Without adjusting the fuel, I don't think you should go above 15psi...

 

what do you mean exactly, injectors.....??

 

I'm probably not right... as i've been known to blow an engine or three...
But i'll be upping the boost shortly. Running a wideband a/f and keeping a CLOSE eye on it. Once i reach the limit of the autothority chips, i have a piggyback (SMT6) that'll be put into use. Not sure where the stock injectors are gonna drop off... just going up a wee bit at a time. New injectors are on the list for the near future, too.

The manual boost controller I'm planning on using is basically the "Audi Boost Machine"... very similar to the one on autospeed.com .

I dont really have a goal PSI... I just keep getting used to the power that my cars make.


944 Fanatic- Ive read quite a bit about too much boost with the autothority chips... and i dont like walking home... thanks for the heads up!


Odd thing- i grew tired of shaking the DME relay to get it to work... so i fixed it today (resoldered, changed the diode, re Clark's Garage)... and now it's only making 14psi. Think it's just a fluke... wastegate spring is probably shot.

-Dan

 

Dan,
Does it make 14lbs consistantaly or does it make 15 then drop off? If it drops off it sounds like wastegate shims. Install them and you'll have even boost all the way to redline.

 

peaks, then drops off fast. Gets worse every day. Figure by the end of the weekend, at this rate, i'll have vacuum at redline
It was making 15psi up 'till a couple days ago... now it's only making 13psi. I really dont think the wastegate is holding. For that matter, i think the DV is shot, too. Going to test later today if i have time. Dont belive there to be any leaks after the turbo, but could very well be wrong. According to my ex wife, i'm always wrong... so...

It's also running richer today. Have steady vacuum (16) at idle, but havent ruled out vacuum leaks. Just SO many vacuum lines to look at...

Gonna search for what shims to use, now
-Dan

 

Speaking from experience, the autothority chips do NOT lean out at high rpm. If anything, they are rich, which is far safer.

 

If you were to look at several different APE chipped cars dyno runs which show the AFR I think you will see that the chips tend to go rich in the midrange rpms, right around where peak torque and generally peak boost occurs and then start to lean out as you approach redline and also as boost typically drops. It doesn't go too lean, it does lean out compared to midrange.

My experience with the APE stage II chips in my 86 951 was exactly this when running all stock injectors, fpr, air flow meter, but with a LBE set at 14 psi max instead of the banjo bolt. Car started fine ran strong and showed signs of running rich out the pipe, but the plugs looked only slightly rich. Later went to a manual boost controller, adjustable fuel pressure regulator and got essentially the same curve while running 16 psi max, i.e. the AFR was in the 10:1 range at peak torque and around 11.5:1 at redline using 42psi idle fuel pressure.

Don't raise the boost past what Autothority planned or mess with the wastegate or fpr without making sure you know what the resulting AFR is throughout the power band.

 

with the wideband a/f on the car, the LOWEST the a/f gets right now is 12.2:1... i wont even get into how rich it gets... but it's way up there. at-redline shifts, im pretty sure i could wipe out a good 10 car-lengths behind me, if there were a spark... some good fumes to ignite
Starts, runs and drives wonderfully. Part-throttle response is reasonable, off-idle is fine (i can slip off the clutch at idle and the car just drives away with no throttle), idles at 900rpm, smooth all the way to redline... but:

It's back to making 15psi, but not holding it... and the 15 isnt coming on as quickly as it was a few days ago (the part i REALLY miss). Starting to be a kinda tempermental car.
Seem to have a history of those... my last fun car would make clean 11 second 1/4 mile runs all day long, then not run right for an entire week... all of a sudden would come back to life and destroy the tires when just looking at the gas pedal... then the transmission would just up and explode. Fast, wild, and extremely tempermantal... I named that car "Keka" (my ex wife's name).

Luckily i love working on cars...

Going to shim the wastegate this weekend.
Hope to have the boost controller finished MAYBE by next weekend... have a couple parts on back-order. Mechanical, built-in overboost protection, adjustable boost curve (and spike), as well as overall boost... hopefully holding the overall boost at the set amount. Not a clue if it'll work right... just experimenting.

 

As a quick update... found a couple vacuum lines that have blown off. Replaced them and plan on replacing the rest of the vacuum lines shortly. Boost is holding at ~15psi, but it's still running quite rich. I have a nice black cloud behind me on boost. Reminds me of a turbo diesel. Still doesnt have the kick-in-the-*** feel it had when boost comes on, either... as the boost is building more gradual, rather than "BANG, all there at 3500rpm" like before.

No oil consumption to speak of. Replacing the cycling valve with a manual boost controller, and got a new saab DV (mine's shot) to put on tomorrow. Have yet to shim the wastegate, but know for sure it's not holding. That should help, i would imagine.

I'm also convinced that the designers were sadistic... pretty painful getting your hands in to do any work. Feel like i should be saying "Yes Mistress Olga", wearing black leather chaps and nipple clamps, as i reach around feeling for vacuum lines...