I'm surprised they didn't raise the limiter, seeing they were adjusting the tune anyways.

 

Sounds like it's got a blower on top

 

They give the reason why, but I would think it can be done with right gears and tuning.

Per Hennessey "SS is limited to 163 mph as factory 6-speed automatic transmission will only allow top speed to be attained in 5th gear."

 

Question--with 415HP, what is the max speed a stock SS will achieve? Is there a limiter built into the controls?

New Cadillac CTS V-Sport, pushing 420 HP (with 3.6 Twin Turbo V6) will supposedly run 172, stock, so I'm not getting what Hennessey is saying at all, as far as the transmission. It takes more than 5 HP (difference between LS3 & TTV6) to go 9 MPH faster...

And yes, the SS in the video was fitted with a supercharger....I question whether it's required to reach 163, although it may reach that speed quicker than a stock LS3. Hennessey SS should run 175, easy....even 180. Something is not kosher here, IMO.

 

The SS is computer limited, but the drag limit I believe should be around 170-174 depending on weather and track conditions. There are videos where Bret Bodine was doing media day rides in the SS pace car and was getting to 155mph without much effort, with four people in the car.

Here is the speeds by gear based on the L99 Camaro:

Automatic transmissions (L99/6L80E)

3.27 gears:
Top speed in X gear:
1st: 40 mph
2nd: 68 mph
3rd: 106 mph
4th: 140 mph
5th: 190 mph
6th: 242 mph

 

stock it should do 165 with enough room - it can easily do 185 if she's blown.... giggity.

 

According to Michigan State Police test results that are done each year for all police pursuit vehicles, the 2011+ Caprice top speed is 154mph. This is a L77 6.0L rated at 355 hp in the Caprice.

I have taken my Caprice to the 1/8 mile track and been to about 100mph legally for a brief second. I am sure my Caprice could get to the 154mph with no issues, but I would never attempt that unless I was on a closed course.

 

Chevy SS Hits 163 mph on Texas Toll Road - YouTube

If Hennessy upgraded to 600 HP and already knows the limits on top speed why aren't they looking at 0-60 and 1/4 mile times?:shrug:

 

My further point is that it's a question of what you get for the cost of the Hennessey package, if it's still only going to run 163 - bragging rights? I'd rather build power without an adder, and fix the things that limit speed now....not so I could go out and run that fast whenever I wanted to (not likely to EVER happen), but why pay Hennessey for the "privilege" of running the same speed as the car should run now? That money can be used much more effectively.

I do realize there may be some here who have every intention of doing a Hennessey upgrade--I have no fox in this hunt, but I'm just curious how anything is really improved with this approach.

 

Did anyone notice the driver adjusting his seat at 150 mph?

 

Saw that. One hand on the wheel at 150+, the car looks really settled and stable at speed. Not a lot of commotion.

nice.

 

Regardless of why, it sounded like the car had more in it. It just wanted to be unleashed but is being kept on a short leash

 

Chevy SS Hits 163 mph on Texas Toll Road - YouTube

Sucks that you can hear it hit the speed limiter at 163mph several times but the car can easily go much faster as you also can hear it still pulling even when it hits the speed limiter...I would think that could be eliminated...I'm thinking maybe 175-180mph...

 

I agree. The car sounds great and has more in it. Let us not forget that some G8 drivers have hit higher speeds with the same trans, so it can be done. I have a feeling that Hennessey keeps the limiter there as part of the warranty package. Remember, even simple hand held tuners can eliminate the speed limiter.

I'm with Diehard. If the the car is limited per Hennessey's choice, then show us what performance improvements they did gain... 0-60, 1/4 mile times.

 

additional "perspective"

 

if you look at the time on the video...this car does not seem to accelerate faster than the stock car. C&D had the car 0-60 in 4.5 and the quarter at 12.9 at around 111. if you look at the time on the video these are roughly the same times, so either he wasn't on it that hard, or the additional horsepower is not worth the money.

 

if you look at the time on the video...this car does not seem to accelerate faster than the stock car. C&D had the car 0-60 in 4.5 and the quarter at 12.9 at around 111. if you look at the time on the video these are roughly the same times, so either he wasn't on it that hard, or the additional horsepower is not worth the money.

Bingo we have a winner maybe GM limits the top end speed because of lift in other words the front end get loose above a certain point. This is just a thought they have wind tunnels and such to test.
z51vett
Doug

 

The HPE 600 package is 12k. HPE 1000 Twin turbo 80k.

 

GM limits the top speed based upon the ratings of the tires that are used in production. By the law the manufacturer cannot allow the vehicle to exceed the speed rating of the tires that they install at the factory. This is the only reason why vehicles come governed from the factory. It is a safety concern, but not necessarily for your well being, its more so they are not liable when you exceed the rating of the tires and they come apart.

 

Soft tops are another reason, for example the ZL1 coupe in not limited but the soft top is limited to 155mph.

 

I don't see how Hennessey couldn't remove the limiter on this car. It's the same exact drivetrain that the G8 GXP has, and those cars have gone over 163MPH (when tuned)...

 

Someone posted they went 152 on here somewhere that was probably speedo don't know how accurate that was.
z51vett
Doug

 

So how much do I have to pay this guy to make my car go 0-60 in 4.5 sec, 1/4 mile in 12.9, and top speed of 163?

Shut up and take my money!

 

Heck just me your money, under good weather and track that's where a stock SS should perform.

I'm thinking just a Roto-Fab intake and Solo HF cats and resonator delete would do this car wonders.

 

Perhaps I should have posted my amazement at the results in the correct color