The problem with this country are all the people who think they are "entitled" and everyone needs to believe what they believe and no exceptions. But someone saying you should be put to death for doing what others fought for to give them a chance to peacefully protest right or wrong... we'll, you aren't any better than the terrorists and dictators we are trying to stand up against.
Sent from my iPhone using Polaris Slingshot Info
I would guess if 1/4 mile racing is what you are after, there are a few things you could do. I'm thinking along the lines of "the racing is the most important" here. I'd go with an 18" rear (if not a 15"), off a stock base unit or an aftermarket with a wider rim. Then I'd get a street legal drag tire, or even just a soft compound racing slick, but make it big enough in size to make up the difference to the 20" rim. That way, you have more sidewall, and it can grip better for a launch. The other thing I would do is get adjustable shocks. I have the QA1's, in two way. I'd set the front at 4, and the rear at 0-2. That way, when you launch, the weight will shift to the rear. With a low setting in the rear, under power the machine will squat more, giving you more traction.
Then again, if all you want is 1/4 times, I'd say you bought the wrong machine.
It's all good. I love the Slingshot. I just also like the speed. May as well try and maximize it.
Generally speaking, wider tires mean more traction, but the relatively light weight of the Slingshot's rear tire tends to act against the increase in width, reducing traction. If the main focus is on acceleration in the 1/4 Mile, the Slingshot is compromised by the relatively light loading on the rear tire. As tire width grows, the lbs/sq in of contact patch goes down, essentially limiting traction. Figuring out a way to increase the rear tire loading to increase the lbs/sq in of contact patch might allow you to make better use of a wider tire. Starting in 2nd gear might also reduce any tendency to spin the rear tire on take-off. You'll probably accelerate a little more slowly, but you may also reduce your overall time by reducing tire spin.
So you are saying as the tire goes wider, so do I to allow for more weight on the rear LOL...
OK, so I've been paying attention... I think. Maybe @WrongWheelDrive and I can share some info. Some Notes:
I understand that by decreasing the sidewall the tire becomes stiffer. @Tango likes the PilotSS tires, but it's not a symmetrical or directional tread (which is fine, but most recommend symmetrical or directional treads). It's interesting to see what everyone's preferences are.
I started with the end goal of having as much horsepower and focusing on the 1/4 mile times and what would be the best wheel width and tire for doing that. I'm a lot closer to answering this. I like the 345 look, but if I end up throwing a lot of HP at it and looking at 1/4 mile times, what is the best tire/rim sizes? Anyone out there have specific tests with numbers? Most seem to be running the 345mm on a 20x12 wheel, but there are differences. The other part of this is the front and everyone seems to be all over the place as far as sizes.
@WraithSS... you have the larger wheels and drive the 315mm rear. Ever have an issue? I would think that your tires are not symmetrical or directional treads as there are very limited tires to choose from with a 22 inch wheel in the back. Also, thoughts on the front for steering as you went from the 225mm stocks on the front to 275mm... you said you had no issues with tracking I think. I wonder if there is a "too wide" point where handling becomes negatively impacted.
@TravAZ changes his tires to go to the track and street... you would be a good one to ask as you run a 305mm rear on the track any 345mm on the street. I can only assume it makes a difference? No? Maybe you just don't want to burn up your 345mm. You also switches to a wider tire on the front (255mm) for the track on the 235mm for street. I'm sure tires themselves make a huge difference, but what are your thoughts?
Any vendors out there want to chime in? Does it all come down to personal preference? There are so many variables in this, but interesting just the same.
@TravAZ - Good catch. I was hoping to go with a 22 inch wheel, but looks like I either need to go with a 315mm tire and 22 inch rim or wider tire on a 20.
Everyone is pretty much running the same BIG rear tire setup. 20X12 or 22x12 45mm offset wheel with a 345/25/20 Toyo T1R tire. It is one of the only directional tires that comes in a large size and works with no modifications. Yes, it even works with the stock shock.
On a different note - I had a 335/30/18 Toyo R888r I was going to mount on my track wheel, but it wasn't directional and honestly didn't look like it was going to fit. It looked almost a 1/2 inch larger than the T1R 345/25/20. Odd deal...
Has anyone tried Toyo PROXES S/T III 335/25 R22 ?
Search For New Tires - Car, Truck & SUV Tires | Toyo Tires
Display MoreTrack - 255/35/18 Toyo R888r fronts and 305/35/18 Toyo R888 in rear.
Street - 235/40/18 Nitto 555 fronts and 345/25/20 Toyo T1R in rear.
