Boost level adjustment and MPG - PeachParts Mercedes-Benz Forum

JHZR2 · #1 01-08-2004, 10:04 PM

Hi,

I have been reading all of the archive about tweaking the boost, and then the ALDA as a result.
My ALDA has not been messed with. I get really good MPG, and my performance is fine for most all everyday use. There are a few short merges that Id like a bit more performance on. Since I know I dont get more than 9psi, Im thinking a dawes boost controller ought to help.

My question is, since the ALDA enriches the fuel quantity based upon boost, if I install a boost controller, will I be burning more fuel typically?

RIght now I have about 6psi at 70 mph, steady with cruise control on, driving along flat terrain. I assume the boost controller will do nothing to change that, and as a result, the amount of boost, and the amount of fuel used will be the same pre and post install.

In other words, the only time when the boost controller (and resulting ALDA fuel enrichment) will occur is at times when boost over the 9psi (max I currently get) is required or can be made. At that point, instead of spooling to only 9, Ill get 11, and thus more fuel, more power and better performance. But regular cruising, which typically only needs 6-7psi will remain the same, because theoretically my wastegate is only now venting at 8-9psi or so.

Am I right?
Thanks!

JMH

#2 01-08-2004, 11:15 PM

The ALDA only increases fuel for the off idle, low boost times. Such as starting at a stoplight.

If you increase the max boost it should not affect your crusing boost amount. It will help during merging, lane changing, passing, etc. It could increase your MPG as you can get up to speed, pass, etc quicker (You won't hold down the throttle as long.)

Anything over 12psi is just turned into heat unless you install an intercooler.

JHZR2 · #3 01-08-2004, 11:17 PM

OK, thanks for the replies... I am planning to either make my own with parts from mcmaster, or buy the dawes controller, and aim for 11 psi max. still conservative, but better than what I have. And, my wastegate spring wil last longer (not that it will matter!)
Thanks,

JMH