Captured this anomaly today that I believe is a similar scenario as described above....as a result of the EBC signal line currently being plumbed post instead of pre-TB.

- The first profile is a spirited 3rd, 4th & partial 5th gear clean pull onto the hwy today. Solid boost control...13 +/- 0.2 psi, each gear. :cool:

- The second profile was 5-10 mins later...where I went WOT, ...then partial throttle ~0.2 second (can't recall why), then back WOT again. BOOST SPIKE FROM ~ 8 TO ~15 psi. :eek:

Yeah, an 8 - 15 psi spike exiting a turn might cause some issues. :crazy:

Edit: I recall why I went WOT, partial, and WOT again. I accelerated up the hwy entrance ramp with two cars ahead of me. When we were on the hwy I planned to bounce to the fast lane, go WOT, and pass. So, I bounced to the fast lane, went WOT when at that moment the first of the two cars ahead of me started coming into the fast lane as well. So, I slowed. The driver realized that I was in the fast lane accelerating and receded back into the slow lane. Then I went WOT again. That was the scenario that resulted in the boost spike shown in the second profile below.


https://cimg3.ibsrv.net/gimg/www.rx8...b94015483f.png
https://cimg2.ibsrv.net/gimg/www.rx8...e184de155b.png

Could be that ...or could be an EBC issue . The issue I talked about is more prevalent at partial throttle.

If EBC related I'd expect intermittent irregular behavior. But I'm not seeing that. I'm seeing solid boost control..., except in this case, i.e. throttle on...into boost, off / partial throttle, back on full. :dunno:

Ah , well if it's from a partial throttle situation ...then yeah , try re-routing signal line pre throttle.

I thought you were going right off throttle then back on again.

...and the v-dyno. 350 HP, 296 lbft. Torque spike from ~240 to 296 ...lack of control NOT cool. :icon_no2: Have to get that EBC control line moved...

https://cimg6.ibsrv.net/gimg/www.rx8...7fa57c5ef8.png

Reviewing a number of my v-dynos I identified a fairly repeatable HP rate / slope increase at ~7k rpm (see post 705). Seemed an odd thing...given back pressure is increasing at that time...working to inhibit HP production. :dunno: So considering potential contributors...turned to what seemed the likely suspect: the Renesis SDAIS (Sequential Dynamic Intake System): the dynamically actuated intake valves designed to optimize torque and HP across the the rpm range.

Considering valve timing, and that my VDI is disabled; the APV was the clear suspect. But my APV opens at ~6k rpm, and I'm not seeing the effect until ~7k rpm. After some discussion w/ Brett came to understand that the APV actuates very s-l-o-w-l-y. Aaah, ok...and that...combined w/ the time the system takes to resolve the inevitable turbulence that will result ... all could explain the ~1k rpm delay between actuation and measured response.

So, how do I optimize APV tuning for my system? By what metric should APV timing be based? Seems logical to base timing on the same metric as the point of the SDAIS system: air velocity and flow. If true, then the APV timing designed to optimize intake air flow and velocity for a NA wouldn't likely be optimal for my system. The APV is tuned to open on a NA at 6k rpm where it is generating ~170g/s. My system generates 170 g/s at ~3.5k rpm, and ~ 300 g/s at 6k WOT. Great...so optimal APV timing is somewhere between 3600 and 6000 rpm. :rofl:

Searched the Forum and found this helpful discussion: "Aux Port Delete FI Discussion"
https://www.rx8club.com/series-i-maj...ussion-190230/

Couple points I gleaned:
This discussion took place ~ a decade ago when the Greddy was the common turbo generating up to ~ 47 lbs/ min @ 65% efficiency. The relatively smaller output of the Greddy wasn't suited to take advantage of the expanded intake volume (APVs open) of the Renesis, which is why at some point the Greddy kit began shipping w/ an APV block-off plate...essentially limiting intake volume expansion by converting the 6-port into a 4-port. Testing done indicated that though blocking the APVs resulted in reducing g/s per psi., i.e.
- APVs closed: 31 g/s per psi
- APVs open: 41 g/s per psi
...it did have the advantage of increasing air velocity..., and forcing the turbo into a higher efficiency zone..., reducing heat, and allowing boost pressure to be sustained higher into the rpm range.

