Phenolic Intake Manifold spacers

[mug23]

So on my Time Attack Subaru WRX STI pictured on my icon, many people that races are using phenolic IM spacers to attempt to reduce heat build up into the IM from the engine block itself and I have also heard people think that it's a waste of time too.

Has anyone here actually thinking of doing something like this to their 6.5? I'm thinking of getting custom made phenolic spacers around 3-5mm or event up to 10mm thick depending if the IM bolts are long enough that will match the IM gaskets to attempt to give it a little bit of distance between the IM and the engine block. I'm also going to wrap the lower and upper IM and the turbo compressor housing with the gold mishimoto heat defense tape to help heat soak into the metal to see if I can bring IAT down a little bit.

Any thoughts on positive or negatives on this project?

[oil pan 4]

I dont see any point in doing it. I can put my hand on the intake in my truck and leave it there and its only luke warm. After shut off it gets a little warm.

Wraping as much of the exhaust as you can get to isnt a bad idea. After all the turbo is just another heat engine.
The wrap would help protect everything else that is plastic or rubber near the exhaust.

[Tommygunner]

I think it may be good idea. If it doesn't cost too much.
IDN about what OILPAN said. He is an old mechanical NA man, and maybe he only drives around the block now and then.
All I can say is. After i have been working my truck hard my intake will be very hot. its nothing I would want to lay my hand on or caress. I know a lot of it is heat transfer.
You have a F intake so no exhaust is going thru the manifold. That is a good thing. Anything to reduce IAT will help. Sheilding the intake should make a diference. Wraping the exhaust and a turbo blanket would be a good idea too.
I run phenolic spacers on my 5.0 mustang. Helps reduce IAT so i can run more timing.
Definatly a little power adder.
If you have the resources give it a try and post up the results. i would be interested.

[mug23]

For me, after a tow of around 5-6K lbs for 2 hours and when I put my hand on the upper IM, it does get pretty hot to touch as also the turbo compressor housing. I wonder also the lower IM will be a little bit more hotter than the upper.

I do believe that adding a phenolic spacer say around 10mm thick with gasket on both sides should make a difference. Don't for get that I will be wrapping the upper and lower IM with reflective tape that will contour to the shape of the manifolds will really help in heat soak.

I have already found sources for the phenolic plastic in the thickness I want here I just need to find a way to have it cut clean to the shape of the manifold gaskets. The prices are not bad either. I will report back once I tackle this project.

[Tommygunner]

The more i think about it even putting one between the upper and lower intake should help quite a bit to lower IAT. Beings upper intake is where the IAT sensor is. If the upper intake is cooler. It wont de-fuel. Hmmm Verrry interesting!

[Paveltolz]

For those who haven't already made upper intake modifications due to changing out to a non OEM turbo, be prepared for some adaptation as an OEM upper intake will no longer align with the OEM turbo charger with the addition of a 10mm or so spacer.

It would be interesting to see if the spacer does have any effect on the lowering of IATs. When I added mine, I didn't bother to get a set of readings that could be compared in a before and after as I had no idea there might be a difference.

Make sure you have continuity between the upper intake and the motor through the intake bolts when you're done though. The IAT Sensor needs a path to ground to operate correctly...send the correct info to the ECM.

Keep us posted.

[nh484000]

Just for everyone's information unloaded and just going down the road my IAT is around 120f when it's 70f out.

[chevyinlinesix]

I have made up phenolic resin intake spacers exactly like you are talking about. My engine however, is not complete so I have no solid numbers. It will reduce the intake manifold's temperature, to what degree is unknown.

Also, it will cause a mus-alignment between the intake manifold and the cylinder heads. You can correct this with die-grinder work.

I believe that having a heat reflective coating on the intake manifold will gain you almost the same results, but with much less work involved. That is of course my opinion

[Paveltolz]

With apologies the OP and others here for completely missing the boat on this one. Failed to recognize the spacer(s) are between the heads and intake...
Still, the continuity issue for the IAT sensor and the alignment issues with the turbo and now the manifold and apparently the heads themselves remain.
FWIW, My lower intakes are ceramic coated to reflect heat back to the valley of death.

[mug23]

Originally Posted by chevyinlinesix

I have made up phenolic resin intake spacers exactly like you are talking about. My engine however, is not complete so I have no solid numbers. It will reduce the intake manifold's temperature, to what degree is unknown.

Also, it will cause a mus-alignment between the intake manifold and the cylinder heads. You can correct this with die-grinder work.

I believe that having a heat reflective coating on the intake manifold will gain you almost the same results, but with much less work involved. That is of course my opinion

Who may I ask did the spacers for you? I just need a way to have the plastic cut clean to match the IM gasket. Do you have pictures of the phenolic spacers already made?

Here's what my spacers look like for my Subaru: