Causes?


Set up : '95 LS - Walbro 255 intank - RC550s - Blox mani - TiAL 38mm WG w/ 7.5psi spring , vac line from IM attached to lower port, top port open - 1G DSM BOV, same vac line - Uberdata - PLX M300 WB - 2.5'' IC Pipes - Spearco FMIC - SC34 - 2.5" DP - 3" Exhaust - Etc.

Just finished this project. Right now I am not boosting, I am trying to tune in the non boost portions (just learning UD) while I put 400 breakin miles on my clutch. But just to make sure everthing was working we decided to try a run into boost. Turned into about 3 runs but the Defi boost guage never seemed to reach 5 psi :crook: PLX reads full "rich" after boost starts and on up.

I checked the couplers for holes .... Vac lines to WG and BOV are good. Turbo spools freely. WG doesn't leak at idle. Nor does BOV ...

Tryin to locate the problem before I'm ready to try tuning it ...

 

maybe its running so rich its causing it to bog a bit n not let it rev high enough to boost more.

 

I was thinking it might be so rich it didn't have the ***** to push full boost .... ran it up to about 6k though ...

 

could have some gnarly exhaust leaks or your spring is in fact a 4psi spring

my wastegate comes loose every now and then and i lose boost and spool doesn't happen till after 5k normally it wakes up around 4500 and is boosted by 5k

Also running pig rich on top end will affect things; i'm running proably a 9:1 afr above 6k since i haven't been able to tune that down (need to fix leaks in my dp and extend it a bit so the o2 reads right)

 

The exhaust is all done up tight. Its a 5 bolt 2.5" DP that flares to 3" right after the AC ... 3" flex pipe , 3" magnaflow , stops at rear suspension for now.

Emailed the serial # on the TiAL box to TiAL and they said 7.5 psi

no dumptube on the WG yet.

 

he's talking about preturbo exhaust leaks. aka leaks in your manifold. which is something im facing right now. popped 2 holes in my ramhorn and im only spooling 2lbs. it happened in the past, pulled it off and welded them shut and spooled a full 7 no prob. now these opened. but thats what you get when you spend 100 on a ramhorn i'll live with it, they are just small leaks, nothing structural

 

I haven't noticed any leaks at idle ....hmmm

 

yeah, i popped a hole in my hf mani, and i couldn't get past 5lbs.

 

Is it a new wg or a used one? Its possible that if its a used one maybe they changed the spring to a 4lb one. Just a thought.

 

bought second hand, but unused still in box etc.