BBi Autosport’s Ultimate Porsche 993, Modding the Last of the Air Cooled Era Porsches

The Porsche 993 variant of the iconic 911 is perhaps one of the most significant of all the 911 models. It was in many ways a game-changing model that incorporated many of the design features still found on 911’s to this day.  It is also the last of the air-cooled Porsche models. The 993 is both the last of the legendary air-cooled 911s and a bridge to the newer technically advanced models. The 993 is also considered by many to be the best looking of all 911s. These things have made the 993 a desirable model for collectors and Porsche aficionados.  Leave it to our friends at BBi Autosport to build the what we think is a mind-blowing, game-changing retro modern build of a road going 993 that combines and functionally integrates state of the art parts straight out of a modern GT race car.

We were lucky enough to get to look at the while it was under construction and will do a full write-up and feature on it when it is completed.

BBi started with a 993 C2. The shell of the car was stripped to the bare unibody and media blasted.  At this point, BBi seam welded the unibody and built a streetable but inclusive cage to provide a better level of protection to the driver and to stiffen the chassis to close to modern 911 levels. The cage was designed to be as unobtrusive as possible but still, give rollover protection. The unibody and body panels were then painted a flawless silver.

The hood and decklid are carbon fiber and the rear decklid has a duckbill spoiler to give homage to the older RS models of the 911. Here the huge wheels and tires are being dummied up to see how the RWB body kit will fit and if the wheel and tire fitment will clear everything.

The BBi Autosport 993 has been partially assembled to have one of the famous Japanese RWB or Rauh-Welt Begriff aero kits installed. There is an air of exclusivity to have one of these kits, each RWB kit is handmade by Nakai-San with a waiting list of over a year. When your kit is ready, Nakai-San personally flies over to a prior agreed upon place to install the kit with an entourage and a lot of fanfare. The car has to be ready to Nakai San’s requirements for him to work on it.  The body and paint must be complete, the aero kit must be painted to his spec.  The suspension, other bodywork, wheels, and tires must be on the car and ready. The whole thing plus entourage seems like a lot of hype for us but its all part of the RWB experience if you are into that sort of thing.

The 993 911 was the first 911 to use a multi-link rear suspension and an alloy rear subframe to hold the engine and suspension as a unit. The multilink suspension was designed to provide better camber control for more grip and to provide dynamic toe in.  Both of these features were used to get away from the traditional 911 semi-trailing arm rear suspension with its strong tendency to give trailing throttle oversteer. The new rear suspension was a revolutionary change that vastly improved how the 911 handled.  Having the engine and suspension on a separately isolated subframe allowed Porsche to use stiffer suspension bushing and motor mounts without increasing NVH.

56 comments

  1. I guess I’m old and uncool too – not that I dislike the look of the RWB kit, but they always seemed like relatively simple flares. Like, it reminds me of the ZG flares that have been applied to everything under the sun, with an extra step of tailoring to fit body lines.

    Also, I know it’s getting into showcar cred and all, but I can’t help but find pushrod actuated rear coilovers in tandem with front struts to be a little funny. A lot of nice details and parts selection though; the whole thing looks really well done.

  2. If the wheel rate is weird at the rockers, then it’s hard to balance the car. BBi paid proper attention to this area.

    1. Sure, like you commented, from scientific squinting at pictures it looks like the rocker ratio was probably done right. I just am questioning how much rockers add to things vs just a coilover in the same place. It doesn’t look like there’s any space limitations, and it’s not like it’s hanging out in aerodynamically critical areas like it would be on a prototype or formula car…

      1. It was plotted on CAD if you can’t take my word on it. However, I can see these things, its one of the reasons why I am pretty good at this stuff! I do agree, this is done more for car crafting than a performance improvement but unlike most sedan rocker arm suspensions, it’s not a decrease in performance.

        1. I do believe you – I was trying to joke that the only way I could independently determine was by squinting at pictures, which as everyone on the internet knows is foolproof and always right.

        2. I Would say the only real reasoning for doing it on a road car is:
          1. You want as little as possible unsprung mass (which means you must be very critical of the weight of the components your using to replace the o.e. setup with.
          2. You want to alter suspension stiffness and damping by shortening or elongating the triangle without having to buy a different spring all the time.

          Other then that: It’s just done for the cool factor.

          Speaking of Cool factor: Nakai-San. Yes the kit looks cool, but I also don’t understand what the fuss is all about? Then again, I’m not a limelight kind of guy. But then again: From an economical standpoint it probably isn’t a bad decision on Nakai-san’s part….

          1. Hey if he can make more money this way more power to him! The entourage thing is probably a hipster fanboi thing, probably not his doing as that is un Japanese to call that much attention on oneself.

          2. Oh right, so his entourage isn’t affiliated with him in the litteral sence, but just following him around filming/taking pictures? That would suck? If I where him, I would probably beat them. Marketing be damned!

          3. Brrrr, just found out: Self tapping screws???? Just had the pleasure of working on one. But damn, they are actually much worse in person….

