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View Full Version : 18's or 20's Road Racing???



ghostRT
01-16-2014, 07:45 AM
I have read here on a thread that some one said running 20's made it safer for them at the track as the lower profile tire would not fold over in a turn due to the weight of our cars ... yet everyone says run 18's and I agree ... main reason is more choices in tires .. so from all you road racers what size is better and in the 18" what size tire is recommended ... I see some of you buy scrubs from the tracks ... If I go that route how do you find them for sale?
Im about to pull the trigger on a set of rims to road race with and don't want to make the wrong choice

Thanks In advance
David

Ron380
01-16-2014, 08:28 AM
Most of us are running 18's, due to having more choices for rims and tires, and the lower prices.
A few high-perf. summer tires have been popular, as well as the slicks.
Some of the guys should chime in soon with info. about those.

CT-MSRT
01-16-2014, 08:52 AM
18's are the 100% way to go. The load ranges are well within tolerance for our cars. You pick up gearing, and the tire and rim choices are much wider and more economical. There are some very extensive threads on the subject that you can look for. Many of us have been running them for years without issue and the costs are far lower for 18" used scrubs than any street tire. They are safe and reliable on the track and the 275/35R18 tires are endlessly available.

Meech
01-16-2014, 09:49 AM
What everyone before me said and just make sure the wheels bear the load (corner weight) of the LX you're driving. 3800 to 4000+ lbs

ghostRT
01-16-2014, 04:59 PM
Thanks everyone ......... 275 35 18 on a lowered car .... any issues driving on the streets with a set up that low ... I will start with street tires first as I want to get a feel of the car .... then I will switch to scrubs .... question where do you guys get the scrubs or how do I go about finding them.
Thanks again in advance

ghostRT
01-16-2014, 07:20 PM
http://youtu.be/9VCcvdrhn3M

ghostRT
01-17-2014, 08:17 AM
bump ....... for any other info.

CT-MSRT
01-17-2014, 09:05 AM
Thanks everyone ......... 275 35 18 on a lowered car .... any issues driving on the streets with a set up that low ... I will start with street tires first as I want to get a feel of the car .... then I will switch to scrubs .... question where do you guys get the scrubs or how do I go about finding them.
Thanks again in advance

this is NOT a combo to be driven on the street. get another set of rims and use them only at the track. many of us are lowered and have no issues with the several inch drop, but do not think that this is something you can slap on the car at home and drive there with. you need at least 9.5" rims to make the best use of the tire size mentioned. Don't go trying to slap those things on your stock 18's.

The whole point of the scrubs is that they are less expensive and perform better than a street tire. It is purely a cost/performance thing. http://www.jbracingtires.net/
Don't waste your time browsing his site for updated inventory. This is merely the contact info. call and get the Continental tires; they are always fresh during the racing season.

joelvan
01-17-2014, 09:13 AM
If you are going to go with a street tire only . may I suggest the 275/35/ 18 BFG Rival. It is the by far the fastest grippyest street tire that I have used on track.

http://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=g-Force+Rival&partnum=735WR8GFR

If you plan to do more than a 4 or 5 events in a year scrubs are the way to go.
I do suggest to learn on a street tire. they are more forgiving to the novice.
I've seen several cars destroyed on cold slicks with a newbie at the wheel.

t500hps
01-17-2014, 06:41 PM
I agree with Joel. Learn on street tires that "talk" to you. And several classes run 18's (AI for one) and getting their scrub tires right at the track might be an option.

