September 2010 - Performance Zone
STOP SMOKING!
By Performance Specialist Bruce C. Mallinson
Many of you have become spoiled by the ECM, ECU or the computer that controls your engine. With a stock engine, you can slam your foot to the floor and the engine will not smoke, but a stock engine will also be sluggish and only accelerate at a rate that the engine manufacturer feels is safe for you. So, you are being controlled by some engineer who knows nothing about you or your driving skills. How does that make you feel?
Back when we drove high-performance mechanical engines, we had to be light on the throttle because the fuel system would give us as much fuel as we wanted. We had to drive these engines with one eye on the turbo boost gauge because you could not get after the throttle until there was at least 10 psi of turbo boost or your engine would put out a lot of smoke (until the boost came up). Now, the stock electronic engines of today are dogs – you have to push way down on the throttle to get your truck to even move! After a while, you get sick of driving this dog and decide that its time to get your rig a performance ECM or ECU.
Performance ECMs are responsive because they are using performance profiles from non-highway applications. An ECM with marine or agricultural codes doesn’t care if your turbo boost isn’t high enough to make clean power. The ECM will dump fuel into the engine when you hit the throttle. So now what happens? You push too far too soon on the throttle and you get smoke because the turbo has not had a chance to build up boost and now you’re upset. If you have installed larger injectors, a performance camshaft or a performance ECM to make more power and response, you now have to drive your truck with one eye on the boost gauge when starting out to eliminate smoke.
With a performance ECM, it’s back to driving like you have an egg between your right foot and the throttle – like we used to drive. This is how I prefer to drive, however my right foot is not lazy – I love a responsive engine and if I put out a little black smoke because I pushed a little too hard on the throttle, so what. I know my engine is getting fuel and is responsive.
If you want responsiveness and performance, our computer will give you both without the smoke. By holding back the fuel until the engine develops some turbo boost, our ECM eliminates the smoke problem. Just remember, if you have larger injectors, a performance camshaft or a performance ECM and you push too hard on the throttle, the engine will make some black smoke until 10 psi of turbo boost is developed. So be gentle with the throttle until that boost is achieved. After that, there should be no smoke.
If you have a small convex mirror mounted so you can see your stack during the day, you can keep an eye on your smoke. But if you pound on the throttle and push too hard without giving the turbo a chance to respond, you’ll get smoke. Take your engine to 10 psi of boost then roll into the throttle and it should be almost clear – it is okay to see some black smoke if it’s a performance engine. At altitudes of 7,000 feet and higher you will see a slight haze of smoke no matter what you do. At that high altitude, the atmospheric density is about half that of sea level, and that will have an effect on the engine’s combustion, so expect some smoke at higher altitudes.
Here is a reminder to anyone who is planning on buying a new turbocharger. When you purchase a new turbocharger and take it out of the box, the V-bands that hold the compressor and turbine housings to the bearing housing are not torqued. You must tighten the clamps yourself! The reason they are not torqued beforehand is because, when installing the turbo, the bearing housing needs to be aligned with the oil feed line and the oil drain line, and then the compressor housing must be aligned with the outlet elbow going to the charge air cooler, and then the turbine housing with the exhaust manifold. So, after all that is done, it is your responsibility to tighten the two clamps – if they come loose, the turbo is junk. Don’t allow this procedure to stop you from installing your new turbocharger, because it is much easier than it sounds.
This past week I got a call from a heavy hauler in Florida who keeps losing the springs in his clutch about every 120,000 miles. There is 760,000 miles on his crank damper and Caterpillar told him he will lose his warranty if he changes it. By now I would have thought that everyone knew crankshaft dampers are only good for a maximum of 500,000 miles. When these dampers are not changed, many other components on the truck will suffer from the harmonic vibration (including the man behind the steering wheel). Some mechanics still say they don’t wear out, but these guys must not read much or take the time to properly research such things, because they most certainly do!
My heavy hauler friend wanted to install a Lipe clutch for its strength, but I would not sell it to him unless he first installed a new damper and mercury-filled engine balancer. If he doesn’t install the new damper and balancer, he will scatter this clutch just like he did the last few and I didn’t want him to waste his money. Something has to absorb harmonic torsional vibration along the crankshaft, and the damper is what does it. That’s why it wears out and why your engine suffers so much when it fails. They are not expensive and they are easy to install, so there is no reason to leave it on your truck after it has 500,000 miles on it. Do yourself a favor and replace it, along with the engine balancer, and you will enjoy a smoother-running truck and less broken parts.
If you have any performance-related comments or questions, I can be reached at Pittsburgh Power Inc. in Saxonburg, PA at (724) 360-4080 or via e-mail to bruce@pittsburghpower.com.