However, fast forward a decade...my 6266 turbo, ~60 lbs/ min @ 70% efficiency, generates more than enough output to capitalize on the expanded intake volume w/ APVs open, and hold boost (as much as I intend to run ;-) to my 7500 rpm redline. My recent boost profiles confirm my system capable of holding 13.5 +/- 0.2 psi to redline w/ APVs open. So, where the Greddy turbo was the limiting factor of the system in the Rene - Greddy system..., the Rene appears to be the limiting factor in the Rene - 6266 system. And Brett's work in "The 450whp Renesis Engine..." appears to support that the Rene does indeed have a flow capacity limit to be respected.

OD did a few slow 50% throttle pulls up to 6.5k rpm w/ his APVs fixed open (truly worst case scenario) ...and saw pre UIM IAT spike 200+F ! This confirmed something else Brett mentioned: below a *certain rpm* w/ the APVs fixed open... there w/b a reversion of combustion chamber gases back into the intake during the compression cycle. That'll set the lower APV opening rpm.

So, the challenge w/b to converge on the APV timing "sweet spot":
- lowest prudent rpm to optimize increased flow for top end HP performance for my system.
- yet above the minimum rpm where reversion occurs.

I came to the same conclusion as I later found Kane did in 2010: Target an "open timing just before the closed APVs become a restriction to flow."

Test w/b by doing a series of pulls starting at OEM timing..., then incrementally reducing timing by 100 RPM...from say 6k to 5.5k to identify optimal timing. The following should give indication to optimal timing:
- g/sec
- IATs
- boost profiles (mid & highs)
- v-dynos (mid & highs)

Don't know how much, if anything, there is to gain here. We'll see.

You make a good point regarding fixed opening rate...relative to the varying acceleration rates of the engine in differing gears. My above post was already long and complex enough...that I chose to omit this nuance, as well as the associated lean spike associated w/the opening of the APVs.

There is certainly no "right" or "wrong" here...just a matter of preference. However, I'm satisfied w/my system performance...just after potential low hanging fruit which may have some high end gains.

Appreciate the input.

I have done a fair bit of testing to find the optimal point to open the APVs . I think I set yours to the same as what I'd set a Greddy to ...so with the more rapid engine acceleration you now have .... there def will be a small benefit from opening a little earlier.
To test I would do a log with apv closed and then another with it opening way too early . Overlay the g/s logs and the ideal opening point is pretty evident.

I do see value in doing a log w/ the APVs closed, but w/b concerned about the "opening way too early" log d/t the combustion charge reversion. That's why I planned to start from the OEM setting, and incrementally back down to optimal timing by watching... among other things... IAT to guard against allowing reversion.

It's not like you are beating on it on a hot day .............one log will be fine. And by 'too early' I mean around 5000 .

I get that..., but prefer to approach it in this way...

Currently traveling and Team's comment got me thinking about calculating an estimate for reduced turbo APV timing.

Quote:

---

Originally Posted by TeamRX8 (Post 4911022)

Well the deal is they open at a fixed rate. ..."

---

Of course, I'll still do the testing..., but from this estimated "ballpark". Clearly, I've made a few assumptions...so it'll be interesting to see how it pans out.

My estimate is based on the following data and assumptions:

NA 8:
- 0 - 60s time: 6.1 s
- Assumed rpm range: 1k - 8k

My turbo 8:
- 0 - 60s time = ~4.2 s:
- Assumed rpm range: 1k - 8k

Then estimated acceleration (rpm/s) for each is:
- NA = 7000/ 6.1 = 1148 rpm/s
- Turbo 8 = 7000/ 4.2 = 1667 rpm/s

Note: This calculation presumes linear acceleration. The turbo acceleration is most certainly greater in the rpm range in question d/t the non-linear "increasing acceleration" associated w/ onset of turbo boost.

APV actuation time on my current setup ...start to finish appears to take ~1000 rpm.

Therefore, APV actuation duration in time = 1000 rpm (FI) / 1667 rpm/s = 0.6 s

Presuming APV actuation duration is constant, i.e. the same NA or FI. Then, on an NA 8... w/APV actuation beginning at 6k rpm, it should complete ~:

6000 rpm +(0.6s x 1148 rpm/s) = 6689 rpm

Presuming my assumptions and estimates are fairly accurate and that Mazda tuned APV opening to that rpm as the "sweet spot" between generating top end HP and avoiding reversion; then tuning to the same rpm should get me close. And I can fine tune from there.

