[doughboy]

Well, after 2 cancellations (by me being too busy and disorganised) the time finally arrived last week for my trip to Birds.

For:

Quaife LSD
Hartge ARB kit
M3 rear subframe bushes
Oil service, 8000 miles. (I don't like long interval oil services)

Arrived at 8am after a 5am start from Manchester, Kevin Bird was still opening up but made me a nice coffee. Car was straight in and on the (spotless) ramps by 8.30.

He put 2 mechanics on it to speed things up. It took about 4 hours to do all the work, plus a test drive and a full vehicle check. They even filled the washer bottle for me!

I had to get home sharpish, so it was straight back onto the M40 by 2pm.

First impressions.

Well I think i have a new car, it looks like the previous one, but don't be fooled. It now behaves like a proper hairy arsed 300 horse power rear wheel drive car, despite being a famliy estate car on the outside

The motorway stability is remarkable, gone is the vague centre position of steering, the wheel now feeling positive immediately in either direction, but not with any 'twitchyness' just a direct fell. The car feels lighter too with much less body roll to remind you of the lurking mass. Even those off camber dips you get on outside lanes don't upset the car at all.

Most telling was the decrease in 'perceived speed' ie. the speed you 'think' you are doing from the vehicle feedback. Where I assumed a comfy 75, it was in fact nearly 25mph more than that, but just rock steady.

BUT, be warned, you need to re-calibrate your steering input or you'll end up backwards through a hedge fairly sharpish. Having taken the standard car to donington park, you really had to throw the car into bends, still on the brakes to get some weight off the back end, maybe even jab the brakes before gassing it again to get the back round, so strong is the natural understeer setup.

Now the main effect of the ARB & LSD setup is what happens when accelerating out of a bend, you can literally feel the car steering from the rear. Not scary, just smooth and directly related to the throttle position. Large roundabouts are a joy to behold. I will master power slides soon!!

Pulling quickly onto a roundabout or junction used to result in bouncing inside wheel, flashing yellow lights and not a lot else. Now the car launches itself fowards with such vigour that it catches you out, the revs rise as the (both) wheels begin to spin smoothly whilst still find bags of grip, then a touch on the wheel gets the back playing ball. All with no fuss or noise, just using the torque the 335i can muster, quickly into 2nd and on she goes.....
Ever read EVO mag when they talk about being 'hooked up' in a rear wheel drive car? I assume this is it, wheels spinning slighty but with maximum forward thrust.

The M3 bushes have removed ALL the slack that I used to think was in the transmission. Now the rear suspension and diff are much more ridgidly mounted to the car chassis. A tiny tap on the throttle has immediate results. It all feels a lot more direct & mechanical and I like it.

It has shown up a lazyness in my gearchanging too, if you're not smooth there's no squidgy bushes to hide your errors.

The diff works very subtley, normally there's no difference, but when accelerating it is remarkable, especially 1st or 2nd gear, you can feel the outside wheel 'pushing' the car out of junctions etc where normally there would be inside wheel slip. Again, accelerating over a broken surface where normally you have wheel bounce and power cut by the TC, the car now leaps forward seaminlgy finding grip from nowhere, you can fell the rear end bounce/thump but the car just finds grip and goes.....

The only down side is a mechanical 'thump' from the rear end when engaging first / reverse from neutral. Almost like the slack in the 'box and diff being taken up as a gear is selected, even with the clutch disengaged it will still have enough drag to turn the 'box shafts and prop. Maybe its amplified due to the M3 bushes and the large cabin space in the tourer? Carefull gear engagement sorts it, but first to second can do it too. Mind you my old cossy was terrible for that, heavy duty gearboxes (which the 335i has) have heavy parts....

Going to non RFT tyres may help to reduce the thump and the softer tyres will replace some of the shock absorption lost by the M3 bushes.

Overall it has made me question the need for a remap, this is a damn fast car, make no bones about it. So many modern cars have so much power, but the manufacturers design them so the power is unusable in anything other than a straight line. I would love a back to basics powerful rear drive fun car like a TVR etc, but I only have space for one car and I need/want a modern and luxurious family car too. I think these simple mods go some way to creating a pretty good compromise vehicle.

