FazdaRX_8

iTrader: (1)

I have seen 0 for both stft and ltft, in my logs and others

Brettus

iTrader: (2)

I have no idea why you wouldn't see a LTFT (in OL) - unless you didn't leave it long enough to build one . I see one in practically every 8 i've looked at .

But i have seen the odd 8 that didn't build one and that did MY head in LOL

FazdaRX_8

iTrader: (1)

its just different ways of getting the beast tuned,
however a note, the mazdaspeed 3 and 6 play with 170% load stock and modified they are as high as 230% calc load.

200g/s
(26.4lbmin)(60)/(10.8)(BSFC(.65 rx7club.com))
225hp = 186whp

270g/s
(35.7lbmin)(60)/(10.8)(BSFC(.65 rx7club.com))==
305hp = 253whp

400g/s
(52.9lbmin)(60)/(10.8)(BSFC(.65 rx7club.com))
452hp = 375whp

17% drivetrain loss

Brettus

iTrader: (2)

Those numbers look a little on the high side for whp given what we see on the forum here . Most (good)NA 8's get around 220g/s and 180whp

FazdaRX_8

iTrader: (1)

220g/s
(26.4lbmin)(60)/(10.8)(BSFC(.72 rx7club.com))
225hp = 186whp

270g/s
(35.7lbmin)(60)/(10.8)(BSFC(.72 rx7club.com))==
275hp = 228whp

400g/s
(52.9lbmin)(60)/(10.8)(BSFC(.72 rx7club.com))
408.1hp = 338whp

17% drivetrain loss

those numbers seem low to me but like you said its a rotory, you should get some of kma logs and enter them into VD or your program and see what the vd gets
this assumes mazda made 220g/s a "real number" I don't think it is

Brettus

iTrader: (2)

Yeah - that looks about right .
My feeling is that the % drivetrain loss is not linear and (the %) does reduce a bit as power goes up.

Brettus

iTrader: (2)

If he wants to post a csv file I'd be happy to do that.

kma5783

iTrader: (7)

I'll post the log for that 4th gear pull when I get home from work later.

I do have VD installed on my computer, what settings do you use to get the most accurate result?

IMO all these calculations are useless because we don't have a confirmed BSFC for the renesis, let alone a FI renesis.

Kane

iTrader: (1)

It brings a tear to my eye to see us argue about things like MFR, and BSFC.....*I'm so proud*

FazdaRX_8

iTrader: (1)

its algebra dude, list your acceptable knowns and your unknowns then solve.

.72 seems to be a good number for BSFC.
and in reality every single engine has its own BSFC, because it relies on the tune.

Thanks kane

9krpmrx8

iTrader: (46)

Good stuff. Complicated it is.

kma5783

iTrader: (7)

I know what kind of math it is.

The problem is you can't solve for 2 unknown variables in that equation, BSFC and Horsepower.

Now once you put a car on a dyno and have a HP figure you can go back and calculate the specific BSFC for that engine.

Point is, these equations are nothing but crude estimates. For every .01 that your estimate is off on the BSFC it's a 4+hp difference on the 270g/s example.

kma5783

iTrader: (7)

Brettus,

Here's the log for that 4th gear pull.

Brettus

iTrader: (2)

****
My ME licence just expired (long story) . Hope to have it back in the next few days all going well .

kma5783

iTrader: (7)

That sucks.

What about settings in VD, I can input it into that.

kma5783

iTrader: (7)

I'm kind of curious as to why my calc load is so low though?

4th gear WOT and max calc load was 135%

Edit:
I'm wondering if I have a small boost leak, we had the idle FT's good, but I've started to develop a negative fuel trim at idle, about -5-6 LTFT, but my cruise FT's are good.

Nah, can't be a boost leak, AFR's are too good going into boost for that, my wideband shows a 10.9AFR under WOT. It would be way more rich if it were a boost leak, right?

kma5783

iTrader: (7)

Also, here's a short 1st to 2nd gear pull from Saturday night...

Brettus

iTrader: (2)

G/s are a little on low side per your reported boost but that could be just that your boost gauge is over-reporting slightly or maf under reporting .

Boost is quite low though so load will be low .

kma5783

iTrader: (7)

Guess it's time to get my EBC setup and see what happens.

What are your thoughts on the -6 LTFT at idle, but FT's being fine every were else?

Just MAF scale right around the idle voltage?

kma5783

iTrader: (7)

Logged another 4th gear WOT run with almost identical results.



Time to make some small changes to the Fuel VE Table and Throttle AF table.

yomomspimp06

what are you using to make those graphs?

Kane

iTrader: (1)

Throttle tip is is good!

What real AFR's are you seeing?

FazdaRX_8

iTrader: (1)

your Maf could just be undereporting which can be a good thing. the graphs look good.

if your maf scale is right and your getting negative fuel trims your injector bank 1 scale might need tweaked. but the cold weather could be messing with it too.

it could also be your gauge, I have seen this same issue, I thought I was around 10psi, Per my gauge, sense I started getting mine back on the road, started fiddling with the ebc and it claims I am only at 8psi.

Chris

iTrader: (10)

9krpmrx8

iTrader: (46)

Yeah boost gauge readings are a PIA.