Turbo Cheater? Increasing MPG

[K73]

OK, so I'm new member, but have been browsing and using the forum for some time now.

My Truck:
2001 F250 4x4
crew cab short bed
2" lift, 35" tires, BD 80hp chip, K&N Filter

My Question:

So while drinking a few beers at a family event this past weekend someone mentioned what he called a "Turbo Cheater". As he explained, it is a DIY mod to change when the turbo would kick in. As most know the magic number for most PSDs seems to be around 2000rpm. This mod would effectively increase the rpm needed to activate the turbo. I could not entirely follow his entire explanation as I think the beers were effecting his speech. But it sounded like there is an intake or vacuum line that can be reduced in size or disconnected. It sounded very simple, but this was the first I had heard of it and I have not been able to find any information on it.

So has anyone heard of this or something similar?

A second question along a similar line... Is there any mods that can be made to turn off the turbo while at cruise speeds? I typically like to run 75mph down the interstate, which is right at 2000-2100 rpm. Of course this is when I can hear the turbo kick on and off, so to avoid this I slow down to 70-72mph. But as soon as I hit a small grade or hill, the turbo kicks in to keep the speed up.

[Clay Henry]

to Powerstroke.org!

[Marty]

Maybe he's talking about d/c the wastegate or BP valve!?

[djsdiesel]

First question why would you want to turn the turbo off? (No possible way unless you take it off the engine or get fancy and make a dump for the exhaust before the turbo) The turbo is spinning anytime the engine is running. The turbo supplies air to the engine, not enough air would mean less power and lower mpg's. Since there would not be enough air to burn the fuel, meaning burning more fuel and creating high temperatures. You want the turbo to be building boost. If you want to see whats it like just go take off the intercooler tube and try driving it. You won't make it over 45 mph and it will take you a mile to get there. Cruising at 75 mph you should be around 6-7 psi of boost. under hard accel w/o chip you should max out around 17 psi. cruising in town should be around 1-2 psi. The exhaust from the engine goes through the turbo (impeller) in turn spinning the compressor wheel (they are connected by a shaft) which forces air into the engine. THE PSD IS A TURBO DIESEL. Built to run with a turbo. If anything you want your turbo to come in faster and build more boost.

[K73]

OK, so I used a poor choice of words. Maybe not turn it off, but change when it will kick in. If you read the first question I posted it was about some modification to effectively change when the turbo would really kick it.

And again, I have never heard of this type of modification and I'm not even sure if this is possible or just someone's fantasy. That is why I asked the question.

[djsdiesel]

Wasn't trying to make you feel bad or anything, if anything you want your turbo to come in sooner not later.

[slammedSI]

Originally Posted by K73

OK, so I used a poor choice of words. Maybe not turn it off, but change when it will kick in. If you read the first question I posted it was about some modification to effectively change when the turbo would really kick it.

And again, I have never heard of this type of modification and I'm not even sure if this is possible or just someone's fantasy. That is why I asked the question.

I personaly i havent seen or herd of this mod, I know if you unplug the wastgate it will make more boost sooner i think. Also doing bigger exhaust will make the boost come in sooner. With less EGT's. What part of Austin are you in?, Im in Pflugerville off 35 and pecan (1825)

[ABOBB]

I think the mod he may be talking about would be something to restrict map sensor line. Those of us who unhook our wastegates for more power know about using a map fooler, to keep our engines from defueling when overboost conditions occur. However... I have heard that it is possible to see a gain in hp when power is not necesary by disconnecting, or blocking the map sensor line. This would keep the computer from adding fuel when the boost rises.. thus using less fuel. Would not be doable for any type of power necesary situation, but just cruising around town.. it might increase mpg. I suppose it could be done using a remote valve of some sort.. so that the map sensor line could be closed off when power is not needed.

[K73]

Originally Posted by djsdiesel

Wasn't trying to make you feel bad or anything, if anything you want your turbo to come in sooner not later.

Don't think anything of it, my skin is much thicker than that. Just wanted everyone to know my intentions as far as what I'm looking for. Since the day I bought the truck back in Nov 2000, I have been completely happy with all aspects (including towing and acceleration). However, I would like to improve the fuel economy and that is why I added the K&N and BD chip. Both offer good bang for the buck.

But I always have my ears and eyes open for any inexpensive solutions to improving fuel economy. I've considered many mods and upgrades, but most are rather expensive and other than increasing range per tank of fuel, offer no real benefit to the overall budget.

Originally Posted by slammedSI

I personaly i havent seen or herd of this mod, I know if you unplug the wastgate it will make more boost sooner i think. Also doing bigger exhaust will make the boost come in sooner. With less EGT's. What part of Austin are you in?, Im in Pflugerville off 35 and pecan (1825)

I'm actually just inside Cedar Park, off of Anderson Mill and Old Mill (just north of 620).

[pipelayerjdh]

Sounds like a boost controller to me. Or maybe changing the wastgate spring.