DoZZa

iTrader: (4)

Hello all,

I have jut finished installing some Defi gauges to my MY06 hawkeye Spec C.

I am wondering if the Defi Boost Gauge is reading correctly.

I have the Defi boost sensor T-piece installed at the dump valve.

I have calibrated the gauge to zero as per Defi's instructions so I know it is set to zero.

My car is a Litchfield Spec C running a twin scroll turbo, Dyno graphs show its runnig at 345bhp.

Now the boost gauge is showing peaks of 1.5bar of boost, this usually occurs from lower in the rev range from about 3krpm upto about 5-6krpm it will stay solid at 1.4 to 1.5 bar, then drop back to around 1.3 to 1.4.

Keeping the car on boost ie above the 5krpm I am seeing the boost go no higher than 1.3 bar.

Does this sound about right for this car.

Its running a K&N panel filter, full milltek system with sports cat and uk fuel map as per Litchfields spec, and 345bhp.

What do you all think?

prodriverules

iTrader: (52)

Sounds right mate and defi's are very good at reading actual readings,never heard of any being out

DoZZa

iTrader: (4)

Thanks for that mate.

I found a thread on another forum and it would seem that I am about right as the car in that thread is pretty similar to mine and his boost seems to behave similar to mine.

Here is the thread. http://www.type-ra.co.uk/vB/showpost...7&postcount=10

I was just concerned that the car might be over boosting as I was seeing peaks of 1.5bar!

I am too used to my previous Subaru, a Legacy GT-B Twin Turbo peaking at 1.1bar.

prodriverules

iTrader: (52)

No worries mate,when running 345bhp on the standard turbo boost would be up peak around 1.4/5 bar and level at 1.3 so thats right where you are.

Shaun

Defi boost gauges notoriously over read, usually showing about +.1bar over what the ecu actually reads.

This is backed up by the fact that your held boost is showing 1.3 / 1.4. The standard turbo / actuator / panel filter will not allow this kind of boost at the top end. At say 7k you will be lucky to see actual boost of 1.2bar.

Your power output is as expected for this level of mods from PowerStation's MAHA rolling road though so nothing untoward there.

TonyBurns

iTrader: (3)

Hmmmm Dozza, your car looks familiar, were you on the M6 toll on monday by per chance?

Tony

dynamix

iTrader: (3)

They are great looking gauges but they are ALWAYS wrong. Pretty much gtee that it is overreading by 0.1 bar.

Butty

iTrader: (2)

Wrong or over-reading are relative terms only to the Subaru ECU reading but not to a "true" reading.
It doesn't make the Defis some eye candy junk because of this.

The sampling point, transducer type, sampling frequency and signal interpretation will vary between different systems to give different readings.

prodriverules

iTrader: (52)

If there always over by .1 then doesnt that make them constant any way thus giving acurate readings?

Shaun

One of my mates constantly bull****s, but it don't mean he is right just because he keeps doing it!

They are inaccurate end of.

TonyBurns

iTrader: (3)

The ones I had fitted to my classic with ppp were spot on with what the boost levels were meant to be, ie 1.1bar, never had issues with defi's tbh, plus if they were that bad, STI wouoldnt use them as an accessory

Tony

prodriverules

iTrader: (52)

,In that case a waste of money and may as well buy some r-spec at half the cost

Butty

iTrader: (2)

How were you measuring "accuracy" to work this out?

Shaun

Tony,
You must of had a "special" set then!

So if STI use them they must be great..... Mmmmm what happened with the the 2.5ltr block case design then, knocking rear struts on the Newage.... shall I go on?

Prodriverules,
I have the official Genome STI DEFI gauges and they are great bits of kit.... but I realise the boost gauge over reads by .1bar and deal with it. I have not said they are crap, I have just stated that the boost gauge over reads by .1bar. A distinct difference.

Butty,
Against the ECU (OE and HYDRA), against a rolling road boost logger and against an oil damped boost gauge, over the time that I have had the defi's fitted. Either these are all wrong and the DEFI's are the accurate method. I would suspect it is the other way round.

dynamix

iTrader: (3)

Agreed

Butty

iTrader: (2)

It seems that my perhaps pedantic approach to signal measurement and processing isn't being taken on board.
I'm not saying that any of the mentioned boost readings are "inaccurate", but trying to explain why people seeing gauge peak values seemingly higher than the mapped boost has a reason.

DoZZa

iTrader: (4)

No mate, was not me. Sorry.

Yes it would seem that from further reading that the boost gauge in particular is prone to over reading by 0.1bar, not a huge issue as long as its giving fairly accurate results.

I could not find anything online regarding other Defi gauges being inaccurate. Only the boost gauge. Anyone have experience other Defi gauges being inaccurate, bar the boost gauge?

Does not matter anyway, they look good, lol

Shaun

DoZZa,
Don't worry about it.... the gauges are fine for what they are meant to be for, as regards to letting you know what is going on for any "exception reporting" stuff.