Superchargers at altitude - help please.

Should I make modifications to my air intake if I install a supercharger at altitude?

I live in Colorado and have been told by two people now that making changes to air induction with a supercharger is not necessary at higher altitudes. The reasoning I've heard is that with thinner air the difference isn't enough to justify the expense and also that if you aren't burning 93 octane it doesn't really matter.

Has anyone had experience with this? If I'm going to go through the trouble of installing a supercharger I want to make sure it's done right.

I also am fairly new to superchargers and would appreciate any other advice. I will make necessary changes to the ECM and will be installing TRD exhaust. Is there anything else necessary that doesn't come in the kit?

Thanks in advance,

 

Better run Premium grade fuel.

What is your normal altitude?

 

Mile High City

 

You still need to run premium. Octane increases with altitude in a naturally aspirated engine, but a S/C pressurizes the engine which simulates a lower altitude plus boost... so don't run regular.

The TRD tune is very fat. You could always get a piggy back ECU, which you'll have to custom wire in, and use that to tune your engine for both the open and closed loops. The MAF calibrator would also work for tuning just the open loop. Either way, while the true gains won't be astounding without a good dyno and shop, the throttle response will be much better since you won't be dumping all that excess fuel at WOT. IMHO it's really up to you if either part is worth it. I just left the stock TRD tune on there and I'm at 3000 feet. I regularly drive up past 6000 feet with no problems climbing hills offroad and I have the S/C to thank for that.

 

http://www.xr-underground.com/forum/showthread.php?t=57099

@TRON