@TravAZ, You have a 345/25/20 Toyo T1R in rear... I'd like to get the 345mm and understand it cuts it close to the shock (any problems with that?), but did you stay with the +45 offset or did you have to use any spacers?
Hey SaltyClownNY!
I work in Albany and live outside Albany as well. If you ever want to get together for a ride let me know!
I'm up by Thacher Park area. I'm always looking for places to go. Sent you an email off this site with my contact info. -T
Thanks @WraithSS. Your SS looks awesome and is the look I am trying to build, but just need a push in the correct direction. I'll find it sooner or later, but great to have the help from people who have done it!
The info helps:
Front= 20x9 +35mm 275/30/20
Rear= 22x11 +45mm 315/25/22
Ridetech Shockwaves. They have about 7" of travel. Approximately 2" above stock height and approximately 5" below stock.
@SlingRider - How is the 345mm tire on the back? Any issues? Do you have stock shocks? I'd rally like to go with as wide as I can go, but worried after spending all that it won't fit. Did you go with a 20x12 rim with +45 offset?
Thanks!
I think I said this somewhere on here previously, but last December I ordered larger front and rear wheels and tires for my base 2015 that I bought in November of 2014. As a retired sales guy I was greatly impressed by the knowledge and courtesy of Jason Tung of
http://www.getyourwheels.com
He steered me to a better product at a better price, and called back several times to make sure everything was correct before confirming the order. He was particularly knowledgeable about the quirks and nannies associated with the sling. My younger, sharper riding buddies (The Rock, JDin, etc.) will have to confirm how good my sling looks since my flip phone and my lack of computer smarts can't do it for me.
Bottom line is, Jason treated me every bit as good as the gang at Slingmods has over the years, and if I recall correctly I made one of the first ten orders from them back when Keith answered the phone.
<snort>... you said flip phone.... LOL 
I'll take a look! Thank you.
And the day will come when something falls off a truck and kills a driver and they get sued for an open cockpit. There is some personal responsibility that must be there. The suit will tell though if there is negligence, but if this is the first and only case, I can't imagine it will move forward. Personally, I want a 4 point harness in mine, but the stock seems good for now.
I agree 1000000000000%. People ALWAYS looking for an easy way out.
Sent from my SM-G955U using Polaris Slingshot Forum mobile app
I just hate the fact that one person has an issue or something fails once and it's the end of the world. YES, it is a tremendous loss for that family and everyone involved with the person who passed and I feel for them. But how many people die each year in an auto? I'm not discounting the tragedy, but just seems like everyone wants to take up arms and lets linch the responsible party. If they find negligence... OK. To my knowledge, they are saying this has happened once. Has there been others that anyone knows of?
There are currently only two kits that use the brackets and tank I designed to fit all the equipment (tank, compressor, valves, etc..)under the rear fin. The one I'm running and the one we installed in @lrobbi Shot. However, Mitch over at Revdynamics has a kit that puts the tank under the Slingshot. He makes a great product and just an all around nice guy. Other than that I think those are the only good options so far to save the storage bins.
what brand shocks did you go with and how much of a lift do they offer?
Air suspension of my own design. @lrobbi is running the system now too. It's approximately half the cost of the hydraulic system and you lose none of your storage space. The seats are black/gray suede Corbeau CR1s. Trying to keep up with you "Wolf Pack" people I keep hearing about.
@WraithSS I've been looking for an air shock system that allows for lowering just like yours. What did you end up going with? I don't want the hydraulic system and my storage bins are filled with speakers now, so don't have the room. Any suggestions? Thanks!
I see some issues here. First and most important is if you ever plan on buying a trailer to tow your slingshot. Going to a one inch wider front wheel, gives it one inch wider trailer width needed to load it. Some open trailers may not have a problem with the added width (some do), but some enclosed trailers may not have the extra room to allow you to safely load the slingshot without pulling your hair and possibly damaging the wheel/tire or inside of the trailer.
Problem number two is that the 225/30/20 has a 25 inch overall height, while the stock 225/45/18 I believe was 25.9 inches. Going almost one inch shorter MAY cause an issue with the abs/traction control/stability control since you're altering tire heights from stock.
The rear is even worse since the stock rear tire height is 26.1" and the 315/30/20 is 27.5"
Using the tires you're planning on (f+r), I'd be surprised if you didn't have an issue as mentioned
Awesome @funinthesun. I'll check out the site again @BKL, but I didn't have luck the first time I went there.
All good info. What I was attempting to do was exactly what @BKL was suggesting and keep them the same size/ratio. Just so I can make sure my math is correct...
