Has anyone been able to hold steady boost at over 22 psi? I've tried to get one to hold at 30 psi but it didn't work out.

 

hello

I installed GM 3port boost controll solenoid ( GM Part # 1997152 ) . I didnt use any any resistor in the cable and didnt have boost pill just simple vacum lines . Zero out my error correction table and used the Merlin book posted flat 22 psi wastegate duty cycle setting but the boost was fluctuate and I had only 19.5psi tappered to 16.8psi Evo 8 engine with the 9 turbo stock igniton and fuel map now. Why are my boost fluctate and didnt get 22psi ?!

With an other 3port boost solenoid I had 27,5psi tappered to 18.5psi @ 7000rpm with 100duty clyle from 4600rpm. Than I think that maybe because the solenoid I have no more boost than 18-19psi @ higher rpm but with the gm 3 port dont know what is the problem ? When increase my wastege duty cycle with the gm 3port over the merlin 22psi flat setting with 10 I got 17.5 psi at high rev.

I dont know why but with correct desired engine load and boost adder setting I coud log always 63.5 wgdc correction and 19.5 load error Never change same value with zero out error correction too ! ( example my boost desired engine load and boost adder settings 280 and the logged 1byte tephra load is 280 too )

Maybe something with the turbo ?! but no smoke or oil and I coud set high boost @ 3500rpm like ~27.5 psi only from 4500rpm I can not hold so much...


The log :

http://rapidshare.com/files/405568326/gm3port_log.csv

 

^ stock turbo does fall off in the higher rpm ranges. you could tighten your wastegate and try again.

 

i know that stock turbo tapper a lot but how I red most if here coud run 22or more psi boost on stock turbo with 3port @ redline ?!

I have stock wastegate and wg spring but how I know it was tightened up full .

What I do not understand is the fluctate 15-16-15-17-18-15 psi under 200-300rpm change ?!

 

Quick question .What am I risking by not fitting in resistor before GM 3 port TBC ? can I damage it ?

 

In theory, you risking the ECU output driver/circuit for the BCS. But many have ran with no resistor for years and have never had an issue.

 

Thx dude . I'm gona run without it then , its waaaay easy-er to create boost curve (at least for me ;] ) .Getting new ECU is still cheaper option then import another BCS anyways .cya

 

Hello

Here is my boost plot and wgdc setting on the Evo 8 with the 9 turbo and the GM BSC compare to the Merlin book wgdc settings. No one has issue with the 9turbo and gm 3port like that much higher wgdc setting need and lower boost ?!

 

and one more issue @wot my load error is always show me 19.53125 from 2000prm to 7000 ?! The WGDCcorection is always 63.5 at idle at cruesing and at wot too ?!!

What coud cause that problem ? When I zero out the Turbo boost error correction maybe I have little more boost at peak...

The logged wgdc is ok the same as in the table !

 

^^
First, setting for ANOTHER car are NOT gonna work on your car. They maybe a starting point, but will defiantly have to be "dialed in" for you setup.

Next, besides boost, you need to log WGDC, WGDC correction and load/boost error.

 

^ is the stock ecu boost control GURU

 

Here is the log with the boost settings posted in the #444 :




Not so informative.. dont know what coud be the problem with load error and wgdcc..

Yes I would use Merlin books setting for a starting point... but it wasnt working.. I'm so far from his wgdc settings and i can not reach the boost that he coud@ higher rpm.

 

Yeah, you need to get load error and WGDC correction logging properly to tune ECU boost. So work on that.

 

I did my log with Evoscan.
Load error : request ID : 8A Eval : 0.15625*x-20
WGDCC : reuest ID : 8B Eval : 0.5*x-64

What shoud I do other way to get the proper log ?

What I dont how will I have 24psi boost @ redline if my wgdc is 100% and only 18psi boost. the forge 25psi acutator coud help on it ? or try to use boost pill with the 3port ?!

 

I'm sure you'll not get 24psi@7k anyway
you should beable to improve that taper tho
looks like you have a leak to me your correction doesn't move off max