My estimate above is that it takes ~ 1k rpm for the APV to open...start to finish, which applied here means that ideal APV tuning for my turbo 8 w/b ~:

Open rpm = 6689 rpm - 1000 rpm
Open rpm = 5689 rpm

Finally, I think Mazda would h/b conservative with their timing... and I m/b able to be a bit more aggressive. So, I think I'll find the sweet spot somewhere ~5500 - 5600 rpm.

Additionally, M/E has two APV Open rpm fields currently set 200 rpm apart: 6000, & 5800 rpm IIRC. The working assumption is that they likely correlate to gears 1-3, & 4-6, respectively. I'll keep the same split.

Just a bit of a diversion...while traveling at the moment. We'll see when I return.

Interesting way to approach it ..... make sure you don't end up losing power in 3rd and 4th etc !

True. I'm primarily concerned with and will likely focus on 3rd & 4th gears, where I'm most likely to be at WOT; while attempting to ensure I don't loose...elsewhere.

Update:

Well, so much for theorizing...:rofl:. Evidently, my assumptions were incorrect...or there are other contributing dynamics I didn't consider.

Regardless, testing clearly indicates better mid & high end performance with APVs set to open at 6050 vs. 5800 rpm shown below.

I did a few pulls at each setting, and show characteristic v-dynos of each here.

424 HP / 308 lbft :D: Still getting the characteristic HP rise on the high end w/ APV open set at 6050.

https://cimg3.ibsrv.net/gimg/www.rx8...bb5a8f4c94.png
APV open at 5800
.
https://cimg5.ibsrv.net/gimg/www.rx8...89bc950fe9.png

APV open at 6050

VD anomalies .... pretty sure you will find that's giving you the high rpm peak .Nothing to do with apv

unless ...you turned it off somehow!

Two issues are a bit perplexing...that I agree... don't make sense............yet. ;)
1. the torque decline from ~5k to 6.2k, and
2. the accelerated HP increase above ~6.5k.

#1 The HP slope / torque decline between 5k and 6.2k doesn't make sense....unless it's not a "decline" per se at all, but rather the system returning to equilibrium after overshooting between 4.5k to 5k. That's easy enough to explore: I'll experiment w/ reduced "SET GAIN" relative to SET.

#2. The accelerated HP increase above ~6.5k. The SSV opens at 3750 and the APV at 6050, both of which I'd expect to maintain or accelerate HP ...given the expanding intake flow w/ a turbo capable of keeping up, which I believe my 6266 is. There c/b some vd anomaly..., but I'm doubtful b/c this phenomenon is too repeatable. I'm beginning to think that the wildcard here m/b my EBC control line currently being plumbed post TB... when my WG solenoid reference line is plumbed pre-TB. We saw earlier how a partial throttle condition, i.e. lower boost post vs pre TB, caused a boost spike. Capturing that on my boost profile m/h been providential. I'm wondering if a similar response is occurring when the SSV and APV open. It's reasonable to expect that there w/b a boost drop post TB when each opens (lesser in magnitude than the partial TB condition), ...then the system c/b similarly compensating w/ a boost spike (lesser in magnitude than the partial TB spike). If this were occurring w/ the SSV...it w/b masked by already expecting high HP acceleration at that rpm range.

If true, this would explain the high end HP rise, and ...when the SSV opens would also be contributing to condition #1 discussed above. :dunno:

Plausible.........theory (we saw how the last one turned out, :rofl:). I'll need to get that EBC control plumbed pre-TB to know.

Super easy if your Jet Air line is connected to the bottom of the charge pipe that's connected to the TB (pipe C8 in the greddy instructions i believe?). Just tee into that line real close to the charge pipe nipple, it's how I had my EBC set up for years.

Thanks, Jesse, but my Jet Air is plumbed pre-compressor via a check valve. I plan to tee into my WG solenoid reference line, which is in my last charge section ...just prior to the TB.

I would have already done it, but am planning to establish my AFR failsafe ...and RPM boost cuts at the same time, which w/b a bit more involved, e.g. pulling another vac hose thru the firewall, opening the dash panels, and add'l wiring in my mini-fuse box. And of course, I want her down as short a time as possible; so waiting till I have time to start and complete the work.

