Twin Vortice Fun with a MINI

They say the best things in life are worth waiting for! That is the case for the TVS 900 supercharger using Eaton’s Twin Vortices technology.

Australian company Harrop Engineering broughttheir TVS 900 kit out in the second half of 2017. Itwas designed and manufactured by Harrop to OEstandards as a direct replacement for the EatonM45 Supercharger installed as standard in theR53 Mini Cooper S. The Harrop TVS900 utilisesthe latest generation Eaton TVS superchargertechnology including four lobe rotors (160 degreehelix) and revised inlet and outlet port geometry toachieve greater thermal and volumetric efficiency.Although designed as a direct replacement there is

a performance advantage as the TVS supercharger is larger. The original M45 is 45 cubic inches or 737.4cc, the TVS is 900cc or 54.9 cubic inches. With a standard Harrop 70mm pulley the TVS will work well on standard motor with an OEM DME. Reduced diameter pulleys or modified engines will require a tune and maybe larger injectors dependant on the motor spec.

My TVS arrived in a sturdy shipping box and was well packed. Harrop did a good job of coming up with a good shipping solution for that long trip from Australia, I like a company that thinks through the whole solution to getting their product safely to the customer. When Harrop calls this a TVS 900 supercharger kit, they are not kidding. Everything you need to change out your M45 to a TVS is here including the electric water pump conversion that is required. So no more issues with that troublesome PTO that drives the mechanical water pump on the M45. Harrop made full use of their access to the Adrad Group foundry to make their cast components. Harrop GM Heath Moore said, “Harrop makes use of their Harrop Casting Technologies foundry to manufacture their cast components “Being able to leverage our vertical integration allows us to have more control over our products and the quality control. Aluminum cast parts allow us to offer an OEM level of fit and function to the kit and importantly the durability demanded by our customers”

The kit also comes with all the hoses and fasteners required to install the TVS in the factory position in the R53. In fact if you were did not know there was a TVS on the car it would be hard tell what supercharger was installed it fits so well. When running only an expert ear can tell a TVS is fitted as it is actually quieter than the M45 originally installed. Some purists, myself included were supporters of the ‘Got Whine’ team and will lament the reduced whine but the trade off of more power will more

than compensate for it. Because of the design of the TVS supercharger the water pump can no longer be attached to the inboard side of the supercharger via a Power Take Off (PTO). Harrop’s solution to this is an electric water pump. As the original car’s pump is mechanical, Harrop had to come up with a solution to feed 12V power to the new electrical pump. To that end they include a small wiring harness with fuseholder in the kit.

You will notice from the photo below that there will no cursing and swearing and damaged knuckles if you decide to change a pulley on a Harrop TVS. It comes with a 70mm pulley as standard and can be reduced to as small as a 55mm. The pulley is held on by six bolts and is positioned to use the standard OEM belt path and tensioner.

So using a statement commonly used on the Internet, what are the numbers? Well that is like asking how long is a piece of string. MINI owners are well known for have their

own car personalized and that personalizing will make for various results as will the various dynos over the country. What I can say is those who have already fitted a Harrop TVS to their cars are having trouble stopping smiling. Californian Jim Ahl is one such soul, Ahl has a RMW 1800 stroker motor that he had Jan Brueggemann fit a Harrop TVS 900 kit to. You can see from the dyno graph below Jim’s motor made 301.7 whp and 228.6 lb/ft of torque. On Facebook Jim commented “I don’t

have any videos but putting the TVS on Jan’s 1800 block along with BVH, cam and header made a big difference. It pulls hard all the way to 7600. Lights it the tires in 1st 2nd. Love it.” I was lucky enough to have Mike Bradley in California offer me a competitive ride in his RMW engined, Harrop TVS 900 equiped R53 and give my butt dyno some experieince of the TVS. Right after Global Time Attacks Super Lap Battle at Buttonwillow last November I headed South to Fontana where a SCCA Autocross was running in a parking lot beside the kart track. The other racers were great, very welcoming and hoped I would enjoy my time with them. Did I say I soon had a grin on my face? Mike’s MINI for sure hauls the mail and I had a great time driving a car that was super responsive and really ripped on the straights. I have to thank Mike for the opportunity and would love to say I let the car owner win but those out West know Mike is a tough guy to beat when he is on form. His mother Sharon Malmen normally runs the car along with Mike and graciously gave up some seat time to allow me to experience the TVS 900 first hand. Thanks guys. Portugal’s Jony Bernardo loved the changes after he added his TVS, “I’m doing about 12 seconds 100 to 200km/h, before the TVS it was taking 14 seconds with the M45. Also something iIve noticed is that beyond 200km/h it’s still pushing instead of dragging with the M45.” Randy Smalley, the team principal of RSR Motorsport has lots of MINI experience considering he ran the last MINI team in the halcyon days of Grand Am racing. Randy and friends still have some of the cars and when he was looking for more power he fitted a RMW stroker motor and after a period of unsatisfaction with another supercharger he switched to a Harrop TVS. He told us, “Makes better boost... especially at hi RPMs. +/- 265 WHP. I think the quality of the cooling pump is much better too compared to the opposition. Money well spent for sure!” So what’s next? Cooper RSR is going in for a baseline dyno session soon and then we will be fitting the TVS. Looking forward to ‘Less Whine’