Trying to understand why OFT maps can get rip of torque dip
 

Hi all,

I am trying to find out the reason why the OFT OTS maps can help get rid of the torque dip. I did a comparison between stock and OFT stage 2 maps on open loop fueling and base timing.
Since I am a noob I could not understand the principle behind it.
For fueling the stg2 maps runs richer on mid engine load and leaner on high engine load. From my understanding lean mean more torque, but more likely to have knock.
For base timing, same as stock!

Am I looking at the right direction? I did try to search 'torque dip' in this forum but not much related info.

Please help I just wish to understand things. Attached file is what I copied from both maps.

Try to compare oft tune with WAYNO ROMs


https://www.ft86club.com/forums/showthread.php?t=127695

Cam timing

Thanks!!

But where to get WAYNO roms?

+1 for Wayno ROMs.

See link posted by @churchx in the message above. Lots of good information on Wayno's site. Great set of files provided with the ROMs as well (definitions, etc).

OFT tunes don’t eliminate the dip, stage 1 slightly reduces it. Stage 2 is for aftermarket header which now the header further reduces dip but still not eliminates it. stage 2+ is for aftermarket catless header which again further reduces dip because no cat but still not 100% gone (some headers do some don’t) stage 2+ w/ E85 will completely eliminate the dip (some will even have a mound instead of dip)

Do these Wayno ROMs reduce the dip further than the OFT Tunes?

That's not main goal of wayno's (or OFT) tunes nor i think they can do much about it. Maybe reduce rpm range at which it is, maybe reduce a bit drop, but there are limits to what just ecu tune can do. Mostly to get rid of torque dip some of aftermarket headers can (usually UEL, also some EL ones, mostly catless). Forced induction also fills it.
But! Imho that dip is greatly overcriticized as some major issue and end of the world. When one daily drives with traffic flow mostly one is at rpm-s below it. On track one anyway drives in rpm powerband above it. And even if one is lazy to shift during daily driving, it's not as if car doesn't accelerate during dip at all, just at a bit slower rate. Really don't get why all the fuss about it. Similar dip somewhere in lower-mid rpms is there for many other cars .. but somehow i don't notice other car owners making such big deal of it as many twins owners do. Heck, until i read about that dip in forums mentioned oh so many times, i didn't consciously noticed it myself, just drove car.

Main reason is that nowadays we have so many cars with small turbos and better torque curves in the mid rev range. In contrast, a NA engine needs to be revved to go fast. If the owners try to accelerate against these cars and they are lazy to downshift, then they see their car to not accelerate that much. The easy thing is to blame the torque dip "monster", instead of trying to understand the nature of a NA engine.

I wouldn't associate that with NA in general. After all, especially US traditionally had loads of big displacement NA engines with plentiful power & torque even down low. Rather in small displacement high-rpm high-efficiency engines (traditionally japanese made) that are very efficient yet need to be revved high, if one is to generalize.
Still, dip in honda-s is "vtec kicked in yo", no complains in eg. porsche caymans, or lexus is350, or WRX or many other cars/engines with characteristic dip .. yes, probably it's human perception factor, when one is spoiled with more and more common forced induction.
My advise would be to ignore it, as it's not as big of an issue as some make it as one, especially if one actually uses gearbox as intended. If anything, imho FA20 has unusually high torque before dip for 2lr NA engine, and at dip "normal" output :).

This is a good question!