We'll see.........

[E92Fan]

Told you so....!!!

And yes, there's a mechanical thump - that's normal because the rear subframe and diff assembly is so much stiffer now

And those rear bushes make a MASSIVE difference don't they?!

[doughboy]

The rear bushes were well worth it, there is just no play in the transmission anymore and the car settles straight into a bend with no 'step out' at the rear when applying the gas.

And you can feel surface and grip changes through your backside now! But no increase in road noise.

[Dave_3]

Thanks for the write-up.

Interesting to hear about the rear bushes. What is the difference between the two versions ? Did you see what they were putting in and taking out ? Do the standard ones wear ... with all that torque loading from accelerating ?

My old RS2000 runs on uprated polybushes throughout, and rose jointed pivot points. Compared to my E92 with slighlty fluffy body movement where you can feel it float/settle slightly into corners, I merely think the Escort down the back roads.

How much of the new-found stability is down to the bushes or ARBs ?

D.

[E92Fan]

Originally Posted by Dave_3

Thanks for the write-up.

Interesting to hear about the rear bushes. What is the difference between the two versions ? Did you see what they were putting in and taking out ? Do the standard ones wear ... with all that torque loading from accelerating ?

My old RS2000 runs on uprated polybushes throughout, and rose jointed pivot points. Compared to my E92 with slighlty fluffy body movement where you can feel it float/settle slightly into corners, I merely think the Escort down the back roads.

How much of the new-found stability is down to the bushes or ARBs ?

D.

The rear bushes are quite different - standard ones are four-point mounted hydraulic bushes, with a large amount of slop and movement. The uprated bushes are solid M3 versions, much stiffer, and reduce the movement of the subframe massively.

The standard ones don't wear dramatically quickly, but the innate movement they have means that the rear end of the car just doesn't settle that quickly. The uprated bushes solve the floatiness and imprecision in the rear axle, giving much tighter turn in and greater control. I have been investigating the situation with the bushes for the last few months now, and can only say good things about uprating the key suspension and running gear bushes.

The new-found stability is largely down to the ARBs to be honest, as they really sharpen up the body control without inducing any increase in direct vertical harshness over bumps. The bushes enhance the overall handling balance of the car, and are well worth doing in combination with the ARBs.

The new-found agilitiy is largely down to the LSD, then the ARBs.

[Dave_3]

Thanks Tony,

Makes me wonder why uprated rear bushes (better than standard fit) aren't offered by someone.

But I suppose more money is made selling shiny lowering kits and wide wheels to BMW owners.

Refitting the rear bushes does not require tweaking of the tracking ?

I take it you are talking about 2 bushes on the chassis - and also on the rear suspension. How many in total ? Need a special tool for removal or normal methods OK ?

D.

[creepy coupe]

What happens re wheel alignment after fitting the new bushes, does the car need to go on a KDS rig?

[Hotcoupe]

Excellent write up Doughboy, and that sounds an awesome tourer you have there.

The problem with reviews like this is...............you just know it's going to be expensive!

[fastloop]

Great write up!

It's really nice to hear how this setup works on a manual 335. My car is quite similar except 90kg lighter at the back (Coupe), so it's great to hear that the ARBs and bushes really tightens up the rear. I guess it will be even better when you get rid of the RFTs.

I can reckonize so many things from your description about how the car was before, so it's good to see that there is a solution for this.
Soon.... only a few more days to go....


How big is the mechanical 'thump'? Is it very noticeable or only something you'll notice if you are looking for it?

[doughboy]

Cheers Guys,

The whole E9x rear suspension, hub carriers and all the linkages are entirely mounted to the subframe along with the diff, only the damper and spring tops contact the chassis separately. This whole assembly is then attached to the chassis at 4 points, each with a bushing. They went in and out fairly easily, no press required or anything like that. This makes production simpler as the chassis mounting is simple via 4 big bolts, the complex geometry for the suspension is then handled by a smaller, more acurately made, very rigid subframe. Its the same subframe for a E9x.

They are fixed position too which means no tracking or adjustment is needed after fitting. The 4 bushes cost £170 and very little labour when fitted with the diff. They are completely hidden once fitted and indistinguishable from OE.

