There has been lots of threads debating if the 03-04s can have both the MREV2 and spacer combo and not run lean. But the answer still has not really come clear to me yet. It seems like the MREV2 / Spacer combo seems to work fine with just that combo only for those who has done it.

Currently i have Z-tube w/ K&N Drop-in, Tanabe Y-pipe and 5/16 spacer, and want to put in the MREV2 on top of my setup.

I want to see who else had put the MREV2 + Spacer combo and had mods ontop without any further remapping or tuning on their 6MT?

 

According to MD, if you're not already running lean when you install the combo, you won't run lean afterwards.

$0.02

 

^^ +1 Why not just dyno your car? If you're not lean already you should be fine. For probably 75 bucks you'll have some peace of mind.

Just my $.03 (I re-raised DTor)

 

That to me is about the most lame answer I have heard. How is one '04 going to run lean and a totally different '04 run rich.

If there is such an anomaly, dyno the car before and run it with a Wide Band. Or buy one http://www.prostreetonline.com/buy/a...oller/30-4100/

$0.04.... gotta keep it going

 

^ he's right. A wideband will definitely tell you the most relevant AFR. A tail pipe sniffer is not always correct and you will most likely be see leaned according to its result.

So get a wideband for a more accurate reading

 

I have been wanting to see results on this combo for non-revups for some time...

 

I don't see how that is a lame answer. The point he was making is that the mrev2/spacer combo, in and of itself, will not cause your vehicle to run lean. If you have done mods previous to this, say intake, exhaust, headers, and hfc/tps, then your car may already be a little on the lean side, in which case the added air flow and lack of compensation from the stock ECU due to the mrev2/spacer may cause a lean(er) condition than what you were experiencing before, whether you were aware of it or not.

Since I'm adding another $0.02, the sum is now $0.06.

Wow, that is such a good example of what were are discussing - Let's say that each mod is worth $0.01, and a lean condition will be cause with, say, $0.04 worth of mods. If you already have $0.03 worth of mods (intake, headers, catback) and you add $0.02 more (mrev2 & spacer), then you will be running at $0.05, which would be lean in our example. But if you don't have any mods and put in $0.02 worth (which we all have in this thread so far ), then you'll be fine.

^^WTF am I thinking...

 

"lean" when?? Open loop? Closed loop? Part throttle? WOT???

 

So, what you are saying is, a totally stock 2004 will NOT run lean, according to MD. Add cats or a test pipe and a CAI and the car MAY run lean.

Question, and I am in no way trying to start poop here. I am new to the import mod scene. It is well known in domestic land that most cars are slightly rich from the factory. Helps prevent detonation and such. If that is the case with the G35, wouldn't it make the A/F ratio almost perfect with these minor bolt ons??

I think you owe me $0.02 now


WOT

 

Everything about this topic has been theory and question (from what have gathered - not just here... everywhere I've searched).

Until people start installing and giving viable opinions it will always be a question.

BTW - I haven’t said this in any other thread, but... everyone keeps talking about running lean... I'm the only one I've seen actually ask the question to Tony (way back when)... And before I asked him (out here) I was talking to DaveO about it... I'm no engineer but based on what little I knew at the time (when MREV2) was first introduced I was thinking it could make the car run lean... the spacer added air flow - the lower collector apparently at least altered air flow but would that increase air flow and run lean?

I haven’t seen any test data that indicates this mod will run lean but I see the question dozens of times - why? Is everyone thinking what I was? Or does everyone have data results that I haven’t found?

If Tony is telling us it won’t run lean solely due to the mod - I for one am not concerned. However, I still haven’t seen any performance data about its value.

All this being said I am a HUGE fan of Motordyne products and have several on my car... just had to ask this perplexing question about the running lean question that keeps rearing it's head.

 

I can only remember one non RevUp dyno (350Z) that showed result of adding MREV2 to a 1/2" spacer. AF increase was marginal (< +0.75) as was the perf improvement. Based on a baseline AF that was high before he started, and the other mods that the car had - all recommendations pointed to either removing MREV2 or getting a tune.
I had asked Tony same questions back then and he always advised that both spacer and MREV2 would impact AF a very small amount. Problem is that too few of us actually took him up and did the Dyno comparison.

As far as I'm concerned after adding MREV2 to the spacer that I had on for almost a year, mid-range "pull" got much better.

I think the confusion is that most intake / exhaust modded cars would benefit from a tune and so with all those variables out there, the safe thing for any MFG to say is to have the car dyno'd to be sure; get flash/EMU to optimize thier product.

IMHO the incredible amount of posts about car is/will run lean with this combo has gotten out of control...although better being safe than sorry and so Tony's position and recommendation is right on the money for most.