Interesting excerpt...referring to the advantage of a dual port WG running NC solenoid control vs a single port running NO/bleed solenoid/valve control...

"Since the resulting pressure differential across the solenoid is not as large as the bleed type...(where the differential is full boost pressure minus atmospheric pressure), smaller increments of adjustment are possible. This gives the ECU (controller) finer control over adjustments to the control loop as it tries to achieve the target manifold pressure setting."
- Designing and Tuning High Performance Fuel Injection Systems, by Greg Banish


Dual port WG w/NC Control vs. Singles port WG w/ bleed type control.

 

Believe I can put this issue to bed: ...no recurrences of boost drop... boost control is rock solid.
.

 

My bad...... my Set is at 35%, my Gain is only at 10% with my set gain at 50 (aka 5psi).

 

Right on...that makes sense.

I'm currently running:
Low:
S: 38
G: 18
SG: 48
W: 84
L: 4

High:
S: 48
G: 18
SG: 60
W: 106
L: 4

 

Looks like you are losing 1 psi now over the run ?
How is virtual dyno looking now ?

 

Yes, ~1 psi drop... that's about right.

Haven't done a v-dyno in a while. Its cumbersome logging w/the laptop... as compared to pulling afr & boost data from my AEM post ride. I've been intending to sort out auto-capturing data on a micro storage chip in the Tactrix, which will greatly simplify M/E logging.

Additionally, she's running great... easily as well as my last dyno...I actually suspect better ~ 320 HP/ 230 ftlbs. So, I've been focusing more on enjoying the ride vs. continually being in "tuning mode". If / when I go E30... and have reason to expect significant HP/trq gains..., I'll do more logging then.

 

A quick shot of temps during and after a typical 3G run. I believe each is in healthy range: IAT, ECT & Cat Temp.

• IAT: declines during run 30 - 28 C / (86 - 82 F), then begins to rebound post run...
• ECT: steady during run, then increases post run 79 - 82 C / (174 - 180 F)
• Cat Temp: (de-catted) increases during run 820 - 913 C / (1508 - 1675 F), then begins sharp decline post run

Edit: My IATs recorded here are still based on the OEM sensor integrated in the MAF, so they don't capture the compressor charge temp rise.

 

Nice ... Is IAT post intercooler ? What was ambient air temp ?

 

I’ve not spliced my aftermarket IAT sensor into my harness. So this is from the OEM IAT integrated into the MAF housing. Ambient temp at the time was ~80 F.

 

50 - 150,000 miles... Still spinning like a top and a joy to drive.

 

So, my temps are in a good range now:

In 95*F ambient...

Lately, I've started thinking about how the cooler fall weather is going to affect the set-up. Generally, I expect enhanced performance...all good, but expect as h/b mentioned in earlier posts that my system m/h difficulty getting temps up to ideal operating range. So, couple of questions:

I see two options:
Opt 1: Install obstructions or covers over the oil coolers.
Opt 2: Since I have low temp oil cooler thermostats (~175F)...Simply reinstall and run my OEM thermos (194F) during colder months.

How have you guys managed the cold temp issue?
Thoughts...other options?

 

I live in a cool climate. My hot days are probably what you are considering "cool"

I doubt you will have issues with cooler temps, I bet you will still see 180F coolant temps even in the cool weather. As far as the oil temps go, yeah monitor them, but I doubt they will fall that much, even in cool temps my oil temp is usually just a few degrees less than my coolant. If they are falling down way below coolant temps then I'd start by blocking one oil cooler off and going from there. (Or just switch out the oil T-stats).

 

I think you will have problems. During cold nights in Florida (40-50 F) , I would have a hard time getting my water temps up above 160 F while cruising. Before doing any pulls I would let it idle for a few minutes to get the temp up before beating on the motor. I would either switch thermostats or block the radiator more with the intercooler..... I guess you will know soon enough....

 

Jesse, I hope you’re right about coolant temps. Definitely w/b monitoring closely.

C/b wrong..., but I do think I’m going to need to do something, likely reinstall OEM t-stats, to elevate oil temp ...since it’s borderline now unless in stop & go traffic, or getting on it.

