Stupid question to the informed.....but i am a newbie owner.
Which ones rob you of horsepower and where can I get info on their removal.
Thanks in advance for any advise.
B.T.W., 78 L48

 

Almost none of the specific pollution control devices (in good condition) really rob horsepower; the really poor tuning the factories did during the 70's was the main culprit.

Carb calibration, cam timing and profile, heads, intakes, and exhaust (lousy catalytic converters and single exhausts) are the worst detractors of performance.

 

Yep. The old pancake style cats were horrible. Tests in the late 70's showed a 40 hp drop on a 200 hp engine with those. Good news is that todays hi-perf cats don't really rob much of any power. I've seen tests on 500 hp engines were they added dual cats and lost less than 2 hp.

 

As odd as it sounds the cam.
I think the carbs since they went to that stupid electric bouncing main needle
And they put limiters on the carbs screws.

As already mentioned the innards of your 350 were chosen to reduce emissions so HP was sacrificed.

 

Low CR, poor head design, restrictive cats, cruddy cam design were the main culprits. The "stupid electric bouncing main needle" was only used in '81 (& the '80 Cali motors) & was only used on the primaries, giving good fuel economy, lower emissions (maybe!), but still used traditional secondaries with rods & hangers that can be changed in the normal way ie. if it reduces performance then it's insignificant when compared to the exhaust, heads, CR, intake, cam, etc, etc. There's people running mildly tuned motors (ie far better than stock) with this carb on top.
I reckon that junking the AIR system would be a good start (that pump can only suck up hp). The EGR system gets conflicting posts regarding its removal, some people think it's needed to prevent pinging, others (inc me) view it as something that wastes valuable volume by filling it with exhaust gas (cams are designed to give overlap to promote exhaust scavenging, along with Headers, so why would you intentionally push exhaust into the cylinders as part of the intake charge?). I think EGR has a place on motors that are running high CR & suffer from pinging on low octane fuel, but that's just a frig to get around the problem. The charcoal cannister doesn't rob power but it is a potential source of vacuum leaks. Ignition timing should be changed to get more power. Cold air intakes are a good thing IMO. EFE? Who knows? Biggest hindrance to mine so far has been the stock exhaust system (2-1-2). Changing it to duals has a good effect.

 

The L-82 cam was a very good cam.
The L-48 needs more cam.

Sometimes posts like that can really give a FALSE impression to some.
Most of the emissions controls were EXTERNAL & easily removed or disconnected. Can be removed:
EXTERNAL- TCS
EXTERNAL- Air Pump
EXTERNAL- Restrictive cat.
http://www.corvettefaq.com/c3/ganeyexhaust.htm

Can be removed or blocked w/ a ball bearing in hose:
EXTERNAL- EGR AL. non-egr intake rec.
EXTERNAL- EFE
EXTERNAL- CCC

EXTERNAL- Carb
The normally used Q-J through 79 CA & 80 Fed. carb can be set up for economy & performance W/O dissassembly.
While better heads are avail. & rec., sometimes it seems few are aware of the perf. possible w/ the heads.

 

that old cat robs HP