Steve Dinan is one of America’s most legendary tuners, having established himself as a builder of ridiculously fast and reliable BMWs. He’s since sold his company, did a stint with an endurance team, and is now back with CarBahn Autoworks. Steve brings his 900bhp BMW M8 down to Rob’s shop and gives him a chance to experience how to gain big power without losing reliability and comfort.
They say you should never meet your heroes but if meeting them is bad then inviting them back to your shop and seeing all your project cars has to be worse fortunately i love making bad decisions steve dinan is america’s most successful bmw tuner his cars were powerful refined and reliable he took a break from building cars to dedicate himself full time to racing
But he’s back with a new company called carbon auto works he’s one of my heroes and for some reason he agreed to show me how he puts together cars it is an absolute honor to have you here at my shop i’ve known of your name and your brand for a long time and it’s been an inspiration even though this isn’t exactly european yeah i will say there’s one anchor point
That we can relate on and it’s that’s from a bmw yeah i recognize that so it’s an all-wheel drive then yes and you mentioned briefly that you did actually touch rotaries at one point i did i also used to work on rotaries i worked at a place called the mazda works in campbell california in 1977-1978 wow and they also worked on bmws as a sideline they mostly worked
On rotaries and i fell in love with the bmws and i quit my job and started dining okay so that’s how i got introduced into bmw’s in a mazda shop the rotaries were so bad you’re like no i’m like over people no i mean they were cool it’s just that i love the refinement of the bmw and that’s kind of what i’m all about i mean i i’m the kind of guy that likes look
I build a race car i buy a factory race car and i go the racetrack and i erase it but for my tuner street cars i like them to be nice cars yeah i want to get them every day and have them start and pass a smog test and idle and be comfortable and have the air conditioner work and all that kind of stuff yeah so what i want to show you is this car here and there’s
There’s a reason why this is this takes a a lot for me to admit this is a thousand horsepower three rotor rx7 this is what kind of got me where i am now yeah so i’ve been known for taking this car on the street and in michigan it’s basically the streetcar how do you get traction with it that’s my that’s a you know what i never knew that too much power is actually
A big problem oh yeah and so that was actually what really fascinated me is that you mentioned you brought something yeah and it’s an actual street car but it also makes basically the same amount of horsepower i want a street car that’s as refined and nice as the stock car just 25 to 50 faster something i can drive every day but has no compromises of durability
Or drivability or emissions or anything it’s 900 flywheel horsepower so it’s less than you know it’s probably 150 or 200 less than this thing yeah but it’s also got all the cal inverters on it does that on pump gas the bmw m8 competition puts out over 600 horsepower stock adding power to a big luxury car like that risks subtracting refinement and day-to-day
Usability but carbon’s promise is that you can eat your cake and have it too obviously we already established this is a very comfortable car it’s like a luxury car yes you’ll be shots at the racetrack how quick the car is now well handles forgiven how nice it is yeah and one of the arts to that is people have a tendency to lower the car too much and then bottom
Out against the bump rubbers right and the bump rubbers are integral part of a suspension system that most tuners just don’t completely understand and we tune them a lot in race cars but how they’re supposed to be dude is we’re driving on the road like this the bumpers don’t touch i believe that that makes okay and then that rides really nice but then when you
Roll the car into a corner the bump rubber engages and it’s a progressive spring and you can double the spring rate you’re using the bump rover as a progressive spring oh my god that way it supports the car in the corner to make it stiff but when you’re driving in a straight line down the highway it still rides nice most people think they’re a crash barrier we
Have to use the bumper as a tuning tool that’s amazing i never have never thought about that you have to change the shape of the bumper and the durometer of the rubber and tune it for the travel that you have that’s a lot of work we have a shock dyno you ever seen yeah yeah okay we put the spring rivers on the shock dyno and we measure the force on it and the
Hysteresis one of my arts on both race cars and street cars is making really good handling cars that also ride really nice and race car terms that’s mostly means just taking bumps well yeah so i might be over simplifying but does that mean if accounting for the bump stop you could use a slightly softer spring yep yeah yeah and then it sinks into the bump rubber