As for size, I had a set of 10 x 18's I ran 275/35/18 scrubs on a SRT8 Charger......stock suspension. At one track it was fine but another I would bottom out on the front plastic skid plate on one particular dip. Speed was part of the problem as I was between 150 and 160 mph (fastest stretch of any track I've ever run). That wheel size and a lowered car could be a problem????

ghostRT
01-18-2014, 08:10 AM
yeah I had planned on running street tires first to get a feel of the car .... and I am buying rims and tires for the track that's why I started this post , I wanted to get the rite set up .... Now one other question with that tire size what the widest rim I can do on the front of an RT I was going 9" front and 10" rear ... will 10" fit the front
and thanks again In advance

joelvan
01-18-2014, 10:52 AM
You can put 10s on the front. you will have to change studs and use spacers. there is no need to worry about using spacers. Me and other racers do it all the time.

ghostRT
01-18-2014, 04:15 PM
what about 9 1/2 on the front

CT-MSRT
01-18-2014, 04:48 PM
what about 9 1/2 on the front

if you are using a spacer, i am selling a full set of 9.5" rims with slicks already on em. They fit SRT's with no spacer, but need one for RT's.

MattRobertson
01-18-2014, 04:49 PM
9 1/2 will either work or it won't... the offset of the wheel will decide and there's no set answer for what that offset will be. If you get serious about doing track days, something to consider is to put SRT knuckles on the front. I did that so I could go with wider fronts on my RT. I presently use 18x9.5" slicks on all four corners. And thats something to think on as well. Sure I can put wider wheels/tires on the back, and a big fat car like an LX/LC can use the rubber, but then I would sacrifice being able to rotate the tires around. Since I am just a weekend track guy I am willing to sacrifice a bit to be able to have a flexible rotation schedule that lets me use tires for an extra couple-three days before they wear down to cords.

And about "will 9.5" wheels tires fit?" As noted, I have SRT knuckles for extra clearance and 18x9.5" wheels. I still use a 3mm spacer in front to make absolutely sure I don't rub; its that close with my track wheels (Borbet Type TS). And those wheels really do like having longer wheel studs that I also put on front/rear.

Look for posts by NYC_SRT8 on his track wheels. I believe Meech also uses them? If I hadn't lucked into a used set of Borbets cheep I would have gone that way.

As for using 20" wheels "so the sidewalls don't fold over"... thats crazy talk. Sidewalls fold over because you don't have enough sidewall strength vs. the load you put on the tire and that is easily achieved on a short-sidewall tire. I'll go find a pic of my car to prove it. I spent a lot of time talking to Hoosier and other tire mfr engineers and I was advised by Hoosier to pump their slicks up to achieve a target hot (I say again hot) pressure of 65 psi to give the tire the strength to hold up such a heavy car under road course loads. That has turned out to mean a target cold pressure of about 45psi. You don't want to just pump the bejesus out of a tire to strengthen it... get some specific advice first and monitor pressures thru the day... but bear in mind we are not talking 32psi here and we certainly aren't doing the drag racer thing of lowering air pressure.

MattRobertson
01-18-2014, 05:06 PM
ok here's that pic showing a sidewall:

these are 255/35/20 Bridgestone RE-050A Pole Positions pumped to around 40 psi cold. This is T2 at Laguna Seca which is a hard brake after a downhill straight into a hairpin. Almost a worst case for lateral gee. That is an SRT wheel whose rim is covered by the tire... except here where it has peeled back and is now well exposed. I get the creeps every time I look at this pic, although the tires never failed and I stll have this set of wheels and those tires still on them (they are my rain day wheels so they don't get much use or stress).

So if someone is telling you that short sidewalls don't peel back, they most certainly do.

http://www.lelandwest.com/auto-tech/images/ls_120802.jpg

OK now check this pic out. This is at Sears Point in the Esses and the tires now are Hoosier R6's in 255/40/18. These are 26.2" tall tires, which makes them *taller* than the 275/35/18 slicks you see out there on the scrub market. This was when I had RT front knuckles and these tires were the widest I wanted to go up front on 18 x 8.5" wheels. Note the sidewalls... they are taller and are holding up just fine. Note that part of the reason for this is road racing slicks are made to be beat on and so they have stronger sidewalls than street tires. At least the Hoosiers do. Their dedicated road race slicks are even stronger than their DOT slicks, which I am using in the pic below.

http://www.lelandwest.com/auto-tech/magnum/infineon03.jpg

As short as these tires are, the 275/35/18 is 25.5". Tires that short have let me gear up one full gear around the track which is a wonderful thing for helping to keep the engine from exploding. Ain't gonna happen on 20's.