Reduced "SET GAIN" relative to SET..., and put a few turns on my compressor outlet elbow coupler clamps (both ends).
Did this first pull today, which mirrors quite nicely a pull from Wed. ... :ylsuper:

• 413 HP / 288 lbft (2/28/20)
• 411 HP / 286 lbft (2/26/20) (shown in v-dyno comparison)

Time to get those boost cuts implemented. ;)
.
https://cimg7.ibsrv.net/gimg/www.rx8...6989fbccc2.png
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https://cimg9.ibsrv.net/gimg/www.rx8...c61e178986.png

Whats your injector duty cycle look like? I can't imagine that you aren't nearing 100% Amirite? Either way good job squeezing out the power.

Stroker - Thanks! Good question. I know my ST & LT trims are solid at zero, and fuel pulse width peaked at 16.2 ms on the above pull. But I'll have to investigate in M/E... or get w/ Brett to determine my injector duty cycle. :icon_tup:

Also TBH my intention wasn't to increase boost...actually to reduce it ...while generating as wide a torque band as possible. I targeted eliminating recurring leaks. First, eliminating the leak at the last charge section into the TB... ultimately by modifying the charge section. Then recently eliminating a leak at the compressor outlet. I'd tightened the elbow clamps previously... eliminating the leak...only to have it return. So, I finally dbl-nutted the clamp T-bolts, i.e. ran two nuts down onto them, which eliminated the leak and is holding.........so far. :fingersx:

Afterwards I reduced my EBC boost settings, but the impact of eliminating the leak(s) exceeded reducing my EBC boost settings. :Eyecrazy: My boost profile on the 413 HP pull showed airtight boost throughout the pull imparting a huge impact on performance across..., but especially in the high rpm range. :icon_tup:

Once the system is stable, i.e. no boost leaks, EBC dialed in, etc.; max boost I'll run is ~ 375 HP / 275 lbft.

But hearkening back to Brett's 450 Renesis theory... namely that the MAF curve (g/s) reaching a plateau in upper rpms is an indication of the engine nearing its max. flow capacity. It's good to see that the MAF curve g/s of my latest pull continued increasing right up till going off throttle, i.e. no duplicate or diminishing g/s on the top end.
.

https://cimg0.ibsrv.net/gimg/www.rx8...41a2e3b599.png

This is the best indicative result we have seen from this kit so far ......so ...........time to put her on the dyno !

Brett,

Thanks! Perhaps....after I get the boost cuts implemented, and my EBC control line moved pre-TB.

She's down for a min repairing a leak at the oil pan ...at the turbo drain bung. Changing filter and refilling oil after work and she s/b back up this evening.

Meanwhile ...was still pondering the inj duty cycle question. if my calculations are correct...based on my inj & FP set-up (below),...my inj. capacity s/b good to low 400s wHP.

P1: 2x 476 cc/ min
2nd:2x 850 cc/ min
P2: 2x 850cc/ min
Tot.: 4352 cc/ min

Running the calculation using:
fw HP: 500 (approximation on 415 wHP)
BSFC: 0.6
Duty cycle: 80%

Required Indiv. Inj. flow (cc/ min) = (fwHP X BSFC x 10.5) / (# injs x inj. duty cycle) = (500*.6*10.5)/(6*0.8) = 656.3 cc/ min.
Total required flow cap. (cc/ min.) = 656.3 *6 = 3937.8 cc/min.
My set-up flow cap. (cc/ min.) =~ 4352 cc/ min.

So, the 413 HP pull should have required, ~3937.8/ 4352, ~ 90 % injector capacity @ 80% duty cycle.

Still need to find and enable inj duty cycle in M/E so I c/b monitoring it.

I have asked epifan to include it in the past, but he wouldn't do it .

Aaaaaah, it's not there. :pat:

So, we can calculate an approximate duty cycle....and then I'd think x-ref that w/ an approximation using pulse width. :dunno:

Already calculated theoretical...I may try to work out duty cycle from pw.

Yes you can get DC from PW .....BUT M/E only reports P1 . I've asked for the others but again ...no dice

:uh:

Bro. - You just can't help yourself... from finding fault. C'mon man you know it. :rofl: Ok, yes......, I used a canned equation, ...didn't simplify, and had to endure the grueling agony of multiplying by the # of injectors... b/c simplifying the equation w/h been so much easier. ;) Wait for it................................................ ..you're right. :yelrotflm

Ok, on to serious stuff...

