entropy
Moderator
Posts: 8671
|
posted November 01, 2009 04:24 PM
 Edited By: entropy on 2 Nov 2009 00:32
fuel pressure logging: hmmmmm...
Once again, I took a tip from TimChin and set up fuel pressure logging.
On the dyno, i noticed a couple things, I wonder if they are normal????????
At 3400 rpm (warmup), not under load pressure was 40.6 steady
under load, the
5300 rpm step = 44.8psi
9460 rpm step = 42.6psi
10400 rpm step = 40.9psi
12260 rpm step = 39.6psi
(just a few of the MANY steps we did tuning for adv/fuel combos)
after dyno steps, idling, not under load, getting ready to shut down 2220rpm = 35.9psi
looks like the system lost 5 psi in the process of the dyno session.
Is it normal for the fuel pressure to vary when the fuel heats up???
The motor was at the same temp for all pressure readings, Andy does not start the session until motor is 100% heat soaked.
I put a new Muzzy pump in it earlier this year.
I THINK, it was back to normal after total cool down in my garage, not positive.
I did check carefully the correlation of pressure gauge & logged pressure at the beginning of the dyno session, but i did not check that they were reading the same at the end. Maybe the transducer gets tired after all that work?
The TB's are off the bike at the moment, next week end, the plan is mount an adj regulator & test OEM injectors at 70psi (like Pierre suggested)
BTW leakdown after dyno was 2.0 - 3.0 - 3.5 - 1.0%, about same as last week, for which I am happy 
____________
This moderator uses moderation in moderation
  
|
almost_les
Zone Head
Posts: 590
|
posted November 01, 2009 04:27 PM
1st gen right? with the regulator on the rail? when it gets warmed up the spring inside is probably getting a little soft. thats all i can think of.
|
entropy
Moderator
Posts: 8671
|
posted November 01, 2009 04:30 PM
quote:
1st gen right? with the regulator on the rail? when it gets warmed up the spring inside is probably getting a little soft. thats all i can think of.
yup, regulator on the rail.
perhaps next Sat test with the adj regulator will be interesting.
____________
This moderator uses moderation in moderation
|
entropy
Moderator
Posts: 8671
|
posted November 02, 2009 05:51 AM
got the adj fuel pressure reg & OEM injectors on this morning, set the reg at 70 psi static.
after work, i'l try to fire it up; hopefully the Bosch 430 map is close enough.
____________
This moderator uses moderation in moderation
|
gixxre750
Novice Class
Posts: 42
|
posted November 02, 2009 11:38 AM
to much leakdown imo. I dont like anything over 1.5%
|
tcchin
Zone Head
Posts: 867
|
posted November 02, 2009 12:46 PM
ouch
|
entropy
Moderator
Posts: 8671
|
posted November 02, 2009 12:56 PM
quote:
to much leakdown imo. I dont like anything over 1.5%
you must have small pistons.
On my 87mm pistons, with brand new pistons, rings, cyl hone, valves & seats, I've never seen 1-1-1-1 or 1.5-1.5-1.5,-1.5
(obviously need a lil run time to let things settle in)
____________
This moderator uses moderation in moderation
|
entropy
Moderator
Posts: 8671
|
posted November 02, 2009 12:57 PM
quote:
ouch
Tim,
any thoughts about the 5psi drop from dyno session start to finish?
real?
measurement?
____________
This moderator uses moderation in moderation
|
Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
|
posted November 02, 2009 04:51 PM
Its possible its something with the vacuum supply to the regulator.
The throttle position needed for holding the engine at a given rpm in neutral, can vary depending on heat soak, oil temp, etc.
So this can change the vacuum signal to the regulator.
Just a thought.
Karl, Make a volume\pressure graph for us so we can point out the anomalies in the flow coefficient of the regulator itself.
Yea like you have time for that. 
____________
Y2KZX12R
CompetitionCNC.com
|
tcchin
Zone Head
Posts: 867
|
posted November 02, 2009 08:08 PM
My slightly incoherent thoughts, assuming that the motor was really heat-soaked before the first pull, include: issues with the vacuum side of the regulator, boiling/foaming of the fuel in the rail, thermal expansion of the pump housing/impeller causing some losses in the pump itself, and thermal voltage issues with the pressure sending unit. I doubt a metallurgical problem with the regulator spring, as the melting point of steel is over 2000F.
Maybe move the regulator to an in-tank model to use the fuel as a heat sink, or at least move it off the fuel rail and insulate everything with foil-backed fiberglass fabric. Also, disable the vacuum stuff on the regulator. Finally, use a 255lph high-pressure pump, as they have better flow rates at high pressures (like the 70 psi you're proposing). I can look up the model numbers for you, if you like.
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted November 02, 2009 09:02 PM
Exactly
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
|
entropy
Moderator
Posts: 8671
|
posted November 02, 2009 11:17 PM
Thanks for the thoughts!
Foaming? good possibility, fuel was way-way low at the end of the dyno session, should have topped it up
The motor seems to be running really strong so i don't want to make any impulsive changes (yet).
Fired it up for a sec yesterday afternoon with OEM injectors & adjustable regulator at about 75psi, so at least I know it'll run with that set up.
Besides watching the fuel pressure this Sat dyno is aimed at:
1. see the hp/rpm response to OEM injectors @ 70psi
and,
2. if hp with that setup climbs past 11.5k like it does with the Marren/Bosch 430's, see what happens at 12.5, 12.75, 13K
.
____________
This moderator uses moderation in moderation
|
tcchin
Zone Head
Posts: 867
|
posted November 03, 2009 12:12 AM
quote:
quote:
to much leakdown imo. I dont like anything over 1.5%
you must have small pistons.
double ouch!
|
KZScott
Needs a life
high on speed
Posts: 7235
|
posted November 03, 2009 05:28 AM
keep us posted!
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
|
|
|
HOME
NEW TOPIC