Viper Coupe Diff Issues

[elanderholm]

I read a comparison of the Viper coupe and the new Z06 from a very good driver who complained about the differential of the new viper. He said the car was fine at 9/10, but it tended to understeer when pushed harder, but then would snap oversteer as he pushed it to 10/10's. IT seems the diff would lock in the back sending the back around. He actually thought something was wrong with the diff, but he concluded it was working as designed.

Anyone who is a very experienced driver who has tracked a new Coupe want to comment? He actually blasted the C&D and other mag drivers for now pushing the car hard enough to find this "interesting" trait. I know the Coupe has some new-fangled diff, but I don't know much about how it works. It seemed to think the Z06 was easy to drive at 10/10, but not as easy to drive at 9/10 compared to the viper.

 

[GR8_ASP]

The diff is the same on all SRT's, not just the coupe.

That said the trait indicated is true on my car (transition to oversteer due to differential lock up). It takes some experience to allow the inside rear tire to spin just below the threshold where torque is transferred to the outside tire. If that transfer happens too abruptly the outside tire will slip and begin oversteer rotation.

With Pilot Sport Cups the issue was less noticeable as I had slight oversteer under steady state, thereby making the transition less severe. Plus the added traction on the outside tire was enough to prevent slippage in most cases.


BTW my experience was this condition worsened with miles as I noticed it during my second track day. The first track day passed with no concern. Not sure why. Could be tire age or clutch break-in or some other effect.

 

[rleminv]

QUAIFE

 

[quick2tr]

BTW my experience was this condition worsened with miles as I noticed it during my second track day. The first track day passed with no concern. Not sure why. Could be tire age or clutch break-in or some other effect.

Same for me, except I attributed it to just pushing it harder. I now find myself trying to approach the inside spin without allowing it to transition (stay in open diff mode). More than once I have found the transition too quick to control.

 

[Kai SRT10]

This observation is spot on.

This "interesting trait" is the reason that many of us have replaced the stock dif with the Quaife.

 

[Vipermann]

I've noticed this too, but some other thoughts:

This happens coming out of a corner, and it places a premium on being able to carefully 'squeeze' more throttle. It's a fine line between pushing the car out of a corner with just a hint of tire squeel, vs. starting a 360, then lifting off the throttle, thus shifting weight forward and making the spin worse. This is compounded by the SRT having so much torque -- it should not be attempted by those inexperienced.

But ... vs. the Vette, it should be said that the Vette is also a bit easier in terms of rear tire traction because it produces less torque. In other words, a Miata would even be easier.

 

[elanderholm]

I've noticed this too, but some other thoughts:

This happens coming out of a corner, and it places a premium on being able to carefully 'squeeze' more throttle. It's a fine line between pushing the car out of a corner with just a hint of tire squeel, vs. starting a 360, then lifting off the throttle, thus shifting weight forward and making the spin worse. This is compounded by the SRT having so much torque -- it should not be attempted by those inexperienced.

But ... vs. the Vette, it should be said that the Vette is also a bit easier in terms of rear tire traction because it produces less torque. In other words, a Miata would even be easier.

He wasn't claiming anything to do with torque of the engine. I mean an S2000 has very little torque and will swap ends like Elton John. He was claiming what the first few posters were talking about. OK, I think I have my answer thanks guys. What is the price of a Quaife? And which model do some of you guys have?

 

[Vipermann]

It has everthing to do with the high torque of the Viper .. the Differential 'manages' torque.

... if the Viper didn't have so much torque, wheel spin would occur less quickly, and any resulting 'transfer' within the Diff would be less of an issue

 

[elanderholm]

It has everthing to do with the high torque of the Viper .. the Differential 'manages' torque.

Every diff manages torque. It sounds like this one manages it ******. The behavior is not what is expected or what one would want. I understand what a differential does. My point is with a different diff you wouldn't have this interesting trait at all. Hence the suggestions for the quaife.

 

[Vipermann]

Every diff manages torque. It sounds like this one manages it ******. The behavior is not what is expected or what one would want. I understand what a differential does. My point is with a different diff you wouldn't have this interesting trait at all. Hence the suggestions for the quaife.

