Strawman Posted June 13, 2008 Report Share Posted June 13, 2008 OK, as I sit here waiting for the KB to be installed on my '08 SGT girlomatic, I'm dreaming about what it's going to be like mashing the throttle and killing whatever beast dare challenge. However, I have nightmarish thoughts of a catastrophic failure and spewing parts everywhere along US1. So, what would be my first line of defense? I understand the bottom end may be the weakest link, what does a forged bottom end entail? What other mods could I do to protect the engine/(auto)trans? Link to comment Share on other sites More sharing options...
FordRocks1 Posted June 13, 2008 Report Share Posted June 13, 2008 OK, as I sit here waiting for my KB to be installed on my '08 SGT girlomatic, I'm dreaming about what it's going to be like mashing the throttle and killing whatever beast dare challenge. However, I have nightmarish thoughts of a catastrophic failure and spewing parts everywhere along US1. So, what would be my first line of defense? I understand the bottom end may be the weakest link, what does a forged bottom end entail? What other mods could I do to protect the engine/(auto)trans? Well, I don't think you'll be going that fast on USELESS-1,too much traffic all the time...anyways, I would wait to see what goes wrong first....unless you have $$$ to modify everything at once but unless you are at count-line or Morosso everday I don't see you busting your bottom end then again it depends how much boost you are pushing..... Link to comment Share on other sites More sharing options...
LuLu Posted June 13, 2008 Report Share Posted June 13, 2008 My last supercharged car was an '03 Marauder, and I went through 3 engines, 2 trannys (4R70W) and two rear ends. the car weighed over 4500 pounds and ran in the 11's on a Vortech T-Trim @ 12 PSI, but it got expensive. Can't move that much weight from a standing start without earning a "hernia". I wouldn't worry about much for a while, the stock 4.6L-3V is very stout, as is the 5R55S auto tranny. The SGT has all the nifty stuff to get your power to the ground, so, don't over do things. Stay at or under 10 PSI, and you should have a lot of fun for a few years. However, remember that supercharging/turbocharging adds a lot of stress to the drive line, and you may expect some things to wear out sooner. If I had to pick the first component that could fail, it would be the torque converter. Keep an eye on tranny fluid temps, and add a second cooler ASAP. Torque builds heat and hot tranny fluid will cause a lot of internal damage. I've used the FRP tranny cooler (M-7095-SR, page 133 of the '08 catalogue) with impressive results. It's a stacked plate design made by B&M that doesn't require a thermostat. Easy to install too, don't forget to top off the tranny fluid, and use only Mercon V fluid. Link to comment Share on other sites More sharing options...
69dejavue Posted June 14, 2008 Report Share Posted June 14, 2008 I would think the weakest link would be the rods as they are just powdered rods. You may wish to switch to an aluminum drive shaft to reduce weight and inertia. Less weight to turn. Drive shafts are cheaper than con rods, etc. Link to comment Share on other sites More sharing options...
LuLu Posted June 14, 2008 Report Share Posted June 14, 2008 I would think the weakest link would be the rods as they are just powdered rods. You may wish to switch to an aluminum drive shaft to reduce weight and inertia. Less weight to turn. Drive shafts are cheaper than con rods, etc. +1...The stock two piece drive shaft is one of the "torque leaks" I often post about. A one-piece shaft is not only lighter and less rotating mass, it delivers more torque to the rear end. Powered metal con rods used in modular engines are quite durable in the compression stroke of a super/turbo charged application, but you have to be realistic in dialing in the boost. More than 10 PSI will build cylinder pressures dangerously close to the failure threshold. IMHO, the aluminum hypereutectic formed pistions will fail sooner than the con rods when the boost is cranked up too high. Believe it or not, what causes a powdered metal con ron to fail, is sudden decelleration i.e. "jumping off the throttle" at high RPMs. With nothing pushing the piston down, the crank has to suck it down against the pressure of engine oil shoshing up from underneath. This causes the con ron to stretch at it's weakest point (the center of the rod) and once it's a tad longer, it starts banging the piston against the head. In the next few strokes, the stretched area of the con rod will fold sideways and you window the block. It happens a lot faster than you think and without warning. The problem is diagnosing exactly what failed. Everything inside gets trashed, and it's sometimes difficult to find the true cause for failure. I'm going to try to attach a pic of what I describe, but I'm not very good at posting pics. My advice is to keep the boost under 10 PSI, keep the RPMs under 62K, and ease off the throttle at high RPMs. Ease out of the power, don't jump off the pedal. If you like to hammer your SGT on a regular basis (as I do) and have a power adder of your choice, it's not that expensive or difficult to upgrade the bottom end. Respectable builds with high quality parts meeting factory specs start around 25-2700 bucks. Figure another 1K in labor and misc. parts, and that's just a little more than half of what you spent on a power adder. Now you can up the boost and the RPM, and rest easy. There is one caveat though, there always is. Upgrading to forged internals will cost you some power. Forged internals weigh more than stock internals, which means greater rotating mass. All thing being equal between the builds and tunes, and the forged bottom will produce less power on an engine dyno. But, not to worry, now you can crank up the boost and get it back. Happy motoring, gents. Link to comment Share on other sites More sharing options...
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