sly-sa22c

I was talking to a friend last night about anything and the subject of cars and handling and we started to throw some random (and potentially radical) ideas around regarding my SA..

the final conclusion we came to was an IRS conversion... has anyone done this that people know of? successful or not? let me know.. ideas, criticism, comments etc..

the other thing that came to our attention (and potentially more feasible) was a rack and pinion setup instead of the steering box.. this would include PS so i was thinking possibly a rack out of a gen2 or soemthing.. anyone got any ideas on this or knowledge of it being carried out?

any input is greatly appreciated as this is my first attempt at delving into something like this.

let me know!

cheers

--Tim

Manntis

Both have been done, with great investments of time and money, as one-offs. There was a production kit to put a VW rack & pinion steering rack in, but the company that made it disappeared and their product is generally perceived as crap.

bwaits from this very forum is rumored to be making a new R&P kit.

sly-sa22c

i realise it'll be a great deal of time and money and i realise that it's alot of effort but i believe the trade off will be better handling and response.

i know i could get an FC for less than what i paid for mine plus the cost anf time end research involved in work like this.

speaking of FCs.. does anyone know the front wheel track?

FIBREMAZ

There were some pics floating around of a 7 that someone had put MX5/Miata rear cradle into. I think this is an excellent way of getting IRS into a 1st Gen. MX5's are one of the best handling cars on the road and the older models are wrecked fairly regularly now so parts prices are not too bad.
Worth a thought at the very least.

sly-sa22c

thanks for that fibremaz, i'll hop on an MX5 forum and see what they seem to reckon.. only question with that is that i dunno if the diff would be able to handle the power.. i spose it wouldn't be too difficult (in the scheme of things) to modify the cradle to fit a skyline diff or similar.

how about a silvia/200sx/180sx/240sx rear end? dont know how the track would match up but there was a guy in canberra who was building a 13BT powered gemini for hillclimb and he said he modified an S13 rear end.. i had a look at it and it was pretty pimp (custom coil overs, beautiful welds etc..)

trochoid

iTrader: (6)

When Mazda developed the new suspension for the 2nd gen, the used a 1st gen as a test mule, lots of work to install the irs. The downside is that the 2nd gen irs is not that great. It still suffers from snap oversteer and the DTSS may work fine for a street car, not great for a track car or pushing the handling to the limits.

There are several different aftermarket systems that will improve the 1st gens handling. The most used is a panhard bar and a tri-link. If you really want to get carried away and spend some time and money on fab work, look into the Mumford rear suspension system.

sly-sa22c

trochoid, i knew about the problems that the 2nd gens have with snap oversteer, which, unfortunately, the gen 1s have a tendancy to do at the limit as well.. hence why i was thinking of the S13 rear end (one of the most stable rear ends i know of)

the gen2 RXs were only brought into it in my thought of rack and pinion steering over the steering box.. any ideas on this as well?

thanks for the help so far, i have a feeling im gonna be trawling the web for quite a time before i come up with anything concrete!

MikeFB

Just put a rotary into a miata- would be a pretty good combo I think.

sly-sa22c

rotor into a miata is a bit "meh" it's been done to death (especially over here in aus) and i want to do something a little different where a bit more engineering and thinking is involved.. plus it's be damn cool to have an RX that handles like an MX :p

FIBREMAZ

trochoid- is this the mumford setup you were talking about?

trochoid

iTrader: (6)

Imho, snap oversteer is mostly the driver, it's all about car control and knowing limits, then knowing how to get out of trouble when those limits are surpassed. I can break both the 1st and 2nd gen loose, swinging the tail out, then shift gears and swing it out the other way, all while under control and still return to a straight line. It simply take practice.

trochoid

iTrader: (6)

Yeppers, that looks like a Mumford set up. Looks a bit complex doesn't it? lol

sly-sa22c

trochoid, i realise this and i can do the same thing in my first gen all the way into 3rd gear but it doesnt help when you start wanting to go faster than the (lets face it) outdated design of a solid beam rear axle comes into play.

i dont spose you'd have a bigger (further zoomed out) pic of the mumford? or even a schematic drawing?

sly-sa22c

hmm.. just googles the mumford linkage and found a pertty good site.. but i still dont really understand the benefits..www.susprog.com/susptype.htm down the bottom of the page there it has the mumford w/ a 4link.. how does it work??

trochoid

iTrader: (6)

To explain the differences, it would be several volumes, lol. For the best, most intelligent and experienced answer, ask in the Race Car Tech Section.

sly-sa22c

trochoid, thanks alot for your help. in the time it took you to reply i did some more research and it appears that the ability to lower roll centre is the main advantage. that coupled with a 4link rear seems to make for an extremely solid setup in the rear.. which is exactly what i'm after, and of course the added grip.

am about to make a thread in the race car section

themayor500

the stearing from a second gen doesnt fit all too well because the body is wider but ive heard of taking the rack and pinion out of a volkswagon rabbit, the old style

sly-sa22c

themayor, i thought the 2nd gen was a fair bit wider, and with the VW route, i've only ever heard bad things. i'd be much keener to stay in the mazda family (although i realise that's probably not possible) or at least stay jap (say toyota or nissan)

Manntis

MX5 suspension and steering FTW - though the IRS seems to be fairly tall in the MX5...

ziig

iTrader: (1)

i have done the rack....didnt have much problems with it I used sepherical joints ends and a Ford capri rack..( lots to be found in the caribbean where this car was) ....biggest thing is setting up geometry correct..but that was no science project..simple string and common sense deal.............it can be done, but alot of people just think the box is sufffient........a Fc rack may be ideal for the applictaion .good luck.........oh as for IRS i think a ford 8.8 from a tunder bird will be a great start....

kuhlrx7

the fc rack is front steer the sa/fb is rear steer allthough the fc rack has been installed a number of times using the fc front cradle swap there are a couple of write ups on this board regarding this. its also been tryed old hot rod style of getting a left hand drive rack fliping it upsidedown and installing it in right hand drive car. there would seam to me to be other issues with this type of set up. way back when the old old board was the only one around there was some that swaped the control arms to face foward and tried front steering some of those people may be still around I never heard the results of their efforts. here is a list of racks that I have heard were tryed with varring degrees of success; omni racks avalibale in diff lengths and ratios, 4 differant vw racks, mazda 323 rack year unk, capri [non american made one],subaru rack unk model, toyota soarer, toyota ae86 rack as well as a nissan sentra rack. you being a aussy have avalible others we do not in the us. I have seen the omni, vw and ae86 rack used in person the vw the ratios are bad and not anuff travel. the omni rack can solve these problems but has its own. the ae86 rack is much better but is too short. the fc rack is to long but could be moded to work if you could get a reverse drive gear it would be my choice. if anbody knows of any more choices please post them or knows of the out come of some of these older projects

brendo s3 rx7

im pretty keen on putting a s4 rear end in my s3.have been 4 a while and plan to do it at some stage...imagine how good it would look mmmmmm.

Manntis

2nd gen IRS uses trailing arms, which can squat on acceleration and lift the front end. I prefer the Miata setup or Chapman struts like the 240Z