2026 Mustang RTR Spec 5 intro & drive by Misha Charoudin

[LouG]

So it looks like Whipple makes the pulleys in all sorts of different sizes. Stage 1 kit is 3.875" and folks looking to crank up the boost have been using 3.5", but they make 4" and even larger.

Like this one:

4.5"

https://whipplesuperchargers.com/i-2226-6-rib-4-bolt-pulley-4-5-black-scp-64500-4.html

(picture says 4.000" but the link is to the 4.5")

There is a 4", a 4.25", a 4.5"

It seems like this might be a solution to tracking a car with a Whipple.

And run it on E85 for extra cooling

And look into better intercoolers and pumps . . .

I know the Forced Induction Interchiller is great for drag strip and street, but they do not recommend it for track.



Anyway, I am guessing you can probably push more than 650 horsepower and keep temperatures stable with the Dark Horse cooling . . .

Man, I have new stuff to think about now . . .


<--- Me, thinking.

There's always water/methanol injection too. I ran it upstream of a Sebring (roots) blower, because I didn't have an intercooler, for several years without an issue.

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[Junkyard Dog]

There's always water/methanol injection too. I ran it upstream of a Sebring (roots) blower, because I didn't have an intercooler, for several years without an issue.

I think Misha would have mentioned that were they using it. Instead, he clearly said they "detuned" the Mustang to 650 horsepower, see around 25 minutes 15 seconds in the YouTube video.

Hopefully @RTR Vehicles knows what they did and will chime in with more information.

 

[Katastrophe]

I think Misha would have mentioned that were they using it. Instead, he clearly said they "detuned" the Mustang to 650 horsepower, see around 25 minutes 15 seconds in the YouTube video.

Hopefully @RTR Vehicles knows what they did and will chime in with more information.

He mentions 650 at the wheels, btw. Not a far cry from the advertised 800+ at the engine.

EDIT: He mentions this at 25:10 of the original posted video. No specifics are given, though...pulley swap and tune perhaps?

 

[Katastrophe]

Also:

NEAR CRASH & BANNED: 800hp+ Mustang RTR Spec 5 // Nürburgring - YouTube

 

[MidwayJ]

Also:

NEAR CRASH & BANNED: 800hp+ Mustang RTR Spec 5 // Nürburgring - YouTube

He was holding up the M3 camera car behind him.

 

[LouG]

I think Misha would have mentioned that were they using it. Instead, he clearly said they "detuned" the Mustang to 650 horsepower, see around 25 minutes 15 seconds in the YouTube video.

Hopefully @RTR Vehicles knows what they did and will chime in with more information.

I didn't mean they were using it. Just that it is another alternative charge cooling option that does tend to lower combustion chamber temps too. It also gave me 1 psi boost increase through denser air/fuel mix.
Thousands of WW2 piston engines can't be wrong

 

[broncoboy22]

I think Misha would have mentioned that were they using it. Instead, he clearly said they "detuned" the Mustang to 650 horsepower, see around 25 minutes 15 seconds in the YouTube video.

Hopefully @RTR Vehicles knows what they did and will chime in with more information.

In this post he mentions 670whp

 

[Junkyard Dog]

In this post he mentions 670whp

Yeah, different figures.

RTR, according to its web site, sells the car with 870 (flywheel). RTR is, of course, simply passing on what Whipple advertises their Stage 2 kit to deliver. Stage 2 is a 3.75" pulley. That delivers 12 psi.

But 870 horsepower, if that is truly what the Whipple Stage 2 kit delivers at the flywheel, is not 200 horsepower less at the wheels, to deliver 670 horsepower (much less 650, as he said at the track in Czechoslovakia, 220 horsepower less).

Even at 670 horsepower, that would be a driveline loss of 23%. So they did something to lower it.

Besides, he keeps mentioning "down tuning" and "we have decided, on purpose, to lower the power"

How ?

A 4 inch pulley delivers 2 psi less, but had he done that, I should think he would say that - it is pretty simple to mention a pulley swap.

He clearly links the lowered horsepower to an overheating cure in both videos. It would be helpful to the rest of us to learn what it is that they did. There are no signs of overheating in either video. Indeed, the temperature gauge stays rock solid at about 195 degrees, an almost impossible to believe figure (90° Celsius).



UPDATE: at 27:15 in the second video linked by Katastrophe in Post # 19, the RTR/Unitesta built by plate shows 820 horsepower and 880 Nm, which sounds more like Stage 1 and 3.875 pulley.

