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Just got these delivered and put on yesterday, 17mm rears, 5mm for front (Q4 btw). I like the more filled out look, not sure if it'll rub though in the rear if the car gets lowered/coilovers. I feel like the rears may be too aggressive, but maybe I just need to get used to them. Definitely need to get coilovers next!

I know she needs a wash.... wifey's been driving it to work daily. Let me know your thoughts!
 

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2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
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Just got these delivered and put on yesterday, 17mm rears, 5mm for front (Q4 btw). I like the more filled out look, not sure if it'll rub though in the rear if the car gets lowered/coilovers. I feel like the rears may be too aggressive, but maybe I just need to get used to them. Definitely need to get coilovers next!

I know she needs a wash.... wifey's been driving it to work daily. Let me know your thoughts!
See also Racer Z's fitment of 255 35R19 tires on 19x9 5 hole rims on all 4 corners. This will fill in the wheel well while providing functionality too.
He says it hasn't rubbed yet on his Q2.

Alternatives are 245 40R19 tires on the stock 19x8 rims (wheel is about 0.6" larger diameter, reducing the gap although possibly creating rubbing issues front and back of the opening, note that Quadrifoglio uses 245 35R19 tires on the front but is 1.5 to 2" lower in front than your Q4) and 255 35R19 tires on 19x8.5 Tecnico rims (saves unsprung weight compared to 19x9s for hopefully better handling).
 

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I have not yet detected any rubbing. Almost 3,000 miles on the 19x9's, but mostly Interstate. I did about 70 hard canyon, mountain twisties chasing sports cars without issue.
 

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I've moved this thread from 'Help' to 'Wheels'.

'Help' is for help with forum issues, such as, how do I post a picture.

'Wheels & Tires' in the Technical section is for help about car technical issues, such as, what spacer size works best. It should get more traffic and responses here.
 

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Just got these delivered and put on yesterday, 17mm rears, 5mm for front (Q4 btw). I like the more filled out look, not sure if it'll rub though in the rear if the car gets lowered/coilovers. I feel like the rears may be too aggressive, but maybe I just need to get used to them. Definitely need to get coilovers next!

I know she needs a wash.... wifey's been driving it to work daily. Let me know your thoughts!
17 mm in the rears? They don't look it from the photos. Sweet ride just the same!
 

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The only downside will now be excessive grime on the rear bumper and side rocker panels :(
Put paint protection film ASAP or it will chip and scratch your paint.
A few things to be aware of with any spacer is the loss of spring rate (loss of handling), lower offset, load on bearings and wear on bushings. Not being a downer, just need to be real about these things. I assume most want their cars to perform the best with the least amount of issues/repairs. Did you also replace your wheel bolts? If not you might be in dangerous territory with only a few threads holding the wheel on the hub.
 

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A few things to be aware of with any spacer is the loss of spring rate (loss of handling), lower offset, load on bearings and wear on bushings. Not being a downer, just need to be real about these things. I assume most want their cars to perform the best with the least amount of issues/repairs. Did you also replace your wheel bolts? If not you might be in dangerous territory with only a few threads holding the wheel on the hub.
EC kit comes with extended studs. The spacers are hubcentric so there is no change to loading on the bearings. Lastly the spring rate cant change as it's a function of the spring drsogn. The wheel rate will change but that's going to be a low single digit percentage.
 

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EC kit comes with extended studs. The spacers are hubcentric so there is no change to loading on the bearings. Lastly the spring rate cant change as it's a function of the spring drsogn. The wheel rate will change but that's going to be a low single digit percentage.
Ok, good on the studs. I am speaking on spacers in general.

Might want to watch this:

 

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You still don't understand the concept of "wheel rate" and spring rate. The spring rate can not change as the spring is not changing. The wheel rate is the effective spring rate - its going to change proportionally to the amount of the change in suspension arm length... which is completely negligible. All as described on your video.

Bearing life is equally pointless to debate. All OEMcomponents have a significant factor of safety built into the design (we don't have thin margin race components). There are no spacers available that are going to significantly dig into that safety margin - especially with the hubcentric design.
 

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Interesting mentioning this after the video I posted. I know the difference but most of the time there is no need to get too detailed as most don't read it anyway. Regardless, the suspension geometry has changed and really not for the better. 5mm, fine go for it. Not going to do much there. 15mm++ will have significant changes.

