BEST Size for BJII SP20

[02-KQ-LASR]

chino, did you notice you reply to yourself?? lol

[Chino]

lol probably man i get excited

[hks_kansei]

get big rims for daily use.

and keep stockers for other use.



I have my 17x7 for daily use (215/45/17), and my 15x6 for track use (195/55/15)

the 15s have more grip than the 17s (17s are Toyo Proxes4, 15s are Bridgestone Adrenalins), and are cheaper too, plus the 15s are ~5% undersized with the 55 aspect and this means the car accelerates better.

[Chino]

hrmmm nar my stockers are 16s and i recon their ferkin **** fopr track.. with 150 more hp you wont notice the difference oh 16 or 17 inch rim.. expecially when the rim is probably half the weight being a jap racing rim

[02-KQ-LASR]

and how are you planning to get 150+ more hp??

[Chino]

either speed circuit rig or build my own, and a hks 3037 or td06-25g i got a few different turbs ill see have to look into what guys are running on their built engines...

[hks_kansei]

Originally Posted by Chino

hrmmm nar my stockers are 16s and i recon their ferkin **** fopr track.. with 150 more hp you wont notice the difference oh 16 or 17 inch rim.. expecially when the rim is probably half the weight being a jap racing rim

I still reckon the 16 will be better for trackwork.

larger rims are usually heavier, try and get the actual weight of the new rims and compare it to the stockers. Then add the weight of the tyres.
my 15s weigh just under 20kg each (inc tyres, steelies), and my 17s weigh 21kg each (inc tyres)

and I can assure you, my car handles much better on the smaller wheels.



dont fall into the "bigger = better" mentality, there's a reason you dont see the V8s using 20s.

[Chino]

Originally Posted by hks_kansei

I still reckon the 16 will be better for trackwork.

larger rims are usually heavier, try and get the actual weight of the new rims and compare it to the stockers. Then add the weight of the tyres.
my 15s weigh just under 20kg each (inc tyres, steelies), and my 17s weigh 21kg each (inc tyres)

and I can assure you, my car handles much better on the smaller wheels.



dont fall into the "bigger = better" mentality, there's a reason you dont see the V8s using 20s.

but a smaller tyre wall 35-40 is better for handling for sure...
maybe its just cause you havent got a stretched tyre on your 17s.. camber? castor? it dusnt really matter man i get where your comin from.. but bleh.. wot im really after here is the perfect offsets for the front and the back for 17x8s with the guards pulled out 20-30mm and a bit of camber.. -1 bleh

[mussing]

A smaller tyre wall is good for handling, sure, but how much of a benefit will that be when the unsprung weight is greater?

[LordWorm]

what kind of track work you doing? circuit? drag?

Smaller wheels with a big of a chunky sidewall will be beneficial on the strip. The reduced rotating diameter will slightly improve acceleration, and the "slingshot" effect afforded by larger sidewalls are well documented in drag racing circles - especially if the tire is specifically designed for the job (drag radials tend to have a very soft sidewall, where as circuit racing radial tires tend to have very stiff sidewalls).

On the circuit i'd probably still stick with small diameter tires, with wide rubber - and select a suitable tire for circuit racing. Reduced wheel mass, and diameter will aid acceleration, and the little bit of compliance afforded by having some chunky sidewall will make the car easier to drive near the limit. Bigger wheels DO NOT automatically mean better handling.

Lots of touring cars use largish rims primarily to house large brake rotors. You don't have that problem. Even if you did a rather large brake upgrade, you'll comfortably get the 16's over them - maybe even 15's....

Speak to chicaboo about his experience running 17's on low profile licorice straps on an astina - he had issues with front wheels "skipping" when powering through corners. I was running the same tires at the time on 17's with a larger profile, and didn't have the issue because the sidewall took up some of the load....

Theres also a diminishing return on contact patch - the wider your contact patch, the more the mass of the car is distributed, and the harder it is to get the tire to nominal temperatures - and keep them there. Theres a reason why we don't all get 315mm wide tires standard on cars - If it was a question of "wider means more grip and better safety", manufacturers would sling the widest tires they could under the cars - this isn't the case....and theres a reason they don't.

[hks_kansei]

exactly my point Lordworm ^

Big for looks, smaller for speed.

[chicaboo]

I think 15x7" is the best for our sized cars. It alows to you have the optimum 45, 50 or 55 profile and 205 or 215 wide tyre. When I went to 16" and then 17" wheels on my Astina, I got heaps of understeer and skipping in the front tyres. 14" was too small (too much sidewall flex) for the Astina though, but 15" was ideal IMO.

There is also something to be said about the sleeper that pulls up next to you with chubby 15" (or even 14") wheels with an agressive tread pattern and a somewhat lumpy idle. I used to touge the hell out of my TX3 with its stock 14" wheels and Yokohama C Drives. But I also have a set of 15" rims for it with el cheapo Nexxen N2000 rubber on them... Since I've killed the Yoko's, I will be putting Toyo RA1 205/55/14 on the stock wheels for hill climb events.

Gav.

[Chino]

Originally Posted by chicaboo

I think 15x7" is the best for our sized cars. It alows to you have the optimum 45, 50 or 55 profile and 205 or 215 wide tyre. When I went to 16" and then 17" wheels on my Astina, I got heaps of understeer and skipping in the front tyres. 14" was too small (too much sidewall flex) for the Astina though, but 15" was ideal IMO.

