I'm looking to put some spacers on my integra this spring, and really just wondering what people suggest to get so the wheel will sit flush with the fenders.

I'm not looking to run WAY out, but just have the end of the wheel flush/barely inside the fender line.

Couple questions:
A.) What's to determine what size spacer you need?
B.) Do you need extended lug nuts if you run a spacer?

Thanks to anyone that can help me out.

 

Anything over 5mm is probably a good idea to run extended studs.

 

run adapters, hit me up if you need a set

if you have a stock wheel with a high offset (+45)
then running a 20mm adapter will make it sit flush

 

anyone know what would be more "safe" for autocross?

I run pretty regularly over the summer, and the idea of adding a piece into the wheel makes me think the spacer would be safer with longer studs vs adding a completely different piece that bolts on to the hub, then bolts to the wheel

 

best way is to use the sandwich style spacer that uses longer studs such as ARP studs.

 

i don't mean to threadjack but i've been doing some research myself on getting the right stance. i talked to a guy in a rim shop and he didnt want to put spacers on my car saying it was dangerous. he was telling me the way to do it is wider rims with a lower offset.
i dont think he was trying to sell me rims he just seemed informative.

any thoughts?

again not trying to threadjack i think were all looking for the right way to achieve that look

 

I think its fine, look at the physics of what hold a wheel on. Adding a spacer dose nothing in regards to that.

I run 25mm spacers on my race car, never had a problem.

 

well it increases the leverage on the bearing. also it affects turning radius and other suspension geometry. and it make the spring rate softer because of the increased leverage. the correct way to do it is with lower offset wheels. If you can do that then longer studs and a spacer will work. im using 15mm bolt on spacers in front which increased turn in and stability a ton.

 

What's actually the difference then between running a spacer and running a lower offset wheel?

Isnt the lower offset just changing the mounting point of the wheel? kinda like what adding a spacer onto the hub would do?

 

On the rim yes, but on the hub/bearing it is still in the same spot.

 

explain... its always going to mount on the same point on the hub/bearing.. that doesn't move. lol

 

Spacers with wheels and low offset wheels will both have the same effect on suspension geometry and turning radius, as well as all the other things you stated. Regardless of what you have all read, with proper installation and quality parts, there will be no issues using spacers over lower offset wheels.

 

how is that ANY different than running a lower offset wheel?


(answer is, it isn't, its the exact same)

 

spring softer...yes if an SLA design, no if a Mac Strut. At some point, adding spacers to an otherwise stock set up will begin to increase loads on tie rods and steering linkage. Bearing failure can be a problem but this is usually over a long haul unless the offset has been increased substantially.

Longer studs or bolts MUST ALWAYS accompany spacers!!!

Spacers effectively change wheel offset and therefore scrub radius. This is not necessarily a bad thing as steering feel can be improved. Front drivers typical posses negative scrub radius - the king pin axis or SAI - steering axis of inclination fall outside the tire's center line. In general there is at least one problem with this, the fulcrum or steering axis is fairly far from the center of the tire's contact patch. I can elaborate if you wish...

Also, increasing track decreases a tire's work load...cornering power should increase. Increasing track width will almosy always raise static roll center location and as such you can fine tune the balcne - understeer vs oversteer by playing games with track width along with all of the other tuning tools.

Negative offset is design in as a safety mechanism for front dirvers since a loss of control can occur if one wheel loses traction; remember that SAI is an axis the the wheel turns around, it is literally the axis the strut spins on (mac strut) or the virtual axis an SLA spins on (created by upper and lower ball joints). If the point where SAI contacts the ground is outsdie the tire's center line - neg offset - and a wheel loses traction it will spin around the axis - counterclockwise when looking down - pointing toward the car's centerline. This is inherently stable. If this SAI axis is on the inside of the tire's centerline, the wheel that loses traction it will want to spin clockwise - think toe out - and de-stabilize the situation.

Also understand that adding more negative camber adds to negative scrub...so if you have dialed in 2 - 3 degrees neg camber you can bring SAI back somewhat by changing offset.

