bad boost guage???

[g2ic02]

When i accelerate my boost guage read something like 25+ pounds of boost. I have an autometer boost guage. I am pretty sure that the guage is wrong, but i wanted to check with you peeps to make sure it isn't really boosting that high(never heard of the stock turbo reaching this). any info on this would be great.

[DRIFTING_SIL_EIGHTY]

you might just have it connected wrong. how did you wire everything ?

[sr240mike]

If your tires arent smoking under full throttle and your engine is still intact its most likely just the gauge.

[g2ic02]

well i have the line from the boost guage hooked into the vacuum line from the t.b. and then the rest shouldn't matter.

as for the tires smoking. i haven't had a chance to go wot. i have a kink in my fuel pressure regulator that i believe is restricting fuel flow. And i have never driven a boosted car before so i can't compare it to anything. but what i was mainly thinking is it even possible for the stock turbo to reach this kind of boost.

[uiuc240]

it could be possible. do you have a line connected to the wastegate nipple from a pressurized intercooler pipe???

Eric

[g2ic02]

yeah but it is in between my intake and my turbo does that make a difference? Or does that line that goes to the wastegate have to be afte the turbo?

[uiuc240]

yeah but it is in between my intake and my turbo does that make a difference? Or does that line that goes to the wastegate have to be afte the turbo?

:smash:

Ummm...yes. If you have it connected BEFORE the air goes through the turbo, it will ALWAYS be in vacuum and therefore will never reach positive pressure. Remember, that little line sends a pressure signal to the wastegate, telling it when to open. If the wastegate never sees 7 psi (or whatever yours is set to), it will never open, and therefore you will overboost as high as the turbo will go.

The only reason your engine hasn't exploded yet is because the stock SR T25 loses all efficiency above ~14psi. This means that even though it might be throwing 25psi in your cylinders, the air is hot and not really adding anything to your combustion charge. So, basically, you're lucky. If you had done the same thing with stock fuel and a bigger turbo, you'd be rebuilding a motor right about now.

Fix it.

Eric

[g2ic02]

thanx. i fixed it this morning. ill let you know how she runs. about the little nipple on the stock intake tubing(about the same size as the line that runs to the wastegate). what hooks to that??

[uiuc240]

That little nipple is the one that you connect to the wastegate line. Run a piece of 3/16" tubing from that nipple to the wastegate line. Done. You will get 7 psi all day long.

Eric

[g2ic02]

i thought the wastegate had to have a line run after the turbo???