INCREASE top end MPH and IMPROVE ACCELERATION:

[ruckdr]

(submitted this on: "6th gear top speed", thread also )

Wayne, (LTHL VPR)
Yes, as asked, what are the 5th and 6th gear ratios,? and can the gear sets be purchased separately ?? How much ??
1st through 4th remain the same ??
Gears are gears and can be installed by any competent, stress competent, Dana trans. guy.
Later,

 

[LTHL VPR]

Thanks for your questions. Answers follow:
1) Ratios: .8 (5th), .62 (6th)
2) Gear sets can not be purchased separately. It's not just a simple swap unfoturnately. Custom parts and extensive work needs to be done.
3) 1st-4th gears remain the same which is GREAT! You can either stick with the stock rear end and maintain great launch and traction, or you can upgrade the rear end to improve the acceleration in these gears and GREATLY improve the 5th, 6th gear acceleration as well (on modified Vipers pushing serious power, in most driving circumstances, we recommend sticking with the stock rear end to keep traction).
4) Since it is not a simple swap out and gears are not sold separately, this is neither an option nor recommended.

Thanks again.
-Wayne

 

[Will]

Wayne,

With the increased top speed, is additional investment in aero mods, to keep the car on the ground, necessary?

Thanks,

-Will

 

[unclgreggy]

Hey apex,
i sent an e-mail about interest in the 750. I never got a response. Will I receive the same prompt service with the transmission as I did on your lethal 750?

By the way, the only one so far who has responded to me is Hennessey - the same guy who has come through on all my other parts. I've sent email to numerous tuners not just you, and no responses. Maybe no one wants my money. oh well.

thanks.

 

[LTHL VPR]

Well, we do our best to answer e-mails and return calls daily. Even with a staff of 7, it's a challenge with all the inquiries. I don't recall receiving an e-mail inquiry on the LETHAL 750 package from you, but then again, I don't know what your name is and you have no signature in your post. Send me an email at [email protected] about your questions, and I'll reply ASAP.
Btw- what e-mail address did you send your questions to? Why don't you just forward the e-mail you sent to my e-mail address above.

thanks for your patience.
-Wayne

 

[Marv S]

Wayne, A 200+ Stock Viper with your gears would make a great Magazine article and demonstrate just how strong the car is with the optimal gearing.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by LTHL VPR:
[BWe expect this package to help stock Vipers reach over the 200mph barrier. Viper with mods: significantly higher.
[/B]<HR></BLOCKQUOTE>

 

[WCKDVPR]

Wayne,

Neat idea. I have a question regarding the 200 mph capability with a stock motor.

With a stock motor a GTS will go approximately 185 mph. This correlates to roughly 5450 rpm in 5th gear, which is pretty much the same rpm as peak horsepower. Therefore, it takes about 400 RWHP to equal the drag of the vehicle at this speed.

Given that with your new 0.80 5th gear 6000 rpm yields 188 mph, you would need to go to 6th to reach 200 mph. 200 mph in the new 0.62 6th gear is 4950 rpm, or less horsepower available to overcome the significantly greater amount of drag at 200 mph vs. 185 mph (drag is proportional to velocity squared). Therefore I think it would be unlikely to reach 200 mph with a stock motor. Have you given one of these a high speed run yet?

However, 5th gear would be much more useable and cruising in 6th would be a reality at near legal speeds, which would be of value.

Keep up the development work as it is great to see performance options available other than the standard headers, exhaust, heads, and gears. Did I mention we could really use a good long runner high flow intake manifold.........

Best regards,

 

[LTHL VPR]

Wow!!
Great responses and questions.
I will try to answer them below.
1) We originally worked on this project to accomplish 2 things: a) Improve the acceleration in 5th and 6th; making 6th gear a usable gear b)improve the top end speed of the Viper (if any of you have shifted the car from 5th to 6th under WOT, you know what I am talking about..

