Help... problems after upgrade

[dacowgod]

Any general ideas what my problem would be..

I have a 95 GSX running 17 lbs of boost from a PTE 5027 50 trim .. 880 injectors 255 pump comp cams 101200's with all the supporting mods. Anyways heres the problem.

DSMLink reads 23 lbs of boostest while i'm only running 17 lbs. DSMLink reads AF/R at 11.62 during boost while my wideband reads around 10.5ish Timing according to dsmlink never goes over 11 and i see anywhere between 4-8 degrees knock. from around 4500 - 5k until i let off the gas..

All the props are set correctly in boostest and A/F and also LTFT and STFT are good..


I havent tried tuning on the 50 trim at all i have been very conservative with it and really havent even driven a tank of gas on the car since its been on there because I wanted to install the wideband before I went out romping on it..

On my Evo III 16g I had installed previously I never had a problem with knock at 20 lbs and boostest was always pretty close above 5 grand.. .. but I was setup then on a 190 pump 650 fic injectors and stock cams and no wideband... Timing was always low on that setup too though..

seems i see guys on the boards all the time running 22-24 lbs of boost on a 50 trim with 93 octane and 20 degrees timing and no knock... dont know why i cant do the same?! .. any suggestions..

 

[dacowgod]

Any general ideas what my problem would be..

I have a 95 GSX running 17 lbs of boost from a PTE 5027 50 trim .. 880 injectors 255 pump comp cams 101200's with all the supporting mods. Anyways heres the problem.

DSMLink reads 23 lbs of boostest while i'm only running 17 lbs. DSMLink reads AF/R at 11.62 during boost while my wideband reads around 10.5ish Timing according to dsmlink never goes over 11 and i see anywhere between 4-8 degrees knock. from around 4500 - 5k until i let off the gas..

All the props are set correctly in boostest and A/F and also LTFT and STFT are good..


I havent tried tuning on the 50 trim at all i have been very conservative with it and really havent even driven a tank of gas on the car since its been on there because I wanted to install the wideband before I went out romping on it..

On my Evo III 16g I had installed previously I never had a problem with knock at 20 lbs and boostest was always pretty close above 5 grand.. .. but I was setup then on a 190 pump 650 fic injectors and stock cams and no wideband... Timing was always low on that setup too though..

seems i see guys on the boards all the time running 22-24 lbs of boost on a 50 trim with 93 octane and 20 degrees timing and no knock... dont know why i cant do the same?! .. any suggestions..

 

[assault187]

dont trust the BOOST EST and AFR on the link.....go by your boost gauge and your wideband. I would try leaning the AFR's out to atleast 11.1 - 11.3 . I have seen knock on my own car from running 10.xx AFR's.

Is your timing curve on dsmlink zero'd out?? meaning a stock timing curve? If it is chances are your base ignition timing is off. If thats the case correct it using a Timing light, and lean it out a bit somewhere in the low 11's to be safe. This should help

 

[CROWN007]

Right click on the boostest and the a/f on dsmlink and put in the settings and it might correct it some even though it shouldn't effect much some people use that for tuning and correct from that to their real a/f and boost.

Does your knock go up gradually? or Spike?

Mine would jump from 2-10 degress and kill the power which was due to bad knock sensor
Then it went up gradually and i was runnin 10 under a/f on wideband.

I had a turbo/fuel set up to run 12's and i ran 16's in 1/4...check everything over boost leaks, exhaust leaks around wideband, etc. Could go to base settings for your set up and start over.

 

[winterftbl]

What are your coolant temps? Do you have a frontmount? MAybe the difference in boost pressure is because you have a bad boost gauge? I am pretty sure your getting knock because your running too high of boost without a proper tune. I would believe dsmlink over a boost gauge. Just me though

 

[adv4nced53]

knock is either due to being rich or lean (on sane amount of boost). the afr that link shows is not the one from your band...it is just a calculated estimate from a few different variables.

1] tune your car to start around 12:1 at WOT and by redline, have it at 11:1.

if it still knocks

2] pull timing at the rpm it knocks

that should do it because it sounds like a tuning issue.

the boost reading is most likely due to a kink somewhere on the line that goes to the gauge. make sure no air is leaking where the line plugs into the gauge. the boost reading from dsmlink is also an estimate but it is usually pretty accurate