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Fairly conservative timing up top. What comp are you running? I guess with the 3.15l and standard cams there is huge dynamic compression

Around 8.25:1. The rod ratio allow the engine to tolerate a little more ignition than a long rod engine too. The map is a long way off being finished. There is room for quite a few more degrees below 2000 rpm at light load and also ramping onto boost. Once the tune is finished i'll post up a completed copy of the map.

Just about to rescale my map now, and then go for a test drive.

Regarding the settings 2 INJ vs TPS, im guessing adding a correction here works similar to a RPM vs TPS fuel map might? Whatever the current load/rpm point is, a correction factor is applied to that load point based on TPS. And with the default values being 1.000, it means entirely by map.

And then I might need to add more fuel progressively from low to the high end of the TPS scale, in order to prop up the AFR's.

I thought I had the tune pretty much dead on right for low end drivability until I drove up a nearby range yesterday. The extra load the engine was under had the afr's dipping into the 16's at 2000 rpm when cruising at 60km/h in 4th. That load wasn't being reflected in the MAP sensor as the engine produces really good vacuum and has good low end torque.

While thats still safe, the same cruise speed and gear on level ground was around 14.7:1. (at this stage im more concerned with completing a run in, so im not too woried about aiming for maximum fuel economy.)

I'll take you up on that offer too Trent, and will email you a copy of the map once ive finished my latest bunch of changes and re-tune.

Cheers,

Ian

sorry ian i was on the dyno yesterday tuning another d-jet when i had a terrible realization i has posted the wrong parrameter (i had remembered the headers wrong), ignore the TPS vs INJ it is inj vs accel you need to play with.

sorry but thats what i get for posting withut the software infront of me... too many tuning suites and so many different names for similar things.

It pissed me off more that i got it wrong as i so often see the INJ vs TPS adjusted and it really plays havoc with a tune and i always set them to the default 1.000

again sorry.

Not that it will do much for you but here it is. 14000 is the pim value for 0.8 bar boost. The scale is calibrated with a 3 bar map sensor. As you can see there is still plenty to do with the tune. The goal at the moment for me is keeping it safe.

dont want it for me, was just curious. something you can do sitting at home, could use a fair bit more timing under light load between 1500 and 5000rpm. standard maps go up to ~50 degrees around 4000rpm, makes a huge difference to the way it drives off boost

Edited by JonnoHR31

sorry ian i was on the dyno yesterday tuning another d-jet when i had a terrible realization i has posted the wrong parrameter (i had remembered the headers wrong), ignore the TPS vs INJ it is inj vs accel you need to play with.

sorry but thats what i get for posting withut the software infront of me... too many tuning suites and so many different names for similar things.

It pissed me off more that i got it wrong as i so often see the INJ vs TPS adjusted and it really plays havoc with a tune and i always set them to the default 1.000

again sorry.

No worries. Ive already had to fatten up the acceleration enrichment a little to cure the flat spots. Ive left the INJ vs TPS at default for the moment too.

pretty much everyone I know adds a little in no 5 and a little more in no 6. very easy to do with injector correction % values. just trim in a bit there. to do it properly though you really need to measure the AFRs and/or EGTs in each runner and get it right that way, but just for a simple mid range kind of set-up adding a bit of fuel to compensate for the extra heat in no 6 and the extra air it gets (plenum design) is a good idea.

I hear what youre saying but i'm sure no one goes through the hassle of checking egts on each cylinder to get it spot on, especially on a stockish to mildly modified 26

Anyone cares to share the numbers for a 26 with stock injectors and plenum just for reference???

  • 2 weeks later...

i have the egt data from the greddy plenum on gtr somewhere on my laptop from the engine dyno testing i will post it up later just for interest sake. std GTR plenum compensation is minimal.

i did post it all up before but not sure where.

If you do it this way you can make changes on the fly to the main map without a A/f meter (say @ track day) because your changes in the main map are secondary to the base map.(providing the base map was setup on the dyno like i posted above)

Interesting, so it is fairly linear and should be reasonably accurate doing this?

yes, it'll keep using the same values. but you shouldnt ever really have your limiter set higher than your last ne point

I thought it interpolated the values, eg 7500 and 8000 points, if you are at 7750rpm it picks fuel and ignition half way between this, if your last value is at 8000 and you rev to 8500 it will keep linearly interpolating the values so it will inject more fuel still? might not be what you want but it won't hold flat surely?

Edited by Rolls

it interpolates between cells but if you go past the end of the map it'll keep using the same value as the last cell on the map (for whatever axis you've maxxed). it wont keep following the previous interpolation.

i certainly would do it, if you set the map up properly it'd never go outside the map anyway but even if it did it'd be safe. for example i have the last low road on my map set rich and retarded and the row just past rev limiter the same for safety.

an extreme example, imagine the last cell had 1 more degree of timing than the 1 before it, if it was set up the way you describe the timing would rise as you get further and further away from the limit of the map, hardly a good thing. much safer to have it flatline.

most newer ecus have protection features and you can set them up to cut everything if you overboost/over rev etc.

an extreme example, imagine the last cell had 1 more degree of timing than the 1 before it, if it was set up the way you describe the timing would rise as you get further and further away from the limit of the map, hardly a good thing. much safer to have it flatline.

most newer ecus have protection features and you can set them up to cut everything if you overboost/over rev etc.

Yeah good point, didn't think of the ignition. Proper protection features will always be better option.

i have the egt data from the greddy plenum on gtr somewhere on my laptop from the engine dyno testing i will post it up later just for interest sake. std GTR plenum compensation is minimal.

i did post it all up before but not sure where.

Hey Trent, do you still have the egt data for the greddy plenum/RB26?

Cheers

Justin

Any luck finding the data Trent?

And could someone pls tell me where can i find the maps and logs that are saved?

If i go to Program files > fc edit universal > maps All i can see is the sample maps that came with the software

Edited by Don Dada

The address its tell me is the same as above

Also if i go into File > open i am seeing the maps and the logs that i saved but it has a little lock on the icon.... i can open the logs from there into map watch and maps on to the main screen but again i cant see them if i go outside datalogit

vista? if so you need to install fc edit anywhere but program files, or turn off the feature that stores everything in program files in a seperate place, cant remember what its called.

Edited by JonnoHR31

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