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.

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

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

 

 

Bro. - You just can't help yourself... from finding fault. C'mon man you know it. 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.

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.

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.

 

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.

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.

 

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

 

It's important stuff you know !

 

Team,

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

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" ???

 

Aaaah... look, ......you've attempted to artfully dodge my point..., while constructing a strawman more comfortable to address....popularity. 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".

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. 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.

 

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

Edit: Btw... Set you up...? 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

 

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.

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



Prep 1
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Prep 2
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Finished 1
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Finished 2
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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. 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.


.

 

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?

 

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.

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

 

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