Dang i also thought it would end next thrusday. I didnt know there was a limited supply. I was gonna try to dyno the thing too

 

As a rule of thumb, a thread larger than 15 pages goes convoluted.
Its the norm.

Yes, it some of it can add up. But its also the most effective NA plenum mod available to the VQ. I know statements like this can't be said lightly, but from everything I have seen so far, its true.

How it relates to other mods on the market is not the primary criteria for which it is priced out. All of the Motordyne plenum spacer kits are made from a significant amount of carefully selected, quality components and materials that unavoidably add up in cost.

There is a lot of custom parts and costs to it.

In the case of the MREV-2 the cost of the lower collector is all there.
The multistep process for machining and manual grinding and manual buffing of the collector add up. It takes a lot of time and skilled craftsman labor to convert a 287 collector into a MREV-2. It takes a small production line to meet the demand. They may not be polished shiney but attention must be paid to getting flow in the right areas.

Performance value compared to a cast plenum is much better if you have a 287 lower collector to exchange.

If you have a REVUP engine, you cant trade in the lower collector so it will cost more, but then again, it also makes much, much more area under the curve.

 

I understand. But I meant the market price of all plenum spacers from all companies, not just yours :P If the market price was lower, usually everyone has to follow the market. On the other hand, posting on a message board can create a new micro-market, separate from the normal market. Irrespective of that, I suppose understand your justification. I still fail to see how a plenum spacer is more expensive than an entire plenum though. Both the Crawford Z and Kinetix full upper plenums are $299.99.

This brings me to another question - with the gains you're seeing, why didn't these other companites just cut through all the hassle and make a simple little spacer? Somehow you are getting more gains from a spacer than others are from larger plenums the house more air volume.

 

So much for the sale lasting a week. Hey tony maybe you could use the sale price for people that have supported motordyne and bought motordyne products in the past? (wishful thinking?)

 

LOL . . . I have asked myself this question, as well . . . And I have come to this conclusion . . . Relative to real benefits gained/realized, the others are either charging too much or Motordyne is not charging enough.

 

Do not put thoughts in his ( Hydrazine) head.

 

IMO practical benefits versus dyno "before and after's" are two different things.

As long as some gains are there, and those gains are repeatable (as is the case with MREV 2) then whether you gained 5hp, 10hp, 15hp does not really matter that much because so many factors can influence the VERY sensitive dyno equipment.

In short, just be happy with the mod you bought as long as it is not CRAP. If it made gains for SURE (crawford plenum, 5/16" spacer, MREV 2, etc) then just be happy and stop worrying.

That said, yes most of Tony's products are offered at a very fair price. Yet I still see people in this thread splitting hairs about not getting in on a first-come first-served sale

 

Damn good question phile.

I asked that same question myself some time back and was confused as to why whole upper plenums were being made. I knew it wasn't necessary.

One of the manufacturers indeed tried making a spacer from a large stack of gaskets... And they said it didn't many any gains so they droped it. There is a nice thread on it here on MY350Z. Search about a year back on "gaskets and spacer".

Some of the old timers here are familiar with it.

But yes, I asked myself why are whole upper plenums being made?... I then thought to myself "Its not necessary to make a whole new upper plenum to reduce pressure drop at the runner inlets."

Having a professional background in fluid dynamic systems, I asked myself why arent they simply using a spacer to lift up the plenum to do the exact same thing? That question is how and why Motordyne started.

I knew there was nothing magic about having a whole new upper plenum that makes HP. Its about fluid system dynamics and pressure drop.
A science. See this link: http://www.motordyneengineering.com/techinfo.asp

All that needs to be done is to reduce the flow restriction at the runner inlets. The stock plenum is too cramped for optimum breathing. Adding a new aftermarket plenum opens up the flow area. Adding a spacer to your current stock plenum does too. And in the beginning, I sold just a simple spacer and it worked well compared to the plenums. There are several independant comparative dynos made by various members of this board posted a while back. With a search you can find them.

Then the design evolved to Iso Thermal and Copper Iso Thermal. This is how the three different lines of Motordyne plenum spacers came to be.
1) The basic plenum spacer (stage 1)
2) The Iso Thermal plenum spacer with a thermal isolating gasket and coolant control valve. (stage 2)
3) And the Copper Iso Thermal spacer with a thermal isolating gasket and polarized copper throttle body heater. (stage 3)

See this link for more details on what Iso Thermal is: https://my350z.com/forum/intake-exhaust/142359-motordyne-iso-thermal-plenum-spacers.html

Then there was the original MREV. It used a spacer with a 287 lower collector and was installed on the REVUP engine. It made rediculous gains. This alone produced more area under the curve than any other NA mod on the market. ...but it also cost more because the 287 lower collector being used.

The MREV-2 is a highly cost effective plenum mod too if you have a 287 collector core to trade in. $446 - $222 core return is $224. In recent testing, it produced more area under the curve than a 5/16" plenum spacer. So $224 is a good bargin. If you have a REVUP engine, you will paymore but there is also much more area under the curve to be made.

If you compare absolute performance of the plenum mods, Motordyne comes out ahead.
And if you compare the price of the diferent mods on the market, Motordyne comes out ahead in terms of value too.

Take for example prices. The cheapest plenum spacer we sell is the basic 5/16" plenum spacer at $265. All other plenum mods on the market either cost more or require you to buy a new strut bar. If you factor in the cost of the aftermarket strut bar. So from this point of view, Motordyne is the cheapest.

