lower boost in higher gears

[forcedfed69]

wot my car hold 16 in first 15 in 2nd 13 in 3rd and 12 in 4th and fifth. any body have an idea of whats going on? it held fine on every gear before i got my new dejon intercooler piping. I think it might be my turbo xs 34 series by pass valve leaking no that i don't have any boost leaks.

 

[RadDsm]

If you are using the 13g like your profile says, its a small turbo, and it has to pressurize all that piping from the new intercooler, so it looses boost in the higher rpms

 

[Ravenous]

Yup, moving more air through the engine than the turbo can output at those higher rpms... you are out of that turbos efficiency range. At least thats how my understanding of it works.

 

[kahl23]

A 13G is a tiny, tiny turbo. To give you an idea, 3/S cars use them as a mid-level bolt on upgrade to replace their 9Bs. It may even be smaller than a T25, but don''t quote me on that. It is most likely running out of breath, as stated above.

 

[forcedfed69]

its def. a 16 g got the serial numbers.

 

[talon187]

did you check for boost leaks? what are the #s on the turbo ?

 

[forcedfed69]

Here's a pic. the numbers are 49178-0???0 someone sanded the numbers off. but it still some sort of 16 g right? you know of any other turbo's with those numbers?<a href="http://s27.photobucket.com/albums/c189/ashly17/?action=view&current=DSCF4314.jpg" target="_blank"><img src="http://i27.photobucket.com/albums/c189/ashly17/DSCF4314.jpg" border="0" alt="Photobucket"></a>

 

[v8s_are_slow]

Internally gated? Is the wastegate flapper tight? It would have more air to have to fill up but would think a 16g wouldn't have this problem.

 

[forcedfed69]

yeah its internally gated. I found out that its a 16 g turbo off a gallant. The only turbo that i could find with the last digits 00. didn't check if the flappers tight. how do i go about that?

 

[silver bullit]

Could be boost leaks.
Could be out of the efficiency range on the turbo IE: 14b works best in low mid range rpm, 50 trim works best mid to high rpm.
Is the stock bcs hooked up? If so this can limit boost due to know, fuel etc...
Boost creep.

 

[forcedfed69]

the stock bc is still hooked up electronicaly but not vac. lines. should i totally disconnect it from the harness?

 

[silver bullit]

the stock bc is still hooked up electronicaly but not vac. lines. should i totally disconnect it from the harness?

1g are fine disconnected, 2g i believe it will throw a cel, So just leave it connected to the wire harness, but Just run the vac lines off/eliminated.

 

[forcedfed69]

yeah, thats what i thought. thats how i have it running. its been like that for two years. just starting doing it when i changed the piping. thinkin the bov can't handle it now that there's no leaks.

 

[forcedfed69]

Hey guys got the dejon u.p. and the super ssq b.o.v recirculating back into the intake and solved the prob. no matter what psi i set it at it holds through all gears.