The 15 Y/O Turbo M42 Build Thread (Now Holley EFI Terminator X Controlled)

[wazzu70]

I would change the req_fuel to the correct number, then multiply the whole VE map by (old number/new number).

You will also have to change the value for all cells that reference VE or req_fuel values.

Can you link an MS expert to the thread so they can give feedback on which cells might be impacted? Get Nando in here??

[Dj Buttchug]

I would change the req_fuel to the correct number, then multiply the whole VE map by (old number/new number).

You will also have to change the value for all cells that reference VE or req_fuel values.

Can you link an MS expert to the thread so they can give feedback on which cells might be impacted? Get Nando in here??

okay so heres an update. I adjusted the req fuel down to 3.4 like the mega manual says, but the car was even HARDER to start and when it was running it ran like shit.

So i up'ed the req fuel back up to six and then increased to 7 and tapered off till my idle deteriorated. final setting now is 6.8 req fuel.

Mega manual states that the req fuel calculator will get in you in the ballpark on 99% of engines.... so im wondering if i fall in the 1%

With my req fuel setting at 6.8 the car idles AMAZING. its JUST like stock motronic.

Tomorrow morning I will see how it starts cold from here. The higher req fuel seems to be giving me better AFRs into boost as well.... im seein low 12s into high 11s now.


my question is this: Is running an abnormally high req fuel terrible? does it have any downfalls? Should I run a lower req fuel and multiply my tables accordingly? Obviously the engine efficiency is effected...


lol


im way in over my head. i can build an engine but i cant even tune it.


fuck

[wazzu70]

It depends which option is best to take. Personally I would go with req_fuel values that make sense so your VE numbers are more comparable to other peoples. At the end of the day though VE and req_fuel are just numbers and the only thing that matters is the amount of fuel the injectors are giving.

Having incorrect req_fuel values may make others helping you difficult as the help generally assumes you have settings correct.

If you just reduce req_fuel without multiplying the VE table your engine will run like butt since you essentially just cut the fuel in half!

[nando]

you also have to adjust your startup curves when you adjust REQ_FUEL, the ones that are set to a % are multiplied by the REQ_FUEL value. so when you cut your REQ_FUEL by half, your startup curves that use it also got cut in half.

and yes, having a correct REQ_FUEL is important, because it affects everything - this is the base PW that every trim/correction, including VE, starts from!

I've never seen a case where REQ_FUEL wasn't close. if you go from 6.8 to 3.4, all you need to do is multiply your VE tables by 2, and effectively it's the same.

[Dj Buttchug]

you also have to adjust your startup curves when you adjust REQ_FUEL, the ones that are set to a % are multiplied by the REQ_FUEL value. so when you cut your REQ_FUEL by half, your startup curves that use it also got cut in half.

and yes, having a correct REQ_FUEL is important, because it affects everything - this is the base PW that every trim/correction, including VE, starts from!

so I should use my calculated req fuel setting of 3.4 and then adjust all my tables ?

[wazzu70]

Yes :)

[nando]

Yes :)

I believe the only startup curve you have to adjust is maybe cranking pulse, but I don't remember exactly - it's whichever one is set to a %. double that curve, and your VE tables, and you're set.

[Good & Tight]

What are your injectors set at to squirt? how many squirts and are they alternating or simultaneous.?

[Dj Buttchug]

will post all my settings in engine constants and warm up enrichments asap

[Dj Buttchug]

here are my engine constants, spark settings and cranking pw settings.

I still cannot get the car to start @70-80 degrees temp. It will try and start SOMETIMES but its so intermittent that I cant pinpoint what changes help or hurt. If I flood clear with the throttle it still doesnt start no matter what.

Im only wanting to deal with cranking settings right now as stated in the mega manual the ecu only reverts to the ve table after the engine is actually started so it has to be something wrong here. If I cannot get the car started and idling cold then I cant go any further. I adjusted cranking pw @ the corresponding temps giving it more fuel, then less fuel. regardless it still wont start so it leads me to believe my cranking spark is off....

[Schnitzer318is]

Any more luck sending that msq and project to my emails?

I spent some time with a soldering iron and my tuning lap top this morning and managed to get it up and running again (ground wire on the power brick had broken inside the sheathing) so I can help out now by actually comparing our setups.

As a side bonus now I am anxious to try out some of the new features of Tunerstudio I noticed when it updated, namely autotune startup enrichments.

[Dj Buttchug]

^ just emailed you back and sent over the tune.

To everyone in this thread helping me get dialed in I cant thank you guys enough. Would like to incorporate the idea "tuned by r3v" into my build or something.

id die without this forum

[wazzu70]

We got yo back!

We all had to learn at one point, and we wouldn't learn without people giving us help. Its the gift that keeps giving!

[Dj Buttchug]

We got yo back!

We all had to learn at one point, and we wouldn't learn without people giving us help. Its the gift that keeps giving!

:up:

So update for tonight is as follows: I thought I had my hot start dialed in yesterday but apparently that is not the case.

Tried to get it started this morning @ around 8am. Engine Coolant Temp at that time was 68 degrees that quickly moved to 70-75. I adjusted cranking pw at the correct temp and got the same results. Still no start. I gave it more cranking fuel too, still nothing.

So I got sick of cranking the car (im surprised my starter still works) and gave up.

Then I went back at about 4pm today and tried again. This time my coolant temp is almost 90 degrees (where i park faces the sun so it gets toasty)
Finally after several tries I got it started. Let it run up to normal operating temp and then I shut it off and tried starting it again. Still a hard start.

excuse my video angle. iphones suck at fitting it to screen...

[Dj Buttchug]

starting issues resolved. Cranking timing was all out of whack. Now moving on to ve and afr tables. ;D ;D ;D