particularly on a revup engine, but it isn't mandatory. May want to wait to retune till you've done other breathing oriented mods

 

Thanks save me from wasting money. I was also looking into buy an exhaust system, saw some on eBay for around $300 now I know you get what you pay for but what's the big difference between one of these and a system for around $1500? They also have headers for around $150. I'm looking to spend around $500-600 for both.

 

won't comment

 

+1.

 

ok then what do you recommend for a quick gain for around $600? I already have a cold air intake.

 

again not something I'd comment on sorry