front tire wearing out

[ViperGarageElite]

Have read many threads on kuhmos failing on the racetrack but my passenger tire has cords showing on the inside edge, 4200 miles spirited street driving. Tread on rest of tire is fine wondering if I have a toe problem? Driver side looks fine, I know these tires don't last but could I need an adjustment on the front end,Have mcs shocks from woodhouse installed before car delivery. Any ideas would be greatly appreciated.What tire should replace too. Thanks

[John N]

ACR’s come from factory with very aggressive camber to improve track handling. You can get an alignment and dial it back for better tire wear, especially if you drive mostly/only on the street. With track spec camber on mine you can’t actually see daylight under tire shoulder when sitting unloaded.

[sadil]

Did you get your alignment checked? What was the alignment post suspension install? Curious on why you even downgrade your stock suspension? If you aren’t driving on the track, stick to camber of 1.5 for the front.

[ViperGarageElite]

Did you get your alignment checked? What was the alignment post suspension install? Curious on why you even downgrade your stock suspension? If you aren’t driving on the track, stick to camber of 1.5 for the front.

Have not had the alignment checked, Mark Jorgensen installed mcs on my gen4 acr and loved the rideabilty with the easier adjustments so when I ordered the ACRe figured to do the same as both cars handle extremly well. I live up in the Buffalo area with not any immediate techs to take it to.The rest of the tire is like new but the inside passenger edge is done. Mark knew that I only street drive due to the fact that we have very limited venues to track on. Pretty sure he had the alignment set up for street use . Can these cars be put on standard alignment machine?

[ViperGarageElite]

ACR’s come from factory with very aggressive camber to improve track handling. You can get an alignment and dial it back for better tire wear, especially if you drive mostly/only on the street. With track spec camber on mine you can’t actually see daylight under tire shoulder when sitting unloaded.
Will these cars fit on standard alignment machine or need something special

[sadil]

They should align fine, as long as you can make it up the shop ramp. The ramp itself is the usual suspect. I would pick a couple shops and just drive there to check out the ramp. As for the wear, it sounds like your alignment is off on one side. Is the other side wearing fast too and just hasn’t corded yet? Or is it perfect? If both tires are not wearing, then it fell out of alignment on one side only. Hit any pot holes or something? And curb hits? If you are just driving on the street, both should have even wear if alignment isn’t off.

[Steve-Indy]

For street use, try the Gen V SRT/GTS as found on the chart in this link:

https://driveviper.com/forums/threads/14208-2016-acr-e-alighnment-specs

[threatta]

I had a similar problem on my ACR-E. One side inside edge wore to the cord faster than the other. Both were wearing on the inside edge due to the camber, of course, but the one side was a little more severe. We checked the front splitter and the support strut had changed position (they'll do that on their own over time) and the side with more wear had slipped into a more aggressive position. We were thinking that was adding additional downforce on that side causing a bit more wear. I changed to a TA spec on the camber and readjusted the splitter (and check it occasionally). Seemed to resolve the problem. Track days seemed to be fine with that setup too (still fairly new to tracking).

[Bill Pemberton]

Key comment is spirited street driving , as not sure how spirited you might actually push the Kumhos. They do not last very long, especially in the front, so it may be just normal depending on your driving.

Comment to Sadil, the MCS is not a downgrade to many , as Mark J. switched these over for quite a few fast track rats who found them super quick. In fact many at the NVE in New Orleans were blown away by the unreal times Mark was turning in a customers Orange ACR and the secret was ................MCS suspension.

[FSTENUF]

4449144492
This was my 3rd set of fronts. They corded in less then 1000 miles on the street. I had pushed out the slugs and had the passenger inner tie rod end develop play. Simple solve backed off the ACR alignment to the T/A in the front and left the rear alone. You will still have more then enough grip for the street. My plan was setting my ACR up for the drive down for NVE4 and be able to make it back with out needing new fronts for the drive back. Just finished 2000 miles with this set up and am completely happy. I own the Orange ACR that Mark installed the suspension on at NVE 2.

