180 speedo may not be unrealistic, with tune to remove speed limiter.

[L J]

Saw roadtest specs for Car and driver online. They said top speed gov limited to 155mph. Surprisingly max speed in 6th and 7th was 155mph and in 8th 145mph.
If true GM allows speed above speed rating of stock tires. New tires I put on are W speed rated.
LJ

 

[hoys]

180 on the speedometer is to allow for the easy MPH->KPH switch as this car is a pretty global platform and only two of the markets it is sold in are MPH.

 

[L J]

Good to know.
I like it has ability to register what is possibly, enough to register top speed with limiter removed.
LJ

 

[stoopid]

The outgoing Regal hit its peak around 155-160 MPH. That's drag limited, not governed. The new one with same engine and similar aerodynamics (drag) likely results in similar results. New transmission isn't likely going to help/hurt since drag is what's limiting the vehicle.

Fwiw, that's plenty fast for any mid sized sedan.

 

[L J]

The 145mph is drag limited in 8th, but in 6th and 7th would be much higher without speed limiter. The lower gearing in 6th and 7th gears, taking in account torque multiplication, should make much higher speeds possible being rpm limited not drag limited.

 

[L J]

Thought these Car & Driver road test specs were interesting, particularly top speeds in gears.

 

[Rhetoric]

Thought these Car & Driver road test specs were interesting, particularly top speeds in gears.

That’s an excellent document for reference. Thanks for posting!

Maybe in a couple years I’ll install a bigger turbo, tune, and track the grocery getter.

 

[stoopid]

The 145mph is drag limited in 8th, but in 6th and 7th would be much higher without speed limiter. The lower gearing in 6th and 7th gears, taking in account torque multiplication, should make much higher speeds possible being rpm limited not drag limited.

I missed this post back in November, and your PDF definitely supports that idea.

 

[L J]

I deleted link to file on my tablet, which worked for me but no one else. More of a mainframe guy, then techie online or PC's.

 

[stoopid]

I deleted link to file on my tablet, which worked for me but no one else. More of a mainframe guy, then techie online or PC's.

The PDF was available to us yesterday but not today. Did you remove it?

To add files to a post (picture, pdf, zip) you use the attach files option (when editing it's a button lower left), then send the file from your computer to the post/forum. It makes a copy of the file for the rest of us to see.

I still have the file from yesterday in my deleted items, so reposting it here.

 

[VTSummit]

I seriously doubt there's a lot more speed left in it simply based on the torque available and how the power required at those speeds increases exponentially. That wall of air is hard to push through. The aerodynamic drag is roughly proportional to the third power of the speed. I'm betting it would only get another 5-7mph over the limiter. More powerful cars with similar aerodynamics aren't good for a whole lot more because of the exponential requirements for power to overcome pushing a wall of air at high speed.
For example, in testing a car I used to race we had it topping out at 145mph which was enough for the tracks we used it on. A rule change allowed us to make changes that resulted in 40 more horsepower, which changed the top speed about 4mph. It wasn't limited by running out of available RPM, it just didn't have the power to go faster. When you see faster top speeds in the lower gears, that's telling you that it's about to run out of power- the engine has to remain in a more powerful portion of it's power curve.

 

[mike69440]

180 on the speedometer is to allow for the easy MPH->KPH switch as this car is a pretty global platform and only two of the markets it is sold in are MPH.

I do not know the reason for the 180mph speedometer scale, but per below it is not for MPH/kph reasons

https://www.vauxhall.co.uk/content/dam/vauxhall/Home/brochure-library/cars/insignia/price-guide.pdf
Holden Commodore RS-V Sportwagon 2019 | Holden Australia
Insignia Country Tourer
Insignia Country Tourer | Echter Offroader | Opel Deutschland

0-60 without flashing the torque converter or spooling the turbo requires 7-1/2 second.
Practical top speed is 130 mph, and you will need about a mile plus of straight, unless you have the Bonneville salt flats at your disposal and wish to risk burning a valve or piston. There are a few interstates in the US that resemble the autobahn, however your state police and insurance company would disagree. There is only so much a production 2 liter engine with out extra cooling and lubrication is capable of.
155 mph governed top speed may be incorrect if tires are not speed rated for +155 mph. Lawyer make sure of that, thankfully.
My sort of fast car develops about 600 RWHP, i.e. 400 more than a stock TourX has for WHP. For you average weight car to have any pick-up over 100 mph, you need around 500hp.
With that kind of oomph, 130 mph comes up quick, 140 is no sweat, like accelerating for 70-80 mph, in a Regal/Tourx. The acceleration pace slows down after 140, and I have no clue what happens much after that, nor do I care to find out. Unless you are in a hyper-car or a at least a super-car that is very aerodynamic, and actually built to operate at these speeds this holds true. Also the brakes on a Regal are good for 1-2 slow downs from 120 or so. Then they are then done and so are you.
Don't try this at home.
P..S. Trifecta told me they will have a tune available this summer. Example results of similar dyno chart attached. You might be able to buy a very nice wagon in America with an America engine that with just a tune could run 14 flat @ 100 mph in the 1/4 mile. What more could the mid middle class want?

