Duty cycle 114%

Clifton · Post by **Clifton** » Thu Jun 15, 2006 7:38 pm

I've heard that you should go over 80% but I didn't know you could go over 100%. Is it really possible to go over 100%? The log says it peaked at 114%.

rs2000 · Post by **rs2000** » Thu Jun 15, 2006 7:50 pm

I think when that happens it means according to the calculations duty cycle should be 114%, but your injectors will be maxed out at 100% duty cycle.

Check your not leaning out

andrew

Clifton · Post by **Clifton** » Fri Jun 16, 2006 3:28 am

Thanks, that makes more sense. AFR's were good.

whittlebeast · Post by **whittlebeast** » Fri Jun 16, 2006 3:38 am

Even if the afr'r are ok... you have to deal with the 114% Depending on the RPM and the injectors you may be able to push things into the 95% range but it is rare that the delivered fuel will remain linier in.

AW

Clifton · Post by **Clifton** » Fri Jun 16, 2006 4:00 am

I'm running 550's now. I have a set of 680's that I started with but the idle wasn't so great so I swapped them before the firts drive. I think I'm going to have to put them back in as I plan to run more boost when not running pump gas.

whittlebeast · Post by **whittlebeast** » Fri Jun 16, 2006 4:15 am

What code are you running ?

boost junkie · Post by **boost junkie** » Fri Jun 16, 2006 4:56 am

I'm runing 780cc on a 2.0L engine. 680's will definately work. Just need a little more tuning.

Mike Braddock · Post by **Mike Braddock** » Wed Jun 21, 2006 7:10 am

Guys,

What are your ReqFuel values and idling VE bins? I ask because I am trying to run a set of 550 cc/min injectors in a 1.6L turbo (calculated ReqFuel = 4.9ms) and can't get it anywhere close to idling even with VE bins of 1% and ReqFuel lowered to 1ms. Needless to say AFRs are off the chart at ~ 10:1! I posted a thread here with my problem but would like to hear your experience with tuning idle with such large injectors. I don't mean to hi-jack this thread; I'm just curious and would like to keep Clifton from running into similar problems. Thanks!

Mike

ptegler · Post by **ptegler** » Wed Jun 21, 2006 8:28 am

Even boosted those injectors seem large to me. Granted I'm
running an NA 2 liter 6 cylinder but an using 14 lbs
(150cc?) injectors and even with those my idela is just
barely 2mS

ptegler

On Wed, 21 Jun 2006 08:10:34 -0700
"Mike Braddock" <mjb@ufl.edu> wrote:
> Guys,
>
> What are your ReqFuel values and idling VE bins? I ask
>because I am trying to run a set of 550 cc/min injectors
>in a 1.6L turbo (calculated ReqFuel = 4.9ms) and can't
>get it anywhere close to idling even with VE bins of 1%
>and ReqFuel lowered to 1ms. Needless to say AFRs are off
>the chart at ~ 10:1! I posted a thread here
>(http://www.msefi.com/viewtopic.php?p=126823#126823) with
>my problem but would like to hear your experience with
>tuning idle with such large injectors. I don't mean to
>hi-jack this thread; I'm just curious and would like to
>keep Clifton from running into similar problems. Thanks!
>
> Mike
> _________________________________________________________
> This post is at:
> http://www.msefi.com/viewtopic.php?p=126825#126825

Paul Tegler
ptegler@cablespeed.com
Posted by email.

Clifton · Post by **Clifton** » Wed Jun 21, 2006 1:13 pm

I put the 680's (actually they flowed 700cc) back in. My fuel requirement is 4.8, 2 inj per cycle alternating. Idle fuel is 32 at 600 and 1300 rpm and 40 and 50 kpa. Timing is 10*. The AFR hunts a little at idle but seems to do better if it's on the rich side, upper 13's. Engine has 500cc per cylinder.

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Duty cycle 114%

Duty cycle 114%

Can you really idle with those large injectors?

Duty cycle 114%