HELP: Cams - Electronic Ignition & Exhaust for my QV?

This one but it might be a little too loud for the street.

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Any significant NA power upgrades will have significant expense; on the low end, I'll estimate that $30K is a basic starting point for your budget if you want to explore new cams, rail injection, etc. The XDI ignition system (once sorted), is reliable and has some advantages to the stock Digiplex units and distributors - but, additional power (if any) is relatively minor.

Getting the car to be crisp and reliable - without power upgrades - is an entirely different matter and lower budget, if the engine is in good shape to begin with. So, that will depend completely on your car and the current situation.

 

Pistons, cams and go thru the valve train, guides, seals,etc..
Raise compression to 10.5:1
Warmer cams, limited by CIS as the metering plate does not like overlap pulsations from aggressive cam profiles.
Stepping into more costs, i.e. ~$10k additional, EFI. That's an easy 30hp increase with the above mentioned changes. Also allows for any cam profile from mild to wild.
Pistons,cams & EFI will get an avg of 35hp & Tq increase. Yeah not a bunch, that's peak though it'll flatten the tq curve bringing the bottom end up nicely. EFI is where you gain throttle response, like a modern vehicle.

Exhaust is another overlooked area. Oem is heavy and though not overly restrictive in new condition these are old systems now. Dumping the massively heavy factory muffler is a great start. Replacing the heavy and leak prone headers is another one.

 

"Naturally aspirated upgrades only..."

Hmmm... $30k for 35HP naturally aspirated or $10 k for 100HP with forced air.

Or

Just make sure the car is in excellent stock condition, put loud mufflers on it if that's your preference, and leave it at that!

 

I highly recommend this option.

Replace the factory muffler with a Tubi, and maybe replace the cat with a straight pipe if you don't have emissions testing where you live. Other than that I'd advise to keep the engine stock, especially the internals like pistons and cams.

If you were to consider spending 30k to get a 30 hp increase, the easiest and fastest way to do that is to sell the QV and buy a 328.

 

Mike C here has a supercharger on his 84 QV.

He has had over 300 hp now with no ill effect on anything else on that car for over 15 years now.

 

He didn't beef up anything. The engine is still factory sealed which was my point earlier, we have a benchmark on a 308 now with this sort of thing. He has changed the ignition but not the fuel injection. I don't know the supercharger type/brand etc.

Shoot him a PM

 

That's one of the first ones I did all those yrs ago
Vortech v9g if memory serves.
I no longer use them though, switched up to rotrex units, far greater efficiency.

 

I think I remember Mike telling me that. He and I were out at TigPrix this past weekend for a nice little track day. Your work has stood the test of time.

 

Thanks, though I think credit is also due to Mike driving the wheels off of it. Regular maintenance and driving is the best course of action. Happy to hear he's still tracking.

 

Here we are last weekend
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FWIW, Pretty much any car can take a 1/3 increase in HP with no need to mod any other components. IOW, a supercharger with around 5-6PSI of boost would do that. That would give you from 80-100 more HP on a typical 3x8 with no other changes.