Vtec04

I ordered this gasket D17 Thermal Intake Manifold Gasket
I have a 2005 Civic VTEC that I put a D16Y8 intake manifold on. I noticed that the aluminium intake unsurprisingly absorbs a lot more heat from the motor than the plastic one, and it gets hot enough that it will burn me if I hold my hand on it for a few seconds, which is not helping anything. I do not know if the air passing through the intake will heat up significantly since it is moving so fast it will have little time to pick up much heat, but my theory is that the couple of extra horsepower gained from a thermal gasket mostly has to do with keeping the fuel rail and injectors cooler more so than keeping the air cooler, but either way this gasket is reusable, which is a definite benefit. I am not expecting to notice any performance benefit, but I don't expect it to hurt performance either. I'll update you when the gasket comes, but do you have any opinion on these thermal gaskets? I am guessing that with a plastic intake manifold, these are a waste of money but with a metal one it could be well worth it, and It MIGHT even be a good value for a performance upgrade. Think about it, a stage 1 cam is considered the best upgrade for the money on these engines, That supposedly gives you an extra 20 HP for $400, which is $20 dollars per horsepower. IF this gasket will gain me 2 HP, which is very possible, for $35, that is $17.5 dollars per horsepower, even better value than a Crower Stage 1 cam. Is that reasonable logic? I really am looking forward to reading your replies, I think I am onto something with this thermal gasket being a great value for an upgrade.

toyomatt84

iTrader: (1)

If you net 2whp, it will only be until the manifold heats up again. Thermal gaskets will only slow that process, and not entirely prevent it. You still have steel studs holding the manifold to the block, and the intake manifold is still in close proximity to many "hot" items in an enclosed engine bay. Couple that with the fact that you wouldn't feel a 5whp gain in a car at any point, let alone a 2whp gain... you could consider the upgrade completely negligible.

So, as for it being a "good value for a performance upgrade", it misses by a very, very long shot. If you don't have a gasket when bolting a new manifold onto a car, its merely a slightly better alternative to a metal gasket. That's all.

Vtec04

Thank you for your reply. I mainly bought it because I wanted a reusable gasket and it probably isn't more than a few dollars extra compared to an OE Honda gasket anyway. I understand the steel studs holding it to the motor, which is why I will use plastic washers between the intake and the bolt heads to help with that a little. As for the intake sitting next to a lot of other hot parts, you definitely have a valid point. I am sure that heat radiates off the back of the block and gets trapped under the intake manifold. However, I think that the heat absorbed from the hot air around it is way, way less than the heat it absorbs from being directly bolted to the motor. If you put your hand above something very hot, you feel the heat. If you put your hand ON something hot, you get burned. Same thing with the intake manifold. Consider this:If a thermal gasket is so trivial, why do companies that make performance intake manifolds, like Skunk2 include them with their manifolds? I am not saying that you will feel a 5 horsepower gain, you obviously would not, but all those "little" things add up. For example, switching to synthetic oil can easily gain about 2-3 horsepower. Not significant by itself. Throttle body coolant bypass maybe gains 1-2 horsepower. A grounding kit has been proven to gain 3-5 horsepower, especially with older cars that have corroded grounds. Header wrap is good for about 1-2 horsepower from keeping exhaust hot and the engine compartment cool. Easy and pretty cheap 7-12 horsepower gain. All those little things really add up.

toyomatt84

iTrader: (1)

I'm a mold maker by trade. I work on aluminum molds, and we typically heat our molds to about 200 degrees Fahrenheit for production. I can assure you that I am aware of the thermal properties and characteristics in play here. (Especially when a molder messes up something, and it has to be fixed in the press... not my favorite thing to do.) We have large ovens that heat up loose pieces for molds in production, and even if you set them at a lower ambient temp (say 180 degrees or so) its only about 20 minutes to take a room temperature loose piece of roughly the same mass as your intake manifold to match that 180 degree temperature. Now, take into consideration that your engine bay is operating around 140 to 180 degrees under load, you're not really going to see an intake temperature drop for very long.

Something else to note; running plastic washers wouldn't be wise. They have a tendency to deform under load and under extreme temperature changes, and you may find that your intake manifold could stop sealing properly after a little while.

