Dual Boost Gauges

nuki · April 16, 2009, 11:13:43 AM

just a quick question. Is it possible to have a boost gauge on each turbo? thanks.

Skifledanabit · April 16, 2009, 11:18:38 AM

I would have thought so, the pressure monitor would be right next to the turbo right? so if you have two turbos, two pressure monitors, then you would be able to get seperate readouts?

arrouk · April 16, 2009, 08:26:01 PM

yes, but there is not a lot of point as when the second turbo comes on line they both flow into the same pipe, befor that any boost produced by the second tub is vented.

read up on how the twins work and you will see what i mean.

matt

nuki · April 16, 2009, 11:33:08 PM

yes i understand that but im after abit of fancyness

i like guages

BlitzBoy · April 17, 2009, 09:05:33 AM

Quote from: nuki;599365just a quick question. Is it possible to have a boost gauge on each turbo? thanks.

No ... as the boost from the second turbo when it comes online goes into the same Y pipe as the first turbo. Even if you had the vacuum take off next to each compressor housing of each turbo, the reading would be corrupted when the flap opens for the second turbo when that comes online, so both boost gauges would read the same when both online even if one turbo is supplying less air (boost). So bit pointless having two gauges, if you like guages just add another gauge that would read something useful

nuki · April 17, 2009, 09:09:37 AM

i have a spare boost gauge thats identical to the 1 i already have thats all just wondered if it was possible

nuki · April 17, 2009, 09:11:14 AM

so your basically saying that the reading on the gauge is coming from the Y pipe? therefore the reading from the boost gauge would be the same? as the 2nd turbo comes in the boost is corrected automatically so both boost guages would be doing the same thing? is that right? thanks -- What i wanted is for 1 boost guage to work only with the first turbo.. then when they 2nd turbo comes in they both work and read the same.

BlitzBoy · April 17, 2009, 09:20:36 AM

Well stock FDs pre 99 did not have a boost gauge. The ECU knows the boost from the Map Sensor attached to the firewall which takes a reading from a vacuum line off the UIM (upper intake manifold) most aftermarket gauges attach to the UIM with a silicon hose.
So if got an aftermarket gauge attached already up to 4.5k rpm approx you are only seeing the boost level put out by the first turbo anyway

nuki · April 17, 2009, 09:25:48 AM

ye because i boost to 10-11 PSI then it dropps abit to about 8 then back to 10-11 when the 2nd turbo comes in.

BlitzBoy · April 17, 2009, 09:40:29 AM

yes you have the correct boost pattern of 10-8-10, so you twin turbo system is working correctly.
Remember when the second turbo comes online even though boost is showing 10 your engine is getting more volume of air from the two turbos

nuki · April 17, 2009, 09:44:17 AM

ye.. both turbos boosting creating doubble amount of air at the same preassure? if i was getting overboost what would the gauge be reading? thanks.

BlitzBoy · April 17, 2009, 09:51:03 AM

yes as the engine is ingesting more air at higher rpm, the wastegate regulates the boost level so when the second turbo comes online the ECU controls the wastegate to open to keep boost pressure at 10psi. if the wastegate was not opening to the correct level you might see spikes up to 12-13psi, this normally happens if you have added a big exhaust decat and downpipe

nuki · April 17, 2009, 09:54:36 AM

and i take it boost spikes are very bad lol

BlitzBoy · April 17, 2009, 10:38:30 AM

yep as the stock ECU/Pump does not proivide enough juice to be safe at 13psi lol

nuki · April 17, 2009, 10:40:43 AM

so power fc and rats nets is next i think then to be safe ^_^ Thankyou for your help