bigbramble Posted August 18, 2010 Share Posted August 18, 2010 Heya, Before you think I am a retard for shooting myself in the foot for having them for sale and talking about why I think they are a bad idea I want to say that I think its better to be honest and give some useful information to other 350Z owners thinking of fitting large spacers or alloy wheels with a greater offset moving them away from the wheel. Even though I was pretty sure they were having a negative effect I liked the look so much I really wasn't sure whether to keep them on the car or take them off. I took them off and I am glad. So anyway here's the full story: First of all I have a 2005 350Z roadster with Rays 18" wheels. Like many 350Z owners I thought the vehicle looked a little too 'E type' like with the wheels sitting a long way inside the cavernous wheel arches. I did some research on the web forum and decided to purchase Hubcentric spacers 20mm front and 25 mm rear. I bought the spacers from MWtech and service was first class. The spacers arrived and were as described and of the easy to fit variety. The quality of the spacers is excellent so I have no qualms with that. The price is also excellent for such enormous lumps of aluminium! I fitted the spacers and torqued them tightly, 115nm for piece of mind (I know its flipping tight). As soon as I drove the car home I felt that I noticed some degradation in the driving experience, in particular; 1) Dull steering. The steering had lost its edge. It had lost feel and was nowhere near as sharp as before. Turn in seemed slower. 2) Car seemed 'crashier'. The damping did not seem anywhere near as good, felt like the body (this is probably of greater effect in a roadster due to the absence of roof structure) was absorbing more of the road shock than the dampers were. 3) Tram lining - vehicle seemed more prone to tram lining over rough tarmac. I can say however that going over extremely bumpy roads DID NOT cause at any time the wheels to hit the arches and I really did take it down some rough old country lanes at a reasonable pace. At first I thought it could have been me being fussy and wasn't completely confident in my subjective view point so I decided to try them for a few weeks the try the car again without. Today I removed the spacers and I instantly noticed the difference. I drove the car for 40 miles with the spacers, removed them and the drove for a further 40 miles. The steering is massively sharper and as a result the car changes direction quicker feeling far more agile. The crashy ride is gone, no scuttle shake at all just excellent damping as it should be. The car turns in beautifully and I feel I have rediscovered a truly great drivers car. So why do I think the spacers are having such a negative effect? 1) Steering - By fitting the spacers you are moving the wheels and most importantly the road contact patch further away from the steering axis. Essentially when you turn the steering wheel it will take longer/more effort to turn the wheels the same amount than without the spacers. This has the effect of slowing the steering and removing a good degree of its lively feel. 2) Damping/tramlining - I have thought about this a lot and I am putting it down to 2 factors. Factor A ) Unsprung weight. By fitting a spacer you are effectively adding the spacers weight to that of the wheel/hub/brake assembly. This is called unsprung weight as this weight is not damped by the spring/damper assembly. Unsprung weight is a great enemy of car designers who look to minimize this. Factor B ) Moving the loading point away from the shock absorbers/putting a greater load on the hub/wheel bearing assembly. By moving the wheels away from the point at which the suspension moves you are increasing the load on the intervening section - the hub/bearing assembly this in turn reduces the amount of impact that is actually damped quite like unsprung weight does. This in turn will also cause the wheel bearings to wear at an accelerated rate. This also effects steering and may explain the tram lining I experienced. Any more theories are certainly welcome. So to summarise, when fitting spacers the +- points are; + The look awesome and give the car a really aggressive stance. +-- In theory the greater distance between the wheels will increase stability, I do think that the tram lining they cause cancels out this factor and personally I feel the car is more stable and controlled without the spacers. - The steering is 'slower' and looses some sharpness - As a result of the steering issue the car loses agility and turn in speed - The suspension feels crashy and damping feels less controlled, scuttle shake is increased (please remember I tested this on a roadster so this may be nowhere near as noticeable on a coupe) - you may experience a tram lining effect much like fitting larger diameter wheels. - Increased wear to wheel bearing and hub components I would therefore say, if you have money to burn and care more about how your car looks than drives - fit spacers. If you prefer the car to be a hoot round the twisties - don't bother. Just so you don't think "who's this jerk talking @*!# when he has no clue" I better say I have some technical credentials. I am a fully trained mechanic with 11 years experience who has been teaching motor engineering for the past 3 years. I really hope this little guide is useful to people and will allow them to make an informed decision. Remember smaller spacers, 5-15mm front may have a lesser effect but ANY spacer will certainly lose some steering speed and feel. Cheers, Ant. Quote Link to comment Share on other sites More sharing options...
