Toyota GT86 CS-CUP tires

[mrg666]

The tires on Toyota GT86 CS-CUP racer are shown as 245 620/17 on 17x8 O.Z. Racing wheels. Are they the same size as 245/40-17 street tires? And the wheels look like Ultraleggera to me. Anybody can confirm?

Another link:https://www.caranddriver.com/news/to...s-of-pure-want

[nikitopo]

The CS-Cup car runs on slick tires. It is a car just for racing and not street legal. If you like the rims, then you can use them. Try in a tire size calculator to find a tire that doesn't deviates too much from stock tire diameter.

[Impureclient]

Off topic but that's crazy that we are sitting with 600 lbs of extra weight compared to these cup cars.

[mrg666]

Originally Posted by Impureclient

Off topic but that's crazy that we are sitting with 600 lbs of extra weight compared to these cup cars.

Yes, but nobody normally wants to daily drive a car in that stripped condition.

By the way, I found that 620 is the tire height in millimeters for racing tire specs. Height of 245/40-17 is (17*25.4)+(2*245*40/100)=627.8 mm

So 245/40-17 is the closest size to 245 620/17; they are approximately the same size tire and TMG's choice for racing with 17x8 wheels. And, before somebody points out, racing slicks have different compound and structure. I was asking the question regarding size only and I wonder what size they install as grooved rain tires.

[fatoni]

I'm waiting for someone to tell them how those wheels and tires are slower than heavier, narrower wheels and tires.

[Clipdat]

^^I really love that livery! Awesome.

Originally Posted by ERA

#letsgoplaces

[nikitopo]

Originally Posted by fatoni

I'm waiting for someone to tell them how those wheels and tires are slower than heavier, narrower wheels and tires.

You didn't notice the comment of Impureclient. These are very light stripped down cars with many changes in the engine area too. They are quite powerful and they are close to the range of an ordinary 86/BRZ equipped with an entry level supercharger. They have enough power to use these wheels and tires.

[NoHaveMSG]

Originally Posted by nikitopo

You didn't notice the comment of Impureclient. These are very light stripped down cars with many changes in the engine area too. They are quite powerful and they are close to the range of an ordinary 86/BRZ equipped with an entry level supercharger. They have enough power to use these wheels and tires.

Not quite.

the Cup has 212 horsepower and 162 lb-ft.

And I imagine that is at the crank, as they where comparing to the stock HP numbers for 205/151

[mrg666]

Originally Posted by NoHaveMSG

Not quite

You are right. CS-CUP has 1110 kg (2440 lbs) curb weight and 212 HP power which means 11.5 lbs/HP power weight ratio. My JRSC has 2800 lbs curb weight and 300 HP power which is 9.3 lbs/HP. That is not even close.

[churchx]

Is 300HP "entry level supercharger"? Imho something like cossworth 2.0 of 250hp with regular pulley and unbuilt engine/unchanged tranny, is more like such. Still, as seen better numbers then those 212 with uncatted header and tune, so exchanging that extra lightening for less gains, i expect these cars to accelerate similar.

[mrg666]

Originally Posted by churchx

Is 300HP "entry level supercharger"? Imho something like cossworth 2.0 of 250hp with regular pulley and unbuilt engine/unchanged tranny, is more like such. Still, as seen better numbers then those 212 with uncatted header and tune, so exchanging that extra lightening for less gains, i expect these cars to accelerate similar.

Yes 300 HP (not whp, since 212 is not whp either) is entry level JRSC kit installed on a completely stock engine. I agree that these cars should have better acceleration than 212 HP sounds like. They have more upgrades than just power such as racing differential, transmission, *and tires* etc.

[venturaII]

Lighter car, close to stock power numbers, yet tires wider than 225, with slicks even. They must be slow.

[mrg666]

Originally Posted by venturaII

Lighter car, close to stock power numbers, yet tires wider than 225, with slicks even. They must be slow.

Yeah *very* slow. Even a minivan ...

[NoHaveMSG]

Originally Posted by churchx

Is 300HP "entry level supercharger"? Imho something like cossworth 2.0 of 250hp with regular pulley and unbuilt engine/unchanged tranny, is more like such. Still, as seen better numbers then those 212 with uncatted header and tune, so exchanging that extra lightening for less gains, i expect these cars to accelerate similar.

Entry level Innovate setup is good for 220whp with stock header and FP/OP with Perrin CB. I know guys with the JRSC are seeing a lot better numbers, and all kits benefit a lot from having header/FP/OP. 250-275whp is fairly common on low boost in those setups.
https://rallyways.com/8932/superchar...anyon-carving/


Hard to say what crank HP would be. If we say that a stock car at 205 crank is 170whp then we could estimate that the 220whp car is around 265-270.