Just got to install my 5/16 Motordyne Iso Thermal plenum spacer kit earlier today. After my 20 minute drive home the plenum was only warm and not scorching hot like it usually is. This really works!
The quality of the kit is top notch. The installation was a breeze also.
Its hard to tell about any power gains, but the care felt really good on the drive home.

Good job Tony.

 

You probably won't notice any power gain, but you might notice that it doesn't get as sluggish on those hot summer days.

The gasket concept is not that big of a deal, there were already a couple of them out on the market. The TB heater bypass has also been available from other places. My hesitation in getting one of those was the fact that they were all 1/8" or thicker. Since I have a AAM plenum spacer installed, there's not much room left between the top of the plenum and the strut bar. Tony solved that by finding a gasket material that is effective at only 1/16" thick. That should fit fine in my Z without any rubbing issues.

 

would you notice a gain if you had the 1/2" spacer? this is something I'm interested in but want to get the best, obviously

 

mrpratt, I think DavesZ#3 was saying the thermal upgrade won't increase power. It isn't suppose to increase power it is to prevent heatsoak from robbing power.

The 5/16th spacer is suppose to increase power not the thermal components. The 1/2 inch spacer is suppose to give a slightly larger gain. Maybe 1-2 horsepower more, from what I've read, but you can't use the stock strut bar with it.

 

thanks for the info, i think i'm gonna get the 5/16th so i can keep the factory strut bar

i didnt really read the thread all that well last night because, well, i was pretty drunk - sorry about that, thats what no class on friday will do to ya

 

the thermal spacer upgrade is likely more evident after some hard runs or laps.

but during normal driving it is likely less noticable.

 

I actually have the 1/4 spacer and recently added the Iso Thermal upgrade.

Definitely no power increase from the gasket itself but huge difference in the heat on the plenum. You can actually put your hand on the plenum after a drive and you won't lose 2 or 3 layers of skin....It will be warm to the touch not blazin hot as usual.

 

+1

 

I can back up the latter part of that. I helped a friend install the Isothermal kit on his car (he's running the Crawford v5 plenum) and we did before and after testing with an IR temp gun. The kit only reduced plenum temp 5-7 degrees.

On another note, I've observed that the plenum doesn't really get hot while the engine is running. It's only after you shut the engine off, that heat soak becomes prevalent. I can run the car all day and the plenum is just warm when still running. If you let it sit about 15-20 min after shut down, THEN it's very hot. So the heat soak may only affect intake temps upon restart, but it will cool back down and equalize as the engine continues to run and the intake air passes through it.

 

I installed the 5/16 on my G35 2 days ago and for the first time I can force VDC to light up at 4500 rpm in first gear under full throttle. It seems to pull better between 4000 -5000 rpm as well as sound a tad deeper. I wish I had a dyno done but in Kentucky they just don't have any, yet. Oh the woes of being a redneck ricer!

 

Please clarify the 5-7 degree difference. Did you measure the temperature, drive it around for a while then measure it again and it only went up 5-7 degrees?

Also, the plenum DOES get really hot while the engine is running. After a 15 minute drive, you can't leave you hand sit on the plenum at all. I've done some measurements with a remotely attached temperature probe and the plenum easily gets to 150ºF. You are correct that it gets even hotter after then engine is turned off, probably in the 180º range. Driving again will bring the temperature back down to the 150º range.

 

MustGoFastR, does the Crawford v5 plenum run coolant through it? If it does then I doubt it is only warm to the touch. It should be just as hot as the stock plenum. Then again, I know next to nothing about the Crawford plenum so I may be completely wrong.

 

The temps were taken both with the car running, immediately after it had been driven for about a half hour, then again after it had sat a while, to get the max temp it went to after 15-20 min. With the Isothermal kit on, the plenum was only 5-7 degrees cooler in both situations than without the kit on.

The Crawford does run coolant through it, but only a small area at the neck, next to the throttle body, like stock (the back half of the Crawford plenum IS stock). The Isothermal kit comes with a shut-off valve to stop this flow; the temp difference was inclusive of this aspect of the kit.

As for the hand on the plenum thing, never tried it stock, really, but with the crawford, it was not that hot; you could put your hand on it while it was running. It was pretty warm, but not scalding. The final temps we were pulling off the plenum after it sat were in the 150-160 degree range; I don't recall right off hand what the temps were while it was running after it had been driven, but obviously, they were lower.

I currently have a stock plenum on, so I will take measurements when I get a chance. I'm also about to put on the Kinetix composite plenum, so it'll be interesting to see temp differences between the two.

 

MustGoFastR,

Is your friend using a Pop Charger or similar short ram intake?

If the air intake temperature is warm (or even hot), the plenum temperature can only approach what the air intake temperatue is.

As an example, if the lower manifold aluminum temperature is normally ~190'F and the air intake temperature is 105 at the PopCharger, Physics mandates the plenum temperature will necessarily be bounded between 105 and 190' F.
The higher the air flow rate is the more closely the plenum will approach the air flow temperature... And much more so if Iso Thermal is installed.

 

He has stock intake with K&N drop-in.

I don't dissagree with you on the temp reasoning; just saying what our findings were and that the Isothermal kit didn't appear to make much of a difference. It was a fun and easy install, but is 5-7 degrees cooler plenum temps worth it?

 

Just from seeing what happened after installing the Iso Thermal kit on my car I think there is more than a 5-7 degree difference between warm and extremely hot. Thats just what experienced with mine.

 

I only have the CCV and the difference after a 60 mile drive is phenomenal. Normally it would be too hot to touch (135+). With the CCV, it's barely above ambient (<100).
I believe your 5-7 degree measurement is faulty.

 

I think the ISO kit's effect depend greatly on where you are located. He is in houston which can get pretty warm like Miami. I too have experienced only a slight temp dip with the kit installed. As a matter of fact I used my neighbors 05 Z as a comparison and his plenum and mine were at the same temp after similar runs.

Maybe it will make more of a difference once ambient temp comes down in a month or so around here.