Last thing: Search for user MikahB. He had a professionally prepped car that used specially-made 19" wheels, and unique tire choices to go with it. If you have the budget that might be a direction to consider. Not for me but I mention it because it was successfully done by someone.

joelvan
01-18-2014, 05:42 PM
Matt, mikah's car had 18X10s with the 275/35/18 Conti"s. That is the largest Conti. tire aloud to run in that series.

Ron380
01-18-2014, 06:19 PM
On the "other" end of the spectrum, I didn't have a lot of budget to work with. I used my stock 18" AWD rims, with Sumitomo HTR Z3's - 245/45/18. Several reasons for those tires, obviously price being one of them. Also, that particular size came with an XL weight rating, perfect for a 2-ton car! ;)

I will say, for a noob like me on the track, I loved 'em! They handled pretty well, gave great feedback, and didn't "dive" over the limit. In fact, with my AWD car, I got fairly good at 4-wheel drifts with it! When the back end started to get loose, just mash the gas! :mrgreen: Another reason for the street tires, was to spare the high loads from straining the rest of the car. I felt that I could replace tires more easily than bushings, bearings, and other suspension parts.

Those tires with the AWD were fantastic in the rain as well, and I have video in that other thread to prove it! :pepper:

MattRobertson
01-18-2014, 07:14 PM
Matt, mikah's car had 18X10s with the 275/35/18 Conti"s. That is the largest Conti. tire aloud to run in that series.

Yeah you're right I just did a search and thats not the car I was thinking of. *someone* did it. The tires they put on were I think Pirelli P Zero Corsa's. Go look at the specs and they have tons of variations in 19" and just a few in 18 and 20. The car was like a ... medium-ish grey. Who remembers who it was? Anyone?

t500hps
01-18-2014, 07:49 PM
Having completed HPDE's in my SRT before getting a comp license to race w2w in a mustang I agree with everything posted here. Run all 4 wheels the same size if at all possible, the ability to rotate them is worth more than the "advantage" of a wider rear tire. And sidewall size is irrelevant, run the right pressures on the right tire and you'll be fine.

TheFrankenberry
10-26-2015, 11:56 PM
Reviving a very helpful thread. I have a 2010 Challenger R/T and am looking at custom track wheel options for next year. I'll compete in at least a dozen autocrosses and enter my first track day events.

I am leaning towards 18"x10" rims with +16mm offset (info from another thread) in order to run 275/35R18 200-treadwear rubber on all four corners. Hoosiers, Conti scrubs or other R-compounds are to remain a future possibility.

I'm working with an R/T spindle and I've read up about people needing spacers and studs to run this wide of a wheel and tire. I want to avoid those additions and hope a custom wheel is the solution.

Before I start talking to wheel companies, is there anything I'm not comprehending here regarding what wheel and tire sizes can work with the R/T spindle and suspension points, regardless whether the wheel is custom or not?

Northern Rider
10-28-2015, 12:01 AM
I run 18's on my 06 300C for these reasons - less unsprung weight & I can get slicks in this size.

I got 2 sets of rims from Forgestar, as they could drill the correct bolt pattern and machine the hubs to the right offset to clear the front Brembos.

The wheel I selected was the C5 for good open cooling; strength and the classic 5 star pattern. Price was good as was the service.

In the pic below we have Nitto-1's mounted - 285 -35-18's. Nice tire - great grip; will handle many heat cycles; good on heavy cars and can tolerate some low levels of water on the track.

http://www.300cforums.com/gallery/data/561/painted_front_spoiler.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9570)

rell6103
11-05-2015, 08:40 PM
Hi All,

I run 18x10s all round on my SRT8 Challenger. I initially went this way for the scrubs option. I was running -2.7deg front camber, and -2.5 rear, and I was still cording the scrubs in ~4 sessions. After a few sets, I decided they weren't worth it. Lately, I've been running the Nitto NT01s, which I really like. They also off them in 275/40R18, as well as the 35 profile. The 40 profile is actually rated for the weight of the beast, and the tires fill up the wheel arch by another inch so it doesn't look so stupid. If you want to go super crazy, there a bunch of metric sized slicks that I've been wanting to try, 680 and 710 diameter that would look pretty awesome.

