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.



Curtis
91' Turbo Z24
http://www.turboz24.com

throttle position, thus relying on only the position of the throttle to increase boost and not a specific gear.

same goes with both, you'd have to only be at a certain gear with certain position on throttle to see boost (and be under load)

I think this is what you mean by it.. am I right?

my choice; TPS.


<a href="http://www.cardomain.com/id/fireside"><img src="http://www.influx.ca/avatars/stevefiresig.jpg"></a>

Yeah, that's what I meant.

TPS is the easiest way for me too do it, just requires a little wire and a diode, that's all.



Curtis
91' Turbo Z24
http://www.turboz24.com

does that mean that controlling boost with the TPS would allow you to choose any gear?

Thus giving you a broader range in which to hit boost with?


<a href="http://www.cardomain.com/id/fireside"><img src="http://www.influx.ca/avatars/stevefiresig.jpg"></a>

Actually, if I did the boost control by the TPS, max boost would still be the same in all gears.

I do currently have a 2 stage control, which is embedded in the shifter and I think that if I keep that 2 stage there as well as the TPS control, that would probably do it.

So, you could run 2 maximum boost settings.

Well, it's too solve some street control issues. I find myself leaving the car in the garage more and more, simply because I don't want too have too deal with keeping the car under control. If I can do anything that makes the car more streetable, the better off I'll be.

I'm lowering the wastegate spring too 4 psi, still going too allow it too hit 10 psi on the street but only at WOT.




Curtis
91' Turbo Z24
http://www.turboz24.com

Well Curtis thats a nice problem to have, although I can understand your frustration.

I guess with a 6lb spring no matter how good of an EBC you're running you'll never be able to keep it below that hey?

with that 4lb spring at least the EBC can keep it there and not let it creep up.

are you using an EBC or an MBC?


<a href="http://www.cardomain.com/id/fireside"><img src="http://www.influx.ca/avatars/stevefiresig.jpg"></a>

My Haltech ECM controls the boost (it has a built in by rpm, which you use too reduce the boost threshold and it also has a 0-5 volt input for trim control, which it uses too adjust the boost from a minimum map too a maximum map), but the minimum boost on any setup is controlled by the wastegate spring.

I just want too make the car more drivable. 1/2 throttle will achieve full boost, so in reality, I have a narrow throttle movement in which too modulate the throttle too control boost. I'd rather have that done for me, and when I over accelerate and slip, just let off the throttle slightly and reduce the boost.



Curtis
91' Turbo Z24
http://www.turboz24.com

GM built in boost control works by rpm and tps. I don't think that's enough in a car that can easily break the tires free. In the Sunbird, Even with the table, I end up playing with the throttle in 1st and 2nd gear trying to find a happy medium. But in 3rd or 4th gear, I want full boost as soon as possible, and the lower values at lower tps settings only make me open the throttle more. It sounds like your car is similar in this way.

When I set up the calibration for the Cavalier I filled every entry in the desired boost vs tps table with the same value. I figure that I'm already choosing desired boost with the throttle, the table's redundant. I've been happy with the results so far.

Some of the Syclone guys set up desired boost vs mph and were happy. With AWD, there's much less chance of breaking the tires free. But if the tires spin, mph goes up and the desired boost increases at the same time. Not a good combination for traction.

The best route, imo, would be to set desired boost as high as possible then limit boost if front wheel speed was a bunch higher than rear wheel speed. But that would probably require more electronics than you have available. I think the second best route would be to link max boost to the selected gear. You're more likely to slip in lower gears, so lower desired boost in 1 and 2. Since you have a manual switch that can be used to trigger the second boost table, you can play with that for more acceleration if the tires seem to be hooking up on a particular day.

I could use my current dual circuit too allow the boost too be controlled in combination with the TPS, then switch directly back too non-TPS controlled setup. So, bascally, button off, voltage into the circuit is provided from the TPS, switch on, I simply feed 5 volts directly into a trimpot, still allowing me too manually adjust the boost, but without the influence of the TPS.



Curtis
91' Turbo Z24
http://www.turboz24.com

That sounds like it might work. A "table bypass" might be the answer. Now that you mention it, I could code the same type of thing into the Sunbird ecm very easily. Thanks.

-->Slow

you don't have to change any springs to change your max boost for your waste gate, if it is a internal wastegate anyway. I just loosened the nut on the actuator rod and made the rod longer by unscrewing it. This makes the boost lower.

Don't be a pussy pull the damn hose.

making the rod longer does lower the boost, yes but it also leaves the wastegate slightly open, increasing lag. Seeing as I don't have in internal wastegate, though there is no rod too loosen.....



Curtis
91' Turbo Z24
http://www.turboz24.com

bah, get a bigger turbo. itl be later coming on boost but itl be a bigger smile when it does & itl run lower charge and exaust temps.



99 Turbo Sunfire GT | Ram 2500 | International Rollback | Mr Hanky the Suburban

I'll just slap a T72 on there, since I already have a 60-1 T4 on there, then I'll get 10 psi at 5000 instead of 3000, it will still smoke the tires when it hits boost, just be slower on the track........



Curtis
91' Turbo Z24
http://www.turboz24.com

The way I see it, throttle position already will affect the speed of boost onset, and if you're not WOT, the RPMS really aren't going up rediculously fast.
I'd concentrate on using gears to control max pressure. I've heard of a lot of people doing that on other types of cars with very good results.


________________________________________________________
-Josh
<img src=>

Actually, 1/2 throttle and WOT are the same boost, so that's why I'm considering it. I do agree that gear would be nice too. I might try too link too the TPS (That requires only minimal wire changes, 1 wire to be exact), then see how it does. If it's not enough additional control, I can then do it by boost. I can also attempt too find a wastegate spring for lower than 4-6 psi too.



Curtis
91' Turbo Z24
http://www.turboz24.com