Boost Gauge Problem

[agentx]

lol. Well I installed another boost gauge because i suspected it wasn't showing the right boost. This one is a blitz unit ... still the same problem. Goes to 1.1 bar in second gear and to a whopping 1.6 bar in 3rd gear. Now the turbo is a measly stock rb20 turbo so theres no way it would go that boost would it? Also I bought the car a couple of weeks ago and the owner told me its tuned by dr drift to run around 12 psi.

What could likely be the issue? Vacuum line is running directly from the plenum where the stock one runs, no t-piece ... i've disconnected the stock one.Can it be the vacuum line because its cheap plastic?

Thanks for the help!

[paulr33]

it could and might work it will just be throwing in shitloads of heat

check the actuator signal on the turbocharger, where does it get its signal from

[blind_elk]

If it keeps generating heaps of boost, it's likely the wastegate isn't opening. And if you keep generating those levels of boost, be prepared to say goodbye to your engine.

So check the actuation of the wastegate, pronto!

[GeeTR]

Goes to 1.1 bar in second gear and to a whopping 1.6 bar in 3rd gear

Jeebuss, if your gauge is measuring 1.6 bar, id suggest thats what your actually running. I cant think of a way for the gauge to "see" more then actual. Sort the issue out quick smart. As mentioned, use some line (known GOOD stuff) from pressure source (plenuem?) to WG with the gauge T'd in between for testing. Could be a flapper issue, buts most likely a leak in the line to your WG.

Edited May 26, 2008 by GeeTR

[skylinekid]

the other thing is tho if u were generating that much boost u would be able to tell by just listening... if its howling its head off then maby it isnt right but if ur boost gauge is electronic and needs to be zero'd b4 starting car double check cuz wen i install mine i was reading 21psi with master gauge reading 14psi so just check that aswell bud

[agentx]

thanks for the replies fellas. I didnt think it would be possible for the turbo to bring out 20+ psi lol. I had a look in the dark and couldn't really see where the vacuum for the actuator is taken from, but I did see that there's a flimsy lookin manual boost controller tee'd into that vacuum line.

I'll check it first thing tommorow morning for leaks etc. Another thing, is it ok for the boost controller to be tee'd there? is that where its put in normally? (never really used a boost controller). Also, if i cant find a leak .. can i try playing around with the boost controller and try to turn the boost down from there? Will i have to get the car retuned to run the lower boost?

Sorry for the couple of noobish questions

Cheers

[agentx]

the other thing is tho if u were generating that much boost u would be able to tell by just listening... if its howling its head off then maby it isnt right but if ur boost gauge is electronic and needs to be zero'd b4 starting car double check cuz wen i install mine i was reading 21psi with master gauge reading 14psi so just check that aswell bud

It sounds ok, nothing too wild. Boost gauge is mechanical and does show the correct vacuum on idle.

Also, http://www.alamomotorsports.com/blitz/MD_BOOST_MW.GIF ... thats roughly what it looks like ... thats showing it in bar right? i.e. 1.5 is 1.5 bar = almost 20ish psi?

[subie]

Hi guys,

don't wanna start the new topic about the same thing..

I think I have the same problem.. my boost gauge reading about 20psi when i boosted..I have R34neo turbo with RB20 wastegate auctuator .. what u guys reckon? could be the Wastegate Auctuator? by the way, i've got turbo smart tee boost and changed it to turbotech tee boost and the problems still there!

cheers

[paulr33]

its in kpa x 100 so 150 kpa is 21.75 PSI

ie; its running unlimited boost - this will fry the turbo and the engine if you keep loading it up and "trying" it

the actuator either isnt opening (no signal, manged signal, or something is blocking it) - it needs manifold pressure signal

if there are other junk devices on the vac line the actuator is using, remove them and try again, see if that clears your issue

the actuator is getting a signal but the flap is either stuck closed or hitting your exhaust

this would be likely with a new dump fit / front pipe fitting to the car

i would remove any boost controllers that are fitted as a process of elimantion, they will just be clouding the issue

and youll try and fiddle with them and keep "testing" it putting more stress etc on the car and turbo

[agentx]

thanks for the help paul, about to go out and look at it. dump and turbo etc everything down there is stock except the boost controller addition. One thing, if i take the controller off and it runs the standard 8-10 whatever psi it runs ... will that affect the running? Will i need to get it tuned again?

cheers

[agentx]

ok just had a look, the vacuum line from he actuator is hooked into a nipple on the turbo itself ... with the boost controller tee'd in between the line. Whats the correction?

[agentx]

a bit of an update guys. Removed the manual boost controller and put the vacuum line from the compressor side to the actuator and took it for a bit of a run. Its still going up to 0.9 bar in 3rd and a bit under that in second. It SHOULD go to 10 psi from what ive read. Couldnt REALLY inspect the hose because of lack of space, will do that tommorow as well. If thats all good ... whats left ?

[agentx]

im talking to myself!

well removed the heat shield etc and had a better access to the wastegate. the hose on it from the comp housing was actually a fuel line so i replaced that with a brand new vacuum hose. The air intake pipe from the filter to the turbo was a bit loose so tightened that up, tried moving the wastegate open and close by hand and it worked ... its not blocked or anything.

now taking it for a spin, its showing around 1.3-1.4 x100KPa on the gauge which if im not hugely mistaken is around 11.6 - 13 psi roughly yea? So i guess thats fine because i do have a bigger exhaust which would increase boost from what ive read?

Can someone drop in and comfirm lol. ive gone crazy working on the car and then reading up about this. The only problem was the boost controller was running very high boost and after taking that off ... the boost gauge confused me cuz its in KpA instead of normal psi etc.

Thanks guys! waiting for someone to confirm so i can rest!

[agentx]

anyone?

[lachlanw]

yeah i have seen 13psi out of a rb20 with exhaust and I/C upgrades

[Super Drager]

I hope you know 1.4Bar(140kpa) is 20psi not 13