Anyway, having gone back to the NT01s, if I could do it all again, I would have gone with 20x9.5s and run the NT01s. You'll get comparable performance, and I like it when the wheel gap doesn't look stupid. I've been happy with the 18s, and I'll keep them for Time Trial stuff.

A link to a few pictures of the challenger with 18s going hard through corners - just scroll the few pictures on the front page
http://www.tracktorque.net/

This one also shows the mad wheel gap that annoys me
http://40.media.tumblr.com/5d635539f049c205861911a65318a23f/tumblr_nv3dc32THo1uctx1vo1_1280.jpg


Car looks bad ass too Northern Rider

Northern Rider
11-09-2015, 12:48 PM
Thanks, Rell6103!

http://www.300cforums.com/gallery/data/570/11391183_10155561368665109_4974029955444601580_n_1 _.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9178)

A knight
11-09-2015, 12:57 PM
Your 300 is sick, northern rider!! Just curious, how do these cars handle around the track? Are they pretty good for their size?

Northern Rider
11-09-2015, 01:27 PM
I think so, and apparently so do my competitors . . . . LOL!


http://www.300cforums.com/gallery/data/570/medium/0185ffc7c42f1a7bdaea33476077341096ef254765.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9681&size=big&cat=)

Tikibeast
11-09-2015, 07:58 PM
Thanks, Rell6103!

http://www.300cforums.com/gallery/data/570/11391183_10155561368665109_4974029955444601580_n_1 _.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9178)


One day when my Magnum grows up...

Northern Rider
11-09-2015, 11:27 PM
Some more photos from this year's racing:

http://www.300cforums.com/gallery/data/570/medium/155.JPG (http://www.300cforums.com/gallery/showphoto.php?photo=9713&size=big&cat=)

http://www.300cforums.com/gallery/data/570/11112996_901110769967864_3309558121228267255_o1.jp g (http://www.300cforums.com/gallery/showphoto.php?photo=9705)

http://www.300cforums.com/gallery/data/570/11010603_10155561368875109_7010342605661991445_n_1 _1.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9697)

http://www.300cforums.com/gallery/data/570/10479044_901110429967898_7962119618007042415_o.jpg (http://www.300cforums.com/gallery/showphoto.php?photo=9689)

A knight
11-10-2015, 12:08 AM
Wow so you were beating cars way smaller than you huh?

Tikibeast
11-10-2015, 12:10 PM
Wow so you were beating cars way smaller than you huh?

What kind of question is that? It's a Mopar, Mopars beat things...imports, Mustangs, your wallet...




Did you notice a significant improvement in lap times when you added the front splitter and the rear spoiler?

Northern Rider
11-10-2015, 03:46 PM
I put the front splitter on 2 years ago - modified from a Chally SRT OEM. I felt more front grip. This winter, we are engineering a better splitter - hopefully. The rear wing is carbon fibre from APR. it has made a huge difference on the mid to high speed twistys!


Sent from my iPhone using Tapatalk

Tikibeast
11-10-2015, 04:56 PM
I put the front splitter on 2 years ago - modified from a Chally SRT OEM. I felt more front grip. This winter, we are engineering a better splitter - hopefully. The rear wing is carbon fibre from APR. it has made a huge difference on the mid to high speed twistys!


Sent from my iPhone using Tapatalk

I've only done one road race on Big Willow a few years ago so most of my twisty experience is canyon carving, but I've been wondering what I could do to increase downforce, unfortunately a spoiler would have to go on top of the Magnum so that's out, I've found a few splitters to add some front end downforce though...

Northern Rider
11-10-2015, 06:15 PM
I had a Maggie. I think a lip spoiler could work above the rear hatch. These cars are really nose heavy.


