Tires
- Thread starter ViperDad
- Start date
SylvanSRT
Enthusiast
staying with stock size wheels you really only have two choices
pilot sport 2
pilot sport 2 run flat
sounds quite limiting until another tire manufacturer steps up and gets us some sticky tires in stock sizes
btw the runflats will work better with the stock suspension tuning/setup
pilot sport 2
pilot sport 2 run flat
sounds quite limiting until another tire manufacturer steps up and gets us some sticky tires in stock sizes
btw the runflats will work better with the stock suspension tuning/setup
Kai SRT10
Enthusiast
Don't you mean Pilot Sport and Pilot Sport runflat?
I don't think they make Pilot Sport 2 tires for our wheels.
Correct. No PS/2 in Viper sizes.
Not sure why it supposedly works better with the heavy tires. Mine seems fine with MUCH lighter wheels and tires. The Pilot Sports non run flat have a similar construction, same sidewall deflection, etc.
Not sure why it supposedly works better with the heavy tires. Mine seems fine with MUCH lighter wheels and tires. The Pilot Sports non run flat have a similar construction, same sidewall deflection, etc.
SylvanSRT
Enthusiast
i dont think it's the weight as much as the stiff side walls
rcl4668
Enthusiast
There are actually a few other options out there:
Pirelli PZero Rosso in sizes that are slightly different than stock but should not impact overall tire diameter and therefore speedometer or gearing. For example, the Pirelli makes a 355 mm width tire. Other board members have used this tire. See www.tirerack.com for sizes and for performance in relation to the stock Michelin Pilot Sport ZP (Zero Pressure) tire.
Hoosier has also just come out with their new autocross and race tires in stock sizes. Again, see tirerack. Note: these are basically racing slicks so I assume this is not what you are after.
Also, if you are willing to change rims (going to 20 inch rims in the rear or, using an emergency brake relocation kit, going to 18s in the rear), you can use the new Michelin Pilot Sport PS2 (arguably the best all around street tire currently available) or the Michelin Pilot Sport Cup (track day/ dry street tire).
Not to hijack this thread, but I am interested in the debate about using the stock ZP tire versus the non-runflat Michelin Pilot SPort at the track: TireRack believes that the nonrunflat will be better because of weight savings and also because the runflats "take away the feel from the suspension." Can anyone with firsthand experience with the two tires comment? I would tend to agree with that view but am also concerned about deviating from the stock tires (e.g., suspension was tuned at the factorywith these stock tires in mind).
Thanks for your input.
/Rich
Pirelli PZero Rosso in sizes that are slightly different than stock but should not impact overall tire diameter and therefore speedometer or gearing. For example, the Pirelli makes a 355 mm width tire. Other board members have used this tire. See www.tirerack.com for sizes and for performance in relation to the stock Michelin Pilot Sport ZP (Zero Pressure) tire.
Hoosier has also just come out with their new autocross and race tires in stock sizes. Again, see tirerack. Note: these are basically racing slicks so I assume this is not what you are after.
Also, if you are willing to change rims (going to 20 inch rims in the rear or, using an emergency brake relocation kit, going to 18s in the rear), you can use the new Michelin Pilot Sport PS2 (arguably the best all around street tire currently available) or the Michelin Pilot Sport Cup (track day/ dry street tire).
Not to hijack this thread, but I am interested in the debate about using the stock ZP tire versus the non-runflat Michelin Pilot SPort at the track: TireRack believes that the nonrunflat will be better because of weight savings and also because the runflats "take away the feel from the suspension." Can anyone with firsthand experience with the two tires comment? I would tend to agree with that view but am also concerned about deviating from the stock tires (e.g., suspension was tuned at the factorywith these stock tires in mind).
Thanks for your input.
/Rich
SylvanSRT
Enthusiast
i cannot speak about the non-run flats. but i am on my third set of the stock run flat tires. and have run quite a few track/driver ed. days and the stock tires are very capable. The car handles even better with the lighter SRT-sidewinder wheels. I did not want to give upthe run flat simply because some of the distances i drive(away from home) and without a spare tire in the car your only option then becomes a flat bed to get you to a tire dealer that probably does not have the tire you need. So even if the non-run flats handle better i was not willing to give up the ability and confidence that the run flats provide.
