Looking forward to seeing the results of that.

 

I too am waiting for a Crawford Plenum / MREV-2 dyno. I hope the results are positive and the addition of the MREV-2 is well worth the money.

 

Wired 24/7, what engine management/tune are you considering? Thanks.

 

Dolva,
As I explained to you, the increase in plenum volume given by the addition of the spacer on the upper plenum will give you more airflow. On some cars this attributes to more HP, depending how lean or rich the car already runs and likes to run.
Now my opinion on the lower "iso thermal gasket" is that it will do nothing by design to increase any sort of performance. And I say this for 2 reasons.
1) the gasket material is a common material used in many application such as sealing water pumps and has no better heat dissapation properties than the stock metal gasket.
2) The material in the gasket is not thick enough to make a signifigant difference on intake air temps, as well as the fact that the air is not in contact with the lower plenum long enough to absorb or dissapate any signifigant amount of heat and make any sinifigant performance gains.
In a nutshell, if a different type of gasket material between the upper and lower plenum would have made a big difference in performance gains, then Nissan engineers would have done it that way from the start, to claim the extra 3hp for themselves..

Now as far as the lower plenum mod you brought in to us, I can not see where machining that plenum in that fashion would make any signifigant airflow difference enough to effect performance gains without doing a full port and polish to the entire plenum and runner assmebly as well as gasket matching the heads and intake, and CC'ing the intake runners to ensure equal volume in each one..

 

Don't bother CC'ing the intake runners, they are different lengths. Volumes wouldn't be even close. See the DIY plenum porting thread for the measurements.

 

not if you did the lower intake plenum and the lower runner going to the heads together, with a gasket match..

 

Not true.
Objective test results with an array of thermocouples prove the Iso Thermal gasket and coolant control valve reduces the upper and lower plenum plenum assembly temperature by 30-60 deg F. Independant test results show reductions as much as 80'F. That's a measurable fact, not off hand speculation.

And the machining process has been proven (objectively) to make gains by both Nissan North America and Wired24/7 independant dyno tests. The gains are not speculation.

Tony

 

Perhaps my interpretation of the results is incorrect, but to me it looked like the mrev++ by itself performed incredibly similar to if just a 5/16'' spacer had been used. Then by adding the spacer to it, it gained a few extra ponies, did nothing really to justify combining the two unless you absolutely demanded that extra +2hp......

 

I agree.
On my G35 it did 2-6 more HP when combined with a spacer. For the test Z at N.N.A. it did about 3-4 when combined with a spacer.
For Wired 24/7 it did around 2-3.

By combining plenum mods, it may be analogous to adding a spacer to a aftermarket plenum. Or adding a 5/16" spacer to a 5/16" spacer. (Diminishing returns.)

More data points will be posted.

 

3-5HP more would be great if it was everywhere in the curve.

 

Thats all good, and I am sure on some cars it might make some power,however in this particular situation it did not. And thats a fact not an assumption. All parameters relative to the engines operation were monitored and datalogged with the Cypher software.
Also keep in mind this was an independant dyno test at my facility at the request of the customer, not me..He paid me to Dyno,install and re-dyno as a comparative measure for his own personal reference..I stand unbiased on the product either way...

 

Just allow me to clarify my point of view..3-4 hp is a mute gain IMHO. I can take a bone stock car and dyno back to back and see fluctuations of 2-10 whp on average...IMHO the only where DOLVA picked up power was from the Spacer as a result of increasing the volume of the upper plenum. There is no way that he picked up any power from replacing his lower plenum with the exact same lower plenum with 1/64th of an inch material shaved off in 2 spots.. I am in now way bashing your product ..

 

Is that the stock lower collector? Or the MREV V2?

 

That looks like a stock one based on the stock "domal" shape of the intake ports. My MREV2 has "flattened" intake ports 1 & 2.

 

So many graphs, it is hard to weed out discrepancies.

One thing that is interesting is how this freaking ECU adjusted injector pulse from 2200 RPM to 4400 RPM with MREV-V2 on my car. Which is good thing because tuning should be easier now.

Hey, I need at least some justification for the swap


Pre_Install:












Post_Install:

 

I don't dispute that the machining process didn't make power when added to a 1/2" spacer.
Nor do I dispute that Iso Thermal won't make power on an "open hood dyno".

But you wrote in several assertions (based on speculation) that are not correct. Be reserved with speculation or assumptions in publicly made statements. By all means discuss technical/engineering/scientific issues on what you know or have a solid background in. Analysis and engineering judgement are perfectly reasonable and encouraged.

Firstly, this is not a common gasket material. It may look the same as many other gasket materials, but it is not. This gasket material has an Aramid base and was carefully researched and selected for the application. Why Aramid?... because it has one of the lowest heat transfer coefficents and highest heat resistance properties available. Much, much better than phenolic on heat transfer coefficents.

This Aramid based material costs much more than regular water pump gasket material and is in no way comparable in cost or function.
This particular material is rated to 550'F and has a heat transfer coefficent 112X lower than steel.

The Aramid Iso Thermal gaskets total heat conductance is 269X lower than the stock metal gasket. Or in other words, it would take a stack of 269 stock metal gaskets to equal the thermal non-conductance of one Aramid gasket.

When the Aramid gasket and CCV are installed (and they both must be used together), it cuts the final plenum heat flux in half.