Stock Tires
F - 225/45/18 ... by my math, ((225mm x .45) x 2) + 457.2mm(18in) = 25.972 inches high
R - 255/30/20... should be ((255mmx.30) x 2) + 508mm(20in) = 26.0236 inches high
So just about the same hight at 26 inches. Is this math correct? Should be the tire width x aspect ratio % multiplied by 2 + the wheel hight. I'm only going off of what I've read, so may be missing something in there but want to learn the correct way if I'm off.
So my thought was to keep the same hight on both front and rear. The issue is tire availability from what I've seen and getting the correct size.
A 315/35/20 should = 28.681 inches tall if my above math is correct (this is going with a Nitto NT555 G2 as it doesn't come in a 315/30/20)
So in order to avoid a trailer issue, I would stick with the 225 tire, but in order to get the 28.5 tire hight, I would need a 225/50/20 tire... no?
Now I know a larger tire will throw off the odometer, but do you think it will also impact the abs/traction control/stability control system if you stick with like sizes front and back? Problem I see is the 225/50 will increase the flex of the sidewall and possibly not hold a turn as well... maybe
@SaltyClownNY if you never plan on driving in the rain or taking a long trip that could end you up in the rain. The Nitto NT05R has been praised by multiple Slingers for DRY, WARM weather driving. In the rain, light moisture on the road you will have a dangerously slippery ass end.
P.S. it's also any expensive quick wearing tire.
Thanks @WOLF and @funinthesun. This is why I joined the group so people who know a bit more can help save me from making a dumb ass mistake LOL.
So if I'm ordering new wheels and tires, I was going to go with 20's all around and instead of a 225/45/18 on the front, I was going to go with a 225/30/20. I was thinking of using a 255 on the front, but the wheel guy said you would get more tracking with the tire on uneven roads. Thoughts?
So what I have for stock (apparently) is:
F 18X7.5
+42 MM offset, bolt pattern 5x114.3
Tire 225/45/18
R 20X9
+45 MM offset, bolt pattern 5x114.3
Tire 255/30/20
Lug nuts 12MM X 1.25 pitch
What I'm planning on going to is:
F 20X8.5
+42 MM offset, bolt pattern 5x114.3
Tire 225/30/20
R 20X11.5
+45 MM offset, bolt pattern 5x114.3
Tire 315/30/20 (would have to look into a 335)
Lug nuts 12MM X 1.25 pitch
Thoughts? Sound like it would all fit? I've seen people post about putting a 255 on the front. Anyone have any issues with steering or tracking on uneven pavement with a wider tire?
Keep in mind all of this is in preparation for more horsepower. I want to do it right and safety is top of the list.
NO! The stock sl rear wheel is a 20X9. After adding 2 1/2" to the width of the wheel, you have 11 1/2" not 12 1/2" and yes, the 345 does fit the 11 1/2" wide wheel and clears the aftermarket rear shock spring
Not sure what others have, but my 2017 is a 20x10 wheel. I was planning on putting a 20x12 on it...?
I'm measuring by running a straight edge along the outside of one side to the other side. That wouldn't be considered a 9 even if they cut out the inside lip as there is no way there is an inch of lip in there. no?
LOL... update... wow, I didn't even notice the size of the rim stamped on it. Saw it in my picture ... I'm a dork. Not sure how they measure it then. So I take it it won't fit a 12 inch and need an 11 1/2 then. Yes? I was hoping to get a 12 in there.
I took a new 2015 20" rear wheel (so it matches the fronts) and had a company that does wheels widen it 2 1/2". To keep the same offset, I added a 1 1/4" spacer and the wheel is centered. It's a 345/25/20 tire and it has less than 1/4" clearance to the rear coil spring, so depending on what you are using for a spring, a 12" wheel may be pushing the limit with a 345 tire. It SHOULD be ok with a 315 though (but I'm not making any recommendations on that)
Thanks @funinthesun. So if I'm following it correctly, the end state is a 20x12.5 wheel with a 345/25/20 tire. Surprised it will take a 345, but nice to know. With the spacer you used, it kept with the same offset too. Now question is, I'm fairly sure I'm measuring an offset of +42 on the stock rim. I see a lot of people talking about a +45. a 3mm difference may make a difference if you are that close to the suspension.
All, I'm replacing the stock tires and wheels. I haven't seen anyone post any info with anyone trying a drag race tire. The Nitto NT05R looks interesting, but wanted to see if anyone has tried this tire.
Also, I measured my stock wheels and it seems they have an offset of +42. I see a lot of folks talking about a +45. Not sure it makes a huge difference of 3mm more one way or another, but thoughts?
