HP Increase
Thread Starter
Racer
Joined: Nov 2003
Posts: 386
Likes: 1
From: Grafton WV
HP Increase
I just removed the E4ME Carb and Dizzy and put on a set of headers and a mild cam and removed all the smog components and the A/C compressor got a Edelbrock carb now.Any idea on any HP Increase due to these Mods ???
Race Director
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Le Mans Master
Joined: May 2007
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From: North tonawanda NY
You didn't state which size Carb..... I'd say a 5-10 hp from the removal of the air pump....distributors usually give you no gain less its a custom advance curve over stock or your having issues at high rpms. (Which isn't a concern on a stock engine) performance wires and coils are more advertising and do little if anything for a street engine most who claim power increases just had worn out failing equipment prior to purchase and replacement.
Last edited by augiedoggy; May 16, 2013 at 02:26 PM.
Race Director
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From: San Jose CA
The power difference between a well set up Quadrajet and a well set up Holley, of equal size, will be within the margin of error on the dyno.
As others have mentioned, the cam will have the biggest "power" difference. I think the headers will help a little but would be greatly magnified by opening the exhaust up.
I also agree with the sentiment on the distributor; it depends on how well set up it is.
As others have mentioned, the cam will have the biggest "power" difference. I think the headers will help a little but would be greatly magnified by opening the exhaust up.
I also agree with the sentiment on the distributor; it depends on how well set up it is.
Le Mans Master
Joined: Mar 2008
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From: Oxford MA-----You just lost the game!!!!
See, it's the same kind of question. Does it feel like it's got more power?
Scott
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Le Mans Master
Joined: Mar 2008
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From: Oxford MA-----You just lost the game!!!!
Burning Brakes
Joined: Apr 2013
Posts: 926
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From: Castle Rock CO
Well like the others have said not really enough information to tell.
I can tell you where I live removing the Smog Components will disqualify me from running my car in the county I live in
Removing components off the car will like the A/C unit does nothing if you never used it. It is about a 5 HP gain from non use.
Dual exhaust will actually provide between 10 to 20 Horse Power gain from a single exhaust system depending on the mufflers. Mild Cam 10 to 20 HP. Headers and open exhaust another 10 to 20 HP
You never really know until the engine is sitting on Dyno and the calculate the Drive Train into the Dyno readings with the Gear Ratio. Net horse power is what they calculate
from the rear tires.
You want HP get a 383 Stroker kit installed for between 300 to 350 HP . Other wise on a Stock L48 Engine breathing well with a few modification will probably never get passed 230 HP on a dyno.
I can tell you where I live removing the Smog Components will disqualify me from running my car in the county I live in
Removing components off the car will like the A/C unit does nothing if you never used it. It is about a 5 HP gain from non use.
Dual exhaust will actually provide between 10 to 20 Horse Power gain from a single exhaust system depending on the mufflers. Mild Cam 10 to 20 HP. Headers and open exhaust another 10 to 20 HP
You never really know until the engine is sitting on Dyno and the calculate the Drive Train into the Dyno readings with the Gear Ratio. Net horse power is what they calculate
from the rear tires.
You want HP get a 383 Stroker kit installed for between 300 to 350 HP . Other wise on a Stock L48 Engine breathing well with a few modification will probably never get passed 230 HP on a dyno.
Le Mans Master
Joined: May 2007
Posts: 5,007
Likes: 1,114
From: North tonawanda NY
Well like the others have said not really enough information to tell.
I can tell you where I live removing the Smog Components will disqualify me from running my car in the county I live in
Removing components off the car will like the A/C unit does nothing if you never used it. It is about a 5 HP gain from non use.
Dual exhaust will actually provide between 10 to 20 Horse Power gain from a single exhaust system depending on the mufflers. Mild Cam 10 to 20 HP. Headers and open exhaust another 10 to 20 HP
You never really know until the engine is sitting on Dyno and the calculate the Drive Train into the Dyno readings with the Gear Ratio. Net horse power is what they calculate
from the rear tires.
You want HP get a 383 Stroker kit installed for between 300 to 350 HP . Other wise on a Stock L48 Engine breathing well with a few modification will probably never get passed 230 HP on a dyno.
I can tell you where I live removing the Smog Components will disqualify me from running my car in the county I live in
Removing components off the car will like the A/C unit does nothing if you never used it. It is about a 5 HP gain from non use.
Dual exhaust will actually provide between 10 to 20 Horse Power gain from a single exhaust system depending on the mufflers. Mild Cam 10 to 20 HP. Headers and open exhaust another 10 to 20 HP
You never really know until the engine is sitting on Dyno and the calculate the Drive Train into the Dyno readings with the Gear Ratio. Net horse power is what they calculate
from the rear tires.
You want HP get a 383 Stroker kit installed for between 300 to 350 HP . Other wise on a Stock L48 Engine breathing well with a few modification will probably never get passed 230 HP on a dyno.
Replacing the heads on an l48 with say 64 or 58 cc heads with thinner head gasket and better quench will bring the compression up to around 9:5 conservatively ... that along with the rest of the bolt on mods will bring the engine well past 230hp ..... The only things different about the l48 block that effects power produced is the cam and dished pistons... small cc chambered heads cure that issue and the cam is easy enough to change.
The other differences IE 2 bolt vs 4 bolt and cast crank vs forged are really a non issue untill your creeping up to 500hp or your beating on it.
Some of the confusion here is rear wheel vs engine hp....400hp 350 which is not hard to make should give you 300-340 rwhp... but that kind of setup will want to make its power in the higher rpm range hence the higher stall converter and rear gear change. Good heads and cam are the foundation for all other bolt ons to live up to their potential as I see it.
Last edited by augiedoggy; May 17, 2013 at 08:16 AM.
Le Mans Master
Joined: Nov 2006
Posts: 7,215
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From: Orlando FL
seriously as stated above, you cant solve the equation without more data..
A + X = 9 solve for X? X could be anything depending on A value
help us out here
Le Mans Master
Joined: May 2007
Posts: 5,007
Likes: 1,114
From: North tonawanda NY
I think its safe to assume everything is stock 1981 except what the OP mentioned as mods and hes looking for a rough ballpark.. My guess is he doesnt know what "mild cam" is installed.
Last edited by augiedoggy; May 17, 2013 at 08:59 AM.
Le Mans Master
Joined: May 2007
Posts: 5,007
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From: North tonawanda NY
Le Mans Master
Joined: Mar 2008
Posts: 5,948
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From: Oxford MA-----You just lost the game!!!!
I think you got him there, bash! But it still doesn't really help us figure out the value of X, does it? For the purposes of this discussion, it's like saying "Your engine is now putting out however much it did before, plus the amount of horsepower increase." Well, that's true, but it doesn't really tell us much. I like your style, though, wiseguy!
Scott
Scott
Race Director
Joined: Jan 2000
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From: San Jose CA
Melting Slicks
Joined: Oct 2005
Posts: 2,056
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From: Redruth Cornwall
Headers would gain some if you replaced the rest of the exhaust otherwise your just flowing into the same restrictions.
Smog components use diddly squat but it sure makes the engine bay look cleaner.
Is the distributor properly recurved for your engine and is the carb set up correctly or just installed out of the box?
Again AC compressor......did you use it before? No real gains apart from cleaning up the bay.
Cam, is it well matched to what you have? we need specs. No point having a cam that doesnt work with everything else.
I have an '81 so am interested in what you have done.