So when you say that the Aramid Iso Thermal gasket has "no better heat dissapation properties than the stock metal gasket." It is an incorrect statement.


This is speculation, stated as if you have pre/post thermal measurements or engineering analysis as the basis.

The real world effectiveness of Iso Thermal cannot be measured on an "open hood dyno". "Open hood dynos" do not measure power as produced on the track or freeway, nor do they simulate realworld driving conditions with the hood closed and with the engine compartment completly heat soaked. The thermal conditions during the typical open hood dyno are entirely different. Thermocouple data will verify this.

The closest the open hood dyno will get to real world thermal conditions is drag racing. At least that is if the hood is open with fans blowing on it for 5-10 minutes... and then the hood closed immediatly before the race.


Correct, Iso Thermal doesn't make a big difference. Heat transfer analysis based on real thermocouple data shows its good for 2HP and change.
No, its not a lot. But its 2 more HP available for the street or track.


This is a blanket statement with no qualification or reference to use with a 1/2" spacer. If you are refering to use with a 1/2" spacer, it would be best to state it.

If this was meant to be a blanket statement, then the statement is incorrect. When dynod by itself it makes very good gains. With a 5/16" spacer, it makes incrementally more. The gains have been proven on the dyno by multiple sources.

In terms of relative effectiveness, this mod by itself is more effective than the 5/16" spacer.

 

That's cool.

But just to clairify, there are three areas where a lot more than 1/64th of an inch material is taken off. Its nearly a 1/4" carved off in 2 of them. And slightly less on the third.

With a less significant but easily knocked off corner in the 4th area.

Place a spacer on a modified and an unmodified collector to highlight the differences.

 

Good of you to admit that using both the MREV-2 and spacer together may not produce enough gains to be worth it. Still need to see more dynos to be conclusive. What I've seen so far on the MREV-2 alone, though, is that it at least matches the performance gains of a spacer, AND it's cheaper, so if you don't have anything yet, MREV-2 is the way to go; for those that already have the spacer or aftermarket plenum, may be best just to stick with what you have and call it good. Be interesting to see if an ECU tune helps squeeze more out of the combo pack. Leaning more every day; hopefully more dynos will show up soon.

 

Actually my one mechanic is an engineer by trade and agrees that the heat transfer properties of the gasket are to negligible to make HP claims or expectations. And the dyno spoke for itself.

If this is the case, then so be it..But in Dolva's case the heat transfering properties did not help. And I just wished manufacturers would better explain these things to people before they take their money and sell them a product. Ultimately it is the shops like myself that have to answer the customers questions and deal with their obvious frustration when their car did not perform as they expected or were lead to believe it would. I think had you explained to Dolva, that this modification would offer him NO LEGITIMATE GAINS given the current configuration of modifications he already purchased from you, he would have not purchased it. I feel bad for taking his money for the install and dyno, and had I sold him the product I would have felt even worse..

Well my dyno operator is an engineer and all the conditions were as close to the same conditions as we could get..The car was ran 4 times prior to install and 4 times pos install under the exact same atmospheric conditions. Both times the car was allowed to sit and cool for aproximately 45 minutes prior to the first run on each set of results.

If an open hood dyno does not measure real world HP then why do you post dynos for all your products?Why not post some technical data like intake temps?Or Track times?Or datalogs of the engines vitals?
Taken from your site FYI...

Open hood dynos, are used in the industry as a standard to measure the HP of a vehicle and the addition of any HP from a particular modification.. Dont make a claim of 10 whp then change the topic to debate the effectiveness of an open hood dyno, which is, by the way, the same measurement you utilize in your sales pitch to sell products, simply because the results on someones dyno did not favor your findings...


2 hp at the track, YIPPEEE!!! Or I could slap on 2 Type R badges and gain 5hp per badge..lol Cmon man, your talking to an avid drag racer and performance shop owner, not some 18 year old fast and furious junkie...2HP is nothing and can be elated to an inconsitancy in the car, and IMO is not worth the cost of what Dolva Piad for his little experiment..

Dolva already had a 1/2" spacer on the car, which he felt made power, and to which I concur that it made power. The extra volume in the plenum did indeed make power by leaning him out a bit and giving the engine a little more air ready to be sucked in..
However, what I am saying, is that the addition of the lower plenum with a 1/2" plenum made no power..What your saying is that the fact that the 1/2" plenum spacer is 3/16" larger than the 5/16" one, that the lower plenum mod does not make great gains with it..So the lower plenum only magically works with the 5/16" spacer then?
Did you explain this to Dolva prior to him ordering it?

 

Not sure, maybe the greddy e-manage ultimate. The guy who dyno'd my car in that thread of mine, I want him to tune my car when the time comes. I mentioned UTEC to him and he said he didn't really like the interface. Well, I'm probably not tuning the car myself, so I think the greddy might be a good comprimise of how powerful a tool it is versus how easy the interface is. In any case I have heard lots of good things about the EMU... even if the UTEC does have advantages over it.

You might want to reserve judgment to see what a tune could do...

Also for the record, when we did the dynos on my car it seemed to me that the iso-thermal gaskets were effective in keeping the modded dyno pulls more consistent. Before the iso-thermal gaskets were installed, the 3 baseline pulls were just getting worse and worse rapidly even at the same coolant temperature. IMO the iso-thermal gaskets may not make a huge difference, but they certainly don't hurt.