[TKO MOTORSPORTS TEAM]

We see the front tire wear problem topic on here all the time. We hate to see people have problems that cost money and cause them not to enjoy their viper to its fullest. We have never had any problems with the Kuhmos. Good grip, good street wear, long track life and fall off is manageable. We usually get 4-6 hard track days out of front tires or 2 full test days novice or pro driver........Rear tire wear is exceptional novice, or pro driver never have any problems with rears.

This is just a reference Our basic /street track setup we use on all customer vipers.

1. We now install our lock our plate kit. This makes sure the setup stays in place and customer doesnt have to constantly pay for a complete setup again and again. Our lock out plate kits is a little extra cost but saves alot of time and money in the long run.

2. Do not adjust caster keep it neutral. There is already enough built in caster and usually the caster split across the front is less then 1 deg. Adding caster to factory rubber bushing control arms or control arms with our bushing kit just compounds problems.

3. If you can or have the opportunity have your car setup on setup rig, scale pads, turntables and string fixtures; still the best way to setup a car even in 2020. If its strictly a street car laser is ok

4. Nitro in tires. Not absolutely necessary because not everyone has easy access to nitrogen but it makes a deference.

frt 2.5 deg neg camber
toe in .080-.125"

rear 2.5-2.8 deg neg
toe in .080-.125"

Remember this is just a reference do what you will with this information. We are just sharing info to possibly help people in the viper community

[FSTENUF]

We see the front tire wear problem topic on here all the time. We hate to see people have problems that cost money and cause them not to enjoy their viper to its fullest. We have never had any problems with the Kuhmos. Good grip, good street wear, long track life and fall off is manageable. We usually get 4-6 hard track days out of front tires or 2 full test days novice or pro driver........Rear tire wear is exceptional novice, or pro driver never have any problems with rears.

This is just a reference Our basic /street track setup we use on all customer vipers.

1. We now install our lock our plate kit. This makes sure the setup stays in place and customer doesnt have to constantly pay for a complete setup again and again. Our lock out plate kits is a little extra cost but saves alot of time and money in the long run.

2. Do not adjust caster keep it neutral. There is already enough built in caster and usually the caster split across the front is less then 1 deg. Adding caster to factory rubber bushing control arms or control arms with our bushing kit just compounds problems.

3. If you can or have the opportunity have your car setup on setup rig, scale pads, turntables and string fixtures; still the best way to setup a car even in 2020. If its strictly a street car laser is ok

4. Nitro in tires. Not absolutely necessary because not everyone has easy access to nitrogen but it makes a deference.

frt 2.5 deg neg camber
toe in .080-.125"

rear 2.5-2.8 deg neg
toe in .080-.125"

Remember this is just a reference do what you will with this information. We are just sharing info to possibly help people in the viper community

Yep you Nailed it

[JonB ~ PartsRack]

Have read many threads on kuhmos failing on the racetrack but my passenger tire has cords showing on the inside edge, 4200 miles spirited street driving. Tread on rest of tire is fine wondering if I have a toe problem? Driver side looks fine, I know these tires don't last but could I need an adjustment on the front end,Have mcs shocks from woodhouse installed before car delivery. Any ideas would be greatly appreciated.What tire should replace too. Thanks

Undesirable, but G5ACR Normal.

Since you are OE-aligned for the TRACK, you are grinding away your inner shoulders. Your OE alignment creates a full flat-footed contact patch when cornering, but an inside-wearing contact patch on highways and roads.

As Steve and others noted, if you rarely track, re-align the car to non-ACR spec be more flat-footed on highways. This means a LOT less negative camber. YOur front tires last longer. But you will give up some "snappy-precise" handling when driving twisties.

Kumhos are surprisingly CHEAP. $300F, $360R Delivered. Under $1300/set delivered USA. Hundreds less than Corsas or SPort Cup II.

Just plan to go thru 4 fronts as you need 2 rears. BUT DONT DRIVE ON CORDING TIRES ! Ditch Them before they Ditch YOU.

[ViperGarageElite]

Key comment is spirited street driving , as not sure how spirited you might actually push the Kumhos. They do not last very long, especially in the front, so it may be just normal depending on your driving.

