First of all I would like to say that I have a Motordyne 5/16" space installed, and it does work.

Do you have data to back up the colder air that the Iso-thermal stuff is suppose to give you? I can't believe that the air has enough time in the air plenum to increase in temperature.

 

With the Iso Thermal (not the copper) my assumption would be that you would get the car tuned with the valve closed right?

 

Yes.

I wrote about it on another thread some time ago in more detail.
Iso Thermal is good for ~2 HP at 5K. To describe it really short, the difference can be reasonably calculated.

The plenum assembly runs at ~140'F when in operation due to heat transfer from both the hot water flow and lower manifild heat transfer. Once the hot engine is shut off the plenum temperature shoots up because there is no longer any air flowing through it. (this tells you right away that the air is cooling it.)

But when the engine is shut off , I measured the plenum temperature rises at about 8 degrees per minute untill it reaches equilibrium at about 170'F. This observation tells us a lot!

I can't remember the exact number but plenum assembly weighs about 17 pounds. And since it is made of aluminum we can look up the specific heat capasity of aluminum. 17 pounds of aluminum at a given specific heat rising 8 degrees per minute tells us an exact amount of heat transfer per unit time.
This heat transfer is continuouly going on wheather the engine is running or if you just shut it down. And the only reason the plenum temperature shoots up is because air is no longer flowing through it.

So now we have identified the heat transfer rate in the stock configuration... And if you assume the engine consumes ~300 CFM, it is that same heat transfer rate that is going into the air flowing through the plenum. (or else the plenum temp wouldnt rise at shut down)

We know the heat transfer rate, we know an average approximate air volume flow rate and can convert it into an air mass flow rate, we can look up the heat capasity of air and multiply that value by the air mass flow rate to find a total heat capasity per minute...

We know the heat transfer rate through the lower manifold that goes into the air, so we can then calculate the rise in air temperature. When the Iso Thermal is installed on the same plenum, the temperature rise at shut down was cut in half to about 4'F/min.
The heat transfer rate was cut in half!!!
And because one way or another all that heat is is getting pumped into the air flowing within the plenum. With the change in heat transfer rate, we can calculate the change in air temperature. From that we can calculate the change in density and from that we can calculate the change in horse power.

I did the full process of calculations and found Iso Thermal is good for about 2 HP. Its not all that much but at least its 2 more that can be added on top of the spacer performance. And the reduced tendancy for ping is another plus!

The calculation is not a complicated process, but its a bit tedious to work out here on a discussion board. I could take the time to write a an actual technical paper on it but I can't think of any magazine or periodical that would want to publish such an abstract for only the VQ engine!

Very few motorheads (except some 350Z and G35 engineers) would have an interest in such an article. Oh well, at least its fun stuff for engineers.

 

Yep. You basically tune it to how ever you are most likely to drive it.

 

did i miss the group buy?!? i am VERY interested in #8...someone please let me know...a pm would be awesome

 

I read a thread about the 5/16 Iso Thermal Spacer where a couple people said they were having hood issues after installation. Is this a common thing or isolated for a few people? Also....is this something that occurs if you just install the spacer without the iso thermal add ons?

Also....let's say you installed the iso thermal stuff but never bothered closing the CCV? Would you still get the benefits from the other stuff? Or is the CCV the main deal?

 

Hood contact is actually a rare occurance given the number of spacers installed. Very few will be tight. The vast majority fit just fine. And somehow some people have been able to it the 1/2" spacer underneath their strut bar!

Its the variance in tolerance stack up in how the car is built.

As for the Iso Thermal you can certaintly leave the valve open and the coolant flow will heat the plenum just like it does in the stock configuration. You would want to do this in cold weather conditions. In this case, plenum spacer performance will be equal to that of the basic plenum spacer. The dyno results of the basic plenum spacer are posted on the dyno section of our website.

By using Iso Thermal it will effectivly reduce power loss from heat soak and is good for approximatly 2 HP across the board.

 

I read about hood issues as well here at my350z. Does the G35 Coupe have more room?

 

Yes. The hood is actually lower on the G35, but there is also no strut bar to work under.

Space under any of these hoods is like realestate. You need to use it both carefully and to the greatest extent possible for the best yeild.

 

Tony: Actually, most of the cooling of the plenum when the car is moving comes from the air flowing thru the grille. Close the hood and idle the car in place and you will prove it to yourself. Unless you can dyno that 2hp gain, it is pure conjecture with no theoretical or practical basis... Sorry.

