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Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 1:55 am
by PeteC
Has anybody tried/succeded in retro fitting independant rear suspention to a live axle chassis?
Sierra difs seem to be easier to obtain than escort ones.

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 9:41 am
by Berw
I've just fitted my last spare crown wheel and pinion to my live axil Phoenix (Lotus Sunbeam Axil and LSD fitted) and I was thinking if/when I destroy this set I may try and convert to an idependent set up, but in reality it will be easier to modify another live axil to fit, and I will probably just do that, not abig problem, e.g We've just fitted a Toyota live axil to my mates Locost, came complete with LSD from the scrap yard, 2 inches widder than the Escort, which was actually a good thing as there where more wheels available with the offset that axil needed. Another friend has a Nissan axil in her locost, came from the rascal van, almost exactly the same size as the escort one and a lot lighter. So don't limit youself to escort Axil.

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 9:52 am
by stylussprinter
Unless your aim is road driving comfort , there's no advantage in fitting independant ( apart from Tim's SSC design which was deceptively clever ) . Plus you then have two lots of geometry to set up and balance their effects on each other.
On track --- forget it . On road , still a real pain for the average guy to get the optimum set up .

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 10:37 am
by DH2
PeteC wrote:Has anybody tried/succeded in retro fitting independant rear suspention to a live axle chassis?
Sierra difs seem to be easier to obtain than escort ones.
Not yet, but I will soon be starting a conversion as part of my rebuild project (thread here). Sierra parts are starting to get a bit scarce now, but there is a fairly plentiful aftermarket for them at present, so it's not too bad.
stylussprinter wrote:apart from Tim's SSC design which was deceptively clever
Can you elaborate a little Rob? As that's not how I'm (well my tame suspension designer) seeing it, and therefore won't be copying it.

DH2

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 10:59 am
by stylussprinter
You have to see it ' live ' as opposed to the drawing on this site . I don't want to say too much because it's a little like stealing but it was checked out by a very good friend of Tim's and ours on this club , who was race manager for a very successful team and currently works for Mclaren on the F1 road car and following models .
Chris , on this forum was heavily involved in it's conception -- he had worked for Bentley and now works for Aston Martin .
I will say that a big point in it's design is anti squat which normal double wishbone designs suffer from .

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 11:25 am
by DH2
stylussprinter wrote:You have to see it ' live ' as opposed to the drawing on this site . I don't want to say too much because it's a little like stealing but it was checked out by a very good friend of Tim's and ours on this club , who was race manager for a very successful team and currently works for Mclaren on the F1 road car and following models .
Chris , on this forum was heavily involved in it's conception -- he had worked for Bentley and now works for Aston Martin .
I will say that a big point in it's design is anti squat which normal double wishbone designs suffer from .
Nice name-dropping, but its worthless without an explanation/understanding of how it works.
There are a reasonable number of photos around, including the build manual. I don't see how explaining how something works is "stealing" - something which is blatantly in the public domain, it's not like I'm asking for dimensions or material specs or anything.

The way I see it (I won't bother name dropping who is helping me with this stuff - I'm not a mechanical engineer) is that the SSC IRS has 5 or 6 fixed links, and I can't understand how that is able to move up and down independantly without putting huge strain on any bushes and/or locking out and bending tubes or damaging mount points.

Squat doesn't mean... errr squat... if your suspension is going to lock out and throw you off the road at even the most convenient moment, let alone worse cases.

DH2

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 12:42 pm
by stylussprinter
I didn't understand either until I saw it move then all becomes clear . If you really like your friend's explanation of why it can't work then you've no need to understand it . Regarding name dropping --- it wasn't my intention to ' show ' off , but just to advise that it wasn't designed without deep thought and reference to those who had more knowledge .

Tim is a good friend of mine and ' could ' decide to sell kits again at some future point in time . If that ever proved to be the case and his design that you think appears not to work at first glancewas fully understood by all then he'd lose possible advantage.
I didn't say before but Tim has Test driven a chassis with this rear suspension and is very impressed with the result .

If he agreed I'd explain but contact is quite sporadic , now he spends time abroad with a rally team plus his home business. Sorry :(

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 1:54 pm
by DH2
OK. Maybe I'll just measure my chassis, my Sierra diff, and model it then - it's not difficult, just time consuming.

DH2

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 4:23 pm
by CMA
I thought about going IRS, but as the extra comfort on the road was about the only benefit I could see but it got seriously outweighed by all the possible negatives/hassles, not as good on track, more settings to mess about with the get it right, alot of chassis work to even get it fixed. If I decided I was that desperate for IRS I'd probably swap the Stylus for an car with IRS already.

Anyone point me to a pic of the fancy IRS, just interested to see it?

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 5:23 pm
by stylussprinter
CMA wrote:I thought about going IRS, but as the extra comfort on the road was about the only benefit I could see but it got seriously outweighed by all the possible negatives/hassles, not as good on track, more settings to mess about with the get it right, alot of chassis work to even get it fixed. If I decided I was that desperate for IRS I'd probably swap the Stylus for an car with IRS already.

