Setting Turbo Boost with boost foolers

[ChrisCNC]

The Boost PSI that can be displayed on the Gryphon CTS comes from the MAP sensor, correct?

If I install a boost fooler so the MAP sensor always thinks I'm at or below 23 psi then the max I'll ever see on the display is that 23 psi (please correct me if I'm wrong).

So if someone wants to get an aftermarket wastegate like the Bighead or TurboMaster, then to accurately set these (like to above 24 psi) then you'll need a separate boost guage, correct? Otherwise you'll always top out at the top setting of the boost fooler and you'll have no real idea where you are at.

I guess I'm unclear on what PHP tunes are able to modify. Are the custom tunes able to prevent defueling at >23 psi boost? Does it take this portion of the logic over, or is that something that can only be handled with boost foolers and upgraded turbo's and wastegates.

I've got a boost fooler on it's way (Overboost Annihilator) and have been making up my mind between a turboMaster or a Bank BigHead wastegate controller but was looking down the road as to how I'm going to get the boost set in an acceptable range once it is installed.

That's a curiosity to me as well (maybe better in a separate thread) but if the information that the tunes gets regarding boost comes from the MAP Sensor then anything over ~23psi is going to be some extrapolated function anyway. But maybe this is well (enough) understood/estimated that it wouldn't really matter anyway. Would there be any real advantage to having accurate boost numbers above 23 psi for moderately modified trucks?

-Kevin
2003 F250 SD Crewcab, 7.3L FX4 4X4

[cj45lc]

All I know is there is no defueling with the tunes so I believe the OA is a waste of $$

BTW jmo but I saw no difference with the Banks Bighead except the lightness of my wallet...lol

[rammertide07]

Going much over 24-25psi on a GTP38 turbo is not good for them. Shortens the life substantially. I replaced my turbo about a year after I got my TS chip and boost fooler. I think the GTP38R can go to 36psi.

And I reccomend the TurboMaster. I would buy one, but they are pretty pricy right now and out of stock. When I go back home for the holidays, my dad has a bunch of metal rods and bars. He also has a machine mill and everything needed that I could make my own adjustable waste gate controller. May not be a good idea to try, but I have fun doing my own mods.

[cleatus12r]

The compressor of the stock turbocharger is "out of it's map" by the time you get up around 23-24 PSI anyway (and even less at higher elevation), but the MAP sensor is unable to identify boost levels above that number anyway. It's a 3 bar sensor (bar being a measurement of pressure) that identifies the first bar as vacuum (of which a diesel has none). So really, we're looking at a 0-5V, 2 bar sensor. The maximum that the sensor would be able to really identify would be 29 PSI, however, no 0-5V sensors actually put out 5V at max due to resistance and other voltage losses. Typically, you're looking at 4.3 to 4.5 volts. In addition, just the way the voltage is interpreted inside the PCM sometimes causes a lower boost reading as well.

It's really not that big of an issue since boost values really aren't that important in the grand scheme of things....it's just a "fun" gauge to watch when you don't care about fuel economy.

A "boost fooler" certainly won't hurt anything. If you've already got it on the way, I would use it. Set your maximum boost to 20-23 PSI and have fun.

[ChrisCNC]

Thanks for the information guys, that helps.

I know I tend to ramble and get off subject! But I am still unclear if I must have a secondary guage to set the boost range. I'm pretty sure I do, but would like someone to clarify.

CJ45lc I see you have secondary guages, I've only got the information displayed from the Gryphon CTS/Evolution CTS which I assume ultimately comes from the MAP sensor. If the MAP sensor is being fooled then my assumption is I have to have a secondary guage to accurately set the boost range.

RT, I looked hard at the turboMaster. I called and talked to the people there and they told me straight up that it will not work with an ATS Ported Shroud Compressor housing without modifying it (the housing). The ATS guys swear up and down that the ears on the housing are the same as stock, and that the Banks WG actuator will work 100% guaranteed and the T.M. should as well. I told this to the T.M. people and they laughed and said, "... do you think we made that up?" but that they'd be willing to work with me to tell me how to modify it. I do have a nice CNC machine that is quite capable of making sweet modifications...no grinding here!

Great information Cody, I appreciate it. I kinda assumed that accurate boost numbers must not be required, or overly useful. If the MAP sensor were upgraded to give you a bigger voltage range over reliable boost numbers it probably wouldn't change the tunes a great deal...just be more work for you

It's easy to get caught up in the whole mod thing and think you need to change something because it's easy and/or everyone else does it. I know I do! I don't want to leave any performance, "on the table", if it's there for the taking, but don't want to try to squeeze blood out of a grape either.

Thanks again guys!

-Kevin

[rammertide07]

Originally Posted by ChrisCNC

I do have a nice CNC machine that is quite capable of making sweet modifications...no grinding here!

I'm jealous. I've tried talking my dad into buying a CNC machine. But he's got a guy in Georgia, south of Atlanta, that has all the high tech CNC machines and a 3D printer.

[cleatus12r]

There have been a couple folks who have looked into going with an actual 3 or 4 bar MAP sensor and then scaling the voltage-to-PSI functions in the PCM to accurately reflect actual boost above 25 PSI. However, that really would only come into play with stupid-huge injectors that need an accurate boost-to-fuel relationship for good driveability under low boost conditions and then accurately control mid-and high boost fueling as to not "choke out the fire". For stock-ish trucks that make less than 500 HP and have stock-ish turbo setups, the stock MAP sensor gets the job done.

[ChrisCNC]

If I had more time, I'd like to make some mods but right now I'm buried (with CNC work). I'm planning on going to the local junk-yard and getting an F250 outside door handle so I can get a pattern to make some solid aluminum ones and then have them chromed. Plus like you mentioned, it'd be easy to make a wastegate that runs solely off of drive pressure like the T.M.. Lots of things but gotta keep the customers happy first!

-K

[ChrisCNC]

Cody,

That makes sense, I would assume that trying to nail daily driving with big injectors (and underpowered fuel pressure) would be a headache for you.

That kinda brings up a question for me, for a stock-ish truck (like mine for instance) of all the turbo's you've dealt with, is there a turbo or turbo mod (compressor wheel) that stands out to you as having a well matched boost map? maybe a particular combination of turbos and wastegates?
Or maybe to put it another way, it there a turbo setup on a stockish truck that you enjoy dealing with because its map range "just fits" the needs of the engine? (i.e., you look like a hero! ) If you were going to swap out a turbo, what ones would you be looking at...wastegated or not wastegated? maybe that's an issue for a separate thread...

Didn't you get a project truck a while back? What are your plans with that? I'd like to get a good 7.3 block and build it up over time, but with my tastes ($$$) the first thing I'd want are billet rods and they're EXPENSIVE. I keep wanting to do stuff to my truck but don't want to go much over 400HP simply because of the PM Rod issue. Got a friend here that went about 475 with forged rods and he perforated his block. On the other hand, my brother-in-law is over 500 with his truck (estimate) and he's got PMR. I don't have the cash to gamble like that...

-Kevin

[ChrisCNC]

Ever deal with these guys? pretty good sounding MAP sensor, at least on paper...

5 BAR / 75PSIa MAP Stainless Sensor Kit (30-2130-75) [30-2130-75] - $163.35 : Muscle Motors - AEM Power Distributor!, Got Muscle?