You're starting to sound like a Vette fan ... the Viper is an amazing car ... go drive one on the track for yourself

 

[Kai SRT10]

I've noticed this too, but some other thoughts:

This happens coming out of a corner, and it places a premium on being able to carefully 'squeeze' more throttle. It's a fine line between pushing the car out of a corner with just a hint of tire squeel, vs. starting a 360, then lifting off the throttle, thus shifting weight forward and making the spin worse. This is compounded by the SRT having so much torque -- it should not be attempted by those inexperienced.

But ... vs. the Vette, it should be said that the Vette is also a bit easier in terms of rear tire traction because it produces less torque. In other words, a Miata would even be easier.

He wasn't claiming anything to do with torque of the engine. I mean an S2000 has very little torque and will swap ends like Elton John. He was claiming what the first few posters were talking about. OK, I think I have my answer thanks guys. What is the price of a Quaife? And which model do some of you guys have?

Expect to spend between $3500 and $4000 for a Quaife, including parts and installation. Are you asking what model car we have, (SRT-10) or what model Quaife (there's only one that fits with the SRT-10) The process is pretty straight-forward. You pull the "pumpkin", send it to Taylor Race Engineering. They put in the Quaife and modify the stub axels and send it back to you. You then re-insert the pumpkin into your car, fill it full of oil, and you're good to go.

The Quaife is a big improvement over the stock dif at the track. The car is much more settled in tight corners. The tendency for inside wheel spin is completly eliminated, as is the unsettling "jump" you get when it locks. Corner transitions are much more smooth, and you can get the power down coming out of the corner a lot sooner and stronger with the Quaife.

Having driven the car hard with both the stock dif and the Quaife, I can say that I strongly prefer the performance of the Quaife compared with the stock dif. Sticky tires and a Quaife were the best track mods I've made to my car.

Kai

 

[Bill Pemberton Woodhouse]

Elanderholm,

Respectfully, please keep in mind this is just one article and one person's opinion , but Vipermann has a valid point. The diff is a distinct improvement over the Gen IIs and without traction control and other aids that thankfully most Viper owners don't want, getting the power to the ground , at times is tough, but it is by no means a sh#$@ rear end as you surmised. My suggestion is get a Viper and then you can make a real life decision.........not everything you see in print is gospel.I , for one, love the on the edge feel of 535 ft. lbs of torque hooking up, it just takes an educated foot to do it properly, and that is very much the mystique of the Viper.

Many very experienced drivers/racers have mentioned it took them up to a year to master the Viper and that was part of it's panache ---- reaching that elusive 10/10ths gives you an edge on the track, but it is something to strive for, it is not given in a weekend.

Best Regards,
Bill Pemberton

 

[elanderholm]

Elanderholm,

Respectfully, please keep in mind this is just one article and one person's opinion , but Vipermann has a valid point. The diff is a distinct improvement over the Gen IIs and without traction control and other aids that thankfully most Viper owners don't want, getting the power to the ground , at times is tough, but it is by no means a sh#$@ rear end as you surmised. My suggestion is get a Viper and then you can make a real life decision.........not everything you see in print is gospel.I , for one, love the on the edge feel of 535 ft. lbs of torque hooking up, it just takes an educated foot to do it properly, and that is very much the mystique of the Viper.

Many very experienced drivers/racers have mentioned it took them up to a year to master the Viper and that was part of it's panache ---- reaching that elusive 10/10ths gives you an edge on the track, but it is something to strive for, it is not given in a weekend.

Best Regards,
Bill Pemberton

I respect your opinion, but I still feel like it's a poor design. I will admit I have only driven a Gen 2 a few times and not that hard. The problem is I won't be able to drive the Z06 and Viper coupe back-to-back ******* a track so I have to find info somewhere. The guy writing the article is a very good driver, almost pro-level. He had many bad things to say about the old Z06's handling so I don't think he is biased.

I understand that some cars are harder to drive, but I think some of the mastery (of my last car and the new viper) comes from some inherent design flaws. No car is perfect. I am just trying to get an idea of what may need fixing. You are right "******" was probably not a fair word!



Thanks.

