WOW! ALDA adjustment makes night and day difference - Page 4 - PeachParts Mercedes-Benz Forum

gsxr · #46 08-28-2005, 12:41 AM

Quote:

Originally Posted by bennett

How far do you turn it CCW? I'm at 5000' elevation and need every ounce of pep I gan get on a 240... My alda has a little drop of yellow glue to show it has not been touch.. would that be from the factory ona 81? My car spent 98 of it's life at sea level till this past spring.

Only turbo cars have an ALDA, which adds extra fuel as boost pressure rises, matching the extra air with more fuel to make more power. Normally aspirated cars like the 240D do not have an ALDA, but they do have an ADA, which compensates for changes in elevation. I've heard you can fiddle with the ADA to maybe get a little change on the 240D but I have no first hand experience. On the ALDA, usually 1.0-1.5 turns works well if it was "virgin", meaning still factory sealed. No idea on the ADA.

All I can say is that at 5000', you're kind of screwed as far as power is concerned. Almost every car will have a pretty noticeable power loss at 5000' or above.

Even turbocharged cars are doggy until boost builds at high elevations. Supercharged cars would probably have the least power loss. I'd start shopping for a 300D turbo to replace the 240D... the 240 is better suited to sea level, IMO!

#47 08-28-2005, 01:07 AM

Quote:

Originally Posted by gsxr

Only turbo cars have an ALDA, which adds extra fuel as boost pressure rises, matching the extra air with more fuel to make more power. Normally aspirated cars like the 240D do not have an ALDA, but they do have an ADA, which compensates for changes in elevation. I've heard you can fiddle with the ADA to maybe get a little change on the 240D but I have no first hand experience. On the ALDA, usually 1.0-1.5 turns works well if it was "virgin", meaning still factory sealed. No idea on the ADA.

All I can say is that at 5000', you're kind of screwed as far as power is concerned. Almost every car will have a pretty noticeable power loss at 5000' or above.

Even turbocharged cars are doggy until boost builds at high elevations. Supercharged cars would probably have the least power loss. I'd start shopping for a 300D turbo to replace the 240D... the 240 is better suited to sea level, IMO!

I have both a 300D turbo and a 240D at about 6000 feet. While the turbo doesn't win many drag races, the ALDA does affect the low rpm performance (and smoke) significantly. The ALDA is fairly sensitive to 1/4 or 1/2 turn adjustments.

On the other hand, the 240D loses drag races against kids on Big Wheels. I have adjusted the ADA and found it doesn't seen to have a big effect on either performance or smoke. I have turned it out a couple of turns from where it was set at sea level and noticed a modest improvement in power and very little change in smoke (but I'll take whatever I can get). Seriously, the 240D is fine as an "around town" car at higher elevations, but it is operating at its limit on the highway. It is happy up to about 75 on level ground, but it loses ground on anything more than a modest hill. If the traffic is moving along at 80-85 you start to feel like a roadblock. It works fine for what we need, but I wouldn't want it to be my only car.