Sooo I'm ordering an HKS Sport axle back to pair with my coupe midpipe... and while I'm ordering that I wanted to get a plenum spacer as well. There is so much information on this site about them... but so many people BS about it and it's spread quite thin amongst other threads about which ones are the best.

Which size/brand would be my best bang for the buck?

Sorry again I'm sure it's a re-post!

 

Motordyne 5/16" cooper spacer

 

^+1 for MD. Depends where you are whether you choose copper or coolant control valve, but I can vouch for the MD 5/16" spacer + iso gasket. Plus, the black hardware the comes with it looks sweet if you leave the engine cover off.

 

^+1 i have 5/16 iso + coupe mid pipe + blitz axle back and i love it

 

What is the advantage of having 1/2" as opposed to the 5/16? and the iso?

 

5/16" gives you low to mid end torque/power traded for top end speed (i.e. gets you to speed limit faster but you can't exceed the limit as much)

not as much heat getting into plenum from intake manifold/engine = keeping air cooler for the ride to the engine = denser air in cylinders = more power

You said you weren't looking for the BS contained in other threads, so i tried be concise.

 

^ ^ ^ thanks buddy. That puts it in plain english for me. I'm no idiot when it comes to cars but sometimes you gotta make yourself look dumb and ask the questions you have been dyin' to get answered!

 

1/2" doesn't lose low end/mid range. It just doesn't gain as much in the low end. It gains more from ~4000 rpms and up.

 

Buy the motordyne.

Willey; nobody really said it loses the low end torque.

 

i was just clarifying info.

 

oh lol

 

Get the MREV2 at the same time, you will love it.

MD is the way to go, and they have A LOT of info on their site...

http://motordyneengineering.com/techinfo.php

 

This is a very important point, depending on what model year we're talking about. OP - what year is your G and/or where's your redline?

MD says you need MREV2 to run spacer on the revup engine (redline @ 7K I believe). You would be fine without on the non-revup (redline @ 6.5K). I have non-revup and do not run MREV2, but have considered it. Since I have a choice, I'd rather spend the MREV2 dollars on a tune.

 

My car is an 03 sedan.. What exactly is the MREV2?

 

^^Something you and I don't need to worry about. It's only for the later, 'rev-up' (higher redline) engines.