October 2008 - Performance Zone
HIGH-TECH TURBOCHARGERS
By Performance Specialist Bruce C. Mallinson
I“Gimmie a turbo with air, lots of beautiful air, shining, screaming, pumping my engine with air!” That’s a parody based on a song from the 1960’s talking about hair, but it also works pretty well at describing today’s turbochargers. All turbocharged diesel engines want lots of air, however many of these engines on the highway today are suffering from not having enough air or from having a turbo that is too small. When an engine doesn’t have enough air, the exhaust temperature runs hotter, fuel mileage suffers, the truck doesn’t run free across the highway, and the life of the turbocharger is shortened.
Ever wonder why the turbo on the DDECIV 60 Series Detroit and some of the 3406-E Cats fail prematurely? It’s because they’re too small. Yes, a small turbo spools up quickly and is great if you spend all of your time in a big city, but when you are going across the super slab that small turbo is chocking your engine and robbing the truck of fuel mileage. We now have a turbocharger for the 60 Series Detroit engines that is 15% larger (we will soon have a turbo that is even larger for the ultra high horsepower Detroits). If you don’t think a 12.7 Detroit can run, you are wrong. We currently have several of them on the highway that are producing in excess of 800 horsepower.
For all you owner operators out there with a Caterpillar engine built between 1995 and 2003, the stock turbo is too small – especially if you have hot numbers in the ECM, a Pittsburgh Power computer or big injectors. That single stock turbo is robbing your engine from the massive amounts of horsepower it is capable of producing. The Holset turbo is a beautiful match for the Caterpillar engine. It’s a shame that the Holset engineers and Caterpillar engineers can’t work together. If they did, we could have Holset turbos on Caterpillar engines from the factory. But as long as Caterpillar stays with turbos built by Air Research, we will always have work to do.
A properly tuned Caterpillar engine is a phenomenal piece of equipment when being supplied air from a Holset turbo. If you look at one of the pictures on this page, you’ll see Nate holding a polished compressor wheel from a Holset turbo. Back in 1992 we built a 1,200 horsepower Cummins for Ken Howard in England for road racing. With all that power and just a single turbocharger, the compressor wheel would often hand grenade before the race was over. Keep in mind that in road racing, with right hand and left hand turns, the driver is NOT driving like he has an egg between his right foot and the throttle, he is mashing the motor. We had to change the structure of the aluminum compressor wheel to make it stronger, which was accomplished by polishing and honing.
We only modified that one turbocharger for Ken back in 1992, but last month I showed Jerry Ray Hairhoger (our performance engine technician) the polishing and honing process and his eyes just about popped out of his head. We now have eight Cat engines running with a polished wheel in their Holset turbo. This polished wheel not only looks great but it also pushes more air through the turbo and will not explode. Being a gearhead, I would love to have two of these wheels on my dining room table at home as candlestick holders, but they would be very expensive decorations, as each wheel is worth $775! You can get a Holset turbocharger conversion kit for your Cat engine for $2,645 – and you even get to keep your old turbo.
We recently did some work to a Cat-powered Freightliner owned by Aaron Bulkley of Texarkana, Texas. After installing a Pittsburgh Power computer, a 20% larger ported and Jet Hot Coated exhaust manifold, a Holset turbocharger, a new crankshaft damper and a
mercury filled balancer, Aaron said, “I knew my Cat was going to run good, however I didn’t think it would run this good!” Needless to say, this Freightliner is now very powerful, very smooth and it runs cool. Another happy camper!
If you wanna be cool, you gotta be smooth! And remember, “There’s no rush like a performance diesel rush.” One final note, Pittsburgh Power mud flaps are now available. The lady holding the white flap in the picture is Aimee – she answers our phones and does all of the secretarial work at Pittsburgh Power – and that is Bubba beside her – he loves working on Dodge Cummins-powered pickups. If you have any comments or questions, please send me an e-mail to bruce@pittsburghpower.com or call me at Pittsburgh Power in Saxonburg, PA at (724) 360-4080.