Sent from my iPhone using Tapatalk

A knight
11-10-2015, 06:48 PM
How are the stock brembos around the track? Do you feel there is any need to upgrade em?

Tikibeast
11-10-2015, 07:30 PM
I had a Maggie. I think a lip spoiler could work above the rear hatch. These cars are really nose heavy.


Sent from my iPhone using Tapatalk

Heavy, but they handle their weight well, it's no Elise/Miata, but the big girl can dance...

Northern Rider
11-10-2015, 07:33 PM
Brembo brakes are great. I pair them with DBG rotors and racing pads.


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Tikibeast
11-10-2015, 07:44 PM
Brembo brakes are great. I pair them with DBG rotors and racing pads.


Sent from my iPhone using Tapatalk

I ran the old R/T with Napa UP rotors and Akebono pads with some success, but for next year with the SRT I'm planning to swap out my EBC reds for EBC Yellow stuff pads and keep my Centric slotted rotors...but I don't think most of us are on your level. Not yet at least.

Northern Rider
11-10-2015, 08:57 PM
Up until this year, my car was a daily driver. I ran Stoptech hybrid pads. When my Hellcat finally came, the 300 got stripped and dedicated to the track., with dedicated racing pads. They do make a difference.


Sent from my iPhone using Tapatalk

A knight
11-10-2015, 09:30 PM
I put the front splitter on 2 years ago - modified from a Chally SRT OEM. I felt more front grip. This winter, we are engineering a better splitter - hopefully. The rear wing is carbon fibre from APR. it has made a huge difference on the mid to high speed twistys!


Sent from my iPhone using Tapatalk

Out of curiosity do you have a write up on the challenger splitter install? I've been wanting to get a splitter for my car. Seems to me to be a nice cheap alternative to some of the more expensive options out there.

Tikibeast
11-11-2015, 11:40 AM
Up until this year, my car was a daily driver. I ran Stoptech hybrid pads. When my Hellcat finally came, the 300 got stripped and dedicated to the track., with dedicated racing pads. They do make a difference.


Sent from my iPhone using Tapatalk

I haven't heard about the hybrids yet, did you run anything else to compare them to?

Northern Rider
11-11-2015, 03:56 PM
You can get these at a few places. This is from Tire Rack's site:

StopTech
Street Performance Pads (http://www.tirerack.com/brakes/brakes.jsp?make=StopTech&model=Street+Performance+Pads&group=Street+Performance+Pads&partNum=ST309.11490&autoMake=Chrysler&autoModel=300C+SRT-8&autoYear=2006&autoModClar=With+Performance+Tires) Performance Street (http://www.tirerack.com/brakes/tech/techpage.jsp?techid=86)


Front
Manufacturer Part #: 309.11490
Note: Front brake pads.




Qty:
Per Axle Set:
1
0 1 2 3 4 5 6 7 8
$79.00

rell6103
11-11-2015, 04:09 PM
You can get these at a few places. This is from Tire Rack's site:

StopTech
Street Performance Pads (http://www.tirerack.com/brakes/brakes.jsp?make=StopTech&model=Street+Performance+Pads&group=Street+Performance+Pads&partNum=ST309.11490&autoMake=Chrysler&autoModel=300C+SRT-8&autoYear=2006&autoModClar=With+Performance+Tires) Performance Street (http://www.tirerack.com/brakes/tech/techpage.jsp?techid=86)


Front
Manufacturer Part #: 309.11490
Note: Front brake pads.




Qty:
Per Axle Set:
1
0 1 2 3 4 5 6 7 8
$79.00



Did you try these pads on the track?! Did they last? I essentially melted/disintegrated the stock pads in its first track weekend. Left uneven deposits on my rotors. Was no good. I've been running the EBC Blue stuff since with great success, both on the track, and as my daily driver. Lots of dust, but they have never squealed.

Northern Rider
11-11-2015, 06:44 PM
Yes. I ran them until last year, while my 300 was still a daily driver. EBC Blues are also a good choice.