2) Changing the tranny gears does give a 'similar' result to changing the rear end gears for 5th and 6th. HOWEVER, cars making serious power 600, 650, 750+, we find that 3.55 rear end gears are too steep for the power. We have found that first gear is useless (no traction=wasted power), 2nd gear is almost useless, etc.. It is not uncommon for cars to have slower 0-60 times with street tires after adding rear end gears in the Viper because of wheelspin and trying to feather the throttle. Cars with serious power have enough trouble hooking up with the stock rear end gears in 1st-3rd gears as it is. We wanted the same benefits of adding rear end gears without the downside of negatively effecting acceleration times in the 0-100mph range. For those that have upgraded gears already, this upgrade will allow you to accelerate even faster in 5th and 6th without making it impossible to plant the tires in 1st and 2nd.

3) AlexRedSnake-
You are absolutely right! This upgrade is not for everyone. However we have plenty of customers who race their cars at different events with speeds in excess of 145mph. Even with stock gears, anything faster and you need to shift into 5th. Since there is such a huge difference between 4th and 5th, most people do not shift into 5th because it accelerates so slowly. This is a great solution for them to be able to use 5th and 6th gears. As a side note: There are people out there with cars that make 750-1000+hp with Vipers and other cars. Do you think they can use all this power on the street with street tires under 65mph (most speed limits)? No way. Not even close. But, they WANT the power, and cars are built for them. Put a 450hp stock Viper,next to a 1000hp Viper both using street tires with average/good drivers, and I bet the 450hp beats it 0-60mph.

4)VIPRGTS- See above. Even on a stock Viper using 3.55 gears, it is not an easy task to plant the tires and use the horsepower in 1st and 2nd gears. You can imagine how much more difficult it would be with another 100 ft/lbstq+

5)WCKDVPR- Thanks for your support! I may have not clearly expressed what I was trying to say. What I meant to say is that we hope this will help enable Viper break the 200mph barrier. I don't see why a mildy modified Viper wouldn't be able to hit 200mph. For our customers and other Viper owners with 650-1000+hp who would never consider a rear end gear upgrade, this is another great alternative to stretch out and increase top end speed. Hope this answers your question and clears things up. To avoid confusion, I edited my original post to make it more clear.

 

[MES]

Only $3K for an entire transmission? with the new gears? sounds like a good value if someone needs a new tranny. I thought the stock transmission was $3K or something around there.

Anyway one concern I would have is the 5th & 6th gears seem weak on the T56 and can't handle the power. Has anything been done to address this?

BTW I agree with the others that a mildly modded Viper w/stock gears can't hit 200 with this new transmission, the math doesn't seem to add up.

 

[LTHL VPR]

Due to Viper owner demand

We have finalized our APEX Motorsports exlcusive

VIPER HIGH PERFORMANCE TRANSMISSION upgrade

This upgraded transmission will drastically improve top end acceleration and help maximize overall top speed. As an added benefit, 6th gear is now much more usable (doesn't feel like you dropped anchor when you shift into 6th give it gas)!!!

We have used a different ratio 5th and 6th gear in the transmission to improve the Viper's top end performance and acceleration. Best of all, it's like getting the benefit of upgraded rear end gears without the downside of making first and second gear a bear to hook up or undrivable.

If you already have upgraded rear end gears...then

HOLD ON!!

Acceleration will be greatly improved and much more linear with this tranny upgrade and you won't have to sacrifice at the expense of drivability in the lower gears!!!.

We expect this package to help Vipers reach over the 200mph barrier. Viper with mods: significantly higher.

Whether you are a Silver State Classic participant, a Viper Days enthusiast, a Kamikaze street driver (we do not condone this), or a street car looking for a MUCH better boost in performance in 5th gear, and a usable 6th gear (it pulls now!), this upgrade is for YOU!

Inaugural SPECIAL:
First to order will receive a NEW Viper 6 speed tranny with upgraded 5th and 6th gears. $2995. We can also upgrade your stock tranny for $2295 (provided it is in perfect working condition and does not require any other work).
We have them ready to ship!!!
Call us at 408.562.1000 to place your order or with any questions!

Happy Vipering!
-Wayne (LTHL VPR)