ATTAK Z Posted August 18, 2010 Share Posted August 18, 2010 Well said ..... an interesting opinion ........ form follows function yet again Quote Link to comment Share on other sites More sharing options...
Zugara Posted August 18, 2010 Share Posted August 18, 2010 So, how much were you selling your spacers for? Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 Hehe I am waiting for the for sale thread to get authorised. £100 + postage. I only live down the road from you really so it would be easy to collect. Quote Link to comment Share on other sites More sharing options...
Husky Posted August 18, 2010 Share Posted August 18, 2010 Makes sense to a fellow engineer I have that much rubber on the ground now though with my wider tyres I don't think I could go back... although you might say I have too much grip... Quote Link to comment Share on other sites More sharing options...
ATTAK Z Posted August 18, 2010 Share Posted August 18, 2010 Hehe I am waiting for the for sale thread to get authorised. £100 + postage. I only live down the road from you really so it would be easy to collect. wow that's a good price (for the buyer) Quote Link to comment Share on other sites More sharing options...
Greekman Posted August 18, 2010 Share Posted August 18, 2010 That means that wheels of lower offset will have the same impact? Quote Link to comment Share on other sites More sharing options...
Zugara Posted August 18, 2010 Share Posted August 18, 2010 Problem is i have a roadster to! Do i want to go the same route? Quote Link to comment Share on other sites More sharing options...
Husky Posted August 18, 2010 Share Posted August 18, 2010 Offset and spacers amount to the same thing. Quote Link to comment Share on other sites More sharing options...
ATTAK Z Posted August 18, 2010 Share Posted August 18, 2010 Offset and spacers amount to the same thing. +1 Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 Makes sense to a fellow engineer I have that much rubber on the ground now though with my wider tyres I don't think I could go back... although you might say I have too much grip... I would indeed! The previous owner of my car put continentals on the front and shitty budgets on the rear (wtf?!?!) but even then it has too much grip on the rear even in the rain Even so once the budgets wear out I will fit something decent just because I passionately hate cheapo tyres on sports cars. To be fair I have been guilty of fitting massive wheels plenty of times in the past in the knowledge it has lessened the vehicle handling abilities. Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 Problem is i have a roadster to! Do i want to go the same route? No. You really should keep it stock, the difference is considerable. Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 That means that wheels of lower offset will have the same impact? Yup yup yup, big wide wheels may well have a detrimental effect on the driving experience. Quote Link to comment Share on other sites More sharing options...
ATTAK Z Posted August 18, 2010 Share Posted August 18, 2010 That means that wheels of lower offset will have the same impact? Yup yup yup, big wide wheels may well have a detrimental effect on the driving experience. more so on the front than the back .............. that's why manufacturers keep it pretty close to standard at the front ..... for instance my Konigs are wider but only increase offset by 5 mm at the front, whereas it's +20 mm at the back Quote Link to comment Share on other sites More sharing options...
kevlo Posted August 18, 2010 Share Posted August 18, 2010 oh bugger ive just bought those exact spacers. any body got these spacers who hasnt noticed the difference Quote Link to comment Share on other sites More sharing options...