Performance breakdown of your commentary:
Synthetic oil: 2-3whp (True, this can be achieved... however, I see no argument to run non-synthetic oil these days; so its really not something I would even consider in a performance debate.)
Throttle body coolant bypass: 1-2whp (If this were true, the gains would again be temporary due to the same heat soak problems the intake manifold will suffer.)
Grounding kit: 3-5whp (I'd love to see some factual data back up that statement, because if anything, it'd only bring the car closer to stock performance figures.)
Header wrap: 1-2whp (Again, this is a heat soak issue and it will only last as long as the engine bay stays cooler. Seeing as the engine itself is going to radiate heat, on top of the fact that the entire cooling system is routed in the engine bay and the exhaust from the radiator flows directly onto the engine... the gains will be negligible rather quickly.)

Granted on the cheap side, all this stuff could cost you as little as $100 or so (depending on how creative you get with your fabrication skills), you're still only looking at a maximum viable 12whp (4whp of which would fade away quickly as you drive the car, and 5whp for some "snake oil" grounding straps). If I were to dump $100 on anything... it'd be some reflective heat tape and intake tubing. I'd route a good filter element (something like the Apexi power filter) in an area that has a good supply of colder air, and then run reflective heat tape on the tubing itself. This would assure that the colder air gets as close to the intake ports of the engine as possible, before suffering heat soak from engine bay components. With the exception of Synthetic oil, the rest of that stuff won't net any discernible gain what so ever.

Vtec04

I agree with you on the heat soak, but I do not believe that a grounding kit will hurt performance in any way besides maybe 3 ounces of extra weight. Please explain how corroded/bad/undersized grounds could improve a car's performance compared to nice thick new grounds. I know that this is not horsepower related directly, but my own test that I did when I installed my homemade wiring upgrade kit showed a good improvement in voltage. Here are the results:
All stock wiring at 800 RPM warm idle with no accessories on:14.1 volts
Full load stock wiring warm idle 800 RPM: 12.8 volts
Rev to 2K RPM full load stock wiring: 13.4 volts
After just grounds:
Warm 800 RPM idle no load:14.3 volts(0.2 volts higher)
Warm 800 RPM idle full load: 13.2 volts(0.4 volts higher)
Rev to 2K RPM full load: 13.6 volts(0.2 volts higher)
After 4 gauge alternator + to battery +:
Warm 800 RPM idle:14.4 volts(0.3 volts higher than stock)
Warm idle full load:13.3 volts(0.5 volts higher than stock)
Rev to 2K RPM full load:13.7 volts(0.5 volts higher than stock)
That is not a measurement of horsepower, and my grounds were fairly corroded but not broken, which is common on a car that old, like I said.. With a newer car a grounding kit probably would not have made as much as a difference. However, higher and more consistent voltage means stronger spark from the ignition coils, better sensor/computer operation and better accessory performance. I am not the only one that found an improvement in voltage and/or performance from installing a grounding kit. Search Google for grounding kit test and you will see what I mean. Here is a person that reported an improvement of several horsepower from a grounding kit, although I do not know if he is telling the truth. https://my350z.com/forum/engine-and-...o-results.html
Here is another person with dyno graphs that shows an improvement in performance from a grounding kit.V6P Ground Cable Kit Dynoed! - Honda Accord Forum : V6 Performance Accord Forums
There are also plenty more. I am a believer in grounding kits.

toyomatt84

iTrader: (1)

As I stated before, a "grounding kit" will merely bring the electrical system up to roughly original factory performance levels. Expecting a positive gain on power, would be overly optimistic.

Vtec04

Oh, I misunderstood you and thought you said that a grounding kit will bring down the performance to factory levels. But like I said, the factory grounds were corroded, which is very common and often overlooked as I stated in my original post where I stated a 3-5 HP gain, so maybe I could have achieved the same results by simply replacing the grounds with new OEM ones. But good grounds can improve engine and electrical system performance over bad grounds

DumpdEJ6

Thermal gaskets only reduce heat soak, and they do that pretty well in my experience. That being said, they don't necessarily "increase" horsepower, they only reduce the loss of power due to heat soak. To put it another way, you're not really gaining anything extra, but you aren't losing what you would normally lose after 15-20 minutes of running your car. So technically they are effective, but not in the way that some people think. They do seem to make a difference in my opinion.

Vtec04

So you mean they seem to make a noticible improvement in power, or the intake feels cooler? Thanks for the reply!

DumpdEJ6

I would say both. It's definitely not noticeable at first, but you know how after driving your car for a while in the summer heat, you can feel some power loss on the butt dyno? That doesn't seem to happen as significantly with thermal intake gaskets. It's possible it's just placebo, but I know I CAN tell a pretty big difference touching an intake manifold with one vs. without one.

