Steering Rack Conversion

Post Thu Jun 08, 2006 8:37 pm

I wanna do a rack conversion on my iS, and i wanna know whats the best rack to use? im after the least turns-lock-to-lock ratio possible.

i'll most likely be putting it in with my other engine, so what i was hoping to do was to use the pump thats made for that rack, and attach it to the engine by fabricating a bracket and pulley, so that my engine can run it. the reason for this, is that i've heard you have to get pas pipes made up when you do rack conversions???

anyway, if anybody could shed some light on this, it would be much appreciated!!

Post Fri Jun 09, 2006 1:15 am

the e36 rack doesnt work with the iS engines manifold apparently

however you do need to get the new PAS pipes made up..

Post Fri Jun 09, 2006 2:44 am

you need to mod the e30 ohse by making a slight bend to claer the frame.
I tought that you can use the e36 rack as long as you don't use a 6 branch? I don't know because i have lhd

Post Fri Jun 09, 2006 7:59 am

Hi Stuart
If you can get an E36 rack to fit an IS then go for the Z3 one with 2.7 turns, the exterior size is the same but i has an extra pipe that runs around the rad, so a bit of plumbing required but it uses the same pump as the M40 so no need for a bracket.

Post Fri Jun 09, 2006 12:54 pm

allo mate, havnt heard from you for a while!!

i heard somewhere before that the Z3 rack was the best, but i wasnt sure about fitment! that extra pipe you're talking about is a PAS fluid cooling pipe, which is why it runs round the rad!

i never knew the pump was the same as the M40 one though, which is f*ck*ng handy!!

by the way, what Z3 rack are you talking about mate?

cheers for the input lads, keep it coming!

Post Fri Jun 09, 2006 12:55 pm

z3 1.9 - 2.9 turns lock to lock

Post Fri Jun 09, 2006 1:01 pm

thats the nuts! cheers Jhonno! the 1.9 is the M44 lump, which is pretty much the same as my engine!

i suppose there not too much difference between 2.7 turns and 2.9 is there?

by the way, does anyway how many turns lock-to-lock my iS would be? i would go out and try it, but i cant be arsed!! and im at work!!

cheers guys...

Post Fri Jun 09, 2006 1:39 pm

all e30's are 4 turns lock to lock

manifold wont allow fitment of the e36/z3 rack on the e30 as it isnt a direct replacement.. it needs spacers etc even tho the m44 is similar

Post Fri Jun 09, 2006 3:27 pm

This is the rack i've got,.

http://www.e30zone.co.uk/modules.php?na ... ering+rack

Its still not on the car yet and i've never found out which Z3 its off.
Maybe you'd have more luck with that than me.

Post Sat Jun 10, 2006 11:26 am

Martin (i forgot your real name, sorry mate!) i'll have a look at what part number that is on monday and i'll let you know

it looks like you might have to 'cut 'n' shut' the steering UJ coupling to get it to fit? when i've got all mine stripped down it will be easier for me to see what i'll have to do

i was thinking about making up my own manifold for my new engine anyway, just by welding/braising the pipes and using the pipe benders at work, so if needs be i'll make one to fit around the UJ?

like i said, this all just ideas at the moment, but i definately think i'll be getting a Z3 rack, as 4 turns and 2.7 is a remarkable difference!!

Post Sat Jun 10, 2006 1:44 pm

I haven't tried any of these yet but i hear you can just
(1) mount the rack in the forward holes in the crossmember and use the original UJ
(2) mount it in the correct position and make up a spacer plate to go between the top of the original UJ and the bottom of an E36 UJ

What i'm trying to do is use two top parts of an E36 UJ and drill out the pin of one of them and just join them together, this makes it the right length for the original position of the rack.
But the problem is the bottom of the steering colomb has the wrong number of splines on it to fit in the UJ, so the option is to get it re-cut (but i can't find somone with the right machine) or to just hammer it on

Hammer optoin is most definatly the cheapest but safety wise........

Post Sat Jun 10, 2006 6:44 pm

yeah thats the trouble eh!! thats why a cut n shut E30 top half-e36 bottom half UJ would be quite appropriate! but i wont know if this is possible until i've got the parts in front of me..

is there anyone reading this post thats already done the conversion??? if so, can you give some feedback???

like, how hard was it?, was it worth it? is it really that different/beneficial? what did you do to make it fit?

any help would be much appreciated...

Post Sat Jun 10, 2006 9:21 pm

The conversion won't work with the standard 318is manifold, do a search on the forum for details of my endeavours.

Post Sun Jun 11, 2006 5:48 am

I have put in a 2.7 rack in my car and def noticed i hardly ever have to; cross my arms to make a turn. The converstion went pretty smooth the hardest part was getting the link on and turn without binding. if your have clearence problems maybe you can use a lhd link as it has more joints and no stright section so it might be easyer to clear the manifold. this is just a guess as i have never even so much as see a rhd e30.

Post Sun Jun 11, 2006 7:44 pm

what happened to you Dutch? i tried searching but i couldn't find the right page. you got a link?

like i said, it looks like i'll end up fabricating my own manifold, but i wont know wht i've gotta do until i've got all the parts!!

why can nothing ever be straight forward?!

Post Sun Jun 11, 2006 8:10 pm

Hi stuartgallafant, I don't know what you want/expect to gain from the conversion but I will leave you with something to think about.

(1) I quote from 'Track and Race Cars' magazine (Feb 2006) : "The steering was interesting, and in my view another example of too small a steering wheel affecting the precision with which the car could be driven. The steering rack ratio was pretty high - plenty of road wheel movement for not a great deal of steering input, any reduction of steering wheel diameter will accentuate this effect. The end result is that driver inputs appear clumsy and lacking in precision."

My M3 CSL has a much quicker steering rack and that in my opinion makes it more difficult to drive on a race track and my brother has commented that I sometimes look jerky and should try to drive more smoothly.

I definately prefer the steering on my Alpina B3 2.7 and I always say that the E30 (with good suspension mods) feels much better on the track. I feel more confident in my E30 than in my M3 CSL, even though the CSL is still substantially faster around a race track.

(2) On my Alpina B3 I have removed the power steering pump completely because I enjoy more steering resistance on the race track. I find it is better if you don't have a light steering wheel when you have to make corrections while in the corner (this is also where a slower rack ratio is better - with a fast ratio you tend to over-correct, especially when you're already shitting yourself that you won't make the corner).

Although I have to admit that slow speed driving such as parking is quite strenuous - it will be even more so when I put on my 245 semi slicks front and rear.

Post Mon Jun 12, 2006 2:25 pm

thanks for your input Andreas.

im not really too fussed about that though, as i wont be hammering my iS round any tracks! just want something to inspire a bit more confidence and a bit less effort! getting the arse out in the car is a chore at the moment coz the ratio is so long, its too frightening! with a shorter ratio rack, i reckon it'll be a nicer drive, and at the end of the day, over-correction is driver error/inexperience!

thanks anyway. anyone else have any opinions???