giveme5bux

Does anyone have links or a methodology for tuning at altitude? This a problem I consistently face when competing in Mexico. Ecu is Motec M800 in a evo 9 turbo'd 2003 Evo 8.

PureDrivePerformance

Good question. I've spoken with some local tuners here in Colorado and there is a general concensus to keep the timing and AFR's the same as you would at sea level.

However, there is a popular tuner who adds more timing. A lot more. Why? I don't know. Maybe to take into account the thinner air.

I personally turn up the boost to make up for the thinner air. I think I lose about 15% of power at 5000 feet.

Here's an interesting article that doesn't answer your question directly. http://2-stroke-porting.com/Air_Density.html

Also, what have you tried that did and didn't work for you?

fmars62

thats a sweet article, thanks for the good read!

ProPilot04

iTrader: (11)

Christian... I'm actually about to head to my tuner to get a map for 91 octane since I'm heading out for Pikes Peak from NY this year.

To wit... the turbo shouldn't need to be adjusted for altitude, as it operates based on pressure.

I know in our aircraft, we adjust the wastegate as altitude changes to gain more power, but we can also adjust the fuel, and the manifold pressure directly, and the engines usually run at a relatively constant RPM.

PureDrivePerformance

Thanks! That makes sense that the turbo wouldn't need adjusting due to the fact it's pressure. I would imagine the density of the air would heat up quicker. Other than that it would be the same psi regardless of altitude.

Now for some

A few years ago a member on here, Warrtalon, did a comparison dyno from sea level to high altitude (Denver). He didn't adjust the tune for the dyno comparisons.

I'm just curious if you would like to do a similar comparison. It can be done on VD at both locations if you're not adjusting the tune on a dyno when you get here.

What division are you racing in?

ProPilot04

iTrader: (11)

2 things.

1. I'm not racing. I'm spectating, but I would TOTALLY love to be racing. I just need to weld a cage into my Volvo and find someone insane enough to co-drive for me lol.

2. I would totally do that to see what it was and how it played out. I could also calculate out the density altitude for more accurate readings HOWEVER...

I have not as of yet forayed into tuning. I read up on it often, but it still frightens me a touch. My car is currently tuned by STM. I really want to have it setup with Tephra so I can take advantage of the launch maps, and the valet rev limiter, and the NLTS mods... I'm not sure if I should hassle Emery about this, or if it's something I'll need to do myself.

But we calculate stuff like that through interpolation in aviation all the time... if someone can give me the general idea of how to do it... I'd be happy to oblige.

A tactrix was next on my list anyway...

PureDrivePerformance

What day are you going? I'm thinking of Thursday for the qualifiying, but you have to be in the gate by 5am. So I may go up Sunday. What to do?

I could road tune you while you're here. Get the VD numbers. When you get home test it out at sea level. You could always throw your STM rom back on after the testing. Just a thought. It would cure my curiosity...I think.

ProPilot04

iTrader: (11)

We'll probably head out and catch a practice day, but we're camping for the event. So we'll be there that night, and early for the racing...

Shoot me a PM or something. I'm not against it. As long as the car works for my drive home.