4d Fuel Mapping

[aphid]

Hey guys,

I've just converted to a Vipec from at PFC setup. Having been blessed with AFM's in my previous tuning efforts, I haven't ever had to bother with 4d mapping. Curious to know how other people combat the issue of varying fuel requirments at the same map/rpm at different tps readings with the multiple throttle/boosted engine the rb26 is. I've got my primary fuel table configured with rpm on the x axis and tps % on the y, then the 4d fuel map with rpm again on the x and map on the y.

At the moment I'm thinking to tune the primary map with an average of around 50% throttle, then enable the 4d fuel map and then correct varying afrs on this table..

Any other hints or previous experience people would be willing to share would be great

Cheers!!

[JonnoHR31]

you cant use throttle as your primary load axis on a turbo car, it wont work properly. set it up so your primary fuel map is boost and rpm, then you just need air temp correction setup properly

[discopotato03]

I was under the impression that you tuned for throttle position and used the manifold pressure reference to correct the TP map .

A .

[ltcree]

I'm no expert with tuning but I remember reading a thread with Guilt-toy tuning a Vipec, think it was on a rb25 though. He might be able to help you out a whole bunch.

[R32 TT]

Doing this on Motec. Primary Table is based on MAP vs RPM. Then a second load table which is TP vs MAP. The second load table only has load points between 80 to 120kpa (ie either side of 100kpa is where the problem happens)

Looked at full blown 4D mapping which the Motec can do, but loads more to do and while its probably great if you do lots of logging and fine tuning, I think the first method will cover the problem ok.

[Guilt-Toy]

Who tuned the car?

[aphid]

In reference to the first few comments, this is more aimed at a MAP setup on an RB26, the issue you run into is to do with multi throttle body / turbo engines

R32 TT: Thanks for the information!

Guilty Toy: I got the ecu from Godzilla Motorsport but I'm tuning it myself.. Theres no real fun in taking it to somebody to do it all for you

But yeah, I've done a conservative tune and am getting pretty consistent afrs with varying throttle amounts so it seems to work pretty well.. Alot of effort to do on the street though..

[Chris Wilson]

Resurrecting this older thread to say that my MAP sensored RB26 with 2860 -10 turbos and 280 degree, 10.8 mm lift cams was transformed from simply very nice, with no surge, to stunning when I had Z axis mapping done (4 dimensional mapping) by a proper Motec trained expert here in the UK. I use it pretty much solely as a track car, but even on track having clean as a whistle part throttle running and response has made it SO much better, and quicker. WELL worth pursuing to get the best out of a multi throttle turbo engine on a MAP sensor, in my opinion, I would never be satisfied with anything less now.