 

[Bill Pemberton Woodhouse]

What you need to understand is that Vipermann gave you the answer, and that is simply if you do not take the massive amount of torque into play when considering the characteristics of the way the car hooks up , etc. you are not viewing this car in a realistic manner. I was shocked at how well the Gen IIIs power out of a corner when compared to a Gen II, and as a Porsche Certified Driving Instructor, Viper Days Instructor, and one of the Lead Instructors at Midamerica Motorplex ( Pacific Junction , Iowa ), I will agree a new Vette is easier to pound out of a corner. Experienced driver or not, it takes a deft foot to get the most out of a Snake, and like Porsches of old, it demands attention and learned skill ---- the mastery of that is what makes it so desirable to many of us. Just because it is tough to drive and is blessed with numerous ,numbing driver aids, does not make something a bad design.

 

[elanderholm]

OK, but just because it drives better then the Gen 2 still doesn't make it a good design. It sounds like the Quaife improves on the design. By the way the reviewer drove the vette with all electronic nannies off. He did that on purpose to see how the car handled sans any electronic aide.

It sounds like, from the above posters, that the quaife allows you to put the power down better. Are you saying that isn't true? Look, I'm not saying the viper is t3h **** or anything, but it sounds like the diff is not putting power down in the best way possible. Every car has it's weaknesses, for example the brakes on the new Z06 are terrible, IMO.

I am not buying the massive amount of torque arguement. A lot of cars make a lot of torque, but don't have the handling characteristics of the viper. The ford GT and modified C6 Z06s for example can make over 500 ft/lbs of torque and they don't have a snap oversteer issue. He (the reviewer) readily admits the viper is the easier car to drive up to 9/10, but after that it has bad handling characteristics. Old porsches were the same. I understand people liked them, or they had character, but that doesn't make the handling good or the design a good design. A good driver can make up for design flaws, but that doesn't somehow not make them flaws. I am just trying to get an idea of how bad it is and if there is a solution.

 

[Kai SRT10]

This has been discussed a lot on this board in the past:

http://www4.forum.viperclub.org/showflat.php?Cat=&Board=UBB21&Number=544192&Forum=UBB21&Words=quaife&Match=Entire%20Phrase&Searchpage=0&Limit=325&Old=allposts&Main=544192&Search=true#Post544192

http://www4.forum.viperclub.org/showflat.php?Cat=&Board=UBB21&Number=637125&Forum=UBB21&Words=quaife&Match=Entire%20Phrase&Searchpage=0&Limit=325&Old=allposts&Main=634031&Search=true#Post637125

http://www4.forum.viperclub.org/showflat.php?Cat=&Board=UBB21&Number=662149&Forum=UBB21&Words=quaife&Match=Entire%20Phrase&Searchpage=0&Limit=325&Old=allposts&Main=662149&Search=true#Post662149

 

[Viper X]

Hey E,

You don't have a Viper, do you? Until I drove one (25,000 + miles now on my SRT-10 with many track events) I didn't quite get the torque thing either, but it is quite real.

I'll bet this driver doesn't have much "seat time" in a Viper on a race track. It takes time to master (if ever) as stated above.

I have taken my SRT-10 to 10/10 many times with stock power and stock diff and never experienced "snap steer".

Having driven with Bill P, I can state that he is a very good, experienced driver, much better than I am. He is telling you like it is.

I too have switched to a Quaife, primarily for strength reasons (major mods, super charger, way too much power, etc.) It is better out of a corner and in general, but the stock diff with stock power is pretty good.

Dan

 

[Bobpantax]

I agree with Bill Pemberton.I drove an SRT-10 convertible last year at Homestead Speedway on the 2.2 mile road course. Compared to the supercharged GTS I had then, the SRT-10 was so easy to handle, I thought, at first, that it must have been specially prepped. It was not specially prepped and was absolutely stock. I even let the rear hang loose a few times aound a few corners just to see how the car reacted. Its all in the feel and the foot. If you can make yourself one with the car, you will feel the symptoms before the snake bites and avoid the bite. The more power you add through mods,the more this will be true. More power requires more learning and a more refined skill set. Those who jump in an enhanced vehicle and go pedal to the metal without some serious training or self training seat time are fools. And like most fools, they will hurt themselves, others and/or their vehicles. Just my two cents.