There is also something to be said about the sleeper that pulls up next to you with chubby 15" (or even 14") wheels with an agressive tread pattern and a somewhat lumpy idle. I used to touge the hell out of my TX3 with its stock 14" wheels and Yokohama C Drives. But I also have a set of 15" rims for it with el cheapo Nexxen N2000 rubber on them... Since I've killed the Yoko's, I will be putting Toyo RA1 205/55/14 on the stock wheels for hill climb events.

Gav.

i thought 35-40 would be best for trackwork.. and more side wall flex for drag? correct me pleeeaasseee.. if i kept 16s (thinkin bout gettin 16s now but just a lightweight japper) and went down from 55 to 45.. my speedo will slow down yer? like its say im goin slower then wot i really am

[chicaboo]

I had Toyo Proxes4 with 40 profile on my 17's, and I really didn't like them at all, for the above reasons. Lordworm had the same in 45 or 50 profile on stock 16's, and they were MUCH better. My Sumitomo 16's with 45 profile exhibited the same problems to less of an extent.

I find a bit of sidewall flex helps let you know the limits of your car. But you can get garbage soft 50 profile sidewalls like those on the Bobjane Allrounder, and then really hard 50 profile tyres like those on the Bridgestone Turanza and Kumho PowerMax. If you stick to performance type tyres, the sidewalls will be on the firm side anyhow, and a 50 or 55 profile will be close to spot on. If you have a rim wide enough for a 205 or 215 wide tread, that's probably your best bet too. Usually 6.5-7" wide.

This is what I've worked out that I like for all occasions mind you. I don't dabble in motorsport, so the ppl who do might suggest something more specific for a given surface and what-not. When I get into hill climb events in my TX3, I will stick to my 14s and 15s however, and go from there.

Cheers, Gav.

[Chino]

my 180sx just handled so ****in good with 17s and a stretched tyre over a 9 inch rim.. yet most of it was oversteer driving didnt have to worry bout understeer. almost ever.. with the way the car was setup.. lots of castor decent amound of camber. im uneducated when it comes to front wheel cars..

[LordWorm]

if you are set on 17's...get 17's...but just bare in mind that, at least in my experience (and chicaboos), 15's or 16's would be optimal for a weekend warrior that likes getting into the twisties and having the occasional thrash on a circuit or drag strip. You don't want to have 3 sets of wheels and tires , for road, track and strip...its cost prohibative. 16's on a good performance tire will be great for all 3 of those. You could perhaps look at using a pair of 16's with some race rubber on them for track work, and a blingy set of 17's on licorice straps for the street....doing that is not uncommon...

But like i said before, you can go to wide - and it will have a negative impact on grip. You can go to low on the profile, and it will have a negative impact on handling. And you can go to big, and it will have a negative impact on acceleration. You need to find a balance...and 15's or 16's on a 205 to 225 wide tire seems to be where its at. Bigger is not always better....the same is true for going to small... not enough width, not enough grip. Too much sidewall, baggy handling. To small a rim....well that's probably not really an issue but it will limit tire selection... you need to find the sweet spot......

[Chino]

Originally Posted by LordWorm

if you are set on 17's...get 17's...but just bare in mind that, at least in my experience (and chicaboos), 15's or 16's would be optimal for a weekend warrior that likes getting into the twisties and having the occasional thrash on a circuit or drag strip. You don't want to have 3 sets of wheels and tires , for road, track and strip...its cost prohibative. 16's on a good performance tire will be great for all 3 of those. You could perhaps look at using a pair of 16's with some race rubber on them for track work, and a blingy set of 17's on licorice straps for the street....doing that is not uncommon...

But like i said before, you can go to wide - and it will have a negative impact on grip. You can go to low on the profile, and it will have a negative impact on handling. And you can go to big, and it will have a negative impact on acceleration. You need to find a balance...and 15's or 16's on a 205 to 225 wide tire seems to be where its at. Bigger is not always better....the same is true for going to small... not enough width, not enough grip. Too much sidewall, baggy handling. To small a rim....well that's probably not really an issue but it will limit tire selection... you need to find the sweet spot......

hmmm on my 3 last cars ive had 295's and theyv bin awesome and thinner and i wouldnbt go anywhere its just waste tyres... maybe its the whole front drive thing but im learning im learning..

well im not really into blind i buy japanese racing rims because their light... thats it not because they look good. because u can feel the difference between i nice set of work, gram lights, volks and an aussie 17 inch rim... it just feels **** on the road.. i recon a wider footprint (lower offset) is better too its just getting them to tuck under the guards so that cops dont winge..

im pickin what you guys are putting down though and its helping me out.. so keepem comin guys thanks

[LordWorm]

Originally Posted by Chino

i recon a wider footprint (lower offset) is better too its just getting them to tuck under the guards so that cops dont winge..

you can reckon that all you want... but going wide as possible is NOT going to provide the best grip.

i reckon 295's will be miles to big on the front wheels of an SP20....

[Chino]

Originally Posted by LordWorm

you can reckon that all you want... but going wide as possible is NOT going to provide the best grip.

i reckon 295's will be miles to big on the front wheels of an SP20....

oh yer for sure lol itd look silly i was probably goin to go a semi slick tyre once i get the big power 225's like u said.. i was just giving you an example of my rear wheel drive cars.. but for now im leaning towards a 16x8 with 225's just amiddle of the range tyre.. cos the car is slow as **** atm.. but thanks for all the input everyone.. i dont really care about the bling and if 16s going to give me better handling on the street and the track then yer..

what do you guys trhink about coilovers?? im thinking their goin to be too hard for a FWD car? im thinkin just a nice set of springs n struts will suffice

[chicaboo]

Eibach Pro-kit and Tokico HP (Blues) give you the best set-and-forget experience hands down.

Gav.