undrgnd

iTrader: (2)

The loss at the top end with the MREV2 is in the order of 2 hp. You must have one very sensitive butt dyno.

RBlover69

iTrader: (2)

how about swtiching to the 1/2 spacer

13SECZ

iTrader: (4)

My loss is a bit more..I taper to about 255whp from 267whp on the dd dyno...So I lose about 12-15whp..that you can feel..and when you drive it you can feel it. Thats my graph though...

Hydrazine

iTrader: (53)

You lost 12-15 HP from the original baseline, or from the new peak reached with the MREV2?

undrgnd

iTrader: (2)

Sorry, I missed your graph. Could you post a link to the before and after dynos where the only difference is the MREV2? I have never seen anything approaching that big a loss, and I would speculate it's not due to the MREV2 alone.

RBlover69

iTrader: (2)

thats what im wondering...its seems that everyone that i see with the 1/2 gains a very nice peak hp number. And everyone with the 5/16 has the mid range but takes a peak hp loss. I myself am looking at strut bars to mate with the 1/2 it seems the only way to keep the peak hp of the already peaky revup motor. Besides maybey the tall boy plenum or cosworth. None which show gains on a revup so far.

Hydrazine

iTrader: (53)

I agree. I have never seen that in my own testing (and I've done a lot) or in any of the independant dynos posted.

And I actually have a pretty big archive of the original MREV and MREV+. ...None of them do that.

undrgnd

iTrader: (2)

Not sure which setups you are referring to, but my personal experience with the APS differs. The distance at the front of the APS plenum, from the flange face to the internal top surface, is ~1.5". This is comparable to the OEM plenum with a 1/2" spacer. Which could be why mostly FI cars use it. It would NOT fit under the OEM strut bar without a stack of washers. I'm pretty happy with the top end of the MREV2/APS on my revup, your observation notwithstanding.

RBlover69

iTrader: (2)

my observation showed nobody with this configuration but you, so if you could show your dyno showing the gains it will be appreciated to actually see what did it improvve over stock.

I thought the aps was a complete plenum not needing the mrev2??? its been a while since the tall boy has even been mentioned ..lol i was intrested in it but lack of info on how it performs on a revup detured me from it.

Hydrazine

iTrader: (53)

The APS is a upper plenum.

I've never seen any test results for it, but when Sport Z Magazine did the article on the Plenum Mod Shootout they also performed volumetric measurements of the various different plenum mods.

The two largest internal volumes were attained with the APS and the 1/2" spacer on a stock upper plenum.

The APS and 1/2" spacer volumes were identical.

...Not that internal volume says much, but at least its one comparative data point.
My guess is the APS and 1/2" spacer would yeild the same results on the dyno.

undrgnd

iTrader: (2)

Just scanning the sigs on here over the past 2 years I have noticed several people with the Tall Boy. And that doesn't include those that don't bother with a signature.

RBlover69

iTrader: (2)

yea but out of the hundreds 350z owners + i rarley seen a revup with a aps tall boy . So u have to understand why i question the results.


And am i right that since the tallboy is a plenum it cannot be mated to the mrev2 or can it be??? Im not sure by ur statements are you saying you have both mounted ???

13SECZ

iTrader: (4)

Sorry for the confusion..but I lost 10-15 from the peak number the mrev setup made..not from my baseline....But my baseline was like a mountain...it never tapered...I however did not make the peak power I do now, nor the amount of pk tq....

I am curious what switching to the 1/2 spacer would do for me...

What do you think I would lose ?...

Oh and I cant find my graph but if you search posts Ive started you will find it....

Mazinger Z

iTrader: (49)

What version of the mrev do you have?

Hydrazine

iTrader: (53)

13SECZ,

Like yours, this plot here shows a 10 HP drop off from the new peak.
http://www.motordyneengineering.com/...-post-dyno.jpg
This plot shows both the largest drop off and highest gain recorded. The peak is about 10 HP higher than the original baseline. Removing the MREV2 from this engine will only make for a slower car.

The drop off at the end of the curve is the nature of the beast. The gains everywhere else on the curve cannot be made without it. It has to do with the plenum tuning frequency and frequency bandwidth Q.

Unless the original stock plenum was terribly designed it would not be possible to make a new plenum that made gains everywhere on the curve with no drop off.

In this case the performance can, overall, be better optimized. This is what the MREV2 does, but, the more the redline limit power is brought up (at the very end of the curve) the more power will be sacrificed everywhere else.

In other words, trading 10HP at the very last 500-700 RPM would sacrifice 10HP everywhere else on the curve.

When you do an analysis of the useable RPM range for each gear and the average power per gear, the average is always higher with the MREV2 if you shift precisely at redline every time.

That is what was done with the Import Tuner data here.
http://www.motordyneengineering.com/...i-analysis.jpg

Comparatively, if you shift at anything less than redline (like in daily driving) the average goes up even more.

As for the differences between the 5/16" spacer and 1/2" spacer, its actually small, but its there.
Its a trade of ~1.5 average HP with a crossover point at about 5000 RPM.
http://www.motordyneengineering.com/...tAnalysis5.gif
http://www.motordyneengineering.com/...tAnalysis6.gif

Maybe its just me, but I personally wouldn't trade the strut bar for it.

RBlover69

iTrader: (2)

for ones that are looking for that nice peak...a aps strut bar maybey the ticket . I see where 13sec is getting at. I to feel wierd when you tell someone your rwhp fell off peak wise but your mid range tq is amazing. But as hydra said its the nature of the mrev2s design and efficiency. Now if he came out with the exhaust , maybey we can gain some top end lmao. jk

13SECZ

iTrader: (4)

I see your point...I guess I will just leave it...It does make good power for n/a....I have the mrev 2...which is what I need for my Rev up..

undrgnd

iTrader: (2)

13SECZ,
I have the MREV2 w/ an APS Tall Boy (in lieu of the spacer). With a less restrictive intake, HFCs, y-pipe, exhaust, and a tune, there is a noticeable improvement all the way to 7K. Considering these mods are strictly bolt-ons, and it is very easily restored to stock, I am very satisfied with the results. I think I whored this shot at least 10X now.

RBlover69

iTrader: (2)

im still confused, ....isnt this ment to be used alone without a mrev2??

Hydrazine

iTrader: (53)

Not necessarily. Its just an upper plenum mod. Like a spacer.

MREV2 is a lower plenum. They are mutually exclusive. Compatible, but not related.