What happend?

[NorCalSRT]

So I went to the drag strip and made my first pass with the MGW short shifter. This was going to be my second pass ever in the Viper (had lots of previous passes in other cars). So I decide this time to powershift. First to second was great, but the shift must have loosend the shifter enough that when I shifted to third, I missed...bad...not an over-rev but rather a grind. Upset, I short shifted to fourth and rode out. Upon entering the return strip I found that I could not get into second! Come to find out that I could not get into any gear! I thought I could let the tranny cool down and all would be ok. After 5 minutes of sitting I got third and fourth back. 20 minutes later, 2nd and 5th. And once at home, 1st, 6th, and reverse (although they felt sticky at first). What causes this (synchro's?).

Thanks for your feed back.

P.S. there was another blue/white GTS coupe there as well (anyone here?)

 

[Kai SRT10]

That has never happened to me. I've hot-lapped my car at the drag strip with 10-15 consecutive passes. No issues.

(edit)

I should qualify this, by saying that I was not powershifting.

 

[valentine_viper]

I don't know what caused the problem, but I'm surprised you were able to powershift at all. The Viper tranny is not very well suited for that. Throws are too long and the clutch travel is pretty long as well.

 

[NorCalSRT]

I agree with you Valentine; and while the shorter shifter helped, the throws are still longish. I drove the Viper alittle today and all feels normal. Is there anything I should be worried about?

Thanks again

 

[Volltage]

I had a similar experience at the track after about 8 passes. Just let it cool down and she was fine. Made me nervous too, but I like it has more to do with your clutch then your tranny.

 

[Racer Robbie]

I had a customer come in with a similar problem once his transmission got hot. He had a lot of miles on his viper and had had the dealer change the fluid. It turned out the dealer installed the wrong fluid so we changed the transmission fluid and everything was perfect afterwords. You have to be extremely careful what fluid you put in these transmissions as there have been different fluids depending on what your synchro's are made of. the best way to tell what fluid is needed is to copy the information off of the tag next to the fill plug on the transmission. The dealers are not always correct on the correct fill as was the case above.

 

[NorCalSRT]

I only have 1500 miles on the car so it's the original fluid. Does the Viper (mine is an 06) have carbon synchro's?

From what I'm gathering, I need not worry...as it seems once the tranny/synchro's cool; all will be ok?

 

[kmg99]

From a design perspective the transmission in the Viper is not designed to be powershifted. The synchros, blocker rings, etc, all rely on an extremely short interruption in power (clutch) to function properly. If you want to powershift reliably under high load you need to eliminate the synchro assemblies from the transmission...what is known as a crash-box.

I have been involved with racing and transmissions for many years, and will say without a doubt that you are indeed reducing the life of your transmission for a very small (probably one or two tenths) potential time reduction at the dragstrip if all goes well, which in your case, it did not.

 

[Racer Robbie]

I have to agree 100% as the viper is not a drag racer. It is a road racing car. Have you ever seen a drag racer with independent rear suspension?

 

[valentine_viper]

I agree with you Valentine; and while the shorter shifter helped, the throws are still longish. I drove the Viper alittle today and all feels normal. Is there anything I should be worried about?

Thanks again

I have done a few drag strip runs on my Viper as well. Although I didn't try to power shift it, I still noticed that the clutch would feel a little spoungy for a few minutes after each run. Probably a heat related issue. Not sure why it happens, but there doesn't seem to be any lasting effects. I have also road raced my Viper a few times and did not notice any problems then. My best guess is that the clutch plates heat up very quickly under drag racing conditions where as road racing does not load up the clutch as quickly or brutally. I have drag raced other manual trans cars and not had this happen, but they did not have the torque of a Viper.

I know there are guys out there that drag race their Vipers on a regular basis. I'de be curious to hear if they have had problems and had to upgrade their clutch.