R15 / CTW / 17" questions
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R15 / CTW / 17" questions
Hey guys,
I have seen a Viper up close with 275/40 tires on 17x10 front rims. I've also seen plenty of Corvettes with 9.5s, and I've driven a SN95 Mustang GT with 245/45R17s on the stock 17x8, then on 17x9 (same tires)
Seems to me that with the right offset, meaning just barely touching the tie rod end part of the spindle, a 17x10 could tuck. Anyone have pics otherwise?
I see the CTW 17s clear 14" 6-piston brakes, but everyone else's 17s limit brakes to 13.4", except the Ronals can't even fit those. But since the CTW can fit those, I'm wondering if a steel 17x10 with the right barrel could clear 14s with "LS1" calipers?
And how much of a weight penalty would the steel really be? In terms of feeling it in daily-driving?
Having a steel 17 widened is no big deal, just specify the backspacing. It seems that with lathed 1LE hubs and J56 rotors, a 6" backspacing would be safe, probably needing less than 8mm of spacer to get it perfect, right?
I'm not eager to waste my earnings, but I am willing to be the first to try it IF it should work.
I realize I'm not likely to feel much improvement over a 9.5, and the 9.5 offers a hair more sidewall protection from nails on the road, but a pair of these 10s will be under $ 200 each, delivered and ready to mount 275s onto.
I have seen a Viper up close with 275/40 tires on 17x10 front rims. I've also seen plenty of Corvettes with 9.5s, and I've driven a SN95 Mustang GT with 245/45R17s on the stock 17x8, then on 17x9 (same tires)
Seems to me that with the right offset, meaning just barely touching the tie rod end part of the spindle, a 17x10 could tuck. Anyone have pics otherwise?
I see the CTW 17s clear 14" 6-piston brakes, but everyone else's 17s limit brakes to 13.4", except the Ronals can't even fit those. But since the CTW can fit those, I'm wondering if a steel 17x10 with the right barrel could clear 14s with "LS1" calipers?
And how much of a weight penalty would the steel really be? In terms of feeling it in daily-driving?
Having a steel 17 widened is no big deal, just specify the backspacing. It seems that with lathed 1LE hubs and J56 rotors, a 6" backspacing would be safe, probably needing less than 8mm of spacer to get it perfect, right?
I'm not eager to waste my earnings, but I am willing to be the first to try it IF it should work.
I realize I'm not likely to feel much improvement over a 9.5, and the 9.5 offers a hair more sidewall protection from nails on the road, but a pair of these 10s will be under $ 200 each, delivered and ready to mount 275s onto.
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Re: R15 / CTW / 17" questions
You might be able to get a 10" under the front, but it will probably stick out just a bit since the max BS you can run is 5.35" with stock 10.5" brakes, a bit more with a BBK and offset hubs.
I'm the owner of CTW Motorsports and you already know that not all wheels are created equal in terms of brake clearance and also weight - steel would be pretty much impossible to give the clearance you are looking for. The reason is simple - flow formed wheels (like ours) semi-forge the wheel barrels thinner, but are extremely strong and give brake clearance second to none. Steel can be flow formed too - but no one is doing it as far as I know and without that, you will be limiting clearance a lot - probably only a 13" kit would fit.
Steel would be a 6 to 10lb penalty in the same size - the steel "soft 8" wheels in 17" x 8" weigh 34lbs/each - they are truck rated, but that is way too much weight. Ronals weigh 25lbs/each in 17" x 9.5" in aluminum, btw.
If I were you I would skip the 14" rotors and go for a 13" kit with 4 piston calipers - you will open up your wheel choices and unless you are going to road race - never need the extra thermal capacity.
I'm the owner of CTW Motorsports and you already know that not all wheels are created equal in terms of brake clearance and also weight - steel would be pretty much impossible to give the clearance you are looking for. The reason is simple - flow formed wheels (like ours) semi-forge the wheel barrels thinner, but are extremely strong and give brake clearance second to none. Steel can be flow formed too - but no one is doing it as far as I know and without that, you will be limiting clearance a lot - probably only a 13" kit would fit.
Steel would be a 6 to 10lb penalty in the same size - the steel "soft 8" wheels in 17" x 8" weigh 34lbs/each - they are truck rated, but that is way too much weight. Ronals weigh 25lbs/each in 17" x 9.5" in aluminum, btw.
If I were you I would skip the 14" rotors and go for a 13" kit with 4 piston calipers - you will open up your wheel choices and unless you are going to road race - never need the extra thermal capacity.
