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Not much, around 1 mph. This is real easy to test, just go to your local drag strip on test-n-tune night, let the car cool down and make a couple of runs. Then put a bag of ice on the intake while you're in the staging lanes and see what the difference is. Just be aware that since you have to take the ice off the intake before the run, the longer the burnout, the hotter the intake will get.
Coating the inside of the intake with epoxy potting compound will put a layer of plastic between the hot metal and the air. Think of it like putting a paper sleeve on a hot metal cup of coffee.
Not much, around 1 mph. This is real easy to test, just go to your local drag strip on test-n-tune night, let the car cool down and make a couple of runs. Then put a bag of ice on the intake while you're in the staging lanes and see what the difference is. Just be aware that since you have to take the ice off the intake before the run, the longer the burnout, the hotter the intake will get.
Coating the inside of the intake with epoxy potting compound will put a layer of plastic between the hot metal and the air. Think of it like putting a paper sleeve on a hot metal cup of coffee.
Depends on the epoxy formulation. This isn't theoretical, btw. I coated the inside of my 96 impala intake and documented a 2 tenth improvement in similar density altitude conditions. It works.
I believe you, I've seen it and tested it. Not on intakes but on reducing temp rises in plumbing and ventilation. That's also why ceramic coating on exhausts still exists... it does work.
The product you want is 22-3300. I used this on my intake when I lived in Virginia which would be prior to 2002, and that intake is still going strong. I sold that engine to a friend of mine and he still uses that intake on his impala.
Last edited by sstonebreaker; 04-18-2019 at 03:06 PM.
Using epoxy as a thermal barrier and / or alter air flow in a LT1/4 intake isn't the same as TPI. TPI runners are exposed to ambient air. If the tech was there to make the runners and plenum out plastic in 1980 -82; when the TPI was going to production, they may have been plastic. GM didn't start using plastic intake manifold pieces until 90-91. I had to Google the LT1 epoxy thing.
The OP is working with 89 TPI I'm guessing looking at thread where he said he had one. TPI the runners and plenum are surrounded by under hood air. You could put damp terry clothe around runners and use a coolant to freeze runners.in staging. With "dry ice" years ago Vance and Hines were setting records in pro stock bike. NHRA took a picture of the bike blew it up to 12 x 18 feet and saw the dry ice in the intake. They made a rule afterwards.
Back to the a/c super ram with a huge plenum so a small evaporator will fit in it. it would need some kind of screening to break up water droplets from condensation.
For considerably less work NOx with a small bottle under passenger seat.
The epoxy would function in a TPI intake exactly the same way as it would in the LT1 intake. The plenum is up in the air, but don't forget that the bottom half of the runners is bolted to the top of the engine exactly the same way as any other intake, and that's where the epoxy would do the most good. The super ram, assuming you can find one, plenum would be real easy to coat since the top comes off. A TPIS miniram would probably be easier to get ahold of.
Two tenths, Damn. I'd kill for two tenths. That should put me into the nines. I'm yanking my intake off tonight. Now do you coat the inside or underside of the intake? Heck, I'll try the throttlebody ac mod too.
You coat the inside. If you click on that link to the camaro forums I posted above, there are some detailed directions on how to do it. Word of warning - the inside of the intake has to be CLEAN.
Last edited by sstonebreaker; 04-18-2019 at 06:25 PM.
Serious question from someone who doesn't know any better.. Feel free to beat me with a stick if this is an outrageously stupid question.
Powder coat is very smooth and very strong.. It is really, really slick stuff.. Seems like air should flow over it very easily.
Any advantage to powder coating the INSIDE of the intake runners and plenum like the extrude hone smooths castings with abrasive so they flow better?
????
Perhaps... the biggest thing is getting enough powder coat in the to get a smooth surface would make the passages smaller... also, powder coating generally has a hard time with corners and such. It would probably be very hard to get a good coat inside a manifold. That being said it would also act as an insulator too.
There is no such thing as a stupid question my friend.
Engine Masters did a test on a BBC. You can read the details HERE
The upshot is that on an 800hp motor, the power varied a whopping 5 hp from a hair drier heated intake manifold, to an iced manifold. With that as a well controlled data point, it's tough to conceive that coating an LT1 intake with anything (short of nitro-methane), will provide a 20hp increase in power.
When you combine that with the trap. Trap tells the HP story, as any drag-track'er knows. Stonebreaker says he picked up 1 mph. You can pick up or drop 3 mph in the same night. IDK.
Engine Masters did a test on a BBC. You can read the details HERE
The upshot is that on an 800hp motor, the power varied a whopping 5 hp from a hair drier heated intake manifold, to an iced manifold. With that as a well controlled data point, it's tough to conceive that coating an LT1 intake with anything (short of nitro-methane), will provide a 20hp increase in power.
When you combine that with the trap. Trap tells the HP story, as any drag-track'er knows. Stonebreaker says he picked up 1 mph. You can pick up or drop 3 mph in the same night. IDK.
I'm struggling w/the epoxy mod. .
One big difference between the test you quoted and the LT1 intake:
Also, with a wet manifold, Engine Masters' attributed the hp to the temp of the fuel, more than air/intake temp. They noted that the air flow readings were higher on the runs where the fuel temps were lower.
You can argue theory all you want, but it's real easy to test this. Just go to the track and make some runs, putting a bag of ice on the intake on some runs and not on others. As long as you keep the coolant temp constant between runs, the timeslips will tell the tale.
