Hey guys looking for a little help with all this boost control stuff. What's the majority of people using? Boost vs speed, time, gear, rpm, manual?? I've read the Holley manual a bunch of times already and still having a little trouble wrapping my head around it all.

I've been thinking of using either boost vs speed or rpm just to get a feel for how everything works. I've looked up videos and they all seem to be the same boost vs time with a trans brake drag racing guy.

If anybody knows a procedure for testing things out without having to turn the engine on that would be greatly appreciated.

Car is a 91 z28 with a forged 370, vs racing t6 80mm turbo, vs racing 50mm wastegate a2a intercooler, mixed pump gas 102 octane, MWC fab 9". I do drive it on the street a bunch and not strictly racing. On the spring I was hitting 7.5 psi of boost but want to start turning things up

Thanks for any kind of help guys and I can upload my tune if it's needed for anything

 

without the engine on you wont be able to see what boost is doing, but you could test that its 'trying' by feeding compressed air into the up solenoid then map boost to tps. that lets you drive the target boost by moving the tps.
for getting started in this sort of situation i like to set a flat boost curve and datalog some pulls to dial in the base tables and correction. for instance im doing the same in my car now, i have a boost curve selection switch set at 8, 12, 16 psi and i make short pulls at the different levels then go back and tweak my bcs tables so the ecu and engine are doing what they are told. once you get there, you can be confident that it will make whatever boost you want it to without too many surprises. this also lets you ease into the higher boost portions of your fuel table
boost vs time, speed, rpm is going to be driven by your combo and use of the car.
good luck.

 

Okay right on. Thanks for that info. I'll give it a shot. I'm sure once I see how things work together it will all make more sense. Thanks again have fun

 

Drag racing is going to be race time vs boost/dome.
For just street use I tend to dial things in with front wheel speed vs boost.

 

Front wheel speed?? What's the gain of using front wheel speed instead of the speed input from the transmission?? In case of wheel spin?? Good info to know. Keep it coming guys. Thanks a bunch

 

What trans are you using?

Andrew

 

I'm using a 4l80e, 3.25 rear gear

 

I would do boost by gear for a street car.

Andrew

 

spin the tires and boost goes up like that. front wheel speed decouples the boost control from traction

 

Okay perfect I'll try it out and see how it goes. Thanks

Gotcha. Maybe I'll try out boost by gear and see how that goes before I wire in a speed sensor up front. Thanks

 

What's your plan, make as much power as possible without having to feather the gas all the time? What tire are you on?

 

Kind of yea but I'll save max power for the dyno. I'm running a MT drag radial 275/40-17

 

Correct, it will give you a real vehicle speed without having tire spin be a factor. Plus then you can do all sorts of fancy traction control type things if you have front and rear wheel speeds. I've never been a fan of the boost by gear in the holley due to how it detects gear shifts and at that point it's still timer based in each gear.

 

If the holley is controlling the transmission it doesn't have to detect the gear change, it knows when it happens. I really like the boost by rpm or the boost by speed for the street.

I believe boost by rpm is also by gear, or did I imagine that? Don't have my laptop rn

 

Nope you didn't imagine that they're pretty much the same thing

 

IIRC boost by gear is time based, but boost by rpm is gear based. On the street I really like the boost by rpm by gear, but the boost by speed works fine also. Having it on a front sensor will help dial in traction.

 

Yea the boost by rpm seems to be the winner on the street. That's what I'm gonna play with to get a feeling for everything

 

Boost vs time is your best bet at the race track, street driving that's debatable

 

You can switch back and forth between any of the strategies with a single click and not loose any of the configuration under each strategy, so it is very simple and harmless to play with them at will

if you have access to front wheel speed it is a no brainer on the street to utilize it.

If you aren’t using a front wheel speed reference, if you break traction it is still going to pile more and more power in by time, rpm ect

 

Does anybody know if the PID settings that are set out of the box are any good P 10, I 30, D 0??

I haven't been getting any boost fill solenoid response and I'm seeing my vent solenoid at 100% duty cycle.

I am using the booost vs speed as it seems the easiest right now but I'm still using the PID settings the controller 10,30,0.

It's getting late and I'm gonna call it a night but in the morning I'll lower those settings a whole bunch and see how that treats me