Power question
Thread Starter
Racer
Joined: Jul 2013
Posts: 423
Likes: 6
Power question
I have a 78 L82 ,Auto trans. the smog pump has been removed and it has headers.. Everything else is stock.. I'm curious how much power/HP was gained when the smog pump was removed and headers added.. Thanks for any info.
Drifting
Joined: Jun 2005
Posts: 1,950
Likes: 498
From: Chino Hills CA
That's kind of a loaded question. '78 air injection cylinder heads are not famous for making horsepower, so you wouldn't really notice much of an improvement with the headers, maybe 5-10 horsepower at top end, kinda like putting on a clean dress shirt over a dirty t-shirt. Removing the air injection pump will free up a few horsepower, but it isn't as hard to spin as, say an A/C compressor, so the total difference may be very minor. Remember, when your engine was new, it put out maybe 200 horsepower at the crank. The present condition of you engine would have the greatest effect on your current power output.
Melting Slicks
Joined: Jun 2007
Posts: 2,623
Likes: 22
From: Boise Idaho
St. Jude Donor '09-'10, '15, '17
Wasn't the stock system some kind of Y pipe single into dual at the rear garbage? I would think if you went with full dual exhaust and no cats maybe 15hp gain. No idea on the smog pump. I had a '77 L82 back in the day and was stock except I put on headers and duals and it actually went pretty good, but was a 4sp with 373s I believe. I remember racing a friend with a new '83 911 and beating him... he was not happy.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You might save about 1 hp and some weight by removing the A.I.R. pump and hardware. All it does is blow excess fresh air into the exhaust outlets so any [hot] unburned hydrocarbons can burn before getting out of the exhaust system.
If you want to remove that stuff, go for it. But, put it on eBay, as other folks whose cars met the same fate now want that stuff back.
If you want to remove that stuff, go for it. But, put it on eBay, as other folks whose cars met the same fate now want that stuff back.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,595
Likes: 7,043
From: New Or-leens Loo-z-anna
You might save about 1 hp and some weight by removing the A.I.R. pump and hardware. All it does is blow excess fresh air into the exhaust outlets so any [hot] unburned hydrocarbons can burn before getting out of the exhaust system.
If you want to remove that stuff, go for it. But, put it on eBay, as other folks whose cars met the same fate now want that stuff back.
If you want to remove that stuff, go for it. But, put it on eBay, as other folks whose cars met the same fate now want that stuff back.
You can easily spin the pulley on the AIR pump with your hand....the headers would be the advantage. I can't advise you to eliminate the old CAT completely......but I do know that converting to true dual exhausts that have "Mini-free flowing CATS" will give you a performance boost that is noticeable.....Ethanol-free gasoline also helps a little with performance/the price-per-gallon increase is off-set by the increase in mpg.
Thread Starter
Racer
Joined: Jul 2013
Posts: 423
Likes: 6
These things were already done when I purchased the car, I was just wondering if it added much power to it,, I have read that those years the cars didn't run as good because of those things being on there..
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
In general no one could really tell you how much HP your car gained when modded because in these cases each example is unique,
I do not get into arm chair debates how much HP an idle pulley for example robs because it's a moot point & time waster but in the real world when a smogger engine like yours has headers with true duals added and parasitic things like air pumps removed what a person always feels is a "seat in pants" power increase which while it might feel big in some cases is very low in actual added HP....
I do not get into arm chair debates how much HP an idle pulley for example robs because it's a moot point & time waster but in the real world when a smogger engine like yours has headers with true duals added and parasitic things like air pumps removed what a person always feels is a "seat in pants" power increase which while it might feel big in some cases is very low in actual added HP....
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