This request for information (and other similar requests) on the BBQ Pits available at Pasir Ris Park was sent to me by e-mail.
There is a detailed Nparks map (above) available on the comprehensive National Parks Board website. When you go online to book the bbq pits, you can choose to view the pit locations before your booking.
I've found another map (above) of the BBQ pit locations at Pasir Ris Park car park A. This copy of the map has been photographed and reproduced here.
To answer M T's question, the nearest BBQ pit at Pasir Ris Park to Downtown East is Pit Number 23. But don't worry, pits 16 to 23 are close together.
I think you can throw barbecued chicken wings from pit number 16 and still hit your target at pit 23 [unless (1) you can't throw, (2) you don't aim, (3) target moves or (4) you rather save your chicken wing for yourself].
For other readers' benefit, you will be pleased to know that wheelchairs can use the cycling / walking paths from Downtown East all the way to the track next to the BBQ pits.
The final few metres off the track to your BBQ pit stone seats, however, require more assistance to overcome as the grass patches are bumpy.
You can see what I mean in the above photograph. This is a shot of BBQ pits from number 1 (in the far back ground where users are gathered) to number 8 (on the left of the picture) at Pasir Ris Park. [Sorry, no picture of pits 9 to 23.]
Perhaps Nparks will consider paving them for wheelchair use as well.
Have a pleasant and enjoyable barbecue!