Wheel Rate is basically the Spring Rate but measured at the wheel instead of the where the spring attaches to the linkage. Figure shows how wheel rate is determined. It is basically the Spring Rate multiplied by the motion ratio squared. If this is altered you then alter the entire suspension. Reducing the wheel rate by pushing out the wheels will thus reduce the entire spring rate. So if you have 540lb/ft of spring rate and 280lb/ft of wheel rate stock, if that wheel rate is reduced by wheel spacers, then in-fact the entire spring rate is reduced.

91032



Not sure why bearing life is pointless to debate? I suppose you have money to burn. Despite the safety margins built in as you state, bearing life is reduced. I am not speaking about full out destruction of a bearing using spacers, more so the increased wear on them that will cause them to fail sooner. I don't think these items are a performance upgrade unless the entire suspension is changed to accomidate the spacers. I agree that there could be some advantages to this if done right but it's just way more complex than throwing on a few spacers for $150.00. To think otherwise is my point of my post. I am not against upgrades at all, but the inexpensive aesthetic components, always, in my experience cause more issues than they are worth on street cars. Spacers may be a necessary evil to clear calipers in situations for racing, adding larger calipers etc...
 

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I'm not a spacer guy myself ... once you alter the scrub radius they never handle quite the same
Exactly Right! You'd have to do some major suspension altercations, fabrications and enginnering to get it right. WHY? It's already right! ;) Already wide track as well.

Where I am sourcing most of my information along with experience. I have another one of his books I will be reading here soon as well.

91035
 

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Put your book down, get out a tape measure, and measure and find the change in wheel rate.

Eventually you will find a single digit percent change like I said several posts ago. It's completely non significant.


Then also realize wheel bearing loading is designed around slamming potholes. Second highest loading comes with cornering forces along with how much weight the car is carrying. By your logic putting on grippier tires or a passenger also will wear out your wheel bearings. Again, actuals are different then theoreticals.
 

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Put your book down, get out a tape measure, and measure and find the change in wheel rate.

Eventually you will find a single digit percent change like I said several posts ago. It's completely non significant.


Then also realize wheel bearing loading is designed around slamming potholes. Second highest loading comes with cornering forces along with how much weight the car is carrying. By your logic putting on grippier tires or a passenger also will wear out your wheel bearings. Again, actuals are different then theoreticals.
Hey listen, I was not trying to take into this direction but you seem to want to go down that path.
From my research (and experience) spacers are fairly useless for performance enhancing.

Again. Are you using spacers as well on your giulia? If so what sizes and why?

You're skewing what I have said to discredit me. A giulia floating in air with the wheels turning will wear on the bearings eventually (even if filled with Dupont Krytox), everything wears on the bearings, but the difference is rapid wear vs. normal wear, bearings failing at 50K miles or 120K miles. Friction is a killer. The load from a wheel is transferred to the axle through the friction of the clamped joint and not through the wheel stud. The bearing thing is minimal (depending) but it's still a factor to be looked at. Disregarding it seems lazy. In mechanical engineering I'd think even 1% is a factor to look at. Even though that one component is a single digit %, how is that single digit % effecting other components in the system? Is that causing other components to have a double digit % change?

That 1% could be fatal for a rocket being launched into Space. Maybe a bad example ( I grew up with an Aerospace engineer father) but still, disregarding that small % is not my idea of good mechanical engineering. ;) I don't have any interest in measuring the change in wheel rate as I am never going to be using spacers for any reason. Again, I appreciate your hard work to become a ME and the knowledge you can bestow upon us forum cretins but I am still not convinced that spacers are harmless and do not change suspension geometry because folks that race and have been in the automotive industry seem to think a bit different on that. I am willing to learn if you have the answers and experience, I may not have a ME degree but I do have a master's and am able to understand if all the information is there and presented properly. From my research, spacers are not something I would bother using for any performance handling gain. Plain and simple the scrub radius is increased which is a problem.
 

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Factors of safety in automotive design are 200-300%. Hell, spring rates of OEM springs are generally only +/-20%. Stop the nonsense of a few percent difference changing things.

My spacers arrive Wednesday and I'm getting them because of the disastrous rear fitment of Q4s. A 17mm spacer creates the same fitment as a stock QV wheel would.
 

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My spacers arrive Wednesday and I'm getting them because of the disastrous rear fitment of Q4s. A 17mm spacer creates the same fitment as a stock QV wheel would.
its your car so you are welcome to do as you please, but I assume the engineers who designed the Q4 used a different wheel offset than the QV for a reason .... Installing a QV wheel or using a 17mm spacer both give you much more positive scrub radius than the engineers who designed the car wanted it to have. .and it will negatively effect the handling..thats not even debatable.
 
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