Chevy 383 Turbocharged Engine Build - Performance Q & A

Kevin McClelland Nov 1, 2009 0 Comment(s)
0911chp_01_z Chevy_383_turbocharged_engine_build Frequently_asked_questions 2/2

For Safety's Sake
Every two years we get to do the seatbelt boogie in our race cars. Some people moan and complain that NHRA and other sanctioning bodies are getting kickbacks from the belt manufacturers. Well, I'm not one of them. Every time I belt myself into my roadster, I trust those belts to keep me within the safety zone of my 'cage and chassis. Sure, most door cars (enclosed) don't get much sunlight on the belts, but our open cars and dragsters have direct sunlight deteriorating the nylon webbing. The last thing you need is a belt failure as you're slamming into the guardrail-or worse, a racer coming into your lane.

One suggestion to make the belt swap a little less painful is buying a new set the next time you need your belts inspected and rewebbed. This will give you an extra set of hardware so you can have them rewebbed before the two-year replacement date and swap them right in. Many cars require disassembling the car a bit to install the belts. Mine is one of them.

As for other safety equipment, like transmission shields, flexplate shields, and flexplates themselves, I think the sanctioning bodies are a little over the top. It's pretty tough for a piece of aluminum shielding that wraps the transmission to wear out! Well, I'll get off my soapbox for now.

A reader wrote in this month asking at what e.t. breaks the NHRA requires specific safety equipment. It varies based on the type of car. When we talk about hardtop (nonconvertible) cars and trucks, you can run down to 14.0 seconds before you need a Snell 2000-or-newer helmet. The next break will be 11.50 seconds in the quarter-mile before you need to install a rollbar and aftermarket seatbelts. You can run all the way down to 10.0 seconds with a rollbar if you haven't modified the firewall or the floorpan with other material. You can run all the way down to 11.50 without a driveshaft loop if you're running on street tires, but if you swap out and run slicks you must run a loop once you hit 14.0. Once you hit 11.0, you must install an automatic transmission shield and aftermarket rear axles.

When you talk about open cars, like convertibles and roadsters, the rules get much stricter. A rollbar and aftermarket belts come in at 14.0 seconds. Also, driver's safety gear steps up with a 3.2A/1 SFI-approved jacket, arm restraints, and gloves when you run 11.99.

This has been a quick overview of what you'll need before you take your fast street cars out to the track this summer. Check on NHRA's website ( for more information and regulations based on the e.t.'s you project for your toys. Be safe so you can be around to read more tips!

Oils Well That Ends Well
Q: I'm building a 383ci engine with a Turbo kit I made. I'm using an Eagle bottom-end assembly, an ARP bolt kit, and Edelbrock heads. I don't know which bottom end to go with when it comes to windage tray. Should I get one that bolts to the main caps or one built into the oil pan? Since the oil pump will also feed the turbo, I'll be going as big in the oil pan (8-quart) as possible. What are the pros and cons of both, and what would you recommend? The turbo is going to be making no more than 10 pounds of boost. Thank you.
Kevin Nesbit
Milwaukee, OR

A: Every time we have delved into windage trays, we found that they are basically worthless until the engine is above 6,000 rpm. This is in the horsepower department on an engine dyno. As for oil control, on the street or an oval or road racing track, they have an entirely different purpose. If you didn't have trays in the pan to control the oil under heavy braking or cornering, you'd run the oil pump pick-up right out of oil, and heavy bearing failure would be quick to follow.




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