minor hesitation but no knock

[Eric Stage I]

91 octane is a killer. Some people can only run 13-14psi on it no matter what.
If your O2's are up around 800, and you still have knock, then I would start dropping boost.
You can try taking the timing lower, but much lower than the default of 17* starts to feel pretty doggy.

 

[we4Mateo]

Im wwell after pulling fuel out of chip and reset ecu and deopping fp to 42 line off blm are 134 still grtting knock at wot but not asviolant im slowly raise wot fuel until i massage knock out fp is a smooth 1;1 raise all the way up to max boost im getting retardof 3 to 5 at wot o2 mill at 780 ish so im thinking either add fuel or pull timing

Or both...

 

[blackdeathtrap]

I do only run octane booster im going to atempt pulling timming and adding fuel will se what i can accomplish i had harrely any knock before the jam nut got loose and fp slowly climbed il keep you guys postes also have helish noise comming from shitty belt so im gonna change that also

 

[Amelio]

is that at 18psi? no alky?

Where are you seeing knock first gear? or are you rolling into it in 3rd ans seeing knock?

780 mv is pretty much dead on for what I shoot at wot but usually 16-17 on pump gas

If your at 18 psi and on 91 oct that may be your issue

 

[blackdeathtrap]

I was wrong we did a pull with more then one persone whatching gauges seems its only 16 psi and yes thats rolling into peddel going to third only get .7 deg 1st to seconds and thats major wheel spin 3rd is were 5.8 deg pops up but it actualy drops to 1.7 half way in third that was with chip adding 140 which is 10 % at wot i bumped it up to 144 will test again tomorow going into third is leaning out a bit

 

[blackdeathtrap]

If this atkeast lower my knock il leave fuel there and pull timming till i hopefully masage it out

 

[blackdeathtrap]

If i cant get knock to go away im sending chip back and ordering alky at same time maybe get new headers and bigger injectors too

 

[blackdeathtrap]

After a pull today im actualy leaning towards saying my knock sensor may need replacing wide open everything is normal trowing around 5 and six deg or timming retard my friend point out knocm gage is eratic ei starts with one green then two green then gos all the way to the red but stil at 5 deg is this normal or so i have faulty sensor or gauge connection issue

 

[blackdeathtrap]

After making adjustment i though was right i took it for a run and almost had a heart atack when i sa 15 deg of retRd let of slowly took it home re check my parameter and seems my 1 parameter which is 1/2 wot fuek was actualy set backwards i will retest the car tomorow now that iv reset everything

 

[GetOwnedVette]

Small vac leak somewhere or cracked hose? My wrx was boggy getting into the boost for a while and traced it to a hairline crack in an intake hose.

 

[blackdeathtrap]

Funny thing is since the hesitation is completely gonne i get knock

 

[blackdeathtrap]

Pulled some timming added fuel 2.9 is as high as i could get er and that was a full launch on a long straight smooth road

 

[blackdeathtrap]

Well i had some time today will wife was sleeping i went out to industrial park long flat road with no building and not a soul in site dint a bunch of launching and adjusting pull timming added fuel no have 0 knock at 17 psi 01 octane launches it at 7 psi mikey thompsons just stuck front ps tire lifted a lil and she just flew most knocj iv can by since was .2 going into second hitting a pot hole pretty hard i think i did it boys

 

[blackdeathtrap]

Now whats is next as the turbo buick world turns

 

[turbo96max]

i had a very similar issue. boost gauge read 16-17 psi, erics tt street chip, but the fuel pressure gauge was going upto 70 psi under load, from 42 at idle vac line on. Yes, its more than he recommends, but ..the my fuel pressure gauge was not lying, the increase in fuel psi was bc the car was boosting way more than 16-17 psi, more ... not sure why , but i changed the vac source feeding the wastegate, from the turbo cover, to a source directly from the upper intake, like where the boost gauge was connected. no more over boosting, and now fuel pressure is correct, ~65 wot.. no more knock. still havent had time to look into the why the difference, but , the car was just over boosting, and the gauge didnt show it

 

[blackdeathtrap]

i dint move any vac line notings budy just tuning got it to run no hesitation and 0 knock wide open

 

[turbo96max]

good news, whats the fuel pressure at now vac off and wot?

 

[blackdeathtrap]

Had to turn it up to 45 line off idel

 

[turbo96max]

and is it still going utpo 70 psi ?

 

[blackdeathtrap]

Not even close 62 at wot at 17 psi which is a perfect 1:1