View Full Version : B18CR+ITB+BC III Cams = maxxed-out ITR injectors?
Hey guys,
Had some tuning done on friday, and it was found that the AFRs were uncontrollably lean in the VTEC range. The fuel pump was measure to be flowing well (Walbro:thumbsup:), however the injectors were measured at 96% duty cycle.
I was surprised by this, I didn't expect stock ITR injectors to be maxxed using the stock bottom end. Modifications are essentially what would be classified as 'medium budget':
B18CR motor
Head: BC spec III cams, cam gears, valves, valve springs, retainers, ARP studs
Spoon thinner head gasket
Bottom end: stock
Intake: OER quad throttle (ITBs), TWM airbox, BMC carbon dynamic airbox with cold air intake from bumper
Exhaust: J's Racing 4-2-1 header, custom catback
I'm still learning these hondas, but I was surprised that I need to upgrade the injectors already. I've got some RC 370cc on the way courtesy of JDMYard:)
I'd hope if the injectors can't flow enough fuel, it means there's a little bit more air entering the engine now... so that should mean with bigger injectors and proper tuning we can get some more power?
Also, after doing a lot of research and speaking extensively with my tuner about ITBs+ECUs, it seems TPSvRPM tuning is what's required instead of normal MAP sensor which requires vacuum. To get a
I think some of the guys on here mentioned that I can get rid of the 'vacuum tree' set up if I use a HONDATA, because that's essentially only necessary when you're tuning of MAP???
I'd be interested to hear when others are changing their injectors?
regards
Shiraz
votek
22-09-2008, 02:12 AM
what kind of power did you make? ive also got the same setup but no ITBs and a tri-y header but i havent dynoed yet
IEVAQ8
22-09-2008, 08:44 AM
who is tuning it...........id love to come and watch..........hehehe
grumpy rooster
22-09-2008, 09:27 AM
H22A, standard bottom end, shaved and ported head, TWM 50mm quads, custom headers, 3" exhaust = maxed out H22A injectors (145kwatw)
barefootbonzai
22-09-2008, 10:26 AM
That's interesting, i had a fairly similar setup to that, but my stock injectors held up fine. Let us know how it all goes.
That's interesting, i had a fairly similar setup to that, but my stock injectors held up fine. Let us know how it all goes.
That's what I thought. Will do
Redlinemotorsport
22-09-2008, 12:49 PM
i am doing exactly the same pretty much.
and havent had problems with injectors.
i am tuning off of tps because the map wasnt strong enough.
where u getting it done?
IEVAQ8
22-09-2008, 01:38 PM
yeh tell us who is tuning it?????????
TODA AU
22-09-2008, 03:30 PM
If your output is less than 200hp @ wheels, try using an adjustable fuel pressure regulator as maybe you're using a stock regulator?
OER quads come with a nice vacuum box & MAP sensor block.
So if your ECU is capable of secondary tables you can use both MAP & TPS mappping.
If not, it's one or the other & you'll get best response & power from TPS mapping.
votek
22-09-2008, 04:32 PM
power figures.........
i am doing exactly the same pretty much.
and havent had problems with injectors.
i am tuning off of tps because the map wasnt strong enough.
where u getting it done?
Is yours B16 or B18? We're tuning of MAP at the moment with PowerFC.
If your output is less than 200hp @ wheels, try using an adjustable fuel pressure regulator as maybe you're using a stock regulator?
OER quads come with a nice vacuum box & MAP sensor block.
So if your ECU is capable of secondary tables you can use both MAP & TPS mappping.
If not, it's one or the other & you'll get best response & power from TPS mapping.
Fuel pressure was measured at 5bar already, is that sufficient fuel pressure? Currently using MAP sensor with the PowerFC and even with the little tuning that's been done, it's feeling very good. If we are not satisfied with the result we will change to Hondata s300. My understanding is that fuel economy may be better with TPS as well, is that correct?
yeh tell us who is tuning it?????????
Dominic at Pro-tek in Thornbury.
power figures.........
