Boosting the efficiency of a tubocharger

[gil]

Turbo compound, Nice.
That will definitely improve your MPGs.

[oil pan 4]

I got the T76 in and it will fit where I want it to.
Now all thats left is the fancey plumbing work.

[oil pan 4]

The second turbocharger is in, now for the testing.

[ever_green]

with my Acura RDX, i just played with the ECU...I only get 7 psi of boost now vs 14 peak to better match the efficiency map. I don't have the map for it but it looks something like this:



This way i can also run stoich (leaner now) until 3500rpm. Stock car used to enrich mixture depending on how much boost. Ignition has been advanced but that's on the engine side not the turbo. I saw no reason to change out the turbo though, because the stock turbo is pretty good with the variable gemetry design and all. overall though if it was up to me, i would totally just avoid turbochargers. Toyota experimented with that for the toyota prius and in the end they decided to go the NA route.

[gil]

Originally Posted by ever_green

with my Acura RDX, i just played with the ECU...I only get 7 psi of boost now vs 14 peak to better match the efficiency map. I don't have the map for it but it looks something like this:



This way i can also run stoich (leaner now) until 3500rpm. Stock car used to enrich mixture depending on how much boost. Ignition has been advanced but that's on the engine side not the turbo. I saw no reason to change out the turbo though, because the stock turbo is pretty good with the variable gemetry design and all. overall though if it was up to me, i would totally just avoid turbochargers. Toyota experimented with that for the toyota prius and in the end they decided to go the NA route.

Do you have any Before and after MPG comparison? I noticed you only have one entry for the fuel economy log. I like your thinking of just lowering the boost.



This Article in Autospeed.com about Turboing a Prius is quite intriguing.
He did see a benefit from the small turbo.

AutoSpeed - The Story of Turbo'ing a Hybrid Prius, Part 1

[gil]

AutoSpeed - The Story of Turbo'ing a Hybrid Prius, Part 2

AutoSpeed - The Story of Turbo'ing a Hybrid Prius, Part 3

AutoSpeed - The Story of Turbo'ing a Hybrid Prius, Part 4

AutoSpeed - The Story of Turbo'ing a Hybrid Prius, Part 5

[ever_green]

Yes i did keep logs on paper and recipts. I will have to organize them and post on fuelly. Overall mpg improved a lot in city but not much in low traffic highway situations. The biggest problem i face on highway cruising is higher loads due to the all wheel drive and 4000lbs weight. Im thinking maybe a psi or two of boost might help during cruise. We'll have to see.

[oil pan 4]

Well the second turbo hasn't effected milage that much.
But the intercooler isn't getting much air flow over it at the moment and in my haste I relocated the air cleaner from where it was drawing cool air to where it draws under hood air.
Giving the air cleaner rammed air and more flow over the intercooler should help MPGs.

[oil pan 4]

It looks like the second turbo and intercooler has improved fuel milage a little bit.
Even with worse cross winds it looks like fuel milage is about 1/2 mpg better over the same up hill 200mile drive.
Testing conditions are so much more consistant on the east coast.

Also the air cleaner is drawing hot under hood air, where the single turbo setup was getting cool air. Diesels like cold air intakes, so long as the intake air is above freezing.