Bob Kenney said:
It is now Tuesday and Im dying to know also!
Does anyone want an overview UNDERSTANDING YOUR FUEL SYSTEM?
- Thread starter BadCarma
- Start date
It is now Tuesday and Im dying to know also!
Sorry for keeping you guys in suspense. Finally got the car back last night. Great news: 349 whp (6 lbs boost CTSC) with A/F ratios between 11.4 and 11.8!
One small problem: The bigger injectors combined with the Apexi are creating an overly rich situation at lower RPM's when the throttle is less then 1/4 open. This will take some trial and error adjusting of the Apexi, unless I want to get a dyno for an entire day and do runs at constant 2000 rpm for 3-4 mins, and then the same at 2500 and then at 3000.
I know when it is too rich when the "check engine" light comes on, which is a pain, but I am ironing it out and I am pretty confident that in several days of driving it will be nailed down.
No issues at bigger RPM's or with the throttle laid down. Just low rpm and throttle open only a little. This is a daily driver and when I am in traffic at constant 2000 or 2500 or 3000 rpm's for 5+ minutes straight, the "check engine" light comes on. I pull over adjust the Apexi for the less then 50% throttle open range for the relevant RPM, restart the car and go. I am getting it close to properly adjusted.
If anyone has expertise in fine-tuning this Apexi unit, I would love to hear from them. Thanks to all.
One small problem: The bigger injectors combined with the Apexi are creating an overly rich situation at lower RPM's when the throttle is less then 1/4 open. This will take some trial and error adjusting of the Apexi, unless I want to get a dyno for an entire day and do runs at constant 2000 rpm for 3-4 mins, and then the same at 2500 and then at 3000.
I know when it is too rich when the "check engine" light comes on, which is a pain, but I am ironing it out and I am pretty confident that in several days of driving it will be nailed down.
No issues at bigger RPM's or with the throttle laid down. Just low rpm and throttle open only a little. This is a daily driver and when I am in traffic at constant 2000 or 2500 or 3000 rpm's for 5+ minutes straight, the "check engine" light comes on. I pull over adjust the Apexi for the less then 50% throttle open range for the relevant RPM, restart the car and go. I am getting it close to properly adjusted.
If anyone has expertise in fine-tuning this Apexi unit, I would love to hear from them. Thanks to all.
jmp said:
JMP, Great news! now I have just read your last post so cut me some slack I wish some info from you.
1. What size injectors are you running and are they peak-hold or saturated? what is the brand and have they been C&C'D, Even brand new ones have been known to run at not specified flow per cc right out of the box.
2. how is she at idle,describe systems if any.
3, What version of Apexi piggy back fuel controller are you running.
I have tuned cars with the AFC and with my motor swap of the sr20det into my CRX I will need a version of it. the motor lays down 205 at the crank on stock turbo but is a very strong motor with a sick bottom end it comes out of a car not imported called a bluebird,the only difference seems to be the standard sr20det is mounted NON transverse in the silvia and swaps into the 240sx .on the bluebird motor it is disigned for transverse mounting,that seems to be the whole of it as the bluebird is front wheel drive and the silvia and 240sx are both rear wheel drive so it all makes sense.both produce amazing hp numbers even with the stck turbo..with proper fuel management and the right turbo upgrade along with quality turbo componants she can deliver 350 whp without opening her up(This is the transverse model JDM sr20 not the one going into the 240sx cars and harder to find with only 20k on her). A CRX with 350 at the wheels is the goal...the car curbs at 1800 pounds!!gonna be sick. anyway looks like we will both be tuning with Apexi and should share info and tips and tricks.
I plan on spending lots of dyno time and IN car tuning, the apexi is just for now until I go to the AEM,I am upset with them for price hikes that bear no reasonable factors other then blatant greed.a year ago they were 1250-1500 and now 2250-2500
WHY? becuase more tuners are trained on them,their are more maps available in the library.I am sorry that does not warrant the hike IMHO.So glad to see that A/F on your car,sounds like you are getting close to a complete dial in.please do get back to me with the info I requested and the AFC you are using.and I have every intention of sharing any and all tuning tips I come up with.
Best Regard David
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jmp
Congratulations on the positive progress; I do hope it continues until all issues are resolved to your satisfaction.
Do you know what duty cycle the injectors are operating at?
What have you done to work with the CT voltage boost to the stock fuel pump?
Are the injectors you are running RC Engineering.
Have you made any modifications to the fuel regulator?
[I believe that CT is a rising rate, AEM is a 1-1 ratio]
David,
The CRX conversion sound like serious fun; I hope your progress is a good as jmp's progress on resolving his AF issues.
Please clarify the difference between peak-hold and saturated injectors. Which of these 2 types is preferred for a boosted NSX engine application and why?
What is the relationship between Lbs of boost and injector size?
How much is that relationship/size effected by displacement increases?
At what size do injectors become too big to operate efficiently?
Bob
Congratulations on the positive progress; I do hope it continues until all issues are resolved to your satisfaction.
Do you know what duty cycle the injectors are operating at?
What have you done to work with the CT voltage boost to the stock fuel pump?
Are the injectors you are running RC Engineering.
Have you made any modifications to the fuel regulator?
[I believe that CT is a rising rate, AEM is a 1-1 ratio]
David,
The CRX conversion sound like serious fun; I hope your progress is a good as jmp's progress on resolving his AF issues.
Please clarify the difference between peak-hold and saturated injectors. Which of these 2 types is preferred for a boosted NSX engine application and why?
What is the relationship between Lbs of boost and injector size?
How much is that relationship/size effected by displacement increases?
At what size do injectors become too big to operate efficiently?
Bob
CT regulator -- Not changed
Voltage -- unchanged
Brand -- Not RC. Premium (hi-resistance) vs. RC's low resistence. My guy recommended this setup over RC.
The Apexi is setup to attempt to deal with all of these variables, which is what makes this complicated.
Voltage -- unchanged
Brand -- Not RC. Premium (hi-resistance) vs. RC's low resistence. My guy recommended this setup over RC.
The Apexi is setup to attempt to deal with all of these variables, which is what makes this complicated.
Bad Carma -- Was wodnering what your opinion is of the accuracy of an Autometer A/F gauge? Obviously, it shows only colored spectrum ranges, but if it is showing in the medium to "rich" range would you consider that reliable? A buddy of mine has not has his newly CTSC'd NSX dynoed and was wondering about this. Thanks.
jmp said:
If you like pretty lights sure why not,as for gauging your A/F toss it. its narrow band and IMHO sucks. you need to go wide band if you want to know whats really going on with your A/F . just MY opinion and you know what they say about those although I beleive it is science in regard to accuracy of wide versus narrow band A/F gauges. if you are thinking of getting one for a show car it doesnt matter but for real world use see above opinion.
Best Regards David
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