Comment to Sadil, the MCS is not a downgrade to many , as Mark J. switched these over for quite a few fast track rats who found them super quick. In fact many at the NVE in New Orleans were blown away by the unreal times Mark was turning in a customers Orange ACR and the secret was ................MCS suspension.
Bill nice to her from you. I would say very spirited and you may be right about the wear. Just the rest of the tire looks great.

[ViperGarageElite]

Undesirable, but G5ACR Normal.

Since you are OE-aligned for the TRACK, you are grinding away your inner shoulders. Your OE alignment creates a full flat-footed contact patch when cornering, but an inside-wearing contact patch on highways and roads.

As Steve and others noted, if you rarely track, re-align the car to non-ACR spec be more flat-footed on highways. This means a LOT less negative camber. YOur front tires last longer. But you will give up some "snappy-precise" handling when driving twisties.

Kumhos are surprisingly CHEAP. $300F, $360R Delivered. Hundreds less than Corsas or SPort Cup II. Just plan to go thru 4 fronts as you need 2 rears. BUT DONT DRIVE ON CORDING TIRES ! Ditch Them before they Ditch YOU.

Do not want to give up the handling this car is ridiculous the way it feels.I am ok with the wear then whats the best way to contact you to order now thanks for the insight
,

[JonB ~ PartsRack]

Do not want to give up the handling this car is ridiculous the way it feels.I am ok with the wear then whats the best way to contact you to order now thanks for the insight
,


Best is email: JonB@PartsRack.com, thanks.

I wish screen names would default in the profile to TRUE NAMES. If a person WANTED to be forever anonymous, they could chhose anonymous with 1 click? As It is I may know you, but dont / cannot know til you unmask via email THANKS

[sadil]

I can tell you right now that you are not effectively using 3 deg of camber while driving “spirited” on the street. It’s just not the same as throwing a car into turns at the track. Temperature, pressure, speed, grip level all work together with camber to flatten the tire out in the turns and gain grip when you are cornering hard. The overly aggressive setup on the street will give you LESS grip when your speeds are not high enough. It is counter productive to what you want if you are just driving on the street. You want to use more of the tire on the street and with less speed and cornering G’s, you need less camber. If you are not tracking, it will feel even better with 1.5 degree of camber and you will get lots of life. Personally I keep my camber at 2.8 and I run the cheapest tires I can find on the street because I know all I’m doing is burning up the edge. I do this so I don’t have to pay 150 bucks 10 times a year on alignments.

[Steve-Indy]

I can tell you right now that you are not effectively using 3 deg of camber while driving “spirited” on the street. It’s just not the same as throwing a car into turns at the track. Temperature, pressure, speed, grip level all work together with camber to flatten the tire out in the turns and gain grip when you are cornering hard. The overly aggressive setup on the street will give you LESS grip when your speeds are not high enough. It is counter productive to what you want if you are just driving on the street. You want to use more of the tire on the street and with less speed and cornering G’s, you need less camber. If you are not tracking, it will feel even better with 1.5 degree of camber and you will get lots of life. Personally I keep my camber at 2.8 and I run the cheapest tires I can find on the street because I know all I’m doing is burning up the edge. I do this so I don’t have to pay 150 bucks 10 times a year on alignments.

Well said, sadil...while I cannot speak for the original poster, the majority of Gen V ACR and ACR-E Vipers built are not driven regularly on race tracks...if ever in many cases. This is not just my personal observation of owners in my region as it has certainly been stated by well respected dealer-folks in the recent past.

We all appreciate what a carefully crafted, dialed in track setup can do for any car being raced. Using the same setup of -2.5 to -2.8 degrees of camber on the street by the more casual owners generally nets the aforementioned asymmetric front tire wear ( usually perceived as unacceptable premature wear...and, thus expense) as well as the added effect of accelerated wear on the front wheel bearings.

Serious track rats are ALWAYS tweaking their setup for each different track as well as the varying conditions...striving to get maximum performance regardless of expense...at least, to a point.

So far, the owners I know have no complaints regarding handling of their ACR's on twisty roads, casual cruises, etc. after changing the front camber to the -1.4 range as found of the SRT and GTS versions.

The choices are up to each owner.

[ViperGarageElite]

I am very thankful to all who responded, the information is fantastic and will most likely follow the advice of street use as both sadil and Steve-Indy posted thanks again.