There isn't a free lucnh as they say. My last track car - 2005 JCW mini came with a stock wheel offset of 45. One of the track set ups was 23mm front and 33 rear - a fairly wide front offset/stance. however, since the mini's front track is narrower than the rear the difference is a little less. This worked very well at Watkins Glen...but not so well on other tracks.

Wider front track than rear = understeer. Wider rear track than front = oversteer. Increasing track up front also increases front grip. Increase track in the rear increases rear grip. BUT!!! you also have to understand how your particular car compensates camber...a wider rear track may soften the camber curve and this may ultimately result in a los of traction and some degree of roll/pitch. I had to add a wee bit more neg camber in the rear of the mini.

 

OP asked about his Integra, so the Mac strut discussion, although informative, is irrelevant. It would apply to newer Civics , RSX's, and other newer Honda models that use Mac struts up front.

Actually, a PROPERLY designed hubcentric spacer (like H&R's TRAK+ system) is the best method. It can use either longer studs or be bolt-on and have its own studs. The type you get will depend on the width of the spacer. The key is that it has the proper lip around the center bore to properly center the wheels, which replicates the stock hub lip that would normally center the wheels.

A flat piece of material will not do this, which then means you're relying on the lug studs/nuts to center the wheel. This can result in excessive vibration and eventually bearing failure.

Do yourself a favor and use quality parts for stuff like this. Don't cheap out just to obtain a certain "look".

http://www.hrsprings.com/products/trak/

 

Patrick,

I understood the OP's question...my openning repsonse was a sentence long and not a discussion and it served to differentiate the two types of suspension designs off the get go...for those who do not know or did not understand.

 

that is a contradictory.

wider front track--->Increases front grip---->changes the "balance of grip" which should make a car understeer less. (understeer is the decrease in front traction)

 

i am learning.

 

A.) test fit your wheels and add M12 washers until you get a look that you like, measure the washers, and order spacers that size.
B.) if using slip on spacers, yes. if using bolt on spacers, no.

 

Heh I missed that. He probably just got mixed up.

 

Difference between a spacer and a low offset wheel is with a spacer, you are just moving the wheel and tire outwards. With a low offset wheel the extra width is better distributed on either side, not just pushed out. If you had a 16x7 +40 wheel and a 15mm spacer, its not as effective as using a 16x8 wheel with +20 to fit a wider tire, assuming its the same tire but in a wider size.

 

Not contradictory at all - pure undisputable physics...increasing front track width increases front roll restance = understeer. Increasing rear track width increases rear roll resistance = oversteer. If you increase track width equally front and rear there is no net change in balance, grip increases over each axle so long as - in particular to multi-link rear designs - the camber compensation curve has not been softened by much.

As Patrick noted above a bit, H&R do make very well engineered spacers.

In either case the tires can perform more work - more than theoretical. Track width considerations are extremely fundamental to suspension tuning...ie, before spring rate selection.

Increasing track width does not lower the center of gravity...just throwing that out there since it seems to a be a somewhat common miss-conception.

 

Increasing roll resistance at one end (similar to going to a larger anti-sway bar) makes that end more likely to lose grip, because the decreased body roll makes the tires have to resist more of the lateral cornering forces, instead of them being taken up by the suspension with body roll. I understand that.

But you also said:

How can increasing front track width increase front roll resistance, resulting in understeer AND also increase front grip? Vice versa for the rear. Seems contradictory. This is just how it seems to me.

If there is an explanation, I want to know so I can further my suspension knowledge.

 

I have to step into a meeting, but it the answer is related leverage; how instant centers and roll centers work and how they affect the CofG. You can also think about it - partially this way - two triangles...both the same height but one has a wider base. Now, make one of the triangles the front axle and the other the rear axle...this is a good visual.

I require good visuals...hopefully that helps a little?

Keep in mind, instant centers and roll centers are really virtual lever arms and fulcrums/pivto points. We dont' necessarily see them but they affect weight transfer at the most findamental level.

 

Regardless of roll centers, instant centers, CofG, etc... how can an increase in track width both increase under/oversteer (loss of grip) AND increase grip at the same time?