And that way on the low speed corners the car soft so it breaks and puts down power yeah and then the high speed corner to get support from the bump rubber and you get your cake and eat it too yeah so on the engine all we did was uh really big intercoolers really big heat exchangers to get rid of it and software with a lot of boost and it went up 220 horsepower
And it makes 800 and almost 890 horsepower this is such a smooth car for everything you’ve modified so i’ve seen this car on the street i could i could almost fall asleep in the past you see how soft and comfortable it is but yet this can also go to the racetrack and that’s that’s something i want to experience yeah i think it’s going to be pretty quick on the
Racetrack too i think you’d be surprised well it’s a little different than the streets we were just on but we are out at willow springs a great place to really let this thing unwind and i really would love to see more about what’s under the hood it’s a 4.4 liter twin turbo v8 with a hot v from bmw and it comes with just over 600 horsepower all right and we
Added uh larger intercoolers to the engine and then two really large additional heat exchangers to get rid of the heat in the intercourse because the biggest problem is when you make a lot of power with a turbo it makes more heat and that robs the power well i felt it yesterday when we were getting out of the car i could feel the heat being pulled out of the car
Oh yeah that was that was impressive it has a huge electric fan in the front that pulls air through and even stays on after it shuts the car off to take the heat soak out of it well you know what i’m surprised you don’t have a laptop in the passenger seat but that’s because of my background that i’m always tuning and driving yeah but in your case this is just
Wrapped up good to go yeah this car hasn’t had a computer plugged into it over a year we built a computer with adaptation ranges where the computer has the ability to learn based on the fuel quality so you can put pump gas in it makes eight and a quarter you put race gas in it makes 8.90 but method makes nine and a quarter it doesn’t require any software changes
That’s awesome well you know what that means to me that means i can just jump in and go just jump in and go have to worry about it okay i’m gonna take you up on that all right let’s do it kind of funny because i i’m wearing a helmet and it’s for safety but i i don’t it’s it’s not that type of car oh my god all of this is just very untouched steve was
Really selling me on the suspension and the things he’s done to upgrade it and i am blown away this is one of my first times ever driving this course and i feel not overconfident i just feel like i am listening i can feel i can hear the road the car’s talking to me it’s not like a fat car even though it is like all this elevation change all these tight turns
And this car is meant for like grand touring it’s a big car and yet here we are maneuvering a very small track with ease i don’t feel like that like lumbering body roll of the car i just feel the the suspension doing what it’s supposed to do i have a theory about mankind is that i think that almost every great thing we ever did we really didn’t understand how
Hard it was if we really would have understood all the pitfalls and all the you know danger of it we probably would never start but i think it’s our our naivete is kind of our saving grace as far as feeding our creativity but because he’s into it now he’ll see it through and he’ll learn a ton and that’s a good thing and that’s you know i think that’s what makes
Us people honestly if it’s not obvious throughout this entire episode i am geeking out with steve like that is an honor to be able to speak to not just a legend because you hear that he’s really smart and knows all these things but to have him engage and show me what sort of knowledge and experience he brings to the table it’s awesome to have you guys watch
These episodes but for me i get the benefit i get to become a better tuner seeing what the sort of focus that steve has on this car and this handling of suspension i am i’m flabbergasted there’s like there’s there’s a straightaway up there but i was like i don’t want to do this straightaway i want to just i hooked this thing back and forth because it was just
Like so planted yeah yeah it what i felt was not what i see no it defies logic because it’s so big and everything yeah and that’s why i said this this small tight course actually showcased one of the things that i want people to know is okay big horsepower numbers i can make big horsepower numbers but refined like that that is that is the the secret sauce to
Your your formula is how refined it is to handle that power yeah so that’s what i think i think this it would have broken the car if if it was any less of a car glad you liked it well steve i can’t thank you enough for letting me drive the car yeah i appreciate it anytime if you want to come up and look at the race car and go over some stuff on your car i’m
Happy to help you with that i will take you up on that offer thank you so much you
Transcribed from video
Driving A 900bhp BMW M8 Competition Tuned By Steve Dinan | Top Gear American Tuned ft. Rob Dahm By Top Gear