Edit:
I did a little research, Seems Like V rated tires, so TourX must be governed to 149MPH or less. Plenty
https://www.tirerack.com/tires/tire...idewall=Blackwall&partnum=35VR8PCTX&tab=Sizes
The OEM Continental ProContact Tx tires are rated "meh", at best from reading the Tire Rack reviews.
Apparently the quieting belt inside the tires do not stay put.
I suggest replacing OEM tires with Extreme Contact Sports. They are soft and barely a Max Performance Summer tire, but it is an excellent high performance premium Grand Touring tire, perfect for the likes of the TourX. Extreme Contact Sports are a summer tire and will only last 30-35 thousand miles, but they will be happy miles.. Get snow tires for the winter.

 

[Rhetoric]

If you switch to KPH in the cluster HUD it changes the scale on the speedometer.

 

[VTSummit]

The Trifecta tune looks promising. The performance of the car is mediocre at best in stock form, but bumping it up 50-60hp would make it much more capable. The car we replaced with the Buick had a 315hp V6... it wasn't crazy fast or anything, but it always got the job done when we called upon Our Lady of Blessed Acceleration.

 

[L J]

I seriously doubt there's a lot more speed left in it simply based on the torque available and how the power required at those speeds increases exponentially. That wall of air is hard to push through. The aerodynamic drag is roughly proportional to the third power of the speed. I'm betting it would only get another 5-7mph over the limiter. More powerful cars with similar aerodynamics aren't good for a whole lot more because of the exponential requirements for power to overcome pushing a wall of air at high speed.
For example, in testing a car I used to race we had it topping out at 145mph which was enough for the tracks we used it on. A rule change allowed us to make changes that resulted in 40 more horsepower, which changed the top speed about 4mph. It wasn't limited by running out of available RPM, it just didn't have the power to go faster. When you see faster top speeds in the lower gears, that's telling you that it's about to run out of power- the engine has to remain in a more powerful portion of it's power curve.

You make it sound like it should not even do 155.
I doubt your race car had a 8 speed automatic with multiple overdrive gears and trq. converter.
You probably would not believe how fast my Quadrasteer E - forced 6.0 Sierra Denali will go, with tune to remove limiter, and speed rated tires.

 

[Lugen]

Saw roadtest specs for Car and driver online. They said top speed gov limited to 155mph. Surprisingly max speed in 6th and 7th was 155mph and in 8th 145mph.
If true GM allows speed above speed rating of stock tires. New tires I put on are W speed rated.
LJ

I only got mine up to 130. It didn’t have much more if any. Manual says it’s limited to 130.

 

[mike69440]

I only got mine up to 130. It didn’t have much more if any. Manual says it’s limited to 130.

I believe you. It is a long process and risky licence wise getting a car with 250 hp past 130MPH. 155 is a long way from 130mph. 130 is fast, faster is just bench race talk. I don't believe C&D actually achieve those speeds. They may have based those numbers on what a computer program spit out.
I doubt they rented the Milford Proving Grounds or the Pista di prova di Nardò della Fiat ring to verify those speeds or had the stupidity & balls to try that out in Nevada somewhere.
Note: No manufacturer in their right mind would sell a 155 mph car with 149 MPH tires.

 

[L J]

I had mine up to 125 and seemed like was not near WOT.
Car And Driver fake roadtest... tell me its not true!

 

[Bimmer]

I don't believe C&D actually achieve those speeds.

I believe they do...

How Does C/D Test Cars?

"Our Michigan testing is done at DaimlerChrysler's proving ground in Chelsea, about 15 miles west of Ann Arbor. We rent the facility's 1.6-mile concrete straightaway, an asphalt skidpad that measures 1000 by 900 feet, and the 4.7-mile banked oval."

A 4.7 mile banked oval would be enough to top out just about anything driven through the wheels...

 

[mike69440]

I'm not C&D, so I really don't know how they tested the TourX.
I have read other articles saying TourX is limited (governed) to 130mph.
How do you reconcile V rated tires (149MPH) on a car that can achieve 155mph?
That is why I questioned the 155mph. I suspect the aerodynamic TourX could hit 155 on a huge banked oval, ungoverned, as long as the LTG Turbo engine could stay together being into to max boost for the minutes it would take to achieve those speeds.