Wide-body w/wheel spacers
Joined: Aug 2001
Posts: 3,833
Likes: 493
From: Stockton, CA
18x12 front and back
I have changed my plan.
I am going to put 18x12 for both front and back with 335-30-18 tires. I already got the tires so now I just need some advice on the wheels.
Questins:
1. What's the front spacing for both front and back? I did the mearsurement myself and I got 3.5" But I already have the Mazdaspeed fender flares on my car so it might be off.
2. My RE Amemiya 2002 GT widebody is going to add 2" per side so with my own calculation, Volk Racing only has this one that I can use
Volk Racing GTU, 18x12 with +11mm offset. With this rim, I get 5.57" front spacing and 6.43" backspacing. Does it sound right?
Thank you in advance. I want to get the rims ordered ASAP because Volk Racing does not keep those sizes in stock and I want to go to seven stock with them.
Chuck Huang
I am going to put 18x12 for both front and back with 335-30-18 tires. I already got the tires so now I just need some advice on the wheels.
Questins:
1. What's the front spacing for both front and back? I did the mearsurement myself and I got 3.5" But I already have the Mazdaspeed fender flares on my car so it might be off.
2. My RE Amemiya 2002 GT widebody is going to add 2" per side so with my own calculation, Volk Racing only has this one that I can use
Volk Racing GTU, 18x12 with +11mm offset. With this rim, I get 5.57" front spacing and 6.43" backspacing. Does it sound right?
Thank you in advance. I want to get the rims ordered ASAP because Volk Racing does not keep those sizes in stock and I want to go to seven stock with them.
Chuck Huang
Rotary Enthusiast
Joined: May 2002
Posts: 971
Likes: 0
From: San Diego
Yeah Chuck, you should consider 18x11 or 18x10.5 for the fronts...it's best to have a somewhat staggered wheel setup, especially with such large wheels. RE Amemiya runs the staggered setup I beleive. Didn't you have some similiar opinions on this Max??
Btw, when is the next SS?! Not for a while is it???
Btw, when is the next SS?! Not for a while is it???
Full Member
Joined: Aug 2001
Posts: 139
Likes: 0
From: IL
Spacers.....
First of all, wheel studs don't hold the wheel, but the friction between the hub and wheel does. That's why properly torquing down the lug nuts is crucial and some high torque cars use 6 studs (SUVs, Vipers).
With that said, using spacers would not increase the load in the studs, because what they do is to provide a "pressing force" on the wheel to the hub. So the only load exerts on a wheel stud is AXIAL, no bending or shear. Therefore, having a spacer or not would not make much a difference.
Effects of spacers can be beneficial. It increases track width hence, as other has already pointed out, decreases weight transfer at cornering ---> increase grip, more power to the gound. But also, the front needs to be balanced out otherwise it would have too much understeer.
Drawbacks of spacer:
1) It increases stress on the wheel bearing. It might get worn out faster.
2) It increases the motion ratio of the suspension geometry, and causes the wheel rate to decrease. In other words, it retards the effectiveness of the spring so when spacers are used, the car would feel "softer".
That's all I can think of right now.
First of all, wheel studs don't hold the wheel, but the friction between the hub and wheel does. That's why properly torquing down the lug nuts is crucial and some high torque cars use 6 studs (SUVs, Vipers).
With that said, using spacers would not increase the load in the studs, because what they do is to provide a "pressing force" on the wheel to the hub. So the only load exerts on a wheel stud is AXIAL, no bending or shear. Therefore, having a spacer or not would not make much a difference.
Effects of spacers can be beneficial. It increases track width hence, as other has already pointed out, decreases weight transfer at cornering ---> increase grip, more power to the gound. But also, the front needs to be balanced out otherwise it would have too much understeer.
Drawbacks of spacer:
1) It increases stress on the wheel bearing. It might get worn out faster.
2) It increases the motion ratio of the suspension geometry, and causes the wheel rate to decrease. In other words, it retards the effectiveness of the spring so when spacers are used, the car would feel "softer".
That's all I can think of right now.
Full Member
Joined: Mar 2001
Posts: 222
Likes: 0
From: Never Never Land, Rotary Fun.
all 4 tires being the same would be more neutral steering..
I'm debating the switch myself, although I'm thinking about going 295 up front and 335 in the back.. I don't know yet. we'll see... I think I need to bump up the coilovers a bit in order to clear though.
I'm debating the switch myself, although I'm thinking about going 295 up front and 335 in the back.. I don't know yet. we'll see... I think I need to bump up the coilovers a bit in order to clear though.
Mad Man
Joined: Jan 2002
Posts: 2,758
Likes: 2
From: Big Island Hawaii
7.32" assuming a 13" wide wheel(overall). The formula is .5x overall width plus the offset. So, 12+1=13/2=6.5x25.4=165.1+21=186.1/25.4=7.32 Should be fine on an FD offhand, but check with Chuck at Rotary Extreme, or just go to his thread in this section on the SSR SP1 18x12 wheels. I know he had fitment issues, and had to re-order his wheels. His final correct offsets are listed. On my FC, I will be running SSR SP1 18x12s with a -13 offset. Carl
BTW his set-up requires flares, larger than the MazdaSpeed ones he was running(I think)
BTW his set-up requires flares, larger than the MazdaSpeed ones he was running(I think)
Mad Man
Joined: Jan 2002
Posts: 2,758
Likes: 2
From: Big Island Hawaii
The height of the tire is the biggest factor when going this big, you are in a 26" tire, and that may cause you problems. They can be r5esolved, but it is NOT cut&dried by any stretch. I will be running slicks in a 345-28-18, but there is no such DOT tire. You may be relegated toa smaller tire due to the diameter of the tire, not the width of the wheel. 
