Injector response time
Thread Starter
Joined: Jun 2007
Posts: 3,387
From: Baltimore, MD, USA
Injector response time
Does anyone know the lag time for 440cc Deatschwerks (Denso)? I think it's close to .7ms but I'm not sure.
FYI, here's a good resource:
http://injector-rehab.com/kbse/lag.htm
FYI, here's a good resource:
http://injector-rehab.com/kbse/lag.htm
Thread Starter
Joined: Jun 2007
Posts: 3,387
From: Baltimore, MD, USA
Here is the reply I received from Mike at Deatschwerks. AFAIC, this is an important first step when tuning. It should save me a lot of fuel map tweaking to compensate for using inaccurate response time and give a much better idle. Larger injectors typically have slower response times than smaller ones but not always. Mine are only 440cc and pretty slow.
Below is the latency information for that injector. 6v-17v in 1v increments, measured in ms
2.912.432.121.821.631.491.371.271.191.111.051.01
Hope that helps
Thanks
Mike
I plan to use the 13v value of 1.27ms which should be close enough. Certainly a lot closer than the FIC default of .5ms.
Below is the latency information for that injector. 6v-17v in 1v increments, measured in ms
2.912.432.121.821.631.491.371.271.191.111.051.01
Hope that helps
Thanks
Mike
I plan to use the 13v value of 1.27ms which should be close enough. Certainly a lot closer than the FIC default of .5ms.
Senior Member
SL Member
Joined: Dec 2007
Posts: 2,603
From: South Florida
^^ That will probably be too high.
Just for a reference, My 630cc's liked .931 and my 840cc likes 1.32
I would try about .600 at first and see if the car likes it. Set the response time, adjust your map to idle with STFT near zero - then use that number for the rest of the map at low load.. hold a rev of around 2000rpm - see if it is steady. If not, you will need to play around with the setting a bit more.
Just for a reference, My 630cc's liked .931 and my 840cc likes 1.32
I would try about .600 at first and see if the car likes it. Set the response time, adjust your map to idle with STFT near zero - then use that number for the rest of the map at low load.. hold a rev of around 2000rpm - see if it is steady. If not, you will need to play around with the setting a bit more.
Thread Starter
Joined: Jun 2007
Posts: 3,387
From: Baltimore, MD, USA
^^ That will probably be too high.
Just for a reference, My 630cc's liked .931 and my 840cc likes 1.32
I would try about .600 at first and see if the car likes it. Set the response time, adjust your map to idle with STFT near zero - then use that number for the rest of the map at low load.. hold a rev of around 2000rpm - see if it is steady. If not, you will need to play around with the setting a bit more.
Just for a reference, My 630cc's liked .931 and my 840cc likes 1.32
I would try about .600 at first and see if the car likes it. Set the response time, adjust your map to idle with STFT near zero - then use that number for the rest of the map at low load.. hold a rev of around 2000rpm - see if it is steady. If not, you will need to play around with the setting a bit more.
I wonder if the FIC value should be total lag time or just additional lag time? If the stock injectors had .7ms lag and the 440cc had 1.27ms lag, the correct FIC value would be .57ms. I dunno, I guess I'll just have to find the lag time that works best.
Last edited by ScionFred; Nov 10, 2009 at 04:23 AM.
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SL Member
Joined: Dec 2007
Posts: 2,603
From: South Florida
You're probably right, 1.27ms seems too high to me too. AEM says that all the injectors they've tested fell between .85 and 1.25ms and the ~440cc injectors listed by Injector Rehab range from .29 to .85ms. Pity I can't get accurate info from the manufacturer but thanks for the lag time tuning tip. It sounds like a good method to tune the lag time.
I wonder if the FIC value should be total lag time or just additional lag time? If the stock injectors had .7ms lag and the 440cc had 1.27ms lag, the correct FIC value would be .57ms. I dunno, I guess I'll just have to find the lag time that works best.
I wonder if the FIC value should be total lag time or just additional lag time? If the stock injectors had .7ms lag and the 440cc had 1.27ms lag, the correct FIC value would be .57ms. I dunno, I guess I'll just have to find the lag time that works best.
Thread Starter
Joined: Jun 2007
Posts: 3,387
From: Baltimore, MD, USA
Senior Member
SL Member
Joined: Dec 2007
Posts: 2,603
From: South Florida