Turbo Boost fooler

Turbo Tim · **Posted:** Sun Apr 13, 2008 11:39 am

If the goal here is to get more boost, then you guys are at the wrong end of the horse.
Even if you “Tricked” the signal to the turbo, the ECU would get upset and still do something to make it run per it’s pre determined program.

To do it and keep the ECU happy, do what the trick boxes do. Just subtract a little bit of the signal from what the MAP sensor is telling the ECU. Of course you would have to have some electronics involved, but very doable. How much you “Tweek” the signal could get you into where you could damage the engine. (As for me, I would try it as I like lots of tire squealing).

Now you can see where just some more boost won’t do what you want, so then let’s trick the fuel pressure sensor as well to up how much the injectors squirt as well to get more power. This too can be done.

I could do it but for the time and money, just go buy a box for a couple of hundred bucks. They even include the wire harness connectors too….

nursecosmo · **Posted:** Sun Apr 13, 2008 12:03 pm

Turbo Tim wrote:

If the goal here is to get more boost, then you guys are at the wrong end of the horse.
Even if you “Tricked” the signal to the turbo, the ECU would get upset and still do something to make it run per it’s pre determined program.

To do it and keep the ECU happy, do what the trick boxes do. Just subtract a little bit of the signal from what the MAP sensor is telling the ECU. Of course you would have to have some electronics involved, but very doable. How much you “Tweek” the signal could get you into where you could damage the engine. (As for me, I would try it as I like lots of tire squealing).

Now you can see where just some more boost won’t do what you want, so then let’s trick the fuel pressure sensor as well to up how much the injectors squirt as well to get more power. This too can be done.

I could do it but for the time and money, just go buy a box for a couple of hundred bucks. They even include the wire harness connectors too….

I think Maxxgraphix's initial post was not asking for more power but rather more fuel economy. Either a slight overboost or less fuel delivered will accomplish that. The reason that a slight overboost will give an increase in economy is that the fuel map in the ECM is set to run just a little bit rich in order to keep NOx levels lowered. By fooling the MAP signal the engine runs with a slight surplus of O2, which is the way a diesel is supposed to run. The down side is the possibility of slightly increased EGTs.

05infernoCRDL · **Posted:** Sun Apr 13, 2008 12:43 pm

nursecosmo wrote:

I think Maxxgraphix's initial post was not asking for more power but rather more fuel economy. Either a slight overboost or less fuel delivered will accomplish that. The reason that a slight overboost will give an increase in economy is that the fuel map in the ECM is set to run just a little bit rich in order to keep NOx levels lowered. By fooling the MAP signal the engine runs with a slight surplus of O2, which is the way a diesel is supposed to run. The down side is the possibility of slightly increased EGTs.

our engines run lean most of the time anyways. i am not 100% sure on
this but i think gas engines run hot when they are lean and diesel engines
run cool when they are lean. but either way if you are going to start
messing with these types of things you need to have an EGT probe an a
boost gauge.

nursecosmo · **Posted:** Sun Apr 13, 2008 1:23 pm

Most, if not all modern diesels run a slightly rich ratio due to emissions restrictions. They run just under or right at stoichiometric which produces a good burn which doesn't make too much PM and uses up all available O2 thus depressing the production of NOx. The problem is that the burn is not as fast or as hot as it could be early in the combustion cycle, and if you remember Physics 101, heat=energy which =>mpg and HP if that heat can be changed to mechanical energy. There is also a small amount of energy obtained from the oxidation of N2. If too much O2 is added through more turbo compression then the gain in heat is offset by the mechanical loss of compressing the extra charge air and EGT may or may not increase depending on the particular exhaust and turbo configuration. Strangely too little air will also cause >EGTs because the burn is still continuing into the exhaust phase of the burn cycle.

Uffe · **Posted:** Sun Apr 13, 2008 4:23 pm

gmctd wrote:

The wastegate is a flapper-valve covering a hole inside the turbine housing, allowing a metered 'leak' around the turbine - WG control is that vacuum-operated cannister mentioned above^ - the vacuum pump is down front inside the engine and pumps steady 26"HG - ECM modulates a solenoid to apply variable vacuum to the WG controller, depending on engine requirement - ECM also modulates another solenoid to apply variable vacuum to the EGR valve - both are probably coordinated to react oppositely, as you have no AFC\TV to assisit EGR under Boost conditions - if you plug the EGR line, you get no EGR - if you plug the WG line, you get no Boost: that's a fail-safe - vacuum on the WG makes Boost, no vac = no Boost

You're right about the Boost guage indicating the life of your engine - even better is the EGT guage - even even better is Boost and EGT, combined

You are a wise man gmctd, and I enjoy your posts. It so happens that I do have both an EGT and a boost gauge. Problem is (according to my signature) is that I have a hard time getting my EGT probe installed because it uses a silly fitting. I think I have cracked it though, I'm going to get it installed next week, if time and my purchased tool allows.

Jury has decided to mount it AFTER the turbocharger, because of fear and complexity

Sir Sam · **Posted:** Sun Apr 13, 2008 4:25 pm

Uffe wrote:

gmctd wrote:

The wastegate is a flapper-valve covering a hole inside the turbine housing, allowing a metered 'leak' around the turbine - WG control is that vacuum-operated cannister mentioned above^ - the vacuum pump is down front inside the engine and pumps steady 26"HG - ECM modulates a solenoid to apply variable vacuum to the WG controller, depending on engine requirement - ECM also modulates another solenoid to apply variable vacuum to the EGR valve - both are probably coordinated to react oppositely, as you have no AFC\TV to assisit EGR under Boost conditions - if you plug the EGR line, you get no EGR - if you plug the WG line, you get no Boost: that's a fail-safe - vacuum on the WG makes Boost, no vac = no Boost

You're right about the Boost guage indicating the life of your engine - even better is the EGT guage - even even better is Boost and EGT, combined

You are a wise man gmctd, and I enjoy your posts. It so happens that I do have both an EGT and a boost gauge. Problem is (according to my signature) is that I have a hard time getting my EGT probe installed because it uses a silly fitting. I think I have cracked it though, I'm going to get it installed next week, if time and my purchased tool allows.

Jury has decided to mount it AFTER the turbocharger, because of fear and complexity

yes, much better to mount after turbo, no risk of metal shavings into the turbo.

warp2diesel · **Posted:** Mon Apr 14, 2008 6:13 pm

One thing that will improve your mileage is having the correct odometer reading.

Check this thread: http://www.lostjeeps.com/forum/phpBB3/vie ... 490#324490

Forget the air leaker, it is a waste of money.

Steve

Turbo Boost fooler

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