No power figures yet, we'll have some after the injectors are in. It won't hurt to have some bigger injectors in even at this stage, as they will be required with further modifications in the future I'm sure.
IEVAQ8
22-09-2008, 04:59 PM
Dominic at Pro-tek in Thornbury.
kool.........any particular reason you chose dom to tune ur car??????????
i mean a honda????????
im not slaging him, i just want to know for future references.........
cheers
and good luck
votek
22-09-2008, 05:01 PM
who tunes your car IEVAQ8?
IEVAQ8
22-09-2008, 05:02 PM
who tunes your car IEVAQ8?
pm sent...........not coz i dont want to announce, but i dont want to take over this thread
For a number of reasons. A close friend of mine has been running a 10 second street-driven R33 GTR and that's been running strong, with all work done by Pro-tek. I've spoken to Dom a few times about tuning ITBs etc. and his claim to experience is backed by his knowledge. I like to be involved in the building and tuning of my car, and I can do that with these guys. Lastly, i live <5minutes away! That's very handy.
AKMotorworks and Melbourne Performance Centre were my next choices, however they are much further away. Makes sense to first try a local workshop if you feel comfortable with them.
For the record, we currently have cars tuned at Pro-tek, STi Melbourne (docklands), Racepace (GTRs, bayswater) etc. so I'm always open to suggestions :-)
IEVAQ8
22-09-2008, 05:05 PM
kool.................thanks for the info...............
if it suits you, and it works for you, and ur happy by almeans stick with him.........
again good luck with it all and hope u figure out the issue ur having
fatboyz39
22-09-2008, 05:05 PM
pics of graph.
Thanks, shouldn't be too much of a drama with the new injectors, hope to have the car back on the dyno end of the week. I've found in the past that the quality of a tune sometimes relates to how much effort you can get your tuner to put in. Helps to develop good relationships with the tuners :-)
IEVAQ8
22-09-2008, 05:09 PM
^^^^^^^i agree 150%
TODA AU
22-09-2008, 09:34 PM
Fuel pressure was measured at 5bar already, is that sufficient fuel pressure? Currently using MAP sensor with the PowerFC and even with the little tuning that's been done, it's feeling very good. If we are not satisfied with the result we will change to Hondata s300. My understanding is that fuel economy may be better with TPS as well, is that correct?
Could be the wrong Walbro pump...
See here: http://www.autoperformanceengineering.com/html/fpspecs.html
You should be using the high pressure 255L/Hr pump.
TPS economy is worse...
MAP is better...
With S300 you can have both... :thumbsup:
fatboyz39
22-09-2008, 09:46 PM
power fc can only tune either TPS or MAP?
I believe it can only tune MAP.
Could be the wrong Walbro pump...
See here: http://www.autoperformanceengineering.com/html/fpspecs.html
You should be using the high pressure 255L/Hr pump.
TPS economy is worse...
MAP is better...
With S300 you can have both... :thumbsup:
I believe that is the pump in the car :thumbsup:
S300 sounds good :cool:
TODA AU
29-09-2008, 12:30 PM
How did you go with this?
Just a thought, it's not something dumb like a blocked fuel filter is it..
Just received my injectors today actually. I had not actually considered the fuel filter. I'll be sure to get the guys to check the fuel filter before fitting the injectors in. Thanks for the suggestion
For those who are curious, got the injectors, i may postpone the fitment of the injectors and further tuning until after i've finished some other elements of the build. I think if the car's going to be off the road for a few weeks, might as well do final tuning after that.
there a tech note on hondata about going lean on high duty cycles.
http://www.hondata.com/techduty.html
Although all this is out of my league.
> Fuel pressure was measured at 5bar already
That's 73.5 psi. Sounds high-ish to me. What's considered a safe level guys?
Nick.
dumped echo
04-12-2008, 10:34 PM
i think i read that normal pressure is around 50psi when the vaccum hose is disconnected
....oh i just checked the honda manuals...b16a1(38-46), b16a2(40-47), b18c5(47-54) with the vacuum hose disconnected and pinched.
In any case...i guess you should test if the fuel pressure drops as you get into the lean areas.
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