I think RMW sells something resembling a kit for the R53, but it'll be a custom setup. And no, due to the design of the Sprintex, it's a nice OEM replacement / mild upgrade, but it doesn't have it to get 300whp. It's essentially the same thing with a 4-rotor screw instead of a 3-rotor. Bit more efficient, but still not going to push the air volumes needed for big power.

Again, if you're looking for 400, build the bottom end, port the head heavily w/ appropriate cam, and put an appropriately-sized snail on it. The sizes of the blowers available make SC options lower on power by design. Big V8's make good power w/ blowers because the blower itself has 40% more displacement than our entire engines do. A 6L motor w/ a 2.6L blower is going to make some good power. However even there, slap a giant snail on there and watch power output double up top.

 

Yes, I agree.

 

 

Like everyone has been saying.........it takes a lot of money, and an lot of know-how to get 300hp to the wheels on these cars..and it's going to involve a custom turbo setup. There is no easy bolt on anything that will get you there. I think I saw somewhere that a stock motor with a Sprintex is still only in the 220-225 hp range. IF you are seriously wanting to do this.....call some of the guys like Jan from RMW, or Way from WMW....they will tell you exactly what it's going to take. Some of the BEST guys in the world are squeezing 400-ish hp out of them....and these are guys that get paid to race them, on the race track. These are not daily drivers.

Can you get 300hp out of a mini? Sure......but it's just not worth the money, that's why they are so rare (like unicorn rare). The "Race" motors most companies sell put down 250hp to the wheels.....and I'm sure those motors aren't what you would call street able. They are $9,000-ish.

You still haven't told anyone how much money you have to spend on this "project". If you don't have $30,000 setting around in a bank account........this is all just a pipe dream.

 

Attainable and sensible are two different things. Additionally, you'll be increasing wear rather significantly beyond designed parameters on your new Sprintex, so you'll just wind up with reliability issues there as well.

On a different note, any of these options get you an electric WP, so that's cool at least.

But no, I wouldn't spend 10k just to have a Sprintex car at 300hp. 10k, spent "sensibly" (laughable, that concept applied here) on the Mini for the purposes of power, and not requiring staying within a particular race class, I would put a Garret or Precision Turbo snail on it with a front mount. Little bit of porting and smoothing on the intake side, lots of porting on the exhaust side. Sleeve the bottom end, forged rods, pistons, crank. Increase head bolt diameter and helicoil block. Bump compression to 9.0:1, megasquirt ECU, and see what the head can flow. That will be the limitation on these. Lightweight valves, dual rate springs, fat turbo cam, and with a built bottom end you'll see probably 8k RPM safely, and that'll allow you to spec out a turbo based on flow rates of the head. Now you're more realistically looking at 350whp.

Cool, so now you've got 350whp, and your diff ate itself. OS Giken time! $1560 is the cheapest I've found. Don't bother with a Quaife at this % power over stock. They're great in street cars - I've had em in VWs - but they're not up to the task of REALLY beating on it. Okay, diff sorted, and now the axles are breaking on you. You can leave them the weak point, or upgrade, and now it'll be the transmission input shaft that fails...

Maybe the BMW setups here are better, but that's been my experience with other German cars.

 

Yep ....all good points. When you put 300+ hp to a drivetrain that was designed to handle 175hp....things aren't going to last. That's why I said you had better have $30k in the bank......after you put a small fortune into getting the motor built....now get ready to buy a beefier transmission, clutch, LSD, axles, etc, etc......big money.

You are money ahead to buy any older LS powered car for $10k...put a single turbo kit on it ...and Bam....600+hp of streetable pump gas power

 

This is all very good info and i greatly appreciate it... i will definitely get in contact with some of these guys and chat more in depth... Thank You all

 

Bingo

 

As a reference, a true 250 WHP Mini will surprise many people, can be completely reliable, plus it can be attained without doing internals, as long as the motor is in good general health.
But it will require a BVH and all the other ancillary bolt on's and tune.

No, with or without internals, the best you'll see with a Sprintex is 275 WHP "ish", and that's with W/M, only way to get more with a Sprintex, would be Nitrous.

The TVS may get you to 300-325 WHP, but there still aren't that many and there just isn't any data on longevity and reliability since the kits are relatively new.

And stay away from the Rotrex, the kits aren't really kits and tuning basically has the same challenges as a turbo conversion, it's all about the linearity of the boost compared to the S/C, if you have to or want to keep the factory ECU. You'll have as much or more into a Rotrex build as you will a turbo conversion, and still have to deal with having a belt driven system.

The most reliable and cost effective way to be at 300+ WHP is a turbo conversion, you can get right around 300 WHP with stock internals since the difference in parasitic loss compared to the S/C will allow you to get there on 17-18 PSI with all the rest of the supporting mods. (Head, Cam, all the rest of the usual cast).
​​​​​More than that, and internals will be required to accommodate the extra boost to keep it reliable.

As for the drivetrain, a clutch will definitely be required, and some kind of LSD will be an absolute must for traction, and the factory parts will handle 400 WHP.

But....

Only on street tires, anything stickier and yes, you'll start breaking axles first, then diffs.
Also, anything over 375-400 WHP, will require either a very wide "good" tire or something really sticky, if you want it to actually be useable on the street, and not just a dyno queen. These cars just don't weigh enough to get usable traction on stock, or slightly oversized rubber, with the FWD in the lower 3 gears, and really big HP. I'm only at 330 WHP, and still break traction in 2nd at 5000 RPM and up, and that's with my heavy a$$ R52, and decent 215/45/17's
​​​​​
At least this is what I've found from doing most of the things you've discussed.

Honestly, if you're not afraid of nitrous and use it properly, it is the cheapest way to see 300 WHP.
Keep the M45, do all the other bolt on mods including BVH, and spray it with a 75-100 wet shot.

Just do it once you've decided you're gong to rebuild the motor anyway, this way if there is a mishap, it won't really matter that much.