"$^£" boost controllers area all rubbish

WHY THE BLOODY HELL DOES MY SBC-ID BOOST CONTROLLER NOT GIVE A REPETETIVELY ACCURATE BOOST?????

I really seem to be ranting a lot more nowadays. Must be getting old....

My sbc-id has never been able to give me a repetetive consistane boost figure. It really is a useless piece of junk. I may be a little forward in saying this, but I think all comercially available boost controllers may be the same too.

I have a theory behind this, and I'm hoping someone is going to tell me that I'm wrong, and tell me that JPS simply installed it wrong (as they did many other parts.... another story)

SO I set the controller to a SET of 50 and a GAIN of 25 this morning. I get 15.7 psi. (I'm targetting 16 dead - just a number, no real reason why) I afjust the SET to 53. I get 16.4. I then tune it down in three stages back to a SET of 50. I get 16.0. Interesting.

This evening I get in the car, with the same settings, SET of 50, GAIN of 25, and I get 16.5. WTF.

Also another little insight is the readout. How come, no matter how hot my car is, no matter how cold the winters day is, when I key on, I get 0psi? Surely it will change depending on temperature. Why does it feel the need to reset it's zero point every time? Is this why I can never get it give a consistant boost figure? Perhaps the pressure in the plenum is the same each time but the readout's zero point changes on each key on? But then I can leave the unit completely alone, and hit three different boost values without keying off? WTF???

I think I'm going to sell it and revert to letting my AEM control boost. It seems to make a much better job of it whilst at the same time runnning all the functions needed to make the engine work.

Any suggestions??

cant help you on your problem mate but after doing a bit of research on the subject of boost controllers i got a greddy profec b it has absolutely no bells and whistles no digital display nothing, it does however do everything it sez on the can- it controls boost absolutely spot on- and is a piece of piss to set up with 3 nobs, gain, low boost and high boost

seems odd Tony,

My sbc-id hits spot on every time.

how long are your pipe runs to the solonoid? sounds daft but have you checked the all the pipes have good connection.

I had a pin hole in the plastic pipe from the control unit, took ages to find & boost was all over the place.

Hmm I'm not so sure it's odd.

I think the problem stems from the boost controllers don't know the intake air temps, so they don't adjust for it....not sure this gated one can either...might be something that only your AEM built in controller can take note of?? Also it's probably down to the unavoidably shit wastegate on the stock setup...it's too small and so air density probably pushes it over the edge IYSWIM.

Can you photograph your setup this may help decide if it's an installation issue.

Cheers chaps.

It certainly shouldn't be an installation issue. The boys at JPS fitted it. I was quick to sing their praises when I picked the car up from them 18 months ago, maybe I should have held my tongue....

I'll take some pics when I get chance, probably this weekend now that I can't make JAE.

Also just to add, I've actually taken to running with the controller turned off, so it's just running on the wastegate actuator. Holds boost fine at 14.7 psi.

I think I'm going to sell it

Not on this forum after that rant LOL

Anyway. My hybrids used to vary between 1.25 and 1.4bar of boost no matter what I did. The wastegate was overwhelmed. Even with a restrictor ring in I think that pulsing the wastegate to control boost was inaccurate given the limits of the stock wastegate - it simply couldn't respond fast enough or make enough of a difference when it did. I too slated my (Apexi AVCr) boost controller back then, if there was a shop it'd be all over it.

Now I have a slightly bigger wastegate it's pretty good. It has a fuzzy logic stylee thang where it uses feedback from it's pressure sensor to try and maintain the required boost level. Sometimes the atmospheric differences throw it beyond it's ability to compensate but usually it's spot on. I've got datalogs of it holding between 1.18 to 1.21 bar of boost across a sustained 5th gear blat. Can't argue with +/- 0.02bar

My boost buildup does seem to tail off over 1bar though, is there some setting like 'feedback' I can fiddle with to make it acheive full boost faster?

-Ian

If it resets to 0 on the peak showing you have prob got auto-peak set and need to turn it off.

Also a gain of 25 is VERY high, I run 5 on my GTR and ran about 12 on the Supra, blitz themselves say between the range of 5-15.................

Not on this forum after that rant LOL

No honestly it works a peach

Gain of 12 huh? Hmmm maybe I'll give that a try.

I can't see it beng largely due to the wastegate, after all I'm asking for only 1 psi over what the wastegate will give me (reliably too) with the unit turned off, and I've still got the 1st cat in so not flowing massive amounts.

Can't remember exactly mate, but it wasn't above the Blitz recommendation of 5-15.......

Give it a try, it could be because they are spooling up too fast which is what that would do?

Blitz have reccomneded Gain settings on the inseide back page iirc- think it should be 5 btw.

Blitz manual says between 5-15 as I said mate