89 dodge shadow psi question

[flipper2007]

Car is a 89 dodge shadow 2.5 turbo its running 6psi of boost vac 15, i just had a new tranny and clutch/w assembly i have a big truck battery in it , had the engine checkd its good and strong had all the belts replaced....so my question is how do i get more boost/psi ...i am new to the turbo scene thanks for the help

[speeduphoria]

stock vac should be a little more than 15 and stock boost more than 6psi. I would start by getting a good aftermarket boost gauge as the stock one can be way off. Double and triple check and possibly redo all the vac lines. Check the distributor timing and cam timing, do a major tune up, then consider adding more boost.

Do lots of reading to understand how things work:
Donovan's Dodge Garage

[EvilcowRoland]

Yes, vacuum and stock boost are off a bit. Your car should be pulling 18-20 vacuum at idle after it warms up and and max boost should be in the 8-10 PSI range. Definately check your vacuum system and the cam timing since you just had belts replaced.

As for max safe boost, I would say use a manual boost controller and set it to around 10 PSI. As long as your fuel pump/injectors are good you won't ever have to worry about running that amount of boost. If you add an intercooler you can take it to 14, assuming everything is in good working order.

[flipper2007]

thanks guys i will be checking all the lines i got the diagram from donovan's dodge garage..

[phantomrt]

Engine vacuum depend on elevation, too. Any chance you live in the mountains? If so, 15 in.hg. of vacuum is normal. If you're less than 5000 feet, you should be getting around 17+ inches.

[flipper2007]

i have been watching and the vac it does get to 18-20psi when shifting, at idel is 15-17 depending of the temp ...could be turbo wearing out? ..i do have a bad ball joint on the pass side i will have to change very very soon could that be holding back some of the boost?from the tire wobbling?i do know it slows it down but would it slow it down enough to lower the psi

[Wpg_Spirit_R/T]

Quote:

Originally Posted by flipper2007 i have been watching and the vac it does get to 18-20psi when shifting, at idel is 15-17 depending of the temp ...could be turbo wearing out? ..i do have a bad ball joint on the pass side i will have to change very very soon could that be holding back some of the boost?from the tire wobbling?i do know it slows it down but would it slow it down enough to lower the psi

Lol well if I were you I were you I wouldnt even be driving it if the tire is wobbling but no the tire would have nothing to do with the boost... as the other people said its probly a vacuum line or timing.

[phantomrt]

The turbo could be wearing out, but that should have minimal effect on how much vacuum the engine pulls.

Vacuum is typically read in inches of mercury, not pounds per square inch. At hot idle, you should have 18+ inches of mercury when the engine is hot and at idle.

We still don't know what guage you are using to verify these readings, so it is possible that there are some discrepancies in those readings. Low vacuum can be caused by several things ranging from incorrect camshaft timing, incorrect ignition timing, bad valves, clogged exhaust and I'm sure there's more that I cannot remember.

[flipper2007]

its a stock gauge..
i think i might need an intercooler, its been cold yesterday and today..yesterday i got the car up to 10psi of boost today i got it to 15psi....i am going to get the ball joint fix'd this week once i do i will buy a new boost gauge....the car was sitting for a 4 months it might have cleared the lines of any air or moisture thank everyone for all the help....

[EvilcowRoland]

Just a caution, I wouldn't go boosting over 10 PSI much with a stock Mitsu turbo and no intercooler. That's just asking for trouble. Even in cold weather you shouldn't be varying by 5 PSI of boost. Definately check everything again, make sure you don't have a broken vacuum line or something.