318iS owners- Interest in exhaust manifold to fit E46 rack?

[jmc330i]

As we know, the E46 rack conversion isn't as straightforward for the mighty 4 pot equipped cars, although there is the option of mounting the PAS rack in the front 'manual' rack holes, but from what I've recently seen, this isn't ideal.
Anyway, long story short, I've decided that mounting the E46 rack in the front holes on my touring is not what I want.

I've found a small garage near me who tig welded an O2 sensor bung into my exhaust and it turns out he is into his BMs, so we got talking...

In the coming weeks I'll be taking my touring over to him and he is going to look at what's needed to make the M42 manifold clear the E46 rack. I'm also going to ask him about making an exhaust system for the 16v cars as I've been struggling to find anything.

Just wondering if there's any interest as he said he'd be happy making a few up (maybe as a group buy).

Cheers

[baggimodo]

I was just about to list a spare E30 M42 exhaust manifold up in the FS section!

Was there much difference between the M42 and M44 manifolds? Would he need one to use as a guinea pig?

[jmc330i]

I've never compared an M42 and M44 manifold - I didn't bother getting the M44 one with my engine as it wouldn't fit without cutting up. I realise this wouldn't matter now I want to cut it up But, I figure starting with an M42 manifold would be better as that's what 99.9% of iS owners will have.

My M42 manifold is cracked anyway - he may also look into repairing this with a new section rather than the dodgy weld I've done lol

I'll try and get round to him next week so he can have a look and we can talk about the best way round it.

[rix313]

E36 manifolds are different to E30 ones so not even an E36 M42 one would work let alone the M44. The M44 one is slightly better from memory.

FYI I had a full system made for my iS race car at Infinity Exhausts in Yate. Might be worth a call there? No disrespect to your man at all but I'd feel more comfortable having an exhaust manifold being made by an exhaust manufacturer.

[jmc330i]

I should of said, he builds custom exhausts as well as other car prep, modification for Motorsport and road cars etc. he has worked for an F3 team in the past and also in rallying from what others have told me.

When I was first there, he had just finished rebuilding an old Ferrari Dino replica (including building the exhaust and manifolds I think) and was prepping what looked to be a very serious bike engined Radical. When I picked up my exhaust, a customer was picking up his 63 plate Z4 after having a full system built, there was an Escort Cosworth waiting for work and they were waiting for an Aston Martin DB6 to arrive for an exhaust build (and some other work too iirc).

I've seen pics of exhaust manifolds he has built from scratch, but will be asking to see one he's done before I hand over any readies! I've only seen the exhausts in person, but they look good and well made from what I've seen so far.

We're only at the talking stage at the moment, so we'll see what happens.


Another option came to light yesterday, and I've now got a contact for a company that build manifolds and exhausts. I've actually seen their work (I own a part system built by them) and its good, but until I speak with them I won't know if they're up for it.

[appletree]

If your M42 one has cracked around number 1 &4 port on the flanges you can weld up the inside with TIG as it's poor quality stainless and then on the outside I used dissimilar wire to weld the outside to the mild flange and it's been fine since.

What's the issue with the e46 rack as I have a Z3 one fitted and it clears everything easy??

[age]

yea this has been puzzling me too, i've an e46 rack in my iS and had no problems fitting it.
its a little tight but everything clears, i was going to get a few mill extra clearance by using e28 m5 engine mounts

[jmc330i]

Nothing wrong with the E46 rack, but I'm guessing you guys have your racks mounted in the front holes for the manual rack?

[NoTurbo]

Mine is in the front holes too. No clearence problems or effect on steering.
What are your concerns?

[DHFiS]

Mine is in the front holes too. No clearence problems or effect on steering.

+1

[fender182]

Ive tryed a few racks now but had no luck, both front and rear holes

[fender182]

on a serious note, mine has a custom mani on it. i can take photos if people want but i have no idea who made it or where its come from. I've tried a few racks on both the holes and can't seem to get any fitment or adjustment. i got the 46 rack to fit but on a tight left the down pipes caught on the steering linkage and locked up the front end so had to re think that.. and haven't come up with a better solution.

[NoTurbo]

Send us a photo. It's hard to picture the problem you are having. There must be a simple solution.

On my old alpina I used 5mm of washers to drop the rack slightly for manifold clearence.

[fender182]

its just the angle of the down pipes, ill get some photos when i can be faked to get out of bed I've tried spacers but had no luck.

where abouts in north london you from turbo?

[trojen]

The Corsa B stering linkage worked a treat with my M42 manifold, bolted up to the front manual rack holes.

[trojen]

As we know, the E46 rack conversion isn't as straightforward for the mighty 4 pot equipped cars, although there is the option of mounting the PAS rack in the front 'manual' rack holes, but from what I've recently seen, this isn't ideal.
Anyway, long story short, I've decided that mounting the E46 rack in the front holes on my touring is not what I want.

I've found a small garage near me who tig welded an O2 sensor bung into my exhaust and it turns out he is into his BMs, so we got talking...

In the coming weeks I'll be taking my touring over to him and he is going to look at what's needed to make the M42 manifold clear the E46 rack. I'm also going to ask him about making an exhaust system for the 16v cars as I've been struggling to find anything.

Just wondering if there's any interest as he said he'd be happy making a few up (maybe as a group buy).

Cheers

I'm abit worried about this - "although there is the option of mounting the PAS rack in the front 'manual' rack holes, but from what I've recently seen, this isn't ideal."

What have you recently seen, need i be worried?