I was into bracket racing big time back in the 1990's and 2000's. One of the mods I had on my car was an electric water pump along with a manual radiator fan switch. This allowed me to run my water pump and fans with the engine off in the staging lanes, keeping the coolant temp constant for every run. As long as the density altitude remained constant, my car would make consecutive runs within hundredths of a second of each other. Not tenths. Hundredths. So measuring differences of a tenth of a second was not a problem.
I went so far as to try icing my intake with dry ice one time. Didn't work due to unintended consequences - I froze the gas in the fuel rails. You can't win'em all.
Last edited by sstonebreaker; 04-19-2019 at 08:14 AM.
Engine Masters did a test on a BBC. You can read the details HERE
The upshot is that on an 800hp motor, the power varied a whopping 5 hp from a hair drier heated intake manifold, to an iced manifold. With that as a well controlled data point, it's tough to conceive that coating an LT1 intake with anything (short of nitro-methane), will provide a 20hp increase in power.
When you combine that with the trap. Trap tells the HP story, as any drag-track'er knows. Stonebreaker says he picked up 1 mph. You can pick up or drop 3 mph in the same night. IDK.
I'm struggling w/the epoxy mod.
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But on a carbed engine the fuel atomizing is going to do a pretty good job of keeping the air relatively cool. You don't get that effect on port efi, that's why efi cars with blowers or turbos need intercoolers... I agree it can't be that much, but the enginemasters test isn't apples to apples in this particular case.
Not really a valid comparison; the VW has fuel flowing through the TB. That fuel is in the process of evaporating, which cools the air. The 'Vette had no such characteristics...nor does it have a reputation for carb icing.
OP could run the AC suction line (which is cold all the way to the compressor) through the TB coolant channels, run the AC in the staging lanes, then shut it off as he stages. I run my AC in the staging lanes anyway, to keep my coolant temps low. So...it's not THAT far fetched an idea.
I agree that it wouldn't do much, w/the speed the air flows through the TB.
i think it is prettty far fetched and i think he could do far better by simply removing the ac completely to cut weight if he really is concerned about it.
wet manifold, Engine Masters' attributed the hp to the temp of the fuel, more than air/intake temp. They noted that the air flow readings were higher on the runs where the fuel temps were lower.
Originally Posted by sstonebreaker
One big difference between the test you quoted and the LT1 intake:
Which is why they make cool cans.
Originally Posted by 84 4+3
But on a carbed engine the fuel atomizing is going to do a pretty good job of keeping the air relatively cool. You don't get that effect on port efi, that's why efi cars with blowers or turbos need intercoolers... I agree it can't be that much, but the enginemasters test isn't apples to apples in this particular case.
The fuel evaporates. Guys, we have newer , DI cars that are exploiting the benefits of eval'ing fuel in the cylinder, cooling the charge. They're running higher compression, and/or more boost, thanks to that cooling effect.
So what's going on here? We get cooling from evap'ing gas in the cylinder....and we get it from dribbling it out a carb nozzle....but we miss that benefits with a port injection? I don't think so. Fuel evaporates regardless of introduce it into the air.
I know the test is slightly different due to the location of the introduction of fuel to the air...but they didn't show squat for power from a heated to a frozen intake.
You manifold coating works....I haven't tried it so I can't argue the point (nor do I want to). I'll leave it at this: I'll put my money/time toward other modifications.
The fuel evaporates. Guys, we have newer , DI cars that are exploiting the benefits of eval'ing fuel in the cylinder, cooling the charge. They're running higher compression, and/or more boost, thanks to that cooling effect.
So what's going on here? We get cooling from evap'ing gas in the cylinder....and we get it from dribbling it out a carb nozzle....but we miss that benefits with a port injection? I don't think so. Fuel evaporates regardless of introduce it into the air.
I know the test is slightly different due to the location of the introduction of fuel to the air...but they didn't show squat for power from a heated to a frozen intake.
You manifold coating works....I haven't tried it so I can't argue the point (nor do I want to). I'll leave it at this: I'll put my money/time toward other modifications.
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Put your money where you want to, but the epoxy mod only costs about $50 and some elbow grease. Probably a little more now since I did that mod nearly 20 years ago.
I'd also point out that meth injection works on NA EFI cars even before any tuning is done. If you were to put meth injection on your car and dyno the car with and without the meth, the car will make more power on meth even before any computer tuning is done. That suggests that port EFI is leaving something on the table with regards to fuel intercooling.
I think any car would see similar gains from Meth; carb'ed, port or direct injection. There is nothing magical that "stores heat" in the intake charge with port EFI.
It's not about "storing heat". The heat of vaporization that goes into vaporizing the gas in a carbed intake and the water/meth injection (which is non-flammable, btw) on a port EFI intake cools the intake charge, making it denser before it goes into the cylinder. Port EFI does this too, but because it happens in the port instead of the plenum, you don't get the full benefit. the port restricts the flow before the intercooling effect. I would think direct injection would see even less intercooling.
You can see the port restriction on boosted cars that have their heads ported. Before the head port, the car might make 15 pounds of boost. But after the heads are ported, the exact same setup may only see 10 pounds of boost, and yet make more horsepower, thanks to the higher port flow.
Last edited by sstonebreaker; 04-19-2019 at 02:55 PM.
04-18-2019, 12:04 PM
epoxies have pretty bad thermal conductivity.
