Hey Everyone,

I recently ordered a Stillen high flow intake and a Z1 plenum spacer for my 2007 G35. I really wanted some budget friendly upgrades that will gain me some power. I have confirmed that I have the DE engine for the spacer but I’m still really nervous to install these upgrades. Do I NEED a tune in order to avoid anything negative from these upgrades? I have heard if you don’t tune I could end up burning my cats or my spark plugs. I’ve called multiple performance and tuning companies and many of them told me I will likely hurt my car more in the long run if I do not tune it. I planned on doing the ECU reset and the idle air reset but I’ve been told this still won’t solve the problems I could face. I was planning on installing both of these myself (with some buddies) in the next few days but now I’m concerned that I should hold on to them until I save some money to tune it. Maybe I just install the intake right now? What have you guys experienced? Do I need to tune? Will I be safe installing these without a tune? Only got my car 2 months ago and I only have 85k miles on my car but I want her to be as healthy as possible for as long as possible. Please give me your opinion!! Anything helps!!!

 

No you do not "need" a tune with those. It does however make the car a lot more fun to drive

 

Are they safe upgrades without a tune? The performance places are trying to tell me I can burn my cats or spark plugs.

 

Totally absolutely safe. They're just trying to sell you. I would however recommend you throw in a new set of ngk iridium spark plugs at the same time

 

Yep, they're safe to run without a tune. The performances shops just want to make a buck off you. Only bolt-on for these cars that requires a tune to run is a larger throttle body, but as seymore said, a tune will really wake the car up.

If you want the engine to last, check your oil regularly!

 

Really appreciate the input guys! Do you think I need to do the ECU reset after I install these?

 

Absolutely!
I installed the motordyne 5/16" spacer a few months ago (was replacing the knock sensor & harness, so it made sense). After I started the car up it ran like crap. Hesitated, bogged, etc. I reset the ECU with Datscan2 ($80 from ConceptZ), and man it really woke the car up.
I'm currently saving up for Kinetix HFC and then a tune from Seymore4, hopefully in the next few weeks!

 

something else must have been going on, I've literally installed dozens of spacers without doing anything after and the cars all ran fine...

PM me when you're ready for that tune tho it really makes a difference

 

I believe it was probably due to the knock sensor being flat out offline. A rat/mouse chewed clean through the harness, so maybe the ECU was confused to suddenly be getting input from it? According to my scan gauge its running 4-6* more timing advance than it did before from what I can tell.
My supervisor informed me today that we're getting a bonus in the coming weeks (initially was told it was a no-go b/c covid, salary freeze, etc.), so I'm jonesing for it to come my way!

 

I couldn't find a spacer that was spec'd for a RevUp engine that would do any good. Am I mistaken? All of my research pointed to Mrev2 and a spacer, but that the spacer alone made -0- difference on my RevUp. Prove me wrong, I have an itch for a spacer! =)

 

It's been a while since I did the research so take this with a grain of salt, but you are correct the rev-up motors don't get a big boost from just a spacer. From what I remember, the best plenum setup for the rev-up motor is to switch to an MREV2 lower plenum (which is a modified non-revup plenum) with a spacer. This will net you similar top end HP numbers as the stock RU motor, but with a lot more area under the curve in the lower rpms. At least that's what I chose to run after doing all the research a few years back.

 

I'll admit I am a sucker for good sound even if there's no provable HP gain. Does it make it sound beefier?

Thanks for the info above.

-Ruzzell

 

The spacer really is a useless mod on the revup without also using the MREV2 (or a DIY one).

If all you want from the rev-up is better intake sound then getting a Z tube is definitely your best option.

 

But if you don’t have rev up then you’ll definitely benefit?

 

Yeah, the non-rev lower plenum was designed to build more power in low-mid rpm range with longer intake runners, however it was a little starved for air due to plenum volume, this is what the spacer fixes. The rev-up engine has a 500 rpm increase redline and a different lower plenum with shorter runners (which are typically used for more high-end power) but is very lacking in mid-range power. Using the MREV2+spacer (non-revup plenum that's ported in a very specific way) gives back that midrange power without actually sacrificing the top end. It's a killer combo on the rev-up engine, the non-rev engine still greatly benefits from the spacer because it's starved for air due to engineering deficiencies but not quite to the extent that the rev-up.

It's still the first recommended upgrade for the vehicle because it's by far the most bang for your buck. All other mods just build on top of this.