Boost Control Ideas

[TurboZ24]

So, which idea do you think is best for controlling boost.....

 

1. Link boost too throttle position, ie 1/2 throttle, half max boost (of course this really doesn't work below a certain throttle, but you get the idea).

 

2. Link boost too gear, ie boost level is simply dependent on which gear you are in, probably only 1st, 2nd, and 3rd+.

 

I also guess any combination is allowed too, but makes for more complication.

[Aaron]

What is wrong with a wastegate?

[TurboZ24]

It's a control issue. I do use a wastegate, but I also control that wastegate with an electronic controller (in my case, my Haltech ECM).

 

The goal is too make the car more controllable. By inputing additional controls, you end up with a variable boost. I want too vary the boost used, because 10 psi on my car is simply uncontrollable on the street below 65 mph and below 4th gear. I'm always having too watch, modulate the throttle too control the boost, etc.

[Aaron]

I see.

 

Lingenfelter was using a wastegate modulator on their twin turbo kits. It was intertwined with the traction control, and when the tires would slip, it'd basically cut boost, it'd drop more exhaust. But this system was probably uber expensive and A LOT of wiring. I would do it by gear. Use like 4lbs in 1st, 6 in 2nd, then go 10 from there on out. Optimal is where the tires are chriping, but not spinning, just a few barks as power strength increases. Have you thoguht about doing the suspension and putting some bigger wheels/tires on it? I'd do that first

[TurboZ24]

got the biggest tires I can fit, the best suspension that you could get, etc. I usually run competition/road racing tires or drag radials.

 

I've even considered doing it by road speed. I have a way I could do that using an ABS rear wheel bearing and use that signal too control the boost.

[z284pwr]

One question? How would this be setup as part of the Haltech or would this be different from the Haltech? Unless you have updated your Haltech I thought the older ones weren't capable of controlling boost by gear/road speed/throttle anyways? Unless there is a way by running the Haltech tunning by TPS and using that to limit the wastegate control?

[TurboZ24]

The Haltech I have does control boost, but by rpm only at the moment, but it does accept a 0-5 volt signal as the trim control. Hook the TPS too the trim control, and there you go.

 

Too do boost control by gear, I'd have too build a resistor asssembly too switch between various resistance values. I have a setup like that now, but it's a simple 2 stage setup (button off, runs one trim control, button on swithes too another trim). For road speed, I'd simply take an ABS wheel bearing on the rear axle, and adjust the A/C signal coming from the sensor too drive the trim input on the haltech.

[TurboGTU]

I like the switch with resister idea..but also a add a verisister(trimpod) to lower or increase the values of the resister network on the fly. Turn the knob down..2-6psi...turn it up...8-30psi. In your case..im sure even 5 psi is smoking them on the streets.

 

So this would be by gear. But in your case...I would perfer is you get a new electronic boost controller that adjust boost like the TGP..RPM, TPS, MPH.

 

Another thing is if theres an input for spark retard..you can use that to controll traction. For years racers retard the timming when they have problems with traction. Have you looked into that.

 

Besides that...I have to check your car out in person! 8)

[skalor]

I wanted to build a low boost circuit in my TGP. I have an extra TGP boost control solenoid and I was going to wire it to a switch so that I can have it open on launch(~4psi) and then flip the switch to get the computer controlled 11 psi. I was even thinking of getting the t-handle shifter with the built in switch. I would think that you would want it based on MPH more than anything else. TPS is still going to limit your throttle angle so your not really gaining anything there.

 

If you retard the timing, doesn't it make the turbo spool faster??

[TurboZ24]

Well, on the TPS related one, basically anything over 1/2 throttle is full boost and ends up pretty much being full power for me, so it would improve the control over boost with the throttle.

 

I do have trimpots on the current dual boost setup, yeah so you can adjust them without the use of the laptop.

 

Yeah, all the boost controller has built in is by rpm and that's pretty much only there too help reduce boost threshold. I can easily add the TPS as stated, though.

 

As for ignition retard, yes I can do that also. The trim control can be used for boost, ignition, fuel, as well as several other features, but only one of those features.

 

Oh, but ignition isn't the best way too really reduce the power much at all. Back when I had ignition problems, running in DIS limp home mode (10 degrees advance), the car ran a 12.87, running with the timing on, ran a 12.49, so, not a lot of difference.

[TurboGTU]

Whats your lowest boost setting?..like actuator connected stright to turbo? And at that boost..do you still have problems with traction? Might want to use a lighter acutuator spring like 3-4psi.

 

Skalor..it does make it spool faster..but the engine isn't ingniting at the "power" making degree. It will still produce a lower tq number. 10 degrees is what the Turbo fords have stock..LG5s are at 9.14*. Might want to step it down to 2-5*.

Dang You just have too much power. Even at 140hp..1st is letting them loose as well as a little of 2nd.

[TurboZ24]

The lowest boost setting is currently 6 psi, but I will be reducing it too a 4 psi spring. 4 psi is still enough too spin pretty hard, so...

 

the only real issue with using low timing long term is the effect it has on the piping and turbine housing. it runs really hot when you retard the timing a lot.

 

I'm actually considering working on the car/motor a little more, then possibly pulling the setup, putting in a milder setup, and maybe getting a kit car for the wilder engine I currently have in the Cav, something RWD and with a wide range of trannies too use.