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Curt A

Great Lakes Region
  • Content Count

    431
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About Curt A

  • Rank
    Master Parts Manager
  • Birthday 10/11/1961

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  • Region
    Great Lakes
  • Interests
    gt500
  1. Why lean makes more power but is dangerous When discussing engine tuning the 'Air/Fuel Ratio' (AFR) is one of the main topics. Proper AFR calibration is critical to performance and durability of the engine and it's components. The AFR defines the ratio of the amount of air consumed by the engine compared to the amount of fuel. A 'Stoichiometric' AFR has the correct amount of air and fuel to produce a chemically complete combustion event. For gasoline engines, the stoichiometric, A/F ratio is 14.7:1, which means 14.7 parts of air to one part of fuel. The stoichiometric AFR depends on fuel type-- for alcohol it is 6.4:1 and 14.5:1 for diesel. So what is meant by a rich or lean AFR? A lower AFR number contains less air than the 14.7:1 stoichiometric AFR, therefore it is a richer mixture. Conversely, a higher AFR number contains more air and therefore it is a leaner mixture. For Example: 15.0:1 = Lean 14.7:1 = Stoichiometric 13.0:1 = Rich Leaner AFR results in higher temperatures as the mixture is combusted. Generally, normally-aspirated spark-ignition (SI) gasoline engines produce maximum power just slightly rich of stoichiometric. However, in practice it is kept between 12:1 and 13:1 in order to keep exhaust gas temperatures in check and to account for variances in fuel quality. This is a realistic full-load AFR on a normally-aspirated engine but can be dangerously lean with a highly-boosted engine. Let's take a closer look. As the air-fuel mixture is ignited by the spark plug, a flame front propagates from the spark plug. The now-burning mixture raises the cylinder pressure and temperature, peaking at some point in the combustion process. The turbocharger increases the density of the air resulting in a denser mixture. The denser mixture raises the peak cylinder pressure, therefore increasing the probability of knock. As the AFR is leaned out, the temperature of the burning gases increases, which also increases the probability of knock. This is why it is imperative to run richer AFR on a boosted engine at full load. Doing so will reduce the likelihood of knock, and will also keep temperatures under control. There are actually three ways to reduce the probability of knock at full load on a turbocharged engine: reduce boost, adjust the AFR to richer mixture, and retard ignition timing. These three parameters need to be optimized together to yield the highest reliable power.
  2. I've been on cobra country , and MFR / DIst web sites . There aren't to many for sale , especially in red . Hense my post of seeing if someone in chicago metro has one I can actually see/ drive. I would get a roller and do the trans and engine myself . I have 35 years automotive experience and did all of the mods on my GT500 . The closest Dist to me is in Detroit area and driving up there in the spring is a possibility ..........
  3. I"m planning on selling my GT 500 the spring of 15' and ordering a Superformance GT40. Any one in the Chicago metro area own one I can look at ?
  4. The 12.9 Litre Weineck Cobra is a 780 cubic inch V8 powered Cobra designed by the Germans as a daily driver for Cthulhu. They’ll never admit that of course, and are still sticking to their official story that this is a car for regular humans, however it’s difficult to imagine anyone with a skill level below Nigel Mansel being able to handle a 1100hp car with no traction control. Only 15 of these were ever made, each was produced by Weineck Engineering in Bad Gandersheim, Germany with a MSRP of €545,000. That may sound like a lot of money, but it’s significantly less than other cars that occupy the 1000+hp club, like the Bugatti Veyron, the Hennessey Venom GT and the Koenigsegg Agera R. That 780 cubic inch V8 is a custom milled machine from Donovan Engineering with purpose built Weineck Engineering pistons, connecting rods, crankshafts and heads. That slightly absurd air-scoop on the hood is actually vital, without it the engine struggles to suck in enough air when the RPM gauge goes above the 4,500 mark. At 7,000 RPM that magical, Cthulhu appeasing 1100hp figure is achieved allowing drivers who have the plums for it to launch the Weineck Cobra from 0-62mph in 2.5 seconds and 0-186 in 10 seconds. An entirely new chassis had to be built to handle the power, so a MIG welded, self-supporting 4 inch tubular frame was developed with the use of CAD systems, the body is deep drawn from carbon composites to both keep strength high and weight low. The production run of 15 cars sold out almost as soon as they were announced, so if you want one you’ll need to join the ranks of collectors who wait for them to pop up at auction. As it so happens, the car you see here has just been added to the lot list for the Paris Auction due to be held by RM Auctions on the 5th of February 2014.
  5. I'm going on 24 days since I ordered my 2014 renewal . Now how long are they taking to ship out ? Member #676
  6. Thanks for deleting my post from yesterday . I also ordered my 2014 kit yesterday. Good news they are shipping faster , lets see how it takes. Isn't this a "see how long it takes " thread ?
  7. https://www.youtube.com/watch?v=fMKe89zcvHU I want one !
  8. Regular hand tools and a HUGE open -end wrench for the EGR pipe nut . I don't remember the size , I installed mine 5 years ago
  9. I thought I had too many.......... AR15 = 30x 30 rd AR15 = 2 Beta C mags 100 rd S&W 9 mm= 10 x 17rd & 6k rds
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