19.9psi Boost
 

My PSI3 monitor is now showing max reached boost as being 19.9 psi is this normal for a standard WRX with PPP?

Nope;)

that's 1.37 bar hmmm

old boost gauge used to show between 1.3 and 1.4 bar as well but just though that was not very accurate but now the PSI3 shows what the ECU is seeing and still showing 19.9 psi, thought it was a bit high but everything is totally standard (apart from blitz nur spec back box)

I think a standard WRX would be around 13-14psi, a PPP maybe 15, but almost 20Psi will surely be a spike, or it been mapped previously to hit this, at low revs and taper off ;)

Its a completely standard WRX300 with PPP, never been mapped. It hits 19.9 and holds steady just under this maybe 19.5psi!!

Sounds scary! Have you got another decent gauge to check this? Boost at this level without enough fuel will almost certainly make it go bang!

Unfortunately I don't have access to another decent gauge to check it, I used to have a half decent gauge with line straight from inlet manifold that read between 1.3b and 1.4b. But only got the PSI3 nowadays and from what information I can find about AFR from the lambda reading, everything seems fine there ie roughly 0.99 - 1.01 AFR on tickover or constant speed and drops to about 0.78 - 0.80 AFR on hard acceleration :S

That's about 11.5 to 11.8 AFR so it's actually not that bad! Is the PSI3 connected to an external pressure sensor?

No, the PSI3 is connected to the ECU via OBD2 port

Thought that! No issue with fuel cut kicking in? On your car it would have cut at around 15/16psi if held on boost for a few seconds.

Do you have the user manual for the psi3?


Might be worth checking to see what the maximum boost it can display is. 19.9 looks like it's topped out.

I've not felt any fuel cut kicking in, will have to take it out again tomoro but its been like this for all the time I have had the gauges in. As far as the PSI3 iirc there is no limit to what it will display, ie if the ecu reads it the PSI3 will display it.

Might have to check the wastegate tomoro if its dry too.

You'd know fuel cut if it happened, nearly puts you out the windscreen!

I think the standard map sensor can only read up to about 1.7bar or thereabouts. I'm wondering now has your map sensor had it?

Does the car feel like it drives as normal or is it a little slower?

oh no it definitely doesn't do that.
This is still well under the 1.7bar tho only reaching 1.3-1.4bar. Maybe, will have to have a look for a new one, if not too bad, might be worth swapping as a test.
I don't think its slow at all, but its hard to tell as only been a passenger in other Imprezas.

I think you need to get a good boost gauge on to confirm the PSI3 is working properly. I've been digging around and found that at least one version of the UK PPP ECU boost target is 13.3psi as standard. We don't know which one though lol.

That sounds a bit low :S

Depends on the turbo I think. There's 450/500 bhp cars running less than what your car is showing!

I meant for the standard turbo. weather is nice, so maybe a bit of playing around today see if I can shed any light on this?!?!

Yeah but your stock turbo won't be a TD04 like my classic has and it's target boost is 13psi standard.

Have a look around mate. Unplug the MAP sensor and check the terminals and plug it in again. Make sure the ignition is off though.

19.9psi is a crazy figure to be showing lol

Mine is running the standard TD04L. Looked at MAP sensor, all the terminals look ok, the outside is a bit dirty just like the rest of the engine bay (next job is to clean it) but without changing it, wouldn't be able to tell if its working properly or not?!?

I thought the turbo would be different! Anyway, that's not important.

The easiest way to do it is check with a known working sensor. Do you know anyone else with an Impreza?

I don't know anyone close with an Impreza, there are always plenty for sale though, might just have to buy one and try it.

Either that or have someone scan it with an OBD reader to see if there's any pending fault codes then you can be sure.

the PSI3 can read all fault codes, just done an ECU scan and says 0 codes current or pending, so happy about that one :)

Is it peaking at 19psi? I can't remember 100%, but I'm sure my last WRX hit 19psi odds on the Prodrive map at times.

19psi is way too high, if it spikes to that there's a problem somewhere. Wastegate actuator was doing this to my car. I think the OP said it holds at 19.9psi. Maybe it is just a spike?? Can you clarify wrx300 2005??

I think it spikes to 19.9psi and holds about 19.5psi, will go and put more Shell VPower in tomoro and go for another drive and try get a video of the boost reading.

Good stuff, that would be great! Get someone else to do the recording so you dont end up in a hedge lol!

Set your gauge to give a live reading rather than peak hold.

Yeah like pie hole says, it shouldn't be holding at 19psi, mine was a 2001 WRX with the 261 bhp Prodrive pack and typical boost was around 1.1 bar or 16psi. I'm sure it reached 19psi at certain rev ranges tho :wonder:

Might be worth dropping JGM or another mapper a PM just asking for some advice?

Im sure this is correct for a wrx ppp newage
mine peaks about 19-20 psi. According to my boost gauge.??