Sent from my iPhone using Tapatalk

Tikibeast
11-11-2015, 07:56 PM
Yes. I ran them until last year, while my 300 was still a daily driver. EBC Blues are also a good choice.


Sent from my iPhone using Tapatalk

Would they be comparable to the Blues or the Yellows in your opinion? I've got the Reds and they're maddenly bad as far as noise and brake fade, but I don't know if I can justify $180 for a set of front pads to go with the Blues...

MctPhoenix
11-15-2015, 09:37 PM
Hi All,

If you want to go super crazy, there a bunch of metric sized slicks that I've been wanting to try, 680 and 710 diameter that would look pretty awesome.



Could you embellish a little on the metric slicks you mentioned? Thanks

rell6103
11-16-2015, 11:45 AM
Could you embellish a little on the metric slicks you mentioned? Thanks

A lot of tire companies make racing tires with the diameter measured in metric sizes.
Hoosier, for example, make these sizes:
280/680R18 (10" rim)
310/710R18 (12" rim)

Dunlop
270/710R18 (10.5 - 11" rim)

Yokohama (Advan)
280/710R18 (11" rim)
280/680R18 (10.5" rim)

Essentially, instead of using the side wall aspect ratio, the middle number is the outside diameter of the tire. For the tires above, these would be 680mm or 710mm. The OEM 255/45R20 tire size is 738mm diameter. The scrubs you would be buying will be the 275/35R18, and these will have an overall tire diameter of 649mm. Nitto make the NT01s in 275/40R18 (which is what I run), which increase the diameter to 677mm. I think the 710mm with a inch or 2 suspension drop would look pretty cool, although there may be rubbing issues

rell6103
04-06-2016, 07:19 PM
So, Mods can shoot me down here, but it seems like an appropriate place to do this...

I've actually got my 18x10 Road Racing Rims up for sale. This allows a square setup with 10inch rims and 275-295 wide tires (depending on the tire).
http://www.lxforums.com/board/showthread.php/382575-18x10-Rims-(for-Road-Course)-Solo-Exhaust-Hurst-Shifter-Diablo-Intune-EBC-pads (update: SOLD)

http://i137.photobucket.com/albums/q237/rell6103/IMG_22948%20Large.jpg (http://s137.photobucket.com/user/rell6103/media/IMG_22948%20Large.jpg.html)

http://i137.photobucket.com/albums/q237/rell6103/P1100877%20Large.jpg (http://s137.photobucket.com/user/rell6103/media/P1100877%20Large.jpg.html)

Tikibeast
05-20-2016, 05:52 PM
What sizes are people running on their 18s? I know 275/35/18 is the go to size for scrubs, but for those with a little less track time sticky street tires provide a better learning curve than slicks so I'm wondering if there are a few different recommended sizes or just one go to size like with scrubs.

drag_racer
05-26-2016, 01:14 PM
What's the widest you can run on an AWD?

I've been thinking about getting some Weld Racing 18's for next year with some good tires for both the strip and road course (don't need slicks yet for the drag strip). Would a 18x9.0 with a 43mm offset work with a 265/40/18? I'm thinking going with the Michelin Pilot Super Sports at first.

Fifty
01-26-2017, 09:01 PM
I wish I could fit 18 inch wheels over those 6 piston brakes. But unless I get creative and have something custom made with a flares barrel, I'm out of luck. Or at least that's what I've been told so far.

White Ops R/T
01-27-2017, 12:33 PM
^^^Maybe the new Demon wheels will work?

Tikibeast
01-27-2017, 12:45 PM
^^^Maybe the new Demon wheels will work?

I wonder how long it's going to take for OEM Demon wheel sets to start hitting the classifieds...

White Ops R/T
01-27-2017, 02:22 PM
Won't take long. I'm sure someone will buy it and want to put on 24" Forgiato wheels

Tikibeast
01-27-2017, 02:38 PM
Won't take long. I'm sure someone will buy it and want to put on 24" Forgiato wheels

:hitanykey:1puke: