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pulling catalytic conv... better performance?

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tweety

tweety

Jedi Trainee
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In my previous post, I asked if my new catalytic converter would be damaged if the air pump was not operational (pulled the belt on my '79 midget)

The new cat is welded into the front pipe so I can't just remove it. But I can replace the entire front pipe for less than $50. That way I'm sure that the cat will not be damaged (I'll reinstall it when I need a smog test again in two years)

<span style="color: #FF0000">Will removing the cat yield much of an increase in performance?</span>
 
If everything else is stock, I doubt pulling the cat is going to give you a noticeable performance boost. It may give you the placebo boost similar to the boost in performance your car gets after you have spent all day washing and waxing it.

But if you want a significant performance boost, you are going to be looking at flat top pistons, a shaved head, a better cam profile, a different carb/intake set up, headers, a better ignition set up etc.
 
Doubt you'd get an increase, unless your cat is clogged. The biggest problem the 1500s had with the cat is that it gets fiercely hot and is directly below the carburetor. I got rid of mine for that reason and just got the straight pipe from Moss.
 
I'll tell you what happened to my 1500 Spitfire a number of years ago. It had a catastrophic converter on it, but the air pump had frozen up and the previous owner just took the belt off the pump. This was about 10 or twelve years ago, and the car still passed Pennsylvania emissions at that time.

I ran the car for about 40,000 miles over 8 years and never had a problem with the engine or converter. On one occasion the car was in the shop for a repair, and the owner of the shop and I went out for a test drive after the repair. He wanted to know what I had done to the car to make it go so fast. I was surprised that he suggested it was a quick car, but he said it was the quickest totally stock Spit he had seen.

I explained that when stuff fell off (a not too unusual occurrence) I didn't always put the parts back on. The air pump was a perfect example, although it never actually fell off the car.

If I had the car here in NY today I am not sure if it would pass emissions without the pump.

The biggest problem was with the air rail. It tended to rust out and I had to patch it several times. I suppose that I could have plugged the holes, but that was too much work, what with me being lazy and all.

My best guess is that all this could be fairly typical for an air pump Spridget, too.
 
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