Revision as of 02:11, 10 May 2011

Independent Rear Suspension (IRS) is superior for comfort and smoothness and since those are not necessary for an economy car platform, Datsun 1200 was instead fitted with less expensive traditional live axle, a non-indendent rear suspension. No RWD Sunny came with IRS, so enterprising modders have shown the way and various Datsun IRS have been adapted.

1 Overview
2 510 IRS
3 Pigdog
4 sssute
5 Other Swaps
6 B210

Overview

IRS is not generally the best for racing. Leaf spring is superior for most racing, however IRS can be setup for racing if the class permits it. IRS will also generally hurt performance as it is heavier than a live axle. But, if done correctly the IRS can handle a lot better for track and hill climb use with the ability to play around with rear camber and toe settings.

On the other hand, a live axle kicks the back end right out of track over anything but smooth concrete. So well-tuned shocks are necessary to control bouncing, but even so it's not very smooth on a light car. You can control axle tramp easily, but preventing skittering on bumpy curves is difficult. Since race tracks are smoother than street pavement it is not generally as big an issue for race cars.

Also see: De Dion for low-sprung weight non-IRS suspension.

The Datsun Sunny family was the "economy" model line. Therefore it has the cheapest solution, a live rear axle. All the Datsun rwd subcompacts used a live rear axle. In some ways this is better than IRS: less weight, more reliable, better for hard launches, easier to tune for handling. But certainly it rides harshly, especially in such a light car. In the 1970s more and more economy cars were being fitted with IRS, and so many new FWD designs incorporated it. It is cheap to fit to FWD car, since there is no rear diff.

Sunny Excellent PB110 and PB210, though upscale with L-series engines, still were fitted with live axles. No IRS.

The Datsun Bluebird family (510/610/810/910/Maxima) had IRS from 1967, but those were Nissan's bigger models, which eventually ecompassed luxury models (810/910). All Bluebird family models except some export assembled versions (Mexico, Australia) and commercials (Wagon) had IRS.

The P510 (1600) and P610 (180B) had IRS, except for wagons, then Nissan went less expensive again for the 710 (Violet/140J/160J) and A10/HL510 (Violet/Stanza) although some models still came with IRS. These cars were the compacts, a bit larger and more expensive than the Sunny family.

Z-cars had IRS from the beginning as befitting thier status as a world-class sports car.

Besides the Bluebirds, some other RWD Datsuns came with IRS including Japan-market Violet (710 and A10), though generally export markets did not get these upscale models but instead the base models without IRS.

Datsun/Nissan Silvia (S10, S110, S12, S13, S14 and S15) came with IRS, but is too wide for the 1200. It can be narrowed with custom machining and welding.

510 IRS

Datsun 510 (1600) model series of the Bluebird family is the source of inexpensive IRS donors. It uses the common Fuji R160 differential as used by the ubiquitous Subarus. The newer 610 (180B) has similar suspension but is a bit wider so less appropriate for a 1200.

Datsunfreak's IRS swap on Ratsun