Having lived in the Denver area for over 10 years, you either accept the fact that your car will make less HP or spend a lot of money trying to make it up. The good news is that everyone has the same problem at this altitude. Our shop tunes and modifies just about every make a model car you can name. Depending on the heat and humidity you lose about 20-24% in HP at this altitude. If you want the same HP, you will need to add that amount to get back to what you had at sea level.
One of my cars has a stock 2.3 with .030 CP pistons and 11:1 compression. It also has the miller MAF setup which compensates for altitude changes. The adjusted HP (sea level) is 177rwhp and uncorrected is 140rwhp. That's about 15rwhp less than a stock 2.3 at sea level. You can make up the difference in an N/A motor pretty easily by head porting, bigger cams, and free flowing exhaust. That would put you at 200-210 corrected rwhp. This gives you back the power you lost moving up here and will also provide a nice improvement whenever you go to sea level.
If your goal is to go beyond that, the sky and your wallet is the limit. My 2.5 build put down 238 corrected rwhp and 190 uncorrected. That is a significant improvement over a stock 2.3 even uncorrected. And the motor was very streetable, but it will cost quite a bit more than a 2.3 build.
We are also developing a standalone setup for the S14 that uses a very common ECU which has significant capabilities beyond the stock ECU including turbo and high HP NA mods.
Our shop is in Parker CO.
Last edited by inastrangeland; 08-12-2012 at 10:07 AM.
Several E30 M3's.
More than I need but not as many as I want....