Mazda Rotary Club

General => General Technical => Topic started by: tezz12345 on February 09, 2008, 02:32:17 PM

Title: boost .88 knock 82 inj duty 92%
Post by: tezz12345 on February 09, 2008, 02:32:17 PM
this is what i have on most outings in my car had it mapped with decat n big exsauhst do them figures look ok????
Title: boost .88 knock 82 inj duty 92%
Post by: karl_tate on February 09, 2008, 02:51:04 PM
IMO both knock and injection duty are waayy to high. i would not rev your car over 4k until sorted.
Title: boost .88 knock 82 inj duty 92%
Post by: John_Hudson on February 09, 2008, 02:52:41 PM
on my old map before upping my primaries i was seeing 90% odd duty and it never gave me any problems, knock seems abit high but that as many will tell ya might be due to a duff sensor
Title: boost .88 knock 82 inj duty 92%
Post by: tezz12345 on February 09, 2008, 02:57:43 PM
it pops a bit and i think thats whats sending knock up. under full boost the knock gauge is low when i have it displayed
but why is having a injector duty over 90 % dangerous
Title: boost .88 knock 82 inj duty 92%
Post by: BlitzBoy on February 09, 2008, 03:11:06 PM
so long under boost knock is low under 60 thats ok, the sensor does pick up the pops and bangs on decell I regularly got 150 readings on decel,
duty cycle is a bit high at 90 but not dangerous, its when it gets to 95 then you need to worry and get a bigger pump
Title: boost .88 knock 82 inj duty 92%
Post by: SiH on February 09, 2008, 05:19:44 PM
Quote from: BlitzBoyduty cycle is a bit high at 90 but not dangerous, its when it gets to 95 then you need to worry and get a bigger pump
Is it not injectors you need to worry about when the duty is that high? ;)

AFAIK recommended accepted max duty cycle a lot of people will recommend is 85%ish, but loads of people run more than that with no issues, you may be stretvhing it a bit though - I\'d say the best thing would be to talk to your tuner and discuss the readings with him :)
Title: boost .88 knock 82 inj duty 92%
Post by: BlitzBoy on February 09, 2008, 06:02:18 PM
Quote from: SiHIs it not injectors you need to worry about when the duty is that high? ;)


no its the pump is the very FIRST thing you upgrade along with a good FPR you increase fuel pressure, therefore you can remap and you will see injector duty will go down
Title: boost .88 knock 82 inj duty 92%
Post by: chrisJDM on February 09, 2008, 09:21:17 PM
if you want to start putting the boost up over standard you really want to look at changing the fuel pump and injectors to be safe as the standard ones will be straining at anything over standard, i think a while back when mine was standardish i had a power fc and had it mapped to 0.85 bar and one time it hit 0.88 bar and the injector suty was something like 92%

Also that knock level does not sound good if you are constantly getting it
Title: boost .88 knock 82 inj duty 92%
Post by: SiH on February 10, 2008, 08:09:48 AM
Quote from: BlitzBoyno its the pump is the very FIRST thing you upgrade along with a good FPR you increase fuel pressure, therefore you can remap and you will see injector duty will go down
Yeah, I get that, but 95% injector duty is down to the speed/flow of injectors, not the pump AFAIK.
I\'m not disputing that you need a bigger pump to feed those injectors, but if the injectors are running at 95% and getting sufficient pressure, it\'s not the pump that\'s the weak link, it\'s the squirters, surely?

I see your point, and i know that it\'s an issue that divides a lot of people - higher capacity injectors at stock pressure vs lower capacity at elevated pressure.
I\'m in no way saying one\'s right or wrong btw, many ways to skin a cat etc :)
Title: boost .88 knock 82 inj duty 92%
Post by: tezz12345 on February 10, 2008, 08:59:03 AM
so what should i do get new pump n injectors lol
gonna sell soon
how much will all that set me back ?
car feels great and only these figures worry me
had not a care in the world untell that commander was put on lol
Title: boost .88 knock 82 inj duty 92%
Post by: SiH on February 10, 2008, 11:22:09 AM
pump and injectors would be a very good move imho :)
Bear in mind that after fitting them you will need the map tweaked for the injectors :)

Or you could jsut turn the boost down a bit ;)
Title: boost .88 knock 82 inj duty 92%
Post by: chrisJDM on February 10, 2008, 12:00:34 PM
if you dont want to spend much money you are probably better of putting the boost back to standard.  If you want to run higher then standard boost you realy want to look at new fuel system - fuel pump, rails, injectors etc, i bought the following kit from the us:

http://www.rx7store.net/product_p/extremefuelfd.htm

is a very good price and has everything you need, although they arent always the quickist at shipping the goods.  Then you have to add on the price of getting that lot fitted.  Then you also need a remap to cope with the changes.

I think some of the vendors above also do a fuel system kit wih everything in instead of having to buy all the seperate parts so you could have a look into that
Title: boost .88 knock 82 inj duty 92%
Post by: Madbadweasel on February 10, 2008, 01:02:16 PM
I need to do this at some point, On the PFC im reading 100% on my injectors at WOT around 7800rpm :(

Kyle
Title: boost .88 knock 82 inj duty 92%
Post by: m4drx on February 10, 2008, 01:08:05 PM
inj dusty in the 90s isnt bad unless its longer than a second or few etc but at 100% you are working your injectors as hard as possible with no room for error. any weakness anywhere will mean lean running and det.
Title: boost .88 knock 82 inj duty 92%
Post by: chrisJDM on February 10, 2008, 01:42:38 PM
madbadweasel - That is not good at all hitting 100%, if you keep doing that your engine is not going to last very long, you will run lean and then bye bye engine
Title: boost .88 knock 82 inj duty 92%
Post by: Madbadweasel on February 10, 2008, 09:19:45 PM
thats why ive dropped my rev limit on the pfc to 7000, seems a shame though, still running stock turbos and 10psi of boost, so i dont understand why there so high? Mapped by Pip at WGT......
Title: boost .88 knock 82 inj duty 92%
Post by: karl_tate on February 10, 2008, 10:14:12 PM
your pump or fuel filter may be partially blocked. what kind of duty are you getting at 7k??
Title: boost .88 knock 82 inj duty 92%
Post by: tezz12345 on February 11, 2008, 06:41:34 PM
is it easy to turn boost down on pfc? have not touched it other than monetring