Team, Thanks for the link. Yes, I have always found Howard's analysis to be on point: informative and helpful. :icon_tup:

Using his method ..., but working backwards from available injector flow (cc/ min) to deriving the acceptable rwHP which c/b safely run we have:

Givens:
1. Allowing as rich as 10:1 afr
2. Calculating for 85% max injector duty cycle

Then, rwHP =

= (tot. inj. flow x 6.35 x 0.85 x 10 x 14.471)
.................(3785.41 x 1.13 x 1.92)

And solving using my current injector flow: 4352 cc/ min

= 4352 x 6.35 x 0.85 x 10 x 14.471)
..........(3785.41 x 1.13 x 1.92)

= 413.9

How coincidental is that...considering my last pull! And this result confirms my above calculation nicely. :ylsuper:

I have actually run most of the combinations in my turbo injector thread out to their max flow. IE ...to the point the engine starts to go lean. So the whp numbers on there are pretty close ...... although I did allow a little bit of headroom as a safety factor.

Well, of course, I s/h expected you'd have a thread on turbo Injectors..., and saved myself a bit of trouble. :wallbash:

Come to think of it.... I'm fairly certain I consulted your Turbo Injector thread when I was planning my build...summer 2017 time frame.
Thanks...good to have another validation. :icon_tup:

...then......... thanks for the lesson in algebraic simplification. :icon_tup:

It's important stuff you know ! :rolleyes:

Team,

On another...or perhaps similar note... how do you have a 22,398 post count to date, ......yet have only given 24 "Likes"? :scratchhe

So, barely one tenth of a percent (~0.1%) of your time among this "community"...since 2005, did you find someone else did or shared something...anything worthy of a "Like" ??? :dunno:

Aaaah... look, ......you've attempted to artfully dodge my point..., while constructing a strawman more comfortable to address....popularity. :rofl: I made no comment regarding receiving "likes". My comment to you addressed giving them. B/c receiving them encourages & validates us, while giving them encourages & validates someone else...their work...and contribution to community. There it is again...that notion of "someone else". :rolleyes:

And before purporting some silliness that we shouldn't encourage one another..., first yes, I certainly hope that each of us on this "virtual" forum has sufficient going on in our real lives that we aren't looking for validation here. :nono: Yet...here we are...in community sharing experiences and ideas concerning our cars. And communities are convened for one purpose: the mutual benefit of it's members. To think that doesn't include mutual sharing experience, instruction, direction, caution, etc....and yes encouragement is...well silly. Additionally, God's Word, which you admirably like to quote, also says:
.....just to list a few.

So, then let's get back to my point ...which actually addresses your earlier comment:
.
.

Admittedly, we all begin from a disadvantage on forums b/c while the written format is good for exchange of data and facts..., it is a poor medium for the exchange of nuance, tone, personality. That said...in community there is a thing called "relationship". It has to be cultivated, ... grown. And it s/b...don't take it from me. Again God's Word...
..
I reject the notion that there is a prevalent negative "mindset" on the forum. On the contrary I have encountered the opposite and endeavor to contribute positively - just give a read of my build thread first post. The idea is... consume...AND contribute. And in doing so... what we put out IS what w/b returned to us. Again The Word:
..
Point IS... communities reflect what we contribute. So, if / since you feel ..."(people) have a certain (negative) mindset about a person ... Pretty common around here.", ...perhaps start w/ the man in the mirror. You know what they say......... about doing the same thing, and expecting different results. :icon_tup:

You began it. I'm happy to end it. Carry on...

Edit: Btw... Set you up...? :rofl: Bro., you're a living dichotomy. Pls don't ask...

Calculated the rate of acceleration in 3rd gear of my latest pull:

RPM / mph / time (s):
- 5316 / 55 / 29.541
- 7575 / 79 / 31.647

mph/s = (79-55) / (31.647-29.541) = 11.4 :ylsuper:

Good work, you still using a 6 speed?

Thanks! Yes, 6 sp...as long as she'll last. :)

Though it's easy to see how a 5 sp gearing ratios w/b better.

Admittedly, fwiw while gratifying...I consider these #s preliminary as they were run only on the best pull. The above ...between 5.3 - 7.5k rpm. I need to run the #s on multiple pulls to establish greater level of confidence.

Additionally, I'm a bit WOT pull averse for testing purposes. Tend to do them only to assess major hardware changes, adjustments or EBC tuning. If/when she goes ...which is realistically a matter of when, not if...; I intend it to be when I'm enjoying, rather than testing her.