Vtec04

This gasket is freaking amazing! I just installed it. Before I installed the gasket, the intake would not seal. I tried EVERYTHING and it WOULD NOT SEAL. I have a post on that too. When I was installing the gasket, I stripped the 2 bolts on the ends of the head. I just have one stud in the middle of the bottom and 2 studs on the ends of the top of the gasket holding the manifold to the head. Only 3 out of the 5 bolts! The gasket seals PERFECTLY! One thing I can say FOR SURE about the gasket is the engine idles WAY smoother. Before, the engine would shake the car at idle and rattle the keys consistently. Now, it still makes some vibration, which I would expect with motor mount inserts, but WAY less. It does not rattle the keys at idle anymore. I think the smoother idle has more to do with not having a vacuum leak anymore than keeping the intake cooler though. It also feels like it has more low end torque taking off from a stop. However, I don't think that it is from keeping the intake cooler, I think it is from fixing the vacuum leak. Anyways, I am very happy with the results of this gasket. I hope gas mileage improves too, as it is only getting 27-28 MPG on the highway.

TomCat39

I'm glad the thermal gasket is working out well for you.

I did witness one person who had troubles when they "upgraded" one of the main engine grounds. My speculation is the thicker gauge wire induced extra resistance to the circuit and played havoc with the ECU.

A quality ground of the same specification as OEM will definitely work better than a corroded ground. Just be wary about "improved" grounds, it might just back fire on the desired result.

Vtec04

I do not think that a ground with less resistance will cause an increase in resistance. At worst, it won't help, but I really don't think it would cause a problem as long as you do not damage anything in the process of installing the new grounds or connect something to the wrong thing. After all, the body, engine and battery negative is all connected together anyway.

TomCat39

I didn't say less resistance....

I specifically said the likely problem was additional resistance over OEM.

Vtec04

Oh I see, I misunderstood you, sorry. But how would a correctly installed, high quality thicker wire cause more resistance? To me that is like saying"I replaced my garden hose with a larger diameter one and my pressure dropped."

toyomatt84

iTrader: (1)

That's actually a true statement. Take a look at Bernoulli's Principle.

TomCat39

Look for a resistance table for gauge of wire. The larger gauge carries a more resistance. It not much but if the circuit is designed for a specific resistance, going out of that range can cause issues.

The guy put a thicker gauge ground strap on his motor to frame and his car had problems. Went back to the oem ground strap and the problems cleared right up.

All I could figure is that the resistance went up enough to cause some problems for the circuit as all that was changed was the one main ground strap.

This is actually the exact opposite. Increasing resistance is like increasing the pressure by shrinking the hose. You are trying to use an analogy that is the exact opposite result in this case.

But even using it, lets say you need X pressure, now you add a bigger hose and the pressure drops and the system has problems.... Same concept really.

Also remember, when you increase the gauge of wire, you are actually using thinner wire. Thicker wire is smaller gauge by American Wire Gauge standards. And the other area it could be is even with the same gauge wire, if the length is increased it's going to increase the resistance. Thus sticking with OEM length and gauge is the best way to stick to the design of the circuit.

Vtec04

Okay, but with all else being equal, a larger diameter wire has less resistance than a smaller diameter wire. For example, a 12 gauge wire has more resistance than a 10 gauge wire with all else being equal, and therefore can carry more electricity.

TomCat39

The higher gauge (12 gauge) wire cannot carry more current than the lower gauge (10 gauge) wire.

It has higher resistance which means it converts more energy to heat and reduces the current flow. At some point the wire will melt before the smaller gauge (10 gauge) will with the same load and current.

I think you are confusing gauge size with resistance and current capability. The AWG is opposite, the higher/larger the gauge, the less capable, the lower/smaller the gauge, the more the capability.

40 gauge wire is like 3/8" tubing carrying water, while 0 gauge wire is like the 2 foot diameter water main under the street. Which will carry more water?

Vtec04

What I meant is that a 12 gauge has MORE resistance than a 10 gauge wire, and therefore the 10 gauge wire can carry MORE current than a 12 gauge, Resistance limits current flow.

TomCat39

Had you actually said that originally, we wouldn't be having this discussion.

I am going to assume English may not be your forte.

m4xwellmurd3r

I think the issue was your wording. At first you said a THICKER gauge (which would imply lower gauge wire) increased resistance (which would be incorrect, since a thicker gauge would be a lower gauge. a thinner gauge would be a higher gauge) later you said a larger gauge (which would be taken as either, a thicker diameter wire, or a larger gauge rating as in, a thinner diameter wire)

I think what you're trying to say is that a higher gauge wire may have increased the resistance and messed with the ECU, rather than saying a lower gauge wire increased the resistance.