Cammed fg fpv 315 boss auto help

[hrt042]

Guys, been tuning for many years with other brands of software. I have tuned stock cammed
cars with HPT and gotten pretty good gains etc until I met the FG 315 BOSS auto with Herrod cams.

If anyone has experience with this engine and Herrod cams or has some ideas please feel free to comment. I am happy to ring or message anyone who thinks they can help. I have spoken to Rob Herrod and his team a few times, they obviously use different software and appear to have some different tables. It's not uncomman for them to have issues with these cars, when I spoke to Rob Friday he was having issues with exact same model himself.

So on the dyno no drama, I got the gains expected by Herrod pretty easily re the cams, no problems, then it was time for a drive, that's where the issues started.

- When driving at say 40 or 50km/h if you take your foot off it will drive along at 1100 - 1200rpm and hold it's speed, so I reduced the drive airflow and the dashpot airflow etc above 900rpm, still no luck, reduced the decel timing to 1 degree, still drives at 11 to 1200rpm. Everything I have changed has made little difference.

- Starting, it was starting cold and occasionally hot. Now not either generally, I can't find any cranking airflow, played with cranking fuel up and down maxxed out the idle p/n air under 800 trying to help it, raised the multiplier, nothing. I can't find anything that will assist with this at the moment.

- the other issue I would like to fix is open loop fuelling at low rpm and idle, the 02 sensors are pulling up to 20% of fuel. I did download a new beta update today which had a table I hadn't seen before in Speed Density called tuning correction. I don't really know what the units are but I assumed lambda. seemed to assist.

Any assistance would be appreciated.

Thanks

[Giannaj]

When starting cold did it also idle very high and once it warmed
up did it start hunting and eventually stall?

[IH8TOADS]

Use the new HP scanner to your advantage. Having good data helps understand how the PCM works and what corrections may be required.

When you take your food off the throttle you want to know your spark source, fuel source, throttle source etc.

If the O2 sensors are pulling fuel it's not in open loop, sounds like your airflow and/or injector scaling needs work. If it isn't a mechanical issue, the airflow and Injector scaling calibrations is the most likely cause.

Don't worry about the SD tuning correction, that won't help in your case.

[hrt042]

The spark is dropping to the required numbers, throttle is around 15%.

I am aware it's not in open loop, but closed loop is the 02 sensors trimming the open loop table, therefore the open loop speed density table is some distance out. It's like a cam in an Ls motor they are always very rich down low in closed loop and in that case you correct the VE table (speed density) to get them right. In a VE for example I have them trimming less than 2 or 3% over the entire table in closed loop. Rob, Speed density corrects his cammed Fords. The injector scaling is stock, it's running stock injectors so that should not be an issue.

[hrt042]

When starting cold did it also idle very high and once it warmed
up did it start hunting and eventually stall?

No it was pretty good, even now once started it idles perfectly.

[IH8TOADS]

Should be pretty easy then, given that the boss motor won't have a unique SD slope and offset per cam angle. If you have two MAP points and two AFR readings for a given RPM breakpoint, you can run some maths to recalculate a slope and offset for he map per airmass and map at zero airmass.

[FPV_GTp]

The spark is dropping to the required numbers, throttle is around 15%.

I am aware it's not in open loop, but closed loop is the 02 sensors trimming the open loop table, therefore the open loop speed density table is some distance out. It's like a cam in an Ls motor they are always very rich down low in closed loop and in that case you correct the VE table (speed density) to get them right. In a VE for example I have them trimming less than 2 or 3% over the entire table in closed loop. Rob, Speed density corrects his cammed Fords. The injector scaling is stock, it's running stock injectors so that should not be an issue.

HI , So what is holding the throttle open ?

cheers

[hrt042]

HI , So what is holding the throttle open ?

cheers

I really don't know, there shouldn' t be anything holding it open, when I first drove the car, all airflow settings were stock and it was still doing it.

[Grant LS1]

I'm pretty sure bog stock car's have the same throttle angle at idle, only assuming it's what allows it to idle considering there is no IAC!

[IH8TOADS]

Like I said...datalog using the new scanner. ETC Throttle Angle Source will tell you where the command is coming from. There is sources for closed pedal, cranking, idle control, speed control, torque control and so on.

No one here will be able to answer your question, you're going to have to use resources available (data logging) to get to the bottom of it.

Have you used the Idle Adaption STIT (idle airflow integrator) to fine tune your idle airflow tables. This alone can take some time.

[hrt042]

Like I said...datalog using the new scanner. ETC Throttle Angle Source will tell you where the command is coming from. There is sources for closed pedal, cranking, idle control, speed control, torque control and so on.

No one here will be able to answer your question, you're going to have to use resources available (data logging) to get to the bottom of it.

Have you used the Idle Adaption STIT (idle airflow integrator) to fine tune your idle airflow tables. This alone can take some time.

I'll have to assume it's in the new scanner, STIT, the answer is no. I have tuned a lot of cammed cars just not cammed Fords, I am pretty attuned to get the idle and airflow sorted. but this one just doesn't seem to have the tables I would expect to support it. I should say I have tuned a manual 290 with large cams that drove very well.

[Central vic performance]

just curious I am trying to figure out if a car I'm working on is one in the same a grey 2009 fg 315 with herrod cams and exhaust fitted by herrod runs terrible hunts and pings they tuned it with a sct I had to put back to the aparently stock file in the sct to read it herrod have told the owner that they cant fix it and offered to take the cams out