When do you know that your engine needs higher-octane fuel? Well, if your engine is stock you can usually go by the manufacturer's recommendations. Your owner's manual should list the specific octane requirements for your given engine. Most of the late-model performance engines are pushed to their limit to make the power the General is quoting. This is where my little story comes in.
As I wrote a few months ago, my son, Daniel, is now driving an '01 RS Camaro equipped with an L36 Gen II Buick V-6. This is a nasty little V-6 that makes great power and knocks down 25 mpg on the open road. When Daniel and I went out to buy the car it was low on gas, so the first stop was the local Chevron station. We whipped out the owner's manual and the fuel requirement was 87-octane. Boy, was I happy we didn't need to feed it with a steady diet of 91!
The next day we were at Infineon Raceway running the Summit ET series and we popped in a bottle of Lucas Octane Booster. The car ran well and had a best of 15.60 at 86 mph. We were very happy for its first time out. Of course, we couldn't leave well enough alone! Back at the shop when I was baselining the car on our chassis dyno, the engine had some burst knock during the acceleration test. Next, it got a bundle of parts starting with a K&N FIPK (to get the air in) and a Flowmaster American Thunder kit (to get the exhaust out), '04 Z06 wheels and tires and an Auburn posi (to stop the intermittent wheelspin), and a set of Hotchkis lower control arms (to stop the wheelhop).
Back at the track the car netted a best of 15.42 at almost 87 mph. We're now running the car on straight 91 and Octane Booster. We were out testing last Wednesday night and I heard the engine knock on a 2,000-rpm dry hop. I was very surprised to hear this and we decided to try a little blend of 100-octane Sunoco race gas. This past Monday was our final points race for the Summit ET series, and we tried the race gas. The car promptly responded with a best of 15.32 at 87.52 mph. We were thrilled and Daniel finished the year in third place, which gives him a seat on the Infineon team at the ET Finals later this year in Bakersfield.
As I said earlier, Detroit has pushed the calibrations on their late-model performance cars to the limit. When do you know you need better fuel? Well, with the very fast-correcting computer-controlled systems on our cars, you may never hear audible engine knock, so blend in a few gallons of your favorite flavor of 100-octane racing unleaded to see if you get better performance. Sunoco, VP, Rockett Brand, and ERC all have unleaded race gas. You should be able to pick some up at your local speed shop or track. Just watch out for the price-it's a little steep at $6.50 per gallon! Happy testing.
Chevy DueceQ I'm restoring a '66 Nova and have a 3.73:1 posi rear, a TH200-R4 tranny, and a TCI front subframe. Do I need a new crossmember, and if so, where do I go? I would like it to be a bolt-in because the car has been in the family a long time-not many Novas left in Iowa that haven't been cut up. Also, I'd like to put in a 383. Do you think this will make a good weekend driver?Craig Via e-mail
A By installing the TH200-R4 trans you will need to move the stock crossmember back approximately 7 inches. This will be tough with the factory crossmember. Get in touch with Total Cost Involved and pick up a universal transmission crossmember. This will require the least amount of fabrication, and they will get you the pieces you need to work best in your '66 Nova. They have some killer pieces, as you know by your new front clip.
Yes, a 383 would propel your little Chevy II nicely. The TH200-R4 trans and your 3.73 gear will make it scream in the first three gears, and when you drop into the 0.68 Overdrive it will cruise right down the road. Enjoy your restored Nova on the plains of Iowa.