E9x rear subframe (bushes items 2 & 3): http://www.realoem.com/bmw/showparts...29&hg=33&fg=30

E9x suspension to subframe drawing: http://www.realoem.com/bmw/showparts...30&hg=33&fg=30

M3 bushes are solid rubber whereas you can see the standard items are an inner and outer section joined by small rubber links. You can move the inner around with your own fingers!! The standard bushes mean you can move the whole rear subframe around in 3 axis' by at least several mm with your bare hands when the car is on a ramp.On the road it must move 10mm+ or more.

The 'thump' is fairly noticeable if you quickly go for first (as in when not paying attention at lights...) you can feel it too. Or when doing a 3 point turn and quickly going reverse, first, reverse, first, this is taking up the slack in opposite directions, worst case. It sounds like something falling over in the boot!!, bottle of pop or similar.

With normal careful gear selection, a gentle pressure againt the syncro first will take up the slack without a thump, then press the gear home. Be a little more patient I guess!

[Dave_3]

Is yours a manual ?

Still surprised that no-one offes a set of uprated bushes - not as solid as the M3, but without the hydraulic float of standard items.

No press or puller required ? Do you need to drop the rear frame ... from those diagrams you link to it looks like it is press fit from undrneath and located by the bolts ?

D.

[doughboy]

Yep mines a manual. An auto would probably get the 'thump' when selecting D or R from N.

I'm sure you can buy 3rd party aftermarket bushes.

Don't forget the M3 bushes are rubber-type production items with all the reliability and noise/vibration requirements that go with that, they are still probably not as hard as aftermarket poly bushes like powerflex or similar.

[E92Fan]

Originally Posted by Dave_3

Is yours a manual ?

Still surprised that no-one offes a set of uprated bushes - not as solid as the M3, but without the hydraulic float of standard items.

No press or puller required ? Do you need to drop the rear frame ... from those diagrams you link to it looks like it is press fit from undrneath and located by the bolts ?

D.

No press or puller required, unless the bush has been deformed or is starting to disintegrate. The entire subframe needs to be dropped, although can be supported using a gearbox stand or similar.

Uprated bushes for the subframe aren't available by any third-party supplier as yet. In addition, the last set of Powerflex bushes I tried on my car didn't even fit properly - they fell out of the wishbone!! Useless....

[E92Fan]

Originally Posted by doughboy

Yep mines a manual. An auto would probably get the 'thump' when selecting D or R from N.

I'm sure you can buy 3rd party aftermarket bushes.

Don't forget the M3 bushes are rubber-type production items with all the reliability and noise/vibration requirements that go with that, they are still probably not as hard as aftermarket poly bushes like powerflex or similar.

There's no thump on an auto, as the torque converter masks a lot of transmission noise and shunt.

The thump you get on the manual is because there is much less flex and slippage in the transmission now you have the Quaife installed. You'll find that if the car is rolling slightly, ie the rear diff is not under load, the thump is a lot less.

Entirely normal though...

[Ant Man]

Are these arb solid? Are they harsh at all or too stiff for road use? I was reading a report on the US section and one owner ditched the ultra stiff H&R arb and reverted back to M3 arb and claims his lap times improved dramatically.

[SoYank]

Doughboy, glad you like the new setup. I enjoyed reading your post because it brought back memories from when I had my mods done although I did mine in stages -- LSD then ARB -- but the feeling was just as you described. Now that you got the go worked in you need the whoa!

[doughboy]

Originally Posted by Ant Man

Are these arb solid? Are they harsh at all or too stiff for road use? I was reading a report on the US section and one owner ditched the ultra stiff H&R arb and reverted back to M3 arb and claims his lap times improved dramatically.

Well they call them 'sway bars' in the US......

Wigth the Hartge kit, I believe the front is 26mm instead of 25mm, but the rear is 20mm instead of 13mm. The main point of ARB's is the relative stifness between front and rear rather than the absolute stiffness. A stiffer rear moves the balance of the car towards the rear.

Roll is generally more limited, but they don't add any 'stiffness' to the ride in the way that uprated springs / dampers would as their effect over fast bumps is negligible.

[Yahoo]

I am really pleased to hear your results Doughboy - sounds great.

