Camshaft And Valvetrain Technology Insight - On The Lobe's Edge

A Look At The Latest Camshaft And Valvetrain Technology Straight From Its Creators

John Nelson Feb 1, 2009 0 Comment(s)
0902chp_15_z Camshaft_and_valvetrain_technology_insight L92_ls3_engine_block 2/27

Why should you care about DOD motors, especially those found in Pontiacs? Chances are good that the L92/LS3 variant we'll see in the new Camaro will have displacement on demand-and plenty of buyers looking for the economical mileage and great power this setup shows it can produce.

So the bottom line is that there are proven base setups with 400-plus-horse motors and minor mods that still maintain great mileage. Curtis admits that he had to tone the cam specs down a little to make the DOD work smoothly, but that setup still puts a properly modded G8GT in the range of 400-410 rwhp. The more aggressive, non-DOD setup has consistently made 450-plus rwhp.

"You, too, can build up a similar sleeper with the more aggressive FTI/NEP G8GT package to your own 4,300-pound cruiser," says Curtis. "Featuring American Racing long tube headers, the NEP/FTI 'muffler eliminator' DragPipes, the FTI camshaft and valvetrain kit, the new NEP air inlet, and New Era's canned tune-and voila! You've got an 11-second four-door Bimmer Killer." But, as Curtis said of the "toned down" version, if a customer chooses that direction, there still aren't too many mid-12-second four-doors getting 23 mpg. Looking at the whole picture, it sounds like an area ripe for growth.

Now, Curtis also mentioned the research with the Escalade-style variable valve timing (VVT) and is very excited about the advantages of having a stout camshaft that acts like a small profile at idle and still makes big power when rpm increases. "It's new to the street-performance arena," he said, "though used in many OEM applications such as the Cadillac Escalade. In the beginning, VVT usage may be limited, but as a mechanical engineer I hate limits."

On the other hand, Curtis believes that the next direction for the hot rodder is getting the VVT system to work in non-VVT applications. In fact, his newest quest is to work with a software guru and create a standalone unit that will advance the cam for around-town cruising. Then, after datalogging the info, he would maximize the timing events and gain more top-end power as the pace increases. "We'll be able to plot the timing event points for optimum power in the software and put them where we want them," he claims, which sounds like a pretty good deal.

When we asked Curtis what else seemed to be popular these days, he had three words for us: turbo, turbo, turbo. "Our typical turbo customer is split between two versions of turbo combinations," he told us. "The low-boost, strong-running daily driver or the four-figure-rwhp and more race-bred combination. In either case, we always use USA-manufactured, premium components such as our own heavy-wall three-piece pushrods, PAC Racing nitrided valve springs, high-temp Viton seals, and titanium or tool steel retainers. These spring packages are overkill and battleship-quality to make sure they can deal with the extra power and heat generated by forced induction.

"The other thing I quickly learned is that both these turbo customers aren't afraid to play with the wastegate, so you must use bulletproof parts, and it is mandatory to have someone who knows what he's doing when it comes to tuning these cars. That's why I have a select and limited group of tuners I work with on my combinations.

"These shops can handle the 1,000-plus horsepower combinations that are cammed really big. Last month, Mike from New Era and I combined our heads to build a 1,030-plus rwhp twin-turbo Z06 that recently went low 10s at 149 mph-but the hottest thing I'm seeing is twin-turbo on cars having completely tame 800-900hp motors. I see a lot of STS and homemade rear-mount systems. Everybody wants an 8-second Nova that idles like a 12-second street car, and a turbo fits the bill. It's a crazy side of the market that's exploded for me, and people require the proper set of cylinder heads and matching valvetrain for them. It's a perfect fit for us."


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