More On My Ram Air
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
More On My Ram Air
Since I got my ram air finished I have noticed several things that are different:
1. My engine no longer pings when I pull the 10-mile long 6% grade coming home (it used to lightly ping the whole distance).
2. I can feel a slight power increase (maybe 5-6 hp) when cruising at 60 mph.
3. My HOT idle speed in neutral increased 200 rpm.
4. My air filter no longer gets sand thrown at it from my fan (I have to drive on a one mile long dirt road to get to my house).
5. With my 14" X 3" air filter now being totally enclosed it no longer ROARS under a full throttle (I kinda miss that).
I am going to be putting about 125 miles on it today so I'm going to do a fuel mileage check to see if it improved. I am hoping to gain maybe one mile per gallon but any gain will be worth the $50 expense and effort.
1. My engine no longer pings when I pull the 10-mile long 6% grade coming home (it used to lightly ping the whole distance).
2. I can feel a slight power increase (maybe 5-6 hp) when cruising at 60 mph.
3. My HOT idle speed in neutral increased 200 rpm.
4. My air filter no longer gets sand thrown at it from my fan (I have to drive on a one mile long dirt road to get to my house).
5. With my 14" X 3" air filter now being totally enclosed it no longer ROARS under a full throttle (I kinda miss that).
I am going to be putting about 125 miles on it today so I'm going to do a fuel mileage check to see if it improved. I am hoping to gain maybe one mile per gallon but any gain will be worth the $50 expense and effort.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
The Benefit Of Cooler Intake Air
I was pretty surprised to find my HOT idle speed in neutral increased from 800 rpm to 1000 rpm just because of the cooler intake air. And then when I drove it I could feel an increase in power; like the difference of having the A/C on or not having it on. The question I now have is how well will it run in freezing weather? As I got a slight increase in power at cruising speeds I'm assuming it'll also increase my fuel mileage slightly.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
WOW............A 3 mpg Increase!
WOW. I just got back from a 84 mile trip and used exactly 6 gallons which means I got an even 14 mpg with my A/C on all the way. I have been averaging 11 mpg so the ram air gave me an additional 3 mpg. Unbelievable but true and I am in shock. I heard some light pinging coming up the hill in the steepest area but not nearly as bad as it usually is.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
As you can see in the picture my L-88 "style" hood had a 3" deep X 15" wide groove running up the middle of it so I enclosed that groove with sheet metal and cut a big hole for my 14" air cleaner to fit up into. Then I modified my air cleaner so it would seal to the hood so pressure at the front of my car would pressurize my air cleaner. My Fresno trip yesterday was 84 miles and I only used 6 gallons. Prior to the ram air I was getting 10-1/2 mpg on every Fresno trip so this 14 mpg was astonishing. Now I'm asking myself "was it the ram air or the cooler air"?
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Is your octane too low?
Is the engine full of carbon?
Is the ignition timing/curve off?
Is it running too lean?
Are the plugs too hot?
Pinging/predetonation is THE most destructive force in an internal combustion engine.
Is the engine full of carbon?
Is the ignition timing/curve off?
Is it running too lean?
Are the plugs too hot?
Pinging/predetonation is THE most destructive force in an internal combustion engine.
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Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Pinging is a second flame front developing after the spark plug fires. It is not destructive, mostly just annoying.
Pre-ignition, as the name implies, is the mixture igniting before the spark plug fires. Caused by a hot spot in the chamber like a glowing spark plug ground strap, excessive carbon etc. You'll know if you have pre-ignition. It will destroy the engine in seconds.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
My '82 shop manual clearly says light pinging is perfectly normal and nothing to be worried about. Its the HEAVY pinging that can break piston rings and detonation that can break pistons. Once I started running my cold air/ram air the amount of light pinging is almost nothing; just during the heaviest throttle/lowest road speed and the moment I ease off the gas it quits. I think its unbelievable I gained a whole 3-1/2 mpg because of the cooler air or ram air. My water manometer is showing a 1" positive pressure inside my air filter so the pressure may be the cause of the better fuel mileage.
After I installed my TH700R4 with the OEM 3.08 gears I was getting around 8 mpg during my trips to Fresno and back. I installed a magnum cam, higher compression pistons and 3.70's and it shot up to 10-1/2 mpg. Now with the ram air/cold air I'm getting 14 mpg so it looks like I'm doing the right thing. Tire smoking acceleration and good fuel mileage when I'm cruising. Can't beat that!
After I installed my TH700R4 with the OEM 3.08 gears I was getting around 8 mpg during my trips to Fresno and back. I installed a magnum cam, higher compression pistons and 3.70's and it shot up to 10-1/2 mpg. Now with the ram air/cold air I'm getting 14 mpg so it looks like I'm doing the right thing. Tire smoking acceleration and good fuel mileage when I'm cruising. Can't beat that!
Last edited by toobroketoretire; Aug 16, 2015 at 11:19 AM.
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
As you can see in the picture my L-88 "style" hood had a 3" deep X 15" wide groove running up the middle of it so I enclosed that groove with sheet metal and cut a big hole for my 14" air cleaner to fit up into. Then I modified my air cleaner so it would seal to the hood so pressure at the front of my car would pressurize my air cleaner. My Fresno trip yesterday was 84 miles and I only used 6 gallons. Prior to the ram air I was getting 10-1/2 mpg on every Fresno trip so this 14 mpg was astonishing. Now I'm asking myself "was it the ram air or the cooler air"?
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
It was a very big job and took an entire week of 12 hour days to complete it but it came out fantastic AND I gained an additional 3-1/2 mpg of fuel mileage. Here's a picture of my modified air cleaner base to give you an idea of what needs to be done to it. I had to add the sides to the air cleaner base so they would reach up to the hood seal. Note how the sides are angled because the bottom of the hood is angled. I used RTV to attach a split 1/8" fuel line hose to the sharp edge to finish it off and provide a better seal to the weatherstripping seal I have on my hood.
And I am pulling in the air from just in front of the radiator where no rain water never gets. My water manometer is showing 1" Wc at 60 mph and 1-1/2" Wc at 80 mph so there is positive pressure going into my carburetor while I'm cruising. But I don't know if its the cool air or the pressurized air that is causing the enormous 3-1/2 mpg gain.
What does the underside of your hood look like? I noticed the OEM hood on my '82 is already set up for cold air/ram air so it can be done super easy on an '82.
And I am pulling in the air from just in front of the radiator where no rain water never gets. My water manometer is showing 1" Wc at 60 mph and 1-1/2" Wc at 80 mph so there is positive pressure going into my carburetor while I'm cruising. But I don't know if its the cool air or the pressurized air that is causing the enormous 3-1/2 mpg gain.
What does the underside of your hood look like? I noticed the OEM hood on my '82 is already set up for cold air/ram air so it can be done super easy on an '82.
Last edited by toobroketoretire; Aug 17, 2015 at 04:24 PM.
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
And here's another picture of my hood with the huge hole cut into it for my air cleaner to poke up thru. As you can see from the indention into the weatherstripping my air cleaner base matches it almost perfectly (which was very hard to do).