This is an interesting statement. To be clear, if I change to 20" or 18" rears, (assume eb reloc and suspension tuned to new tires) the Michelin Pilot Sport PS2 is one of the best for street use and "sticky" enough for spirited driving on the street? (sorry all you lawful VCA driving graduates and drivers, I am a bad boy) Can I expect it to handle 3-5K miles front and rear? I already have my drag wheel and tire set up. I would really like to hear from Viper owners who use them?
I apologize if this is a hijack.
Larry
Racer Robbie
Enthusiast
I just installed copperhead 5 spoke wheels that are 34 lbs lighter than stock and Michelin non run flats that are 10 lbs lighter than run flats. Jon, at Parts Rack, had originally sold me Pirelli Rosso tires that I returned after measuring them and finding out they were 3/4 smaller in diameter than the OEM Michelin size. I felt this would screw up the ABS and throw off the front to rear bias and front to rear weight ratio. A far as your speedometer I was told by Luke, at The Tire Rack, that it does not matter what wheel or tire size you use.
Atro,
A few facts. The speedo translates average wheel speed into MPH. The tire size matters. I know of no car in the world that is not true for. The Gen III measures the wheel speed directly, therefor differential gear ratios do not matter (many cars, including Gen I and II us transmission output shaft speed for speed sensing). Maybe that is what he meant.
I do not think tire diameter is going to have a measureable effect on brake bias or front to rear weight bias for the difference you mentioned.
What Luke has mentioned is that having consistent sidewall deflection numbers from front to rear as stock for dynamic chassis response. That is not directly related to tire diameter, but related to sidewall height and stiffness.
A few facts. The speedo translates average wheel speed into MPH. The tire size matters. I know of no car in the world that is not true for. The Gen III measures the wheel speed directly, therefor differential gear ratios do not matter (many cars, including Gen I and II us transmission output shaft speed for speed sensing). Maybe that is what he meant.
I do not think tire diameter is going to have a measureable effect on brake bias or front to rear weight bias for the difference you mentioned.
What Luke has mentioned is that having consistent sidewall deflection numbers from front to rear as stock for dynamic chassis response. That is not directly related to tire diameter, but related to sidewall height and stiffness.
Racer Robbie
Enthusiast
GR8,
I think you should call and talk to Luke direcly at The Tire Rack yourself before you keep putting me down for providing people on these forums with information that he was so nice to take time out of his busy day and give me. I believe Luke is an expert in his field and knows vipers inside and out as I believe he owns one.
I think you should call and talk to Luke direcly at The Tire Rack yourself before you keep putting me down for providing people on these forums with information that he was so nice to take time out of his busy day and give me. I believe Luke is an expert in his field and knows vipers inside and out as I believe he owns one.
I think you are missing the point. You are speaking for Luke when you make statements like this. When there is an obvious error it looks bad for both Luke and yourself. I would keep to first hand knowledge if you are uncertain about the accuracy of the comment.
There is no way any automotive person is going to say that tire diameter has no effect on the speedometer reading. Unless it is reading GPS it will be affected.
Sorry if you do not like it when someone disputes things that are stated as facts. If they are not factual they should be disputed, before more misinformation is passed on.
There is no way any automotive person is going to say that tire diameter has no effect on the speedometer reading. Unless it is reading GPS it will be affected.
Sorry if you do not like it when someone disputes things that are stated as facts. If they are not factual they should be disputed, before more misinformation is passed on.
SylvanSRT
Enthusiast
the polished SRT-sidewinders may be lighter than the painted blems is all i can figure. i had accurate shipping weights in the same boxes and packaging with the oly difference being the weight of the wheels
Racer Robbie
Enthusiast
Like I said Luke made the statement and I passed it on. When I questioned him on why this is he said the spedo gets it's reading from the ABS system. I told him I have never heard of that and he said that is how it is on vipers. Those are his words, not mine. Like I said before call him and discuss it with him.
Sorry that you misunderstood what Luke was trying to say. I am sure he was trying to indicate that you can change gear ratio without impacting the speedometer. That is true for the SRT because the speed is measured by the ABS system using the wheel speed sensors.
The misunderstanding is that the system has no means of knowing or compensating for differing tire diameter. So changing a tire size will lead to an inaccurate speedometer reading. Those are the facts. You can take them any way you want. I need not call Luke to understand that aspect.
I do have a pretty good idea of Vipers and how they work given that I have been an owner for more than 10 years and do my own work on them. From now on I will refrain from trying to correct you when you say something that is not correct (I do not mean to sound condescending but as an automotive engineer for my entire career I do have a fair bit of knowledge about cars).
Thanks and keep on greasing them there caliper mounts so the calipers move freely.
The misunderstanding is that the system has no means of knowing or compensating for differing tire diameter. So changing a tire size will lead to an inaccurate speedometer reading. Those are the facts. You can take them any way you want. I need not call Luke to understand that aspect.
I do have a pretty good idea of Vipers and how they work given that I have been an owner for more than 10 years and do my own work on them. From now on I will refrain from trying to correct you when you say something that is not correct (I do not mean to sound condescending but as an automotive engineer for my entire career I do have a fair bit of knowledge about cars).
Thanks and keep on greasing them there caliper mounts so the calipers move freely.
Racer Robbie
Enthusiast
I guess we can say the we agree to disagree
SRT10_SWISS
Enthusiast
Ron,
you are 100% correct!!!!!!!
by side, a person who is going to say that tire diameter has no effect on the speedometer reading ( besides is GPS controlled) should definitely change his job....
.
you are 100% correct!!!!!!!
by side, a person who is going to say that tire diameter has no effect on the speedometer reading ( besides is GPS controlled) should definitely change his job....
.
Racer Robbie
Enthusiast
As I sid before Swiss "Like I said Luke made the statement and I passed it on. When I questioned him on why this is he said the spedo gets it's reading from the ABS system. I told him I have never heard of that and he said that is how it is on vipers. Those are his words, not mine. Like I said before call him and discuss it with him."
I will not reply to this post anymore as it is quite evident that some people do not know what the words " Those are his words, not mine" mean.
Good day,
Robbie
I will not reply to this post anymore as it is quite evident that some people do not know what the words " Those are his words, not mine" mean.
Good day,
Robbie
SRT10_SWISS
Enthusiast
Robbie,
sorry if you feel defensiv, my statement was about the guy who said it to you.
Have a good day
.
sorry if you feel defensiv, my statement was about the guy who said it to you.
Have a good day
.
2002_Viper_GTS_ACR
Enthusiast
When you guys are done fighting, I bought pops the non run flats, because I think they are the better choice. Course he didnt know they were coming, but now that they are in his office, I dont guess he gets to make any choices.
Thanks for the recomendations.
Jon
Thanks for the recomendations.
Jon
Racer Robbie
Enthusiast
SRT10 SWISS
"Robbie,
sorry if you feel defensiv, my statement was about the guy who said it to you."
Thank you.
Robbie
"Robbie,
sorry if you feel defensiv, my statement was about the guy who said it to you."
Thank you.
Robbie
Luke is wrong on speedo accuracy. ABS module reads tone wheel which will vary based on Tire size, not rear axle gear ratio. I know, I developed the system. So depending on new tire size, speedo will be inaccurate if other than factory tire size is used. You can re-program new tire size into ABS module to get it accurate again. Gen I & II cars has speedo pickup in transmission. Therefore gear ratio AND tire size effected the speedo accuracy.
rcl4668
Enthusiast
kickinasp -- I am confused by this statement. First, what does the sentence "ABS module reads tone wheel which will vary based on Tire size, not rear axle gear ratio" mean? Specifically, what does "tone wheel" mean? Second, are you saying that if I use a larger size rim for the rears, say 20x13 and I put on a tire like a 345/25/20 that retains or closely matches the rolling diameter of the OEM wheel/tire that this will result in speedo inaccuracy? Or are you saying that if I use a whel/tire combo that deviates markedly from the stock rolling diameter that this will result in an inaccuracy?
Thanks in advance for clearing this up.
/Rich
***All*** speedo sensors that use wheel rotation rate to computer speed have to assume a known circumference of the tire - which is the distance traveled per wheel rotation. It doesn't matter whether the speed sensor is from the transmission or from the ABS system - its still measuring the rate of wheel rotations.
If you change the wheel/tire outer circumference to something other than which the system is calibrated for, then you will indeed make the speedo reading incorrect. All three generations of Vipers use wheel rotations. There is no way you are going to make the Viper speedo independent of wheel/tire size unless you somehow change it to be reading from a GPS or something other than the wheels, transmission, ABS, etc.
Racer Robbie
Enthusiast
Thanks kincinasp. That is what I thought but Luke was swearing otherwise.