 

Undergnd,

There actually is.

And it is calculated based on empirical thermocouple pre/post data and heat transfer analysis. I did the measurements and analysis quite some time ago. On both a theoretical and practical basis the analysis would be plausible to an objective engineer.

It was previously explained in significant detail on a few threads here at MY350Z, G35DRIVER, and even the other boards. Do a search if you really want to see it. It is not difficult analysis but it does require tedious calculation. It’s not something that can be whipped out inside of a 15 minute internet post. If you would like to see a complete analytical article published on the subject... I just may do it.

I’m currently hooking up a Innovate Motorsports LM-3. It will have the capability to data log, record and plot thermocouple data.

What I will do is data log plenum thermocouple data both pre and post Iso Thermal installation. I’ll plot and post the results and provide a fully plausible analysis complete with pre/post infrared thermal images of the plenum.
When time is available.

Right now I am focused on research an development for other completely new mods. Good research is painfully slow and time consuming, so that analysis will happen when after some of the other stuff gets done.

You may have noticed I don’t advertise or claim what cannot be backed up by dyno results or plausible analysis based on empirical data.

I put my reputation on it.

Tony Colette

 

hydra, i dont envy you having to prove yourself to the Z/G-Unit is a though thing.. props goes out to you for putting our many questions to rest..

 

You are proabably one of the only companies that supply mod's that actually do real engineering and tests. Instead of just putting out claims, and take the time to explain it for us! Thanks for the info, yet I will just stay with my Motordyne 5/16" spacer for now.
I would like to say that the instruction for the spacer where the best written instruction I have ever used - and I mean any instructions! And, as you can see from my sig, I have done a lot of mods.
My hats off to your company.

 

Haha!

Thanks guys! BTW Good news from the dyno!

Of course I have recieved a million requests from people to purchase the MREV for their 287 HP engine. And I always have to turn them down because they already have the 287 HP lower collector and all they need to do is add a spacer. This is what makes a MREV.

But you know that machining process I have been doing to make the MREV PLUS lower collectors?... Well I dynod it on a 287 engine yesterday and it worked surprisingly good. ..I've been advertising to the REVUP guys that the machining process to the lower collector is good for about 2 HP but based on a quick analysis of yesterdays data, it did much more! At least on the 287 engine it did about 5 HP more! And it made gains over a wide portion of the curve.

I'm importing all the data into Excel now for detailed analysis and plotting. It will be posted soon.

...Very interesting results on a G35 Sedan. (basically a 287 HP engine with a little more restrictive exhaust)

Here was the dyno test sequence:
1) Dyno of a stock plenum
2) Dyno of a 5/16" plenum spacer
3) Dyno of only a modified lower collector (with no spacer)
4) Dyno of a modified lower collector (with a spacer)

What is so interesting to see is that the machined (modified) collector, by itself, outperformed the 5/16" spacer! ...not so much in peak power, but it clearly added more area under the curve and more torque!

The modified lower collector was then dynod with the spacer and the two symbiotically worked together to make even better gains.

The 287 lower collector machining process makes power in a way the spacers and plenums cant. I don't want to say how, but it does. It even added power at a surprisingly low RPM.

A modified 287 collector is a worth while mod on its own. (for 287 engine or as a MREV+ mod for the REVUP engine.)

Weather you are stock or have a spacer or have a plenum, this mod makes power independantly of them. If you do have a plenum or spacer it works even better with them.

We have a new way to make HP on the 287 engine!!!

All the technical details will be available soon. I'll start a new thread on it shortly.

Tony

 

So, how much will it be to get *everything* ...
the modifed collector, the spacer, iso-thermal gasket, etc?

 

Great news Tony! Prepare to get inundated with emails and PMs.

I promise to wait patiently for the core exchange program.

 

You could simply order the 5/16" Iso Thermal plenum spacer... and I will have to set up the Motordyne website so 287 HP lower plenum core exchanges can be made.

 

^^ +1

Thanks Tony! I knew you wouldn't forget about us.

 

But how much will the core exchange be?

 

Right now its already listed on the website as the "MREV PLUS" optional upgrade.

But now I will need to update the website for the same machining process to be performed on an exchangable core.

It may also be done where we would send out a modified collector first (so you won't be without a car for X number of days) and then you could send in your stock collector for a core refund.