Hi,

I am looking into getting a CAI and a tuner in the next couple of months. I live and drive in Denver Colorado and in the Rocky Mountains. Do I need to get a tuner and then get a custom tune from a local shop to drive at altitude? Or will the canned tunes suffice?

Thanks

 

I have the same problem in Albuquerque. A standard, run of the mill tune from any of the good tuners WILL be richer up here than it should be. Thankfully, it is not as rich as a properly tuned carburated vehicle would be if tuned at sea level and driven up to Denver, but it is still too rich. And just to clarify, the car is running closed loop during part throttle, so it will maintain proper A/F during most of your driving conditions. It is only during open loop WOT that things get too rich due to altitude.

You really only have two choices: 1) Get a completely custom dyno tune done locally (not cheap) or 2) data log your car with Brent's or Doug's "standard" tune and a wideband O2 sensor than let them tweak it to properly match your car. Again, not cheap, but at least you end up with a wideband o2 system installed...

FYI, I followed the third route: install wideband 02 system (LC-1 from InnovateMotorsports) but then never getting around to taking the correct datalogs and sending them off to Doug.

 

Ok thanks for the information. Sounds like number three is gonna be my direction heh.

 

I have a problem with my car running rough and someone mentioned to me that my tuning might be wrong for my altitude. I live on the east coast in new jersey. i also have encountered inaccurate fuel gauge, car overly rich and O2 stuck rich codes. SO, altitude could really be a problem?

 

Generally, as altitude increases, the engines run richer and richer at WOT. It's not NEARLY as bad as with a carburator (heck, you could have a great running carb car that simply couldn't RUN at 12000 going over a mountain pass), but it does still impact us. Once you get to the mile high club (no airplane required!), it has definitely made the car too rich to maximize power without being leaned out a bit.

But even here at Albuquerque, it isn't so rich that it causes the car to run rough.

 

Generally, as altitude increases, the engines run richer and richer at WOT.

Absolutely true. This is because the PCM goes to open loop at (or near) WOT. This means no learning / adjusting fuel trim. Whatever values the MAF Transfer Function uses fixes the amount of fuel used.

Altitude is just one more reason that justifies my stand on tuning cars. If you're REALLY into making your car as fast as it can be, read my replies (#8 & #9) here:

http://forums.bradbarnett.net/showthread.php?t=473910

Tuning yourself makes your car perform better than any other similarly modded cars. I'm running equivalent times to other local GT500s. They all have a "Stage 2" tune with CAI and pulley that makes around 12-psig boost. All I'm running is a conical K&N filter, stock inlet tube and the stock pulley making 9-psig boost. The only difference: My own tune file!

Tuning your own car is not rocket science guys. If I can teach myself how to do this, so can you.

 

So could my tune be bad for the location im in(NJ's Alititude)? i been trying to figure my problem out for weeks and no luck. Should i just seek out a dyno tune?

 

I live in Farmington, NM... we are a mile high here too... I'm running a Mac StraightShot CAI with a canned tune that I received with my Preditor II purchased from MAK Performance. The tune I'm using is the 87 Octane Performance tune, I've had to add +7% to the MAF to keep from getting Lean Burn codes. Other than that, the car runs and performs well, of course, I'm not looking for the absolute fastest car, just one that is a little above the showroom GT.

 

That is strange. You definitely should be running too rich, not too lean. Have you hooked up a wide band to it to see what the mixture actually is?

 

Chris at Tillmans has tuned some cars in your area. Give him a call and he can fix you up with a great tune.

 

Anyone else read this as a Tunes for Attitude? "I need to tune my car to match my bad @ss personality."

 

No but give Chris a call and he'll give you all the ATTITUDE you can handle.

 

F*cks THAT supposed to mean?!?!?! LOL