How fast could the TRX go without its speed-governor?

SorbSRT · May 8, 2021

Playing with this salt flat calculator —> http://www.wallaceracing.com/Calculate HP For Speed.php

Unsure if the frontal area of the TRX is correct but these numbers show a max speed between 150 and 155 is a reasonable assumption.

TRX vehicle Speed of 160 MPH takes 482.34 HP to overcome air drag. Rolling resistance is 37.44. Needing a total of 519.78 HP to run 160 MPH.

Boostedroofer · May 9, 2021

SorbSRT said:
Playing with this salt flat calculator —> http://www.wallaceracing.com/Calculate HP For Speed.php

Unsure if the frontal area of the TRX is correct but these numbers show a max speed between 150 and 155 is a reasonable assumption.

TRX vehicle Speed of 160 MPH takes 482.34 HP to overcome air drag. Rolling resistance is 37.44. Needing a total of 519.78 HP to run 160 MPH.

View attachment 12667

Yet the 1klb lighter trackhawk is electronically limited at 180....

Having seen the video of the 0-130 sprint by Dusterhoff.....

There was alot left to go much faster than 150.

TRX_tuned214 · May 9, 2021

I hit 135 and it had a lot of room to go. Back roads in Texas.

Boostedroofer · May 9, 2021

TRX_tuned214 said:
I hit 135 and it had a lot of room to go. Back roads in Texas.

Mind listing what you've done to it so far such as who tuned it and pulley/injector size...

Also miles driven while upgraded.

TRX_tuned214 · May 9, 2021

Boostedroofer said:
Mind listing what you've done to it so far such as who tuned it and pulley/injector size...

Also miles driven while upgraded.

Bailey’s in Fort Worth. I’ve got 2k miles. Not sure on exact specs. Pushing 720whp

thewrx · May 9, 2021

well its settled then, your right.

Would you mind telling me exactly how speed ratings are calculated for passenger auto/truck tires?

SorbSRT · May 9, 2021

Boostedroofer said:
Yet the 1klb lighter trackhawk is electronically limited at 180....

Having seen the video of the 0-130 sprint by Dusterhoff.....

There was alot left to go much faster than 150.

Aerodynamics have everything to do with rolling resistance. You can take a look at what Jeep did here —> https://www.whichcar.com.au/news/2019-jeep-grand-cherokee-trackhawk-suv-speed-record-on-ice with a stock Trackhawk. Jeep got to 173 MPH. Hennessy made it to 175 MPH with a stock Trackhawk on a 2.5 mile straight. So, it may be limited to 180 by the factory but in reality, it needs more aero or HP to get it over that mark.

Boostedroofer · May 9, 2021

SorbSRT said:
Aerodynamics have everything to do with rolling resistance. You can take a look at what Jeep did here —> https://www.whichcar.com.au/news/2019-jeep-grand-cherokee-trackhawk-suv-speed-record-on-ice with a stock Trackhawk. Jeep got to 173 MPH. Hennessy made it to 175 MPH with a stock Trackhawk on a 2.5 mile straight. So, it may be limited to 180 by the factory but in reality, it needs more aero or HP to get it over that mark.

No it needs different gearing. You can gear a John Deere Tractor to go 100mph with the right gears..... it's been done.

Not saying Aero doesn't have a factor, I'm just saying you're missing a major component.... gearing and tire height.

The trackhawk has a 3.70 rear end with a 30.5" tire and the TRX has a 3.55 with a truly 34.5" tire.

Based on the real world data it all technical reasoning the TRX could realistically surpass the Trackhawk..... the Trackhawk per the math runs out of gearing at its rpm limiter while the TRX achieves the exact same speeds at 5800-5900RPM which leave plenty of top end to spare.

TRX

Trackhawk

SorbSRT · May 9, 2021

Boostedroofer said:
No it needs different gearing. You can gear a John Deere Tractor to go 100mph with the right gears..... it's been done.

Not saying Aero doesn't have a factor, I'm just saying you're missing a major component.... gearing and tire height.

The trackhawk has a 3.70 rear end with a 30.5" tire and the TRX has a 3.55 with a truly 34.5" tire.

Based on the real world data it all technical reasoning the TRX could realistically surpass the Trackhawk..... the Trackhawk per the math runs out of gearing at its rpm limiter while the TRX achieves the exact same speeds at 5800-5900RPM which leave plenty of top end to spare.

TRX

View attachment 12676

Trackhawk

View attachment 12677

Lol, now that’s funny…

Boostedroofer · May 9, 2021

SorbSRT said:
Lol, now that’s funny…

No that's facts. How is it you're not understanding this?

