Hat / Bonnet
Spectre 9849 Polished Carburetor Hat - $99
Spectre hat with 4” intake and 5-1/8” outlet
Once it was decided to run a turbocharger, a list of components was made. Slowly but surely the list was reviewed and each item meticulously researched. All products have to be well made, performance capable, and affordable. None of the parts used in Turbo Camaro are the best of the best, but they are likely the best bang for your buck.
Take the carburetor hat (bonnet or plenum) for example. The purchased part is a Spectre 9849 single intake regular height hat. It is 3.5” tall, 9” long and has a 4” intake, fitting any carburetor with a 5-1/8” inlet. It fits nicely on the Holley 4776 600CFM DP with mechanical secondaries. It’s polished aluminum and quite hefty. The size is good, but like any part mounting to the top of your engine, be sure you have enough clearance between it and the hood. Overall it feels like a high-quality part, but at $99US it’s not cheap for what it is. Hopefully, the profit made on these is paying off all the R&D staff, as they probably cost very little to manufacture.
EV 4150 Pro Polished Hat - $280
Interestingly enough, purchasing a carb hat isn’t that simple. They come in different sizes and finishes as well as with or without an internal divider. Not to mention several manufacturers (like Spectre) offer low-profile versions for those with short hood clearance.
Can you just buy anything that fits and have it work the same as the most expensive one? The answer to that is no. A $40 hat made out of an old cast iron pot on eBay is not going to work as well as the $280 Extreme Velocity (EV) Pro series. The Extreme Velocity site claims to make more power than any other hat on the market.
Let’s break this down: EV’s dyno sheets show an average overall power increase of 5% over competitors using their hat. The Spectre hat will likely run Turbo Camaro to 350HP for its cost of $99. If the EV gets an additional 5%, that’s almost 18HP. Each extra HP would cost $10 for a total difference of $180. That’s not the best deal, but it depends on your project. For a little Chevy 250, that $180 was better spent on a DevilsOwn Alcohol Injection kit, which increases power by 5-10% while helping with detonation and intake temperatures. It’s not always about how much an item is, but how you can spend your money efficiently.
Spectre Hat modified to clear the valve cover.
The Spectre hat worked perfectly for the original build setup but upon installation of the turbocharger, the decision was made to have the pressurized piping cross over the valve cover. A riser was required to raise the Spectre hat up enough to clear the cover, but even then the downward angle of the hat opening hit the cover. Approximately 1.5” of the hat was cut off to allow it to cross over. With a silicone 4-3” reducer, the hat functions the same and now has the clearance we need.
If you have any questions, please feel free to contact us at turbochargedcamaro@gmail.com.