If you want to factor in the relative HP gain value, just look at the Sport Z Magazine plenum mod shoot out to see which made the most gains. Divide gains by price and Motordyne has the best value.

If all you care about is getting the most power gains, once again, look at the Sport Z Magazine plenum mod shoot out article. Motordyne took both first and second place in terms of area gained under the curve.
http://www.motordyneengineering.com/dynos.asp

There is also a misconception that the aftermarket plenums have a greater internal volume. I must admit I assumed this too untill it was actually measured by Sport Z Magazine.

In their comparison, they found the plenum mod final internal volume was ranked in this order:
1) Motordyne 1/2" plenum spacer with a stock plenum
2) APS Tall boy
3) Crawford Cast
4) Angled Spacer
5) Motordyne 5/16" spacer
6) Kinetix

So if internal volume was the only determining criteria, the plenums are not on top. ...but internal volume isn't necessarily a good metric to determine performance by anyways. All that really matters is area under the curve as shown by the dyno.

By this metric, the Motordyne 5/16" basic plenum spacer took first place! And it was the smallest, cheapest spacer tested. A classic example of David Vs Goliath.

And the 5/16" is still the cheapest if you include the cost of a strut bar. If you exclude the cost of a strut bar, Motordyne comes in second in terms of cost relative to the Skunk spacer.
...But do a search on Skunk spacers before determining if you want one.

Overall, the most comprehensive comparison of plenum mods to date was done by Sport Z Mag. And the smallest, cheapest spacer available made the most total gains! That not only demonstrates the best performance, it demonstrates the best value too.

Basic 5/16" plenum spacer demonstrated the lowest cost and the best gains. ...And now, the 5/16" just got smoked by MREV-2.

Tony

 

I appreciate the thoughtful and thorough reply to my questions. That helped alot I'm probably going to order the spacer and the MREV-2 sometime in the next month.

 

I have been following this thread, and one question I have that comes to mind that I haven't seen answered is how do you ensure consistancy in the machining process if it is all done by hand? How can you say that all the MREV2s will perform identically? I'm not an expert in these areas so forgive me in advance. It would seem that some MREV2s would gain more HP than others (maybe +/-1 or 2 HP). I'm just wondering how many standard deviations of accuracy you can assure in the machining process to ensure a standard product off the assembly line. It seems as though you've only tested a handful of MREV2s, although in various combinations, but not a lot of MREV2s on one car to see if the results remain constant and are repeatable.

 

good point.

 

Not all of it is done by hand. The majority is done on a mill. The remainder must be done by hand, but I have gone through a coaching session with the shop foreman and manager showing them exactly what I want and how it should be done.

They also have the sample model I personally made for their guide. They keep it near by during the learning process.

Anyways, the guys are up to speed on the quality. I inspect each one for evaluation on rejection, rework or approval and they are doing a good job now. They have the hang of it and are making them exactly like I want them.

Yes, there can and will be some variation but it just comes with the territory That can't be completely avoided. Besides, you would be surprised at the amount of variation on a fully stock lower plenum. In many ways, the sand casting process is less consistant than what the shop guys can do.

But yes, I do have strict quality controls in effect and I do it to the best reasonable limit.

 

Tony, you mentioned the skunk2 spacer, was that spacer also tested in the Sport Z shootout? I'll have to try to find that mag around here...

 

Another thing, you may want to patent the process. This way your idea is protected and no one can copy it without going through you first and providing some sort of agreeable compensation. Nissan and your aftermarket competition comes to mind.

 

No. You would have to ask DaveO the article editor for details on that.

 

Yes, that is in the works.

Thanks!

 

Long before the "stock 'O gaskets" attempt, I recall the first plenum mod even before Crawford's first attempt was, big shocker... a plenum spacer made of some composite material from a Japanese company called Esprit. Might still be some refferences to it floating around in the My350Z archives. It was rediculously expensive for what it was, though, and I don't recall anyone in the states ever getting a hold of one. That's when Crawford came on the scene. They went with what they were equiped to build and got good results. They're not a machine shop, so welding a larger front to the stock upper plenum was easier than the spacer concept. Other companies (Kinetix, APS) jumped on the bandwagon with their own variations, given the proven success of Crawford, so spacers took a back seat for a while and came back around later on. Interesting to watch how these things evolve. There simply weren't any machine shops around atthe time to give the spacer thing a try, so a Z car tuner gave something a little different a go with what he had to work with and the aftermarket high volume upper plenum was born.

Ok, I just dated myself as one of those "old-timers", didn't I?

 

Now, the intersting thing about this, to me, is that in the plenum shootout, the dynos did indeed show the 5/16" spacer taking first place and if memory serves, the Kinetix came in 2nd to last, above the AAM angled spacer. The Kinetix v4 and 5/16" spacer are supposedly very close in volume (according to info. I received from Kinetix), so it's a mystery to me why the spacer performs so much better. Another tidbit: the newest Kinetix V+ plenum has 10% greater volume, moving it up on the list to just above the Crawford (again, according to Kinetix).

 

Yes. I agree. This is why I was saying internal volume is not a good metric to guage plenum performance.

When you try to draw a relation to the numbers, it appears there is little or no relation between internal volume and performance.

 

wow.. a lot of good info..

Thanks Hydrazine for clearing some of the things up on your product line.