I have opted for the M3 ARBs (26.5mm fronts and 20mm rears), but these are hollow and so will be slightly more forgiving then the solid Hartge, H&R, Eibach equivalent. I think that a car with an LSD can handle the extra stiff ARB with more of a tendancy for controlled oversteer.

I on the other hand am not considering an LSD, but do want to reduce the roll on my e91 335i. Next week I am having some Eibach Pro springs, M3 ARBs, M3 sub-frame bushes and non-rft Eagle F1 assymetrics fitted as well as some cosmetic BMW Performance goodies.

I hope this setup will replace the rigity that I will be losing going form run flats to non rfts , whilst also reducing roll and improving the handling characteristics of the e91 - time will tell though I guess.

Ben

[Ant Man]

Originally Posted by doughboy

Well they call them 'sway bars' in the US......

Wigth the Hartge kit, I believe the front is 26mm instead of 25mm, but the rear is 20mm instead of 13mm. The main point of ARB's is the relative stifness between front and rear rather than the absolute stiffness. A stiffer rear moves the balance of the car towards the rear.

Roll is generally more limited, but they don't add any 'stiffness' to the ride in the way that uprated springs / dampers would as their effect over fast bumps is negligible.

Do you feel them working though? If Yahoo is correct and they are solid (which I thought they were) then they will be enormously stiff even compared to M3 arb and I'm curious to know if they feel harsh when cornering fast? How much did they cost too pls?

[Ant Man]

Originally Posted by Yahoo

I am really pleased to hear your results Doughboy - sounds great.

I have opted for the M3 ARBs (26.5mm fronts and 20mm rears), but these are hollow and so will be slightly more forgiving then the solid Hartge, H&R, Eibach equivalent. I think that a car with an LSD can handle the extra stiff ARB with more of a tendancy for controlled oversteer.

I on the other hand am not considering an LSD, but do want to reduce the roll on my e91 335i. Next week I am having some Eibach Pro springs, M3 ARBs, M3 sub-frame bushes and non-rft Eagle F1 assymetrics fitted as well as some cosmetic BMW Performance goodies.

I hope this setup will replace the rigity that I will be losing going form run flats to non rfts , whilst also reducing roll and improving the handling characteristics of the e91 - time will tell though I guess.

Ben

The pro kit springs have almost the same stiffness as the Msport springs but are progressive instead of linear. Have you considered getting shorter shocks to go with them? Eibach recommend Koni sport as a very good match.

[Yahoo]

Originally Posted by Ant Man

Have you considered getting shorter shocks to go with them? Eibach recommend Koni sport as a very good match.

I may do in time. The main reason for me to change the shocks would be if I found the damping to be too crashy/bouncy given the drop. But to be fair, the drop on the Eibach pro is only 20mm front and 0mm rear - so I don't see this presenting too much of a problem.

My main reason for changing the spring is to even out the stance of the car front to rear, the pro kit should achieve this.

Once the rfts and the ARBs and bushes have been changed I will take stock and see if anything else is required. I feel that what I am planning so far are necessities for the e91 to get it to handle like my old stock e92 - and hopefully a bit better.

[doughboy]

Originally Posted by Ant Man

Do you feel them working though? If Yahoo is correct and they are solid (which I thought they were) then they will be enormously stiff even compared to M3 arb and I'm curious to know if they feel harsh when cornering fast? How much did they cost too pls?

Absolutely they are working, but they don't add to 'stiffness' over bumps etc.

ARB's control body roll relative front to rear, springs & dampers also control body roll to a certain extent and the feel over bumps etc.

The handling is transformed and NO stiffness is added to the ride quality.

They are solid judging by the weight, although Tony may be able to confirm. The OEM 335i ones are solid too and the front Hartge bar is only 1mm thicker than the standard 335i.

The rear Harge bar is 20mm instead of 13mm which is the main difference.

If M3 ones are hollow, this will be for weight saving only and then they may be made of a different material or geometry to maintain a suitable torsional strength.

Remember also, even the M3 is STILL set up for understeer - the safe option for manufacturers. I'm trying to get away from that, and the Hartge kit deliver on this.

They were £475 plus fitting I believe.