That said...the below #s are for the same pull, i.e. post #729, run separately in beginning, middle, and end pull rpm zones.

RPM range ---- mph/s
- 3 - 4.5k: ------ 10.0 mph/ s
- 4.5k - 6k: ---- 11.8 mph/ s
- 6 - 8k: -------- 11.5 mph/ s

Update: Hood Vent install:

Installed Verus vents in my OEM hood today, and saved minimum $400 vs. a bought vented hood. I'm hoping to achieve improved passive bay cooling, reduction of pressure, and enhanced rad / IC flow. If not, I like the aesthetic addition anyway. :ylsuper:

Wifey and I took a ride today after installing the vents at hwy cruise temps were:

80*F ambient:
- ECT: 180*F
- IAT: 92*F
- Oil T: 180*F

I'll have to see if I have any record of ECT, IAT, and oil T near the same ambient temp on previous days to compare,

EDIT: The below temps are from last summer, post #385, when my IC was installed in a v-mount configuration, which actually performed quite well also.

90s*F ambient:
- ECT: 180*F
- IAT: 100*F
- Oil T: 180*F


https://cimg7.ibsrv.net/gimg/www.rx8...01127986d1.jpg
Prep 1
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https://cimg2.ibsrv.net/gimg/www.rx8...93f38fb020.jpg
Prep 2
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https://cimg3.ibsrv.net/gimg/www.rx8...878265ee80.jpg
Finished 1
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https://cimg2.ibsrv.net/gimg/www.rx8...ec2fc9db4b.jpg
Finished 2
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https://cimg6.ibsrv.net/gimg/www.rx8...9dab305b26.jpg
Finished 3
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Was thinking the same ............. further forward would be more effective at speed . But they still should work ok.

Thanks. No, I investigated placement... and reviewed a number of CFD maps like the one shown below of as similar body styles to the 8 as I could find to determine what I believe w/b the optimal mounting location. I found quite a bit of similarity in hood pressure coefficient zones: dividing the hood into quarters front to back...lowest pcs, i.e. resistance to venting, in Q1, and progressively increasing thru Q3...until finally going positive, i.e. air flowing into the bay, in Q4 as you near the windshield.

Additionally, the first ~7" of our hoods are over bumper & bracing, i.e. not yet over the eng. bay. My vents are installed 12.5" back on center-line, which positions their front edge just behind the rear of the coolant overflow bottle, and places 2/3 of the venting access in Q2. Equally important is I've evacuated everything behind the fans (accept the overflow bottle), so air has a straight shot to the vents essentially positioned directly above the fans.

Altogether... hopefully good design and placement. :fingersx: I may look at doing some in bay ducting to assist flow to the vents if I can come up w/ something simple and effective.

Edit: The ECU and fuse box are the rub on our cars. Have to decide whether to install forward and inside (toward center-line) of them, or behind them...moving out of good pc zones. I didn't want dual vents so close to center-line...so sought to find balance between these two options.

https://cimg2.ibsrv.net/gimg/www.rx8...50078ae6a2.png
.

There was a guy who did testing on the rx8 for this purpose ...his thread is still on here . Lowest pressure zone (for pulling air out) is further forward than where you have them .

Missed that thread. Though to Team and your points a few inches more forward and toward the centerline w/h increased effectiveness. Just didn't like them there. So, hoping they w/b sufficiently effective where installed.

Pulled the hood off again today and spray insulated the inside of the honeycomb bracing to seal up the hood and increase rigidity. I'll know soon enough how she fares as temps head into the 90s.

I know..., right? :rofl::yelrotflm

Brett, or anyone,

A search returned ~ 3 dozen threads. Give me the title or shoot me a link of the thread referenced here... if you recall it. I'd like to review it as well. Thx.

The only thread I found w/ some testing was "Self Vented Hood with GT500 Hood Vent", which only tested airflow for his mounting location, not at other mounting locations across the hood.

Here's another reasonably comparable CFD. Note how this AND the previous CFD posted actually indicate a reduction in pressure coefficient just approaching the crest of the front wheel hood humps. :yesnod:

I'll test and post results of my set-up when time permits.

https://cimg0.ibsrv.net/gimg/www.rx8...1d2a7ac4ca.png

When I ran a vented hood, it really helped the turbo heat escape especially at a stop light. You could definitely roast a marshmallow over the passenger side vent. No data on it though :)