I wanted a tech thread to see how many people are running the Greddy Profec B and what your settings are. I think this is good to info for newbies that get them. I will go first...

Low Boost -
Initial % turned to 50%
Gain is 13%
Set Gain is .60
Warning is 1.3bar
Pull Back is 20%

I make about 1.0bar with this. I dont do a high boost setting as I can just turn the dial up to 70%.

Next....

 

Low Boost - 1.1 bars MY CAR
Initial % turned to 34%
Set Gain is 32%
Warning is 1.3bar
Pull Back is 10%
If I set gain 10% the car is sluggish....


I did notice that on k24/18gs 47% is about 1.3 bars...

 

yeah for a K24/18G we did the % at about 20 to keep it at 1.0bar as that is best for K24/18G.

 

well I must admit I have one with Protomotive hybrid k24's. my max boost runs at 1.18.
I dont have a clue what those setting mean however.
I thought it was just going to be a **** and I turn it to what boost I want.
but seems more like a guessing game, you make some setting and then see what boost results? should be a more direct way, to non gear heads settings dont seem to directly correlate with a boost number so ah...........

 

Tom,

That is how the Greddy works and I found it odd at first too, but after some time with it, setting it becomes second nature. Once you get that initial % setting dialed in (start low, like at 30% and increase 2-3 points at a time), you can then easily adjust the boost either way by changing the percent just a few points up or down. But you do have to monitor your new percentage setting for a few pulls each time you re-set it, to see the actual difference and then decide if you want to go a little more, a little less or keep it where it is.

There is an HKS EBC unit that came out last year that has a feature where you set the "target" boost and it is supposed to do what is required to achieve and maintain that target level. It also has a programmable code to lock the settings and some other useful features. Seems like a nice system and I have been meaning to ask Todd at Proto what he thinks of it and find out if it is a worthy replacement of the Greddy, as it would make setting much easier and very simple.

My settings are as follows:

Set: 45% (but this varies a little with outside air temperature)
Gain: 20%
Set gain: .85
Warning: 1.30
Limiter: 20%
Last Boost: "on"

 

Has anyone GPS datalogged the difference that these settings make? I would not look at the speed vs time numbers themselves but rather torque curves (read long Gs) overlayed on each other ...and... the performance numbers as well of course.

Markski the difference for the K24/18G must be due to the spring used in the WG rather than the turbo I guess.

 

Jean,

These cars are all extremely different. Vivid has the K24/18G - 600 level (without fuel), Mark has a custom build with huge turbos and I have the K24/18G with fuel - 700 level. Tom has a 600 level. So the three people reporting settings have very different cars...Since Marks car is one of a kind, his settings are probably unique to his vehicle. The K24/18G Greddy setting listing should probably include a fuel or no fuel note and be viewed with that in mind...

I have not GPS recorded any settings, but I will say that by seat of the pants, it's impossible for me to feel any difference when changing the "gain" and "set gain" settings. The initial "set" percentage has the most dramatic affect, as it directly increases or decreases boost and it is still difficult for me to feel .1 bar of boost difference.

For those of you that are interested...the gain is used to adjust boost consistency, so you have to watch your boost and if it spikes you lower the gain and if it falls off you raise the gain setting until you have steady, even boost readings on the display - then you leave it alone. The "set gain" adjusts boost response i.e. spool up response, but I have been unable to feel any difference having tried a number of settings. It is supposed to be set near the initial % setting, but not too close, as that can cause spikes...so again, you have to play with it. It is a little bit of work to get this set up, but once it is, you don't have to adjust it any more...other than overall boost for race fuel, cold weather, etc. and that is relatively easy.

 

Excellent post John. It's a good thing that adjusting the gain seems to make little difference. This indicates that the wastegates are relatively easy to control and thus there is little variability throughout the range of rpm/boost/flow/power/temp/etc. The spring is well matched to the boost level, the WG gas exit design is efficient, there is little variation in exhaust back pressure, etc. Some WG setups are really tricky to control and it is usually a function of what is happening after the gas exits the WG door although inlet factors also play a role, especially in external WG designs. It is so nice that we do not have to deal with boost spikes!

 

John

What I meant in my comment to Markski is that the boost level you reach when you dial in the set xx%s, it is an increase over the base spring in the wastegaste, therefore if you have a 0.7 bar spring in there, 30% will mean 0.9 Bar or close to it. This is irrelevant of the engine setup or the turbo brand, at least this is my understanding. So depending on what the spring is in the K24/18G WG, your set xx% will give different people different max. boost readings. How fast or how slow you get to that peak boost is what the other settings will give you.

As to comparing different cars , you are right, and certainly it is not meaningful, what I meant is that all these settings, unless they have been datalogged (while making sure no spikes etc..) you cannot tell simply by seat of the pants, what works best, which is in line with your observations. Therefore it is a must to datalog your runs very carefully if you want to know what is working best... Long G curves on the datalogger can be read the same way as a torque curve on the dyno, so the value of these tests is great if they are done, like everything else, the right way.

 

Actually, Todd, Bobby, and I did a bunch of testing with the set gain on my car... and found out that the car responds better better with the "set gain" turned up to 28-32% ...
when I had it at 10% my car was sluggish... so I went into my EVo8 and tried to do what I did to my Porsche... I changed the value form 10% to 20 then 25 and finally 32 %... and I found the Evo to do the opposite of the Porsche... it became more sluggish....
I really dont know why but thats what happens... so my evo is at 10% and and the P car at 32% for set gain...
mark

 

I made a correction on my first post. The settings go: gain, set gain, warning, pull back, peak. Then there is also the first dial turn which cranks up the boost. The set gain is when you want the wastegates to open. The gain is how strong you want the boost to come on.

 

thanks John, but it still seems weird. you play with the settings, dont know what you get and then do pulls to find out where you are? There should be a better way but I am sure if I understand how this thing worked they must have made it this way for a reason?

 

Tom,

I fully agree...it's a strange way to make and determine the effects of an adjustment. I am not sure why it's that way, either. I like the idea of the HKS unit, where you set the desired boost and the electronics make it happen, but I'm all dialed in now and I have the custom CF mounting plate, so there is no reason to change...

 

Mark, I think the reason for the disparity is the fact that the Evo is single turbo and the Porsche is TT, the air volumes (vaccum signal) that the selenoid valve of the Greddy has to handle is double that of the single set up, also to add to this, the vaccum lines are far longer, so the gates take a little time more to react, what I use best for these TT applications is the Blitz type controller, it has a double selenoid arrangement to take care of that extra volume, the TurboSmart 2 controller also works great.,cheers.

 

Sonny,

can we get some info on your beast?

Jag