Anyone point me to a pic of the fancy IRS, just interested to see it?
Can't remember where it is but if you PM me with your email address , I'll send a copy of the most recent build manual ---then just schroll down to it .

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 9:14 pm
by MattD
CMA wrote:I thought about going IRS, but as the extra comfort on the road was about the only benefit I could see but it got seriously outweighed by all the possible negatives/hassles, not as good on track, more settings to mess about with the get it right, alot of chassis work to even get it fixed. If I decided I was that desperate for IRS I'd probably swap the Stylus for an car with IRS already.

Anyone point me to a pic of the fancy IRS, just interested to see it?
http://www.clubstylus.be/build/manual/l ... manual.pdf

To Antnicuk - And how are your IRS plans going Tony ??

Re: Retro fit independant rear suspension

Posted: Fri Oct 28, 2011 11:22 pm
by Antnicuk
Hi Matt, All
I looked heavily into it. I initially considered the MX5 route which is possible but i thought i would look into the Fisher Fury route using ford bits as i was given a cossie diff and shafts.

I had lengthy conversations with Steve at Fisher and the details and prices are below. I was going to make it the same as the fisher IRS but the cost of parts was prohibitive to me. Below is the email steve sent me with the parts. I was going to construct my own framework under the car to carry the fury w/bones and hold the diff.

In the end i narrowed my atlas which allows me to run 8 inch wide wheels without rubbing. I love how controllable the live axle is, its very forgiving considering i have over 400 HP. and after much thought i dont really want to start again with whole new set up. As Rob says, the development happens over years and it would mean wasting the last 3 years. I dont think the live causes me a problem that IRS would solve and since fitting an ARB it feels a lot better. I am at Bedford next weekend so hopefully it will be dry and i can test my other mods. (Shortened front uprights, lowered ride height and corner weighted again)

If it wasnt so expensive i may have given it a try and kept my live axle to covert back if i didnt like it. I think that a well set up IRS would be good for track and road but i'm not sure I would be able to set it up well enough to see the benefits, especially as i dont really use the car on the road.

Hi Tony
Sorry for the delay getting back to you I`ve been a bit hectic getting a race car ready for the weekend, the prices you want are as follows
Top rear Wishbones-£105 per pair
Bottom Rear Wishbones-£190 per pair
Rear Uprights-£130 per pair
Rear Spacers-£30.00 per pair
Driveshafts-£217.00 per pair exchange
Rear bearing carriers-£100 per pair reconditioned
Drive flanges-£70.00 per pair new
these prices are +vat I can do rose jointed wishbones at no extra cost but that does not include the rose joints.

Re: Retro fit independant rear suspension

Posted: Mon Jul 30, 2012 10:03 am
by Berw
My car has just thrown the CW and pinion, and I note from my earlier post here I put it on in November last year so 3 weekend use say fast 60 laps or 180 miles, obviously not up to the job so going IRS.
I've seen an M5 E34 LSD Diff for sale locally for 500 pound so will use that as it will be up to taking 400+ BHP and have down loaded the Stylus build manual that is in an earlier post, I also have the Hanes Roadster book, so will use them as a basis for the design, will probably go rose joints as my current axle is rose jointed and we can reuse them. I was thinking about E30 uprights.
My engineer is a great guy and we can fabricate all the subframes and wishbones, plus shorten the drive shafts.
Any comments/advice appreciated (except dont do it, I have no choice I run a Lotus Sunbeam rear axle and CWs are not readily available to me).

Is it out of the question to acquire an ATLAS axle strengthened etc :?: Have a browse on the TURBOSPORT FORUM then schroll down to parts for sale --- I've seen some very nice axles on there , most already sorted due to the turbo boys chuvving mega bhp through their retro cars :wink:

Re: Retro fit independant rear suspension

Posted: Thu Feb 21, 2013 3:21 am
by Berw
Having just got my new smart phone synced to my computor I can post some pictures of the IRS being fitted to the Phoenix. As can been seen we still have bit of work on triangulating the structure but all is in place and the car can sit on the tyres. The rear end is from a Nissan Silvia and is used by the drift boys at up to 800Bhp so should last, it has a LSD fitted with 3.7 ratio, the rear end is fully rose jointed as per the photos.

So far I am to this for around 1200 pounds which includes the purchase of 2 diffs, LSD, Uprights, refurbishing the diffs, (we bought 2, one 3.9 with an LSD and one 3.7 without, so we put the LSD in the 3.7 and built the 3.9 as a spare), fabrication of the diff carrier, prop and wishbones and all the rose joints. All the work done proffesionally by Niza racing (see face book) but a bit far from home for most of you.

Re: Retro fit independant rear suspension

Posted: Thu Feb 21, 2013 10:47 am
by DH2
Interesting to see, since I am doing similar to my Stylus.
I know it is a track car, but to my uneducated eye you appear to have very little bump travel (and potentially alot of rebound) from those photos... do you run some insanely high rate springs to compensate for under-damping?

DH2