 

Yeah, time will tell. I’d planned to reinstall my DP rad, & front mount my new 8” IC over fall /winter months. Thx for the suggestion... food for thought... now w/the thought of balancing summer & winter temps I’ll need to reconsider how much of the rad I need to “front” / cover w/the IC...especially given the greater efficiency of the DP rad, and FMIC config will reintroduce airflow via the bottom horizontal, which is largely blocked in my current config. I’ll just have to see what makes sense when I do the work.

W/b surprised if I don’t need to install OEM oil t-stats.

 

Just drove my new 8 on a 1200km road trip . It has twin mazdaspeed oil coolers . With ambient temps quite low around 10C the oil temp was hovering between 65-75C which IMO is way too cold . So I blocked one side and saw an increase of around 10C . Need to investigate if they even have a thermostat in them as the temp went up and down a lot . My turbo 8 with one oil cooler has no such issues.
I also noticed on long downhill stretches that the water temp on aftermarket gauge dropped way down (stock gauge stayed at normal). Put this down to the thermostat closing when no load was on the engine meaning the aftermarket gauge wasn't seeing flow . Not a problem but did confuse me for a while.

 

Wait, ...what??? “..new 8”. . Going for a fleet of ‘em? The red beast is not enough? .

 

'Low ambient temps here are mid 60s F now...and each month will drop ~10 F degree on average thru end of year. So, I expect I’m going to experience similar. Giving thought now on how best to manage coolant and oil temps for both summer and winter ambient temps. We’ll see...

Yeah, the OEM coolant gauge is worthless.

 

Brett, I have an aftermarket water temp gauge, it's after the thermostat and the behavior you described is what I see, just the thermostat closing. As for the oil coolers, where is the temperature measured, before entering the engine? I have twin OEM oil coolers and it works fine in winter here in Japan, 75C is ok for oil temperature.

 

Posting this...in the event it m/b helpful to others...

I worked out this diagram to assist in my thinking correctly about my EBC tuning. Just a high level depiction...to aid in the tuning process. It's an iterative process..., that when principles are understood converges on optimal system settings. Of course, PSI values are relative.

Assisted in diagnosing & resolving that my earlier boost drop issues were EBC setting and back pressure related.

Edit:

 

It would be more accurate to show what you get with no boost controller and show another line for what the EBC does to modify it.
Basically an EBC does three things:
1 Brings boost on sooner using 'set gain' . Also known as 'start boost'.
2 Raises the boost level using 'set' (can also be affected slightly by 'gain')
3 Helps minimise droff or creep using 'gain'

 

Wasn't my original objective to show the comparison...just the correlation between Greddy Profec B2 primary settings to the resulting boost curve. But...right on...I can see the value in showing the comparison. Will edit shortly...

 

Yup this is a nice clear description of the Profec, sums it up very nicely, the spool-up is very noticeable with it on, even on my tiny little Greddy.

 

Thanks,Jesse. Hopefully will help others new to the Greddy PB2.

On another note...What's the tentative schedule for your new build...over winter?

 

Update: Boost control

Old hat for some..., but as I had to sort it out...posting it for others...
I learned a number of things recently concerning managing my system boost control. Namely that it w/b impacted by minimally the following factors:

• WG control line model, I.e. NO vs. NC models
• WG spring # fitted
• Back pressure
• EBC settings

Changing any one of these changes the boost profile.
1. The EBC NC model is superior to the NO model - see post #413
2. There are inherent "losses" in each system d/t charge sections, 90 deg couplers, IC, etc., associated with producing usable MAP.

• I've not tested..., but it's reasonable to expect these "losses" will vary w/ boost, I.e. 10-15 % of boost being generated... as does exhaust back pressure. Therefore, increased boost = increased losses.
• W/out a manual / digital controller, boost is set & limited to WG spring # - losses.
• With a controller boost range is:
  • Min boost = WG spring # - losses.
  • Max boost = ~2x WG spring # - losses. (d/t increasing back pressure)

3. Finally specific EBC settings obviously affect system boost curve...follow direction in the manual.

Notes:

• Increasing WG spring # increases achievable boost in both cases.
• Reducing back pressure increases the boost level that c/b run at a given WG spring # w/an EBC.

To the chase...

• Set WARNING to desired boost + 1 PSI
• Set LIMITER to ~ 3%
• Set "START GAIN" to ~65% target PSI.
• Set GAIN to ~18%.
• Increment SETby 2% until desired boost is reached.
• increment GAIN by 2% and decrement SET by 1% if boost drop off is experienced to reduce dropoff.