Im trying to get turbo savvy and ive got a question and i plotted some points. Im looking to reach 300hp(like many), and I am trying to understand how exactly the car will react by looking at the compressor maps. I can deduce that this is a good mid to end range turbo for my gsr, but I am confused about how the car will react just to the right of the surge line (say 3800 rpms). Pretty much the boost will be built between 4k and 7.6k, which I am fine with. Also, say i wanted to calculate this with adding in lower compression pistions. Say I got pistons that lowered my engines internal compression to 8:1, would I just assume that my earlier calculations of me building 34.4 psia(with the assumed 2psia pressure loss) to be 32.4 psia (since the pistons lowered the internal compression)? Heres a link as well to the compressor map. General advice is always welcome, even if its harsh. I dont know enough to get upset if someone disagrees yet lol. Thanks peeps.




Modified by aimbot at 10:51 AM 6/15/2008

 

 

As you lower the compression, you'll only change the recovery response of the car, not power. Your plot will shift slightly up and to the left, in essence making it necessary to put in more positive pressure to be at the same place on the map for CFM volume. Keep your compression closer to stock with this size for better results. You have to also consider VE of the engine, max rpm, engine demand flow of engine itself (which isn't that bad considering the setups on H-T), to get it PERFECT. and even then, that is not necessary.

You also need to consider in your calculation the amount of pressure drop your intercooler will have. That will affect the number of pounds of boost used to calculate.

This is why your question isn't answered much.. Lots of calculating that will not be spoon-fed to you. If you want to understand Turbocharging to the fullest, Corky Bell's Maximum Boost is still available.