8 replies to this topic

[r35sugahh]

Just got a set of AdvanRacing GT 18 Custom ordered for my car but Im having trouble finding tires to keep the AWD system from future damages and the Overall Rolling Diameter within specs...any suggestions or experiences you all had would be much appreciated, TIA

[droptopp]

You want drag radials or performance tires?

[AutoXGTR]

What are you using your GTR for?

 

Street driving, track, drag racing, time attack, autocross, high performance driving school/events?

 

What suspension are you using- if lowered, how much drop

 

In general, front and rear tire diameters need to match. One way to select a tire size is to find one that will fit on both front and rear wheel widths but with 10" front and 12" rear this would be more difficult.

 

OEM tire diameter is 28" but you can use smaller tire diameters down to under 26". However for ground clearance it is good to keep it from 26.3" to 27.5". With a smaller tire diameter you would be increasing wheel gap with OEM suspension so some drop in suspension about 0.5" to 0.7" is OK. However the more drop the less clearance you have for extra wide tire sizes especially in front.

 

Using your new wheels vs OEM

Front 18x10" et35 will be 3.6mm further from the inner suspension and poke out 16.4mm more which is fine.

Rear 18x12" et27 will be 21.1mm closer to the inner suspension,  and poke out 17.1mm more. A 10-15mm wide wheel spacer would offer more space on the inside, rear tire if wide will poke out quite a bit.

[AutoXGTR]

So for limited street use and some street drag or limited track duty here is an example:

 

Toyo R888R Streetable Track R compound tires Treadwear 100

 

Front 305/35-18 fits rims 10-12" wide, perfect for 11" wide rim, tire diam. 26.4" 

Rear 335/30-18 fits rims 11.5-12.5" wide, perfect for 12" wide rim, tire diam. 25.9" 

 

Or use 305/30-18 for both front and rear wheels- this makes them match on tire diameter. Wheel widths will pinch or stretch tires to fit, the front wheel will limit the wide tire size and the rear wider wheel will allow the tire to stretch out wider. Should work fine and gives a 26.4" tire diameter which is usable for minimum ground clearance, not really good for OEM suspension due to wide wheel gap.

[AutoXGTR]

If you are looking for drag tires on a budget and for street use here is an example:

 

Toyo Proxes TQ Drag Racing tires treadwear 0

Rear 315/35-18  fits rims 10.5-12.5" wide, perfect for 11" wide rim, tire diam. 26.8" , note on Backorder

Front Toyo Proxes R888R  305/35-18, tire diam. 26.4"

 

Also check out Nitto tires

[droptopp]

The dimensions are almost identical to a TE37 saga face three up front and face four out back. For a drag setup Mickey Thompson ET Street S/S 345/35 and 275/45 - both 27.8 rolling circumference

[r35sugahh]

Yes, Im doing drag radials so my options are limited for what Im looking for but I saw a lot of people after digging thru a lot of old threads that for the 18x10 and 12s, 275/45R18 and 345/35R18 is the best combo to run while keeping the Rolling diameters within spec and when matching the front tires to the rear, the front Wheel Diameter is approximately 711mm and the rear is 709mm

[droptopp]

Yep just put on my fourth set, zero issues at any speeds or loads.

[r35sugahh]

Awesome, this puts my worries down lol, I just ordered my set, thanks everyone!!