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Originally Posted by lakatu
Great info nthfinity as usual  . I still wasn’t clear though. |
why thankyou St-A, and Lakatu
8)
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Are you saying that there is no way around the lower reliability of turbo charging a car? I am not referring here to bolt on components but tuners like Ruf or RS Tuning that perform complete conversions.
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basically, there are no ways of reducing stress of upping performance levels; however, it is ofset by using stronger materials which have higher tolerances... thus reliabilty still exists. that is one reason why profesional tuning companies are so popular... they often offer warentees on thier work... would Ruf, Techart, Dinnan, etc. sell so well if they offered no guarentees of thier work? i dont think so.
i dont think it matters so much weather its just turbocharging a car, or other performance upgrades which would degrade the motor more rappidly even naturally aspirated.
from reading material i have had, the highest performance motors seem to be designed to last 50,000 miles, unlike normal cars engines wich are now designed to last sometimes 200,000+ miles with proper maintanence.
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It is obvious that higher boost and for that matter higher horsepower creates greater strains on the mechanical components of a car. But does lowering the temperature with larger intercoolers and other changes (i.e. stronger connecting rods, valves or whatever else they might do) that tuners make when increasing the boost offset the damaging affects of higher boost?
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As St-Anger mentioned, cooling the presurized air 10C is much like increasing boost pressure... as air takes up less space when its cooler. so basically, more oxygen is able to be fed to the motor with less stress on the compressor for a more powerful burn at the stoechieometry. so that in itself helps tremendously when extending the life span of the motor... heat is an eternal enemy of an engine.
unfortunately, heat isnt the only problem, as you mentioned. increaced power will induce much more stress all the way from the motor mounts/chassis, right through to the wheels, and everwhere in between. so replacing an iron connecting rod with a titanium one, forged sleves, will allow for extending the life of the part under higher strains, and make it more reliable. even further, sometimes a gain in performance is a trade off in material used to strengthen, or lighten... for example, Aluminum needs to be 4x thicker then steel to maintain the same strength. also, when mixing metals in an engine, advanced corrosion occurs at the contact points... so Titanium touching iron would corrode much faster then Iron touching Iron.
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Do Porsche engines come from the factory engineered to sustain the higher stresses that tuners place on them or do owners of tuned Porsches have to accept the fact that there is a trade off for the higher performance in the form of lower reliability?
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i think St-Anger could answer this better, but i would suggest that it is yes on both accounts. Porsche would not be a respectable maker of cars if thier engines were sold at the peak of its potential... the likeliness is that it would break often.
but costomers... and more often, tuners know that there is definately a trade off between product life, and increasing power.
in the most extreme cases, a race car is basically designed for everything to work for one weekend. if a part is suspect to failure, then cirtainly extras are on hand... but a daily driver such as a 911 turbo is designed to last a great deal longer, and a variety of driving habbits and styles... the race car is just designed for where it is at, at any moment.
cirtainly, everything in the race car is built with the utmost strength, and use of lightweight components, where there are more compforts in street cars, and lower tollerences at the cost of longetivity.
one thing that really amazes me is how high the bar has risen in the last 5 years alone in high performance cars. who would have thought there would be so many cars available today with 400+hp? has materials cost finaly come down? or perhaps it has been the invention of new materials, computer modeling and simulation such as seen in finite element analysis programs?
sorry for the lenghty responce... but i hope that makes some more sence.
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