cyclopat

I'm considering the TDR heat shield for my m45 miata. I've seen a few threads reporting positive results with underhood temp reduction. However, I am more concerned with intake temps at the manifold. I have checked my inlet temps at the air filter and they are roughly ambient. My IAT sensor is right before the intake manifold and often sees temps in the 200-250f range during boost. Has anyone logged a reduction in post-supercharger temps by adding heat shielding to their header? Or is it only effective for reducing temps at the air filter?

Balto

That's what happens when you don't run an intercooler. But to answer your question directly, no, I don't think it will make a difference.

sixshooter

iTrader: (12)

Good grief 250F IATs are high! You'd likely make more power sourcing 60F ambient air to the TB and not using the supercharger, lol.

Yes, heat shields help and so do intercoolers. You will make a significant difference in power if you get below 100F in boost. Those little superchargers are known to make atrocious amounts of heat due to their inefficient design. This is why smart people go turbo. Not saying you're not smart, just saying you're nearing being smart enough to change.

Balto

Yea mine got that hot, with almost 300F in hard pulls before the intercooler. Now it's at most 20F over ambient.

cyclopat

Yes, I'm aware an intercooler is the best way to solve this problem, was just curious if this would help any. Also, I know a turbo would be better, but I'm just trying to work with what I have. What's your setup Balto?

cyclopat

Kind of a side topic, but how much difference will lowering intake manifold temps make if I am already at or near MBT at my current intake temps (running E85)? This was determined through virtual dyno pulls, so may not be entirely accurate, but close.

Balto

MP62 Hotside with a TDR intercooler setup.

Example: On Wednesday it was 40F outside. Even after reaching operating temp (engine ~86C) at 70MPH my intake temps were 6C. Only 2F over ambient (roughly).

sixshooter

iTrader: (12)

Just as much as it would if you weren't at MBT.

Cooler air is more dense and will produce significantly more power no matter the fuel,even at the same timing. PV=nRT, of course.
It's not like we are making this stuff up ourselves.

Balto

This. I noticed a significant gain, especially mid range (not to mention just general driveability)once I put the IC on. I will also note I didn't notice any throttle response issues from throttled volume that everyone else seems to talk about. idk.

good2go

iTrader: (2)

I have the TDR blanket with an MP62 hotside and a TDR IC. Having the blanket definitely makes a difference in the amount of heatsoak the compressor sees. Before I got the blanket, you could not place your hand on the compressor when the engine was warm and running; it was simply too hot to bear- like touching a radiator. After the blanket, I can rest my hand on the blower as long as I want. Granted, this is at idle with the hood up, but the difference is definitely noticeable. That being said, and if you're stuck on the MP45, your cooler IAT dollars would be better spent on an IC than on a blanket (or get both).
.02

sixshooter

iTrader: (12)

.

cyclopat

I'm not disagreeing that cooler air makes more power. Its the positive displacement supercharger factor that makes this difficult. The outlet temperature and volume of the supercharger won't change. By then passing through an intercooler, you drop temp, but also drop pressure. Yes I understand the ideal gas law. I guess I'll have to break out the calculator to estimate which has a greater impact.

cyclopat

So I sat down and ran the numbers. Assuming a 20% pressure drop across the intercooler, I calculated a 13% increase in density compared to my non intercooled setup. That seems ample to consider adding an intercooler to my setup. Then, I would have to ability to add a crank overlay, resulting in an additional 12% increase in density(or 27% over my current setup). So in a perfect world, that could be worth about 40hp. We don't live in a perfect world, so I think an extra 20hp seems likely from an intercooler and crank overlay. Thanks for helping me to look at this logically, although my wallet may disagree....

sixshooter

iTrader: (12)

Pointy headed OEM engineers think it is important enough to add thousands to the costs of production. That's a good indicator as well.

cyclopat

Ok, I've been thinking about this more and I can't make sense of it. I can't see how the intercooler is going to add power. A roots supercharger only pumps a fixed volume of air per engine revolution. Making this air cooler and more dense doesn't change the net amount of extra oxygen being forced into the engine. To me it seems the benefit to intercooling is to lower intake temps to reduce the propensity for knock, thus allowing more boost or timing to be added. If I already am at MBT and pulleys remain the same on the supercharger, where is the extra power coming from?

bahurd

iTrader: (8)

LEARN MORE ABOUT INTERCOOLING TECHNOLOGY

sixshooter

iTrader: (12)

Do you think that MBT is a static value? Do you think it won't be found at a different timing with 80-100 degree cooler air? And generating a significantly different output value?

sixshooter

iTrader: (12)

I found this funny because of the author, but there is some good data as to why nobody wants to use a roots-type supercharger anyway.

http://www.lextreme.com/icvsnic.htm

Spaceman Spiff

Making the air cooler, and thus more dense, quite literally changes that number of individual oxygen molecules per unit volume of air. 250F IAT to 60F should net you a density increase somewhere in the 20% neighborhood. The more O2 in the combustion reaction each engine cycle the more power you make, all timing, fueling, and tuning aside.


I also think a 20% assumption on IC pressure drop is probably too conservative.



But end of the day, why even bother crunching the numbers when you have 15 years of empirical evidence that an IC does wonders for your setup?

sixshooter

iTrader: (12)

https://en.m.wikipedia.org/wiki/Roots-type_supercharger