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Re: R15 / CTW / 17" questions
I'm the owner of CTW Motorsports and you already know that not all wheels are created equal in terms of brake clearance and also weight - steel would be pretty much impossible to give the clearance you are looking for. The reason is simple - flow formed wheels (like ours) semi-forge the wheel barrels thinner, but are extremely strong and give brake clearance second to none. Steel can be flow formed too - but no one is doing it as far as I know and without that, you will be limiting clearance a lot - probably only a 13" kit would fit.
Probably true, but the 14" rotors are within $5 of the 13.4s, and that's difficult to refuse.
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Re: R15 / CTW / 17" questions
Actually one of our race customers moved from those wheels to ours, using the same exact 245-45-17 tire and had some interesting feedback.
1) The car felt like it picked up 20hp due to the lowering of rotating mass (14lbs/each*4*4(the equivalent sprung weight equivalent) = about 225lbs felt reduction in weight. The car is in the 325hp range at 3000lbs.
2) The car had razor sharp turn-in. This is due to the 245 tire on a wider 9.5" wheel, but some of it also has to do with the weight reduction.
3) As he runs 6 to 24hr races in the car, the shock fluid is a lot cooler and they don't fade as quickly - in some cases not at all. That is all due to the lower mass being controlled by the same shocks. The car also rides better - making those long rides less strenuous.
1) The car felt like it picked up 20hp due to the lowering of rotating mass (14lbs/each*4*4(the equivalent sprung weight equivalent) = about 225lbs felt reduction in weight. The car is in the 325hp range at 3000lbs.
2) The car had razor sharp turn-in. This is due to the 245 tire on a wider 9.5" wheel, but some of it also has to do with the weight reduction.
3) As he runs 6 to 24hr races in the car, the shock fluid is a lot cooler and they don't fade as quickly - in some cases not at all. That is all due to the lower mass being controlled by the same shocks. The car also rides better - making those long rides less strenuous.
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Re: R15 / CTW / 17" questions
Also, the little fitment issues like tie rods and the Firehawk Ronals, or other kindafits stuff is just a little bit less common with 18s.
It is very easy to get caught up in stuffing the widest wheel and tire. While a 9.5 can work out excellent in the third gen, a 9" wheel set could be an excellent choice overall. So you could be onto something. I was mostly suggesting you not go with steel.
My ideal would have been a TSW wheel that looked a lot like some Simmons wheels I can't / won't swing. But, as with a lot of wheels, the perfect look was matched with offset I didn't want. Had they been 18" x 9" and correct offset, I would have bought them; I decline adapters / spacers.
So keep shopping until you find what you want. Not steelies.
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Re: R15 / CTW / 17" questions
17" tire options are drying up, so much so that you need to shop tires first and then shop wheels to fit. The days of getting whatever tire size you want is gone, especially in good autocross tires. 18" tires tend to be offered in the larger widths that will "stuff" the wheel well.
Drag radials are still offered in the 17" 275 and 315 sizes, but that won't get you the 1G cornering you want.
Drag radials are still offered in the 17" 275 and 315 sizes, but that won't get you the 1G cornering you want.
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Re: R15 / CTW / 17" questions
17" is not as popular as it once was - no arguing that. You can't even get a 335-35-17 anymore (early Viper size).
But there will be a decent amount of options in 17" for years to come - short sighted companies choose to ignore 275-40-17 at their own peril, that is probably the most popular size in terms of 90's performance car sizing - hands down. Reality dictates that there should be Rivals in that size, yet nothing.
I do think 18" is the optimal size for 3rd gens, with 17" being close behind - if only for tie rod clearance. But you can push 1g on 245-50-16 tires with mild suspension mods and into the 1.4g range on road race tires in 275-40-17; some of our CMC racers on spec tires run that without downforce.
But there will be a decent amount of options in 17" for years to come - short sighted companies choose to ignore 275-40-17 at their own peril, that is probably the most popular size in terms of 90's performance car sizing - hands down. Reality dictates that there should be Rivals in that size, yet nothing.
I do think 18" is the optimal size for 3rd gens, with 17" being close behind - if only for tie rod clearance. But you can push 1g on 245-50-16 tires with mild suspension mods and into the 1.4g range on road race tires in 275-40-17; some of our CMC racers on spec tires run that without downforce.
17" tire options are drying up, so much so that you need to shop tires first and then shop wheels to fit. The days of getting whatever tire size you want is gone, especially in good autocross tires. 18" tires tend to be offered in the larger widths that will "stuff" the wheel well.
Drag radials are still offered in the 17" 275 and 315 sizes, but that won't get you the 1G cornering you want.
Drag radials are still offered in the 17" 275 and 315 sizes, but that won't get you the 1G cornering you want.
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Re: R15 / CTW / 17" questions
Actually one of our race customers moved from those wheels to ours, using the same exact 245-45-17 tire and had some interesting feedback.