 

[Junkyard Dog]

I hope he gets the issues with fuel and brakes sorted so we can get a video where he pushes the Mustang. He was driving gingerly in that Nurburgring video.

I also hate it that they changed the track so we do not get that long top speed run at the end. That was always a fun part of the older videos, seeing some very fast cars hit their top speed for several seconds.

 

[LouG]

I hope he gets the issues with fuel and brakes sorted so we can get a video where he pushes the Mustang. He was driving gingerly in that Nurburgring video.

I also hate it that they changed the track so we do not get that long top speed run at the end. That was always a fun part of the older videos, seeing some very fast cars hit their top speed for several seconds.

I think that's for track days now. I see they've put movable track pass barriers on track for Touristenfhartenen (?), must be getting a lot of punters.

 

[Junkyard Dog]

Misha actually responded to me within minutes (surprised), but he asked me to reach out to Unitesta.

Hopefully, Unitesta responds.

It would be nice to figure out how to keep a Whippled Mustang reasonably cool on track.

 

[RTR Vehicles]

I think Misha would have mentioned that were they using it. Instead, he clearly said they "detuned" the Mustang to 650 horsepower, see around 25 minutes 15 seconds in the YouTube video.

Hopefully @RTR Vehicles knows what they did and will chime in with more information.

Hey guys, glad you’re liking the project. We’re fired up to keep pushing it forward. The EU-spec Mustangs naturally make a bit less power than the US cars, mostly because of the additional emissions equipment like the GPF. The power level we’re running leaves some room for the knock sensor to do its job under hard driving, which is exactly where we want to be for this first EU-spec Mustang with real racing duties.


We’re learning a ton in this first iteration and doing a lot of logging. The plan is to keep evolving this Spec 5-TA program with Misha as we go, and with that evolution will come more power.

 

[Junkyard Dog]

Misha actually responded to me within minutes (surprised), but he asked me to reach out to Unitesta.

Hopefully, Unitesta responds.

It would be nice to figure out how to keep a Whippled Mustang reasonably cool on track.

No response yet from Unitesta. The email is written in English, though.

 

[DH401]

So it looks like Whipple makes the pulleys in all sorts of different sizes. Stage 1 kit is 3.875" and folks looking to crank up the boost have been using 3.5", but they make 4" and even larger.

Like this one:

4.5"

https://whipplesuperchargers.com/i-2226-6-rib-4-bolt-pulley-4-5-black-scp-64500-4.html

(picture says 4.000" but the link is to the 4.5")

There is a 4", a 4.25", a 4.5"

It seems like this might be a solution to tracking a car with a Whipple.

And run it on E85 for extra cooling

And look into better intercoolers and pumps . . .

I know the Forced Induction Interchiller is great for drag strip and street, but they do not recommend it for track.



Anyway, I am guessing you can probably push more than 650 horsepower and keep temperatures stable with the Dark Horse cooling . . .

Man, I have new stuff to think about now . . .


<--- Me, thinking.

Really not much different than a GT500, whipple’s have better cooling than a GT500 blower as well and there are lots of GT500s at the track having no issues with getting too hot. I had the privilege of being able to drive my fathers GT500 a few times on track and while the power is pretty addicting I find myself being significantly more tame exiting corners than I do in my Dark Horse. Being lucky enough to have experienced both I wouldn’t consider a whipple for my car when it is solely a road course car not for the foreseeable future anyways. I am 93 tuned by PBD with Kooks catless headers and stock besides that and while I am still not the fastest car on the front or back straight I am not too far behind say a 992 GT3RS or comparable level of car.

 

[Junkyard Dog]

93 tuned by PBD with Kooks catless headers and stock besides that and while I am still not the fastest car on the front or back straight I am not too far behind say a 992 GT3RS

I have my doubts about how well you can keep up with a 992 GT3RS on the straight.

The GT3RS is a full second less in the quarter mile and approximately 10 mph faster, as compared to a Dark Horse.

If headers and a Palm Beach Dyno tune on 93 octane pump gasoline could pick up that kind of acceleration, Kooks would not be able to keep S650 headers in stock, and PBD would be stuck in long term back order from a tsunami of consumer demand.

Modern GT3RS owners complain about the increased weight of the 992 platform, lol , at 3268 lbs.

Our two ton track barges can only dream of being so svelte . . .

It takes a lot of horsepower to make up for an extra 730 pounds of fat . . .

And the GT3RS starts out with more horsepower . . .

You are a great source of information here (and I mean that), but I think you have a perception problem when trying to keep up with a rival's Porsche on the track . . .

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