[NoTurbo]

its just the angle of the down pipes, ill get some photos when i can be faked to get out of bed I've tried spacers but had no luck.

where abouts in north london you from turbo?

Norf

[jmc330i]

Mine is in the front holes too. No clearence problems or effect on steering.
What are your concerns?

Bit of a long story, but basically a mate has recently bought 2 E30s, an M52 touring and a stripped and caged M40 moredoor, both came with E46 racks.

The M52 conversion got swapped into the moredoor to become his track/hillclimb slaaag, but he reckoned the steering went a little light as he added more lock and didn't feel like the touring when he was pushing it - he likes opposite lock moments lol
He swapped everything except the rack, so my first thought was perhaps it wasn't an 067 rac in the moredoor, but a standard E46 rack.

I went over to his to take a look and couldn't see anything wrong. The rack was a purple tag and it drove fine as far as I could tell. I put it down to him being strange and being used to hillclimbing and drifting jap crap, but he was adamant it felt different to the touring.

Being a 4pot the rack was mounted in the front holes and he'd left it there when he changed engines, I couldn't see it being a problem as that's what everyone does with M42s.
So we swapped in the rack that came with the touring thinking there might be something wrong with the moredoor rack. We only swapped the rack and mounted it in the front holes as we kept the track rods and steering linkage. He tracked it up and the steering felt the same to me, and he still wasn't happy!

Only thing that now differed was the rack position. So, out it all came and we fitted the rack in the rear PAS holes where it should be. We were running out of time by this point so we only tracked it by eye, but even I could tell a difference in the steering feel when I was using more lock. I've since driven it after it was properly tracked and it does indeed feel better than when the rack was mounted in the front holes.

Its difficult to explain, but I could now see that the steering seemed to feel light when more lock was applied, almost like it was over assisted after say 1/3 turn of the wheel.
With the rack mounted in the rear holes, the steering feel (assistance if you like) feels more consistent from lock to lock.


I'm wondering if the manual rack (being mounted in the front holes) has more leverage (if that's the right word) to help with slow speed, high lock manoeuvres and this extra 'assistance' makes the PAS rack feel lighter at more lock.


Having driven back to back runs with the rack mounted in both sets of holes, there is a difference in steering feel. It's not really noticeable with small amounts of lock, so it probably won't be an issue for those who pootle around town, but I like to drive my car and IMO I don't like the steering feel with the PAS rack mounted in the front holes.

[ross_jsy]

It's because it changes the steering ackerman

[daimlerman]

It's because it changes the steering ackerman

I think that you are right.
Mounting the rack further forward will affect the wheel angle on lock,and the effect will be more pronounced at greater angles of lock.

The interesting bit,though,is why did BMW mount manual racks further forward?

Regarding using spacers to lower/raise the rack,those that do this will probably induce 'bump steer'.The rack and steering arms should be level at the car's normal ride hieght,and at the same hieght at both sides both sides.Even a single mm difference will induce bump steer.

[jmc330i]

The interesting bit,though,is why did BMW mount manual racks further forward?

Didn't manual racks come first? In which case, they would've changed the mounting position for the PAS racks.
As I was thinking above, maybe the manual rack was positioned to help with slow speed manoeuvring. With a PAS rack, this isn't needed so the rack position was changed??

[daimlerman]

The OEM homo's will be along very quickly to correct me,but as far as I can remember,PAS was an option from the start,with it being standard on facelift stuff.

So re-positioning the rack for PAS means that BMW were aware of the compromise that they induced by lightening the manual steering?

As a complete aside,I swapped a PAS rack on my touring just before taking it abroad on holiday,casualy wondering why I got an odd clonk when manouvering,I later(much later ) found that I had the rack mounted using one forward hole and one rearward hole!
The clonk was the steering shaft u/j touching the tubular exhaust manifold.

[jmc330i]

The OEM homo's will be along very quickly to correct me,but as far as I can remember,PAS was an option from the start,with it being standard on facelift stuff.

So re-positioning the rack for PAS means that BMW were aware of the compromise that they induced by lightening the manual steering?

That does make sense. I've never driven a manual rack, but I wouldn't think the rack would feel too light at higher angles of lock, so I'd say BMW designed the manual rack position to be easier to turn with more lock and the PAS rack position further back as the extra assistance isn't needed, maybe because the steering becomes a little over assisted....

[jmc330i]

As a complete aside,I swapped a PAS rack on my touring just before taking it abroad on holiday,casualy wondering why I got an odd clonk when manouvering,I later(much later ) found that I had the rack mounted using one forward hole and one rearward hole!
The clonk was the steering shaft u/j touching the tubular exhaust manifold.

Lol, how did it handle with the rack fitted like that?

[daimlerman]

TBO,the only thing that I noticed was the odd knock when the steering shaft u/j caught on the manifold down pipe.Mine,as you will remember,is an M50 with a Fritz Bit's manifold.

I guess that your conclusion will apply to me as well,the steering is only affected at extremes of lock,and most people will not notice the change in ackerman angle,just those who spend time at speed and on opposite lock will notice the difference!

I have noted a difference in straight line stability,though,between 14'' and 15'' rims.This seems to happen above about 85mph,the steering starts to feel very light on the smaller wheels.This research was,of course,conducted on my private test track...

[NoTurbo]

Interesting. I remember that I used shorter tie rods but can't remember what they were from. Only thing I notice on my 318is is understeer and the outside tyre slips on hard cornering. But that will probably be fixed with a strut brace.