1) The car felt like it picked up 20hp due to the lowering of rotating mass (14lbs/each*4*4(the equivalent sprung weight equivalent) = about 225lbs felt reduction in weight. The car is in the 325hp range at 3000lbs.
2) The car had razor sharp turn-in. This is due to the 245 tire on a wider 9.5" wheel, but some of it also has to do with the weight reduction.
3) As he runs 6 to 24hr races in the car, the shock fluid is a lot cooler and they don't fade as quickly - in some cases not at all. That is all due to the lower mass being controlled by the same shocks. The car also rides better - making those long rides less strenuous.
1) The car felt like it picked up 20hp due to the lowering of rotating mass (14lbs/each*4*4(the equivalent sprung weight equivalent) = about 225lbs felt reduction in weight. The car is in the 325hp range at 3000lbs.
2) The car had razor sharp turn-in. This is due to the 245 tire on a wider 9.5" wheel, but some of it also has to do with the weight reduction.
3) As he runs 6 to 24hr races in the car, the shock fluid is a lot cooler and they don't fade as quickly - in some cases not at all. That is all due to the lower mass being controlled by the same shocks. The car also rides better - making those long rides less strenuous.
I'm not sure about the shock thing, they don't even come with any way to add a temp gauge. Plus they only control the springs, so the only ways to ease their burden are lower-rate coils and driving more gently.
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Re: R15 / CTW / 17" questions
17" is not as popular as it once was - no arguing that. You can't even get a 335-35-17 anymore (early Viper size).
But there will be a decent amount of options in 17" for years to come - short sighted companies choose to ignore 275-40-17 at their own peril, that is probably the most popular size in terms of 90's performance car sizing - hands down. Reality dictates that there should be Rivals in that size, yet nothing.
I do think 18" is the optimal size for 3rd gens, with 17" being close behind - if only for tie rod clearance. But you can push 1g on 245-50-16 tires with mild suspension mods and into the 1.4g range on road race tires in 275-40-17; some of our CMC racers on spec tires run that without downforce.
But there will be a decent amount of options in 17" for years to come - short sighted companies choose to ignore 275-40-17 at their own peril, that is probably the most popular size in terms of 90's performance car sizing - hands down. Reality dictates that there should be Rivals in that size, yet nothing.
I do think 18" is the optimal size for 3rd gens, with 17" being close behind - if only for tie rod clearance. But you can push 1g on 245-50-16 tires with mild suspension mods and into the 1.4g range on road race tires in 275-40-17; some of our CMC racers on spec tires run that without downforce.
The extra width is costly, for little benefit in daily road use at 500 HP, but wider looks better, and inspires confidence.
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Re: R15 / CTW / 17" questions
[QUOTE=jmd;6105027]It is very easy to get caught up in stuffing the widest wheel and tire. While a 9.5 can work out excellent in the third gen, a 9" wheel set could be an excellent choice overall. So you could be onto something. I was mostly suggesting you not go with steel./QUOTE]
Yes, it is easy, but then you gotta change tires or park the car for winter, and spend another $800 for new rear tires every spring.
I'm inclined to start with a couple of different steel 17x9s, one with a 4.5" BS and one with a 5", see how they sit. I need more of a visual baseline than online pics or a Wheelmate can provide. The steel 9s are under $100 each.
Also, I saw this old book from the '90s, showing a blue 91 or 92 Z28, showing 255/45 Eagle GSCS tires and claiming 1.3 Gs on those.
Yes, it is easy, but then you gotta change tires or park the car for winter, and spend another $800 for new rear tires every spring.
I'm inclined to start with a couple of different steel 17x9s, one with a 4.5" BS and one with a 5", see how they sit. I need more of a visual baseline than online pics or a Wheelmate can provide. The steel 9s are under $100 each.
Also, I saw this old book from the '90s, showing a blue 91 or 92 Z28, showing 255/45 Eagle GSCS tires and claiming 1.3 Gs on those.
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Re: R15 / CTW / 17" questions
Remind me again, why did you ask the question in the first place? Seems you already have the answers to everything.
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Re: R15 / CTW / 17" questions
I'm inclined to start with a couple of different steel 17x9s, one with a 4.5" BS and one with a 5", see how they sit. I need more of a visual baseline than online pics or a Wheelmate can provide. The steel 9s are under $100 each.
Also, I saw this old book from the '90s, showing a blue 91 or 92 Z28, showing 255/45 Eagle GSCS tires and claiming 1.3 Gs on those.
Also, I saw this old book from the '90s, showing a blue 91 or 92 Z28, showing 255/45 Eagle GSCS tires and claiming 1.3 Gs on those.