AGP wastegate w/o boost control

[strangelove]

Well I've got this AGP Wastegate just sitting here looking at me and I can't decide if I want a boost controller or a boost gauge. I like the idea of keeping the car looking as stock as possible and I'm not looking forward to running wires and gauges into the cab. So how can I install the new wastegate and adjust it manually without using a bc or bg. Meangreen mentioned that I should set it at 13 PSI any more would give me partial throttle boost. So if I loosen the arm on the wastegate that should give me 12 to 13 PSI of boost until the wastegate actuates and releases boost, right? Then from there I could increase boost be adjusting the wastegate arm as needed.

[SR-PT4]

If you're going to start playing with boost using an adjustable wastegate or a boost controller, you absolutely positively without a doubt MUST have a boost gauge. Without the boost gauge you will have no clue, not the slightest idea, how much boost you are making. Without a boost gauge you really only have two settings: 1)motor did not blow up, 2)motor blew up

Every motor is slightly different, by just enough, that any recommendation for a starting point setting is just that. But you MUST monitor it closely, and you can only do that with a boost gauge. In all honesty, it was really stupid of Chrysler to sell a turbo car without a boost gauge.

[Mean Green]

Yes, I said to set the agp wga at 13, BUT you need a dual stage boost controller to deal with the bad PTB you will get without one. 1st stage of the bc set at 15 = no PTB in any gear. 2nd stage of the bc set at 18. On the 2nd stage of the bc you will get bad PTB in 1st and 2nd gears so you don't want to switch to the 2nd stage of the bc until you are in 3rd gear. SR-PT4 is right. You stand an excellent chance of blowing your motor without a boost gauge. [xx(]

[strangelove]

Thanks for the heads up, guess I'll have to just sit and admire my wastegate for a while, until I get a BC and BG, then it will be[8)]

[love bandit2]

quote:Originally posted by Mean Green

Yes, I said to set the agp wga at 13, BUT you need a dual stage boost controller to deal with the bad PTB you will get without one. 1st stage of the bc set at 15 = no PTB in any gear. 2nd stage of the bc set at 18. On the 2nd stage of the bc you will get bad PTB in 1st and 2nd gears so you don't want to switch to the 2nd stage of the bc until you are in 3rd gear. SR-PT4 is right. You stand an excellent chance of blowing your motor without a boost gauge. [xx(]

whats "PTB"???

[hharper1321]

PTB or PTOB is Part Throttle Overboost. In other words, you depress the throttle halfway, suddenly you're at full boost. Sounds fun right? Possible side effects include - leaning out the motor because enough fuel is not being fed for full boost, blowing motor up from said lean condition, non driveability, and general feelings of malaise. Cures: a dual stage Boost controller, and electronic boost controller, going big turbo, throwing the AGP WGA on Ebay and getting an S2 WGA and letting the PCM control boost, or adopting the style of driving like a granny with an egg under your right foot, or going WOT all the time, but no in between....either way, GET A BOOST GAUGE!

[love bandit2]

why would that lean the motor out? are these cars speed density?? Wouldn't the mass air meter tell the computer to compensate for the added airflow into the engine??

[hharper1321]

Our cars have pretty small turbos, hence our nice wide torque band that starts at a low, "street-friendly" RPM. Actually, we can generate boost so shortly after idle it's ridiculous! The problem is, if you try to bypass the factory boost control (like you HAVE to do with an AGP WGA) and start asking the turbo to make whatever boost you want, it will be able to make lots of boost during part-throttle operation, but the engine will not be able to use nearly the amount of air that the turbo is trying to cram into it. What happens? Two things.......First, the engine can't supply enough fuel for the air being forced in, so you go lean. Trip the knock sensor, have timing cut. Hopefully. Worst case you go "BOOM". You'll also notice a fluttering sound. Cool, kinda like 2F2F, right? Wrong, that "fluttering" noise that people talk about is actually the mass of air slamming into your closed throttle plate when you let off and then rebounding and slamming the compressor wheel back into the housing, causing the turbo to stall. Naturally, this places very large stresses on the bearings and wheels until the air is exhausted by the recirculating or blow off valve. Like I said, the cure is, maintain PCM control of boost with a Stage 2 WGA, or go big turbo. Or, do what a lot of people do, go with an AGP WGA, make max power on the stock turbo, but re learn how to drive, knowing you control the fate of your motor with your right foot. Don't sneeze while granny accelerating, though!! [}]

[love bandit2]

ok, so if I got the stage 2 WGA, wouldn't I also need the S2 computer?? I know they don't make a stage 2 kit for PT Cruisers, so could you tell me how this is all set up?

[hharper1321]

You should really become a member of pt-c-r-e-w.com (take out dashes, or just click on my homepage button above here). They have a Mod Bible section with the GT upgrade path spelled out in easy to under stand plain english, and several threads on installing and tuning various WGA's. That way, I don't have to repeat it here verbatim. Not trying to be a dick, it's just a lot of typing! With an S2 WGA, you would just replace the OEM WGA with the S2, and tune it. It's not quite that easy, because the S2 is a bitch to tune, but, once it's right, you can spike 17-18psi and hold 14-15 at redline, with no PTB issues, and all your PCM protection in place. Anything over 18psi, you want to think about adding fuel....Of course, the Stage 1 computer should be your first mod, as it's the base for everything that comes after.....And you are right, although promised, there is NO Stage 2 PCM for the PT, and SRT PCM's WILL NOT function correctly.