          4. I seriously do not want to know what you pay for the work and the parts. Screws are just sticking out the metal on the other side. Not everything is as straight as you want it to be. There is no real finishing underneath it all? In all honesty I’ve seen better amateur projects. I would honestly just buy the parts if that was an option. Because the two I saw where rusting on the panel the sawsall was put to use on. Thats just sad. The panels where just left as is, where I would have least taken the time to cut whole panel to match the overfender. The seams on the inside where left completely open, so dirt can get inside. leading to problems in the future. It isn’t exactly California out here.

            It are just cars where the following applies: Pretty from afar, but far from pretty. And i’ve driven better standard Porsches then that one when it comes to road holding.Mostly down to the extreme offset rims. For that amount of money you have to expect something decent. Thats RUF territory, and their work is excellent bar none.

            I kind of feel sad for the owners in a way.

          5. I have heard the same things, raw metal left to corrode, simple sheet metal screws, open unibody. This is from people who know cars looking at the work afterward. Many of these cars are simply slammed on the ground without proper suspension work. The stance crew for Porsche.

          6. Yep, you could say that for sure, that they are for the stanced crew. Some demon camber at it and all done. This isn’t race derived by any means: Look at the canards for example. with that acute of an angle it’s doomed to fail.

            It is good for the price of those porsches though: In a couple of years those are just clapped out and rusted out Porsches again. Hopefully prices will be dropping. Because in essence they are nice cars and you could do heaps of nice things with them.

            I like the style in a sense, but not the execution.

  3. It warms my icy little heart that you guys are as baffled by the RWB experience as I am. As phenomenal as this build will undoubtedly be, I’d love to see this sort of time and effort spent under stock bodywork.

  4. If this Porsche is raced regularly, I forsee it chewing up front tie rods like candies with those tires!
    It’s a very cool looking car nonetheless.

  5. I apologize, I’ve been crazy busy and haven’t commented in far too long. BUT I have to say, Thank You! Vintage metal like this 911 being given new life is pretty sweet. Thanks for the in depth look Mike. I’ve been catching up on some articles this week and couldn’t help but be drawn in here to say what a treat this is. It just blows my mind how quickly Air Cooled Porsche’s are becoming unobtainable; this workover would put things in the astronomical range, but I can dream! I remember when I lived in AZ 15 years ago as a poor newly wed student, I found 3 912s for $4-6k and 911s could be found in the teens. Gotta get back in time!

  6. Well, it’s been a while since I’ve posted and i’ll Try and write this one last time, because(like so many times before) my post disappeared. Mike, thank you as usual! This vintage metal with modern tech is awesome. I just can’t believe how these air cooleds have skyrocketed. Add this much tech, and your project GT3 was probably a steal compared to the astronomical price something like this would command when finished. I remember 15 yrs ago when I was a poor, newly wed student and I could get 3 decent 912s between 4-6k and you could still find a 911 in the teens………gotta get back in time!

  7. Bruce, its because comments have to be approved so we can catch spam before it gets out. We approve all of them but sometimes in off hours, it may take a bit.

  8. Wow, love the rear suspension. Especially, tying the rocker and shock mounts to the triangulated cage.

    A little disappointed with the front suspension. Right now, it has more bumpsteer, as mentioned. They have the top mounts set to reduce negative camber, and they are not triangulated to the firewall. A strut bar, at the very least, should be installed.

    Also, not a big RWB fan. I think it is mostly about looks and exclusivity. Certainly, not about aero or increasing vehicle performance. I mean huge tires, and no downforce is not a recipe for high speed confidence at the track.

    Can’t wait to see it finished, though. I’m sure, it will be a monster street car.

    1. The camber plates are moved out because the lower control arms are longer to increase track and make room for the large wheel and tires. The camber and caster are set at the bottom. The camber plates control the steering axis and the scrub radius with these huge wheels and tires.

  9. Love that shifter, especially the use of 7075. Lovely alloy, that; I’ve had a roughly 45 lb block of the T651 flavor (an offcut from an aerospace company I worked at for an extremely short time) waiting for me to find a proper project for it. Well, that, and access to the facilities to machine it properly.

    Truly a fantastic build all around. Wouldn’t mind seeing this kind of attention to detail being put into a 914/6

  10. ok so Porsche went to a proper multi-link rear suspension in the 90’s. When are they gonna go to a proper double wishbone in the front and ditch the McCrap struts?

    1. Porsche has had double wishbone front suspension on the 911 GT3 R racecar for awhile. It seems that they are trying to distinguish the street car from the ‘proper’ racecar.

      Of course, it is probably because Porsche is in a unique position, where they get to dictate to the customer, instead of the other way around.

      The Germans need some proper competition to up their game. Let’s hope the MR Corvette motivates them to raise the bar.

      1. The latest mid-engine R has the unequal length A-arm. Did the last RSR have it too? The 993 was Porsche’s answer to the 300ZX which I feel was the first Japanese world-class sports car made. The Z woke them up and the FD and MKIV continued the pressure.

        I was hoping that the 992 would have new front suspension but no. On the other hand, they have been plenty of fine handling strut cars made. The only disadvