Bought not Built

Productive day yesterday -

• JBR Air Dam Installed
• Throttle Body Coolant bypass done (Lowes Special, not sure why someone would bother buying a kit when it costs under $5)
• FPRV replaced with new OEM - need to verify that solves the issue but I believe it will. See earlier in my thread comparing positions of the relief portion of the valve being stuck in weird places, this one looked solid and far down the tube, whereas a failed one seems to be caught halfway up the neck of the valve.

Also on my 2007 Volvo V50 T5 I replaced the Oil Filter Housing since the PCV has been whistling for far too long. Pretty cool to see the platform commonalities with the Speed3, since its from the FoMoCo era of Volvo.

 

Update: FPRV solved the lack of pressure build during KOEO but does not solve the WOT fuel pressure issue. Everything is great everywhere except for when it starts to build into boost and RPMs, then it plummets down far below 1600.

Not sure where to start diagnosing, HPFP or ITFP, and how? Might pull off the HPFP and inspect the internals there for scoring. May also be a good time to go ahead and swap out the ITFP for a new one as well while I'm at it, but don't want to throw parts at it just yet since I have an event in 2 weekends.

 

When I had these symptoms it was the hpfp internals/spring. I ordered a new CS unit which includes a new spring. Problems solved.

not saying this is your issue but I also replaced FPRV while I was diagnosing this.

you can also try giving the RV on top of the hpfp a good cleaning. That did nothing for me but it might be your issue.

 

Yeah I'm not sure of the mileage on these internals, that could well be it. The RV was rebuilt less than a year ago, I don't think it would be so gunked up in a short amount of time - I keep thinking it might be that it isn't torqued down properly, I had issues with that causing idle fuel issues when I first rebuilt it.

 

Just as a note, my auto tech internals were 6 seasons old. Lots of track use over that time. They showed scoring and were seizing up at WOT. I have logs showing fuel pressure dropping to 0. Once replaced, that problem never came back.

 

So it would appear that I solved the issue by simply tightening up the spill valve nut a like 1/4 turn more so it was mega-tight.

I took it off, pulled it apart, and cleaned / lubed it all, put it back together and was only getting like 50psi at idle. Remembered how I had the same issues because the nut wasn't tight enough when I rebuilt my hpfp a year or so ago, and then said screw it, linear correlation time.

Well it turns out that you need to tighten down that MF, and after really going for it I saw steady pressures at 1700-1800 WOT, higher than they were before.

My guess is that because the tolerances are so tight, and the springs so small, that even a fraction of an inch has a large correlation to fuel pressures due to the tappet travel under the Spill valve, and mine must have backed off just a hair to where it would hold fine everywhere until when it was being pushed to the limit.

Still glad I replaced the FPRV because that was definitely going bad, but happy I didn't have to spend another $200 - we'll see if it holds over a few more test pulls and at my next event.

 

TQ spec for PRV is 16-24 Nm, 12-17 ft/lbs, really not all that much but more than you'd think, glad to hear you got it sorted with the good old TQ spec of "good n' tight"

 

The O-ring is deceptive when figuring out how tight it is, I think that's what threw me off prior where it starts to catch and make it feel tighter than it is.

 

Where exactly is the screen located? Inside the rail or inside the sensor?

 

There is a particulate screen in the FPRV and in the HPFP, if you look through the guide you will find it, just a small filter.

Mazdaspeed E85 Safe HPFP O-Ring Rebuild Kit (corksport.com)

 

So i just replaced my prv and didn’t notice a filter. Is it inside the fuel rail or inside the actual valve?

 

In the valve on the rail side

 

Have one handy....two sixes in swapping engine mode....

 

Had a fantastic time at Autocross this past weekend, car again performed well, far better than it should given the abuse it's been through.

2-day event, 6 runs each day. Couldn't figure out the line on the first day, did pretty poorly. Second day's course was tweaked a bit and the slaloms flowed much more smoothly for me - either I was out of practice or the car is just better set up for less twitch-oriented driving.

Yet again, this car continues to shine through - my buddy exploded his trans (pics below) on his second run on the first day and couldn't compete, so on the second day he co-drove my car, making him the latest of my autocross/trackcross crew to abuse my car. Car did 12 runs on Sunday, performed without a single hitch, seemed super happy.

Still want to compression test some point soon before slotting in the turbo over the winter - Fuel pressures were great, temps were fantastic (thanks TR8), and my time on Sunday made me #7 out of about 50 which is cool considering the competition.

 

Below is a list of parts amassed for the BNR S3 swap in over the winter (February-ish), looking to do what I've done for basically everything on this car which is buy lightly used at a massive discount. Including cost here so I can track my total in / out by the end of the build vs. buying brand new. I figure a lot of my current stuff, like PnP OEM Intake manifold, intercooler piping, etc. can be sold to recoup some cost.

• BNR S3v4 - (used) - $940 shipped (New @ $1100 + shipping)
• Grimmspeed 3-port EBCS - (BNIB, 3rd party) - $100 shipped ($169 + shipping)
• 3-bar Bosch MAP Sensor & Bitwise harness (used) - $70 shipped ($110 + shipping)
• Focus ST non-PI Intake Manifold kit (BNIB, 3rd party) - $340 shipped ($540 + shipping)

What I am on the hunt for:

• Intercooler Piping for ST manifold
• Dual gauge pod (for oil temp and pressure)
• Oil Temperature Gauge
• IWG Exhaust Manifold (Maybe?)
• Corksport Skid tray

I've gone over a few times whether an exhaust manifold is worth it, especially one as cheap as an XSPower V3 manifold. I know about the cracking issues, but also don't want to spend $1k on a CS or other manifold for a low-power build like this, and I'm not sure I like how it might make the exhaust sound.

Is it worth it to do the XSPower from a flow balance perspective if I've got the ST Manifold?

 

I'd say xs power manifold is certainly worth it for flow balance, adapted performance has the cheapest price on it typically

You can do a single guage pod if you get the innovate oil pressure / temp guage https://www.innovatemotorsports.com/mtx-d-oil-pressure-temperature.html
Vent guage pod works great for it.

If you're after intercooler piping you can make the kit yourself, silicone intakes sells parts you just gotta figure out exactly which ones you need, there's a list in one of the st manifold threads somewhere on here.

 

That's actually a great gauge - I might end up doing that instead. Was looking for a dual since I already have an oil pressure gauge from when I first bought the car, but if it comes to it I'll spring for the two-in-one.

I saw this piping thread (Focus ST mani install (and how to keep your existing piping) | Mazdaspeeds.org, The New Era in Mazdaspeed, CX-7 & Ecoboost Forums!), may end up giving it a shot if the time comes. I'd honestly rather just use a purpose-built kit if it pops up in the couple months, but if I can keep my BPV connected to the intake I'll just do whatever lets me do that.

At the end of the day it's just piping, can't be that hard. I believe my current Ultimate Racing piping kit is very similar to the CX-racing solution which would hopefully match up pretty closely.

 

+1 for XSPower. Mine never cracked. I opted for the EWG option. I suggest you do the same if getting it. The manifold comes with a block off plate if you don't want to run an EWG but the option is there if you want to get one later on.

I ran it with a 44mm Tial gate open dump tube. It was loud when going WOT and sounded pretty mean but decent during light cruising.

 

I just ordered one of these dual gauge pods to replace my home made one. I sent them a message and they gave a code for free shipping!

https://latenightracing.org/collection/c668w5coyqhrzkqyuuedcuvzojkjmp

 

That's actually a solid idea, had no idea the EWG version came with a blockoff plate - with an S3 is a EWG necessary? I guess I'm not understanding if I would be holding myself back in terms of full-on capability and making the most of the car. I do love an open dump WG.

Can't believe I hadn't found that, thanks for the link!