Greekman Posted August 18, 2010 Share Posted August 18, 2010 i am just a tooth mechanic... and i think its prob not so much black and white. wider stance should give better stability. i understand how the steering may feel a bit numb and slow since the main weight gets further from the centre of rotation and than can not be rectified unless you fiddle with the toe angles. also as the main weight of the wheel is further from the hub the is more leverage on the coilover. thats why the ride becomes crushy. nothing a set of aftermarket coilovers with adjustable dumping and rebound cant sort out. forces on the hub increased for the above reasons true. spacers have dont weight anything really so the whole weight of the unsprung mass is about the same. example. if you use a dumbell with a 5 kg weight only on one side of it, grab hold of it with the weight facing away from you and try and move it about on a carpet. you will feel all of the above on your wrist. opinions if i forgot about something please. Quote Link to comment Share on other sites More sharing options...
rog518 Posted August 18, 2010 Share Posted August 18, 2010 go on paul buy them you know you want too!! Quote Link to comment Share on other sites More sharing options...
rtbiscuit Posted August 18, 2010 Share Posted August 18, 2010 i had these one mine and used to track the car and didn't find it massively different. a decent Geo setup would help to counteract some of that. admittedly mine were on a coupe, so the stiffer chassis may well have hidden some of those characteristics. Quote Link to comment Share on other sites More sharing options...
350zStephen Posted August 18, 2010 Share Posted August 18, 2010 I have 20mm Eibach spacers fitted only to the rear of my zed at the moment due to problem with the a stripped to fit the fronts. I have noticed the handling is terrible compared to standard. The car tram lines Steering will not sit straight unless I am on a completely flat surface Once I get the fronts fitted, if the car is the same, they are coming straight back off. Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 i am just a tooth mechanic... and i think its prob not so much black and white. wider stance should give better stability. i understand how the steering may feel a bit numb and slow since the main weight gets further from the centre of rotation and than can not be rectified unless you fiddle with the toe angles. also as the main weight of the wheel is further from the hub the is more leverage on the coilover. thats why the ride becomes crushy. nothing a set of aftermarket coilovers with adjustable dumping and rebound cant sort out. forces on the hub increased for the above reasons true. spacers have dont weight anything really so the whole weight of the unsprung mass is about the same. example. if you use a dumbell with a 5 kg weight only on one side of it, grab hold of it with the weight facing away from you and try and move it about on a carpet. you will feel all of the above on your wrist. opinions if i forgot about something please. Its very black and white, with the spacers off the car is massively improved. Aftermarket coilovers would almost certainly make the problem even worse as they are generally stiffer than stock suspension so the hub/bearing and body would take even more of a beating. Spacers certainly do weigh something but I don't think its just the unsprung weight but a combination of things that ruins the ride and steering. Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 I have 20mm Eibach spacers fitted only to the rear of my zed at the moment due to problem with the a stripped to fit the fronts. I have noticed the handling is terrible compared to standard. The car tram lines Steering will not sit straight unless I am on a completely flat surface Once I get the fronts fitted, if the car is the same, they are coming straight back off. Sounds familiar. I also think the car is not as stable under braking but I didn't want to push the point Quote Link to comment Share on other sites More sharing options...
spursmaddave Posted August 18, 2010 Share Posted August 18, 2010 Can't say I have noticed a huge difference but then I don't have a ragtop probably a lot more noticable in one of those than a coupe Quote Link to comment Share on other sites More sharing options...
bigbramble Posted August 18, 2010 Author Share Posted August 18, 2010 Can't say I have noticed a huge difference but then I don't have a ragtop probably a lot more noticable in one of those than a coupe The steering difference will be just as great on the coupe. Take them off and drive it and you will see. I think its also worth remembering that the ragtop has an extra 75kg of reinforcement over the coupe, and EVO seemed to think there was just about nothing in it in terms of structural rigidity. Quote Link to comment Share on other sites More sharing options...
spursmaddave Posted August 18, 2010 Share Posted August 18, 2010 I drove it for 4 months without and I don't notice a huge difference since I put them on Quote Link to comment Share on other sites More sharing options...
Husky Posted August 19, 2010 Share Posted August 19, 2010 i think its fair to say most people dont track the car and for most zeds a play down a country road is the only "hard" work they will ever see. People shouldnt be scared of purchasing spacers at all. I can understand if you want every millisecond on a track but for normal driving who cares. Im not disagreeing with any of what you are saying but people shouldnt be thinking their zed will drive like a corsa afterward as this is not the case. on the note of my wide tyres, i'd be interested to have a direct comparison with another zed actually as mine corners rediculously well now with all the rubber on. Quote Link to comment Share on other sites More sharing options...
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