Bambi · May 9, 2021

I’m just here to watch another redneck vs engineer fight

The TH must generate far less lift than the trx. I will give you with a gearing change the TRX may hit 170+ but it may turn into;

SorbSRT · May 9, 2021

Bambi said:
I’m just here to watch another redneck vs engineer fight

The TH must generate far less lift than the trx. I will give you with a gearing change the TRX may hit 170+ but it may turn into;

It’s also nice to know that Formula 1 racing has it all wrong. They should scrap those aero cars immediately and switch to TRX’s and Raptors. Just throw a set of gears in them and you’re winning championships.

Man, think about all that R&D money wasted on wind tunnels and horse power. Heck, if all I ever needed was a lawn mower Briggs and Stratton and a go-Kart, with the right set of gears, I could’ve been a world famous international race champion!

Boostedroofer · May 9, 2021

Bambi said:
I’m just here to watch another redneck vs engineer fight

The TH must generate far less lift than the trx. I will give you with a gearing change the TRX may hit 170+ but it may turn into;

There's no need tonch change the TRX gears.... the foundation to achieve it is already there along with ability to walk the Trackhawk.

You lower the TRX and put 33s on it and it still would stomp the Trackhawks feathers in the dirt.

Neither the Grand Cherokee or the TRX are designed to be aerodynamic, nor are either of them 2500-3500lb cars that are prone to high speed launch control.

His data is incomplete, that's al that was pointed out.

Shall we start the which is more important....

Horsepower or torque debate now.... that's gonna be the most fun!?

Boostedroofer · May 9, 2021

SorbSRT said:
It’s also nice to know that Formula 1 racing has it all wrong. They should scrap those aero cars immediately and switch to TRX’s and Raptors. Just throw a set of gears in them and you’re winning championships.

Man, think about all that R&D money wasted on wind tunnels and horse power. Heck, if all I ever needed was a lawn mower Briggs and Stratton and a go-Kart, with the right set of gears, I could’ve been a world famous international race champion!

Dude. You're #s are as off as a Chinese Astophysicist.....

We're talking top speed, not the rate of time to get there.

Hints Aero is about drag reduction to achieve maximal speed in short period of time.

Just saying.

Boostedroofer · May 9, 2021

Now to your point about drag....

The wide Body chargers and rams are slower than the narrow bodies by a 4-6mph top speed.

The charger hellcat wide body needed 10 extra HP to achieve the 203hp it did, while the narrow body gets to 206mph with the standard 707hp.

3.5"s additional drag on a 4700lbish car.....

Now shall we discuss the amount of Chargers or Challengers that went airborne? You won't find many since they're fucking heavy pigs.

Aeor for supercars is a must due to lift as result of lighter weight. Splitters/ diffusers/ and spoilers only purpose is to guide air and create down force..... issues 5k-6k-7k-8k lb Suv/Trucks don't have.

Bambi · May 9, 2021

Boostedroofer said:
We're talking top speed, not the rate of time to get there.

Hints Aero is about drag reduction to achieve maximal speed in short period of time.

Just saying.

Sorry dude but this is just incorrect. Why aren’t the salt flats top speed cars shaped like a brick? Because the faster you go the more hp you need to overcome air resistance.

Boostedroofer · May 9, 2021

Bambi said:
Sorry dude but this is just incorrect. Why aren’t the salt flats top speed cars shaped like a brick? Because the faster you go the more hp you need to overcome air resistance.

Yes, but the problem is as long as RPMs are available speed will still build.

I'll just leave this here to blow the brains of the super scientists around here.....

Factory 400hp laramie.... tops at 121mph....with smaller tires and less available rpms. 2000 less as matter of fact.

Further proving my point.

04Ram2500Hemi · May 9, 2021

Bambi said:
I’m just here to watch another redneck vs engineer fight

Now that’s funny!

Bambi · May 9, 2021

Boostedroofer said:
Yes, but the problem is as long as RPMs are available speed will still build.

I'll just leave this here to blow the brains of the super scientists around here.....

Factory 400hp laramie.... tops at 121mph....with smaller tires and less available rpms. 2000 less as matter of fact.

Further proving my point.

Air resistance doesn’t really become the limiting factor until over 150. I went 116 in a diesel jeep gc. Doesn’t prove much

Two · May 9, 2021

I'm still trying to figure out how the weight of the vehicle has anything to do with the top speed.
Until now I thought it was all about aerodynamics and power.

If weight matters, those salt flat guys have it wrong, since their cars are generally quite heavy.