can't hold more than 17 psi without boost spike

[forcedfed69]

aright guys.i was pushing 18 pounds with it no prob. no spike just holdin in every gear. I put the dejon intercooling piping on it and it was fine holdin at 19 fine but the next day i noticed it spikeing at 22 and holding no more than 17. screwed arond with everything and nothin its driving me crazy. I'm thinkin its the bi pass valve leaking becase my old tubing had some leaks and now they don't and the bi pass valve can't handle it. Thinkin bout just gettin a evo 16g ported with all the goodies forced fed exaust mani and evo 02 housing ported. thanks for the help.

 

[MrBoxx]

What type of boost control are you using? Where is it tapped? How is it set up? What turbo are you using?

And do you have any sort of logging equipment? An AFPR for that 255lph in your profile? Injectors? If you don't have any of these things, you have no business boosting anywhere above 15psi.

 

[forcedfed69]

I think its a 13 g turbo from a first gen eclipse. kid told me it was a 16g but abviosly it not if i can push more then 12 pounds without fuel cut. stock injectors 255 walboro fuel pump.hallman new style boost controller, taped into the blow off valve line but i tapped it into the j pipe and same thing. no logging equitment. but it was fine a year ago running 18 pounds and i was running a 14.1 at 95.

 

[MrBoxx]

I think its a 13 g turbo from a first gen eclipse. kid told me it was a 16g

Does it say TDO5H or TD04H on the compressor housing? Are the compressor fins staggered, or uniform? There is a BIG difference between these two turbos. You may have a 14b also. This is the first thing you need to find out before we can help you any further.

but abviosly it not if i can push more then 12 pounds without fuel cut.

Fuel cut has NOTHING to do with your turbo size.

stock injectors 255 walboro fuel pump.

You need an AFPR and something to control those injectors with; AFC, DSMLink, AEM, etc.

hallman new style boost controller, taped into the blow off valve line but i tapped it into the j pipe and same thing.

Leave it tapped at the J-pipe. Don't tap the BOV line for anything other than the BOV.

no logging equipment. but it was fine a year ago running 18 pounds and i was running a 14.1 at 95.

Get a logger, ASAP. This should have been one of the first things you should have gotten before turning the boost up. You also should know what turbo you're using before running that much boost. If you think your BOV isn't holding the pressure, then you wouldn't be spiking; you'd be LOSING boost.

 

[forcedfed69]

The fins are staggered on the turbo. copressor side says tdoh5 exaust side says tdoh4. i have an apexi afac. but still it was holdin boost fine before i but the new piping in 1st and second gear holds 19 fine second and third 17 to eighteen. 5th 16. the higher the gears the less boost. dunno. thats why i want to do all new, so your saying if it's a 16g thats on it now i can push more than 12 psi without fuel cut off but with my 14b i got fuel cut off at 17psi

 

[MrBoxx]

So you're running upwards of 20psi on a 16g, with a 255lph fuel pump that has no fuel pressure regulator and stock injectors, with no form of fuel control or logging software?

I think you can see where I'm going with this line of questioning. Holding a high amount of boost and fuel cut should be the least of your concerns right now.

 

[forcedfed69]

alright i hear where your comin from. the turbo compressor says tdo5 and they are staggered fins but don't alot of turbo's from a 13g to a 18g say that on the compressor? i really don't know what size turbo's on it but even when i se it at 15 pounds it feels real slow. I think i'm just going to order all new stuff turbo ect. so i know whats going on. Where can i find a logger at?

 

[kyleh]

what's the serial number on the turbo?

 

[PIMking]

You cant just judge on the butt dyno. go to the track for results. and play it safe these guys know what they are talking about dont boost over 15-16 psi. unless you feel that its fun to pull and replace an engine soon.

 

[forcedfed69]

I got ya guys. thanks. Some of the numbers are 49178-o??00. The only turbo i found with those is off a galant. Here's a pic. But i know it's bad running that much boost. Which i turned it down to 15. But there should b a reason for the sudded boost loss - spike now that i replaced the intercooler piping. Thinkin its the blow off valve heard the xs are not so good. i dunno what else to fix besides this. I'm going to get the logger this week with a pda. Will this tell me whats goin on?<a href="http://s27.photobucket.com/albums/c189/ashly17/?action=view&current=DSCF4307.jpg" target="_blank"><img src="http://i27.photobucket.com/albums/c189/ashly17/DSCF4307.jpg" border="0" alt="Photobucket"></a>

 

[silver bullit]

Boost leak test, every time you remove all the inter cooler piping you should check and make sure.

Take a pick of the inlet of the turbo?


What mods do you have anyway?

 

[forcedfed69]

inlet? you mean the turbo blades? there staggered no shaft play left or right or up and down. In and out an eighth to a quarter inch. When i first changed the intercooling piping it held for the day the next it spiked and doesn't hold more than 17 when i had it set there. mods. all dejon intercooling piping, 16g from a galant, 255 walbaro fuel pump, apex -i three inch tubo back, hallman boost controller, dejon intake and k&n intake set up, turbo xs r34 blow off valve recirculating.

 

[silver bullit]

In and out an eighth to a quarter inch.

Sounds like the turbo needs rebuilt, also sounds like the bov is not tight enough or to loose and allowing compressor surge allowing in and out play.

How is the bov adjusted, it may be the reason with your problems.

 

[forcedfed69]

Ther's no adjustment on the bov. just the washer method its a tubo xs. think i'm going to bye the hks setup and c where it goes from there if nothin new evo setup.

 

[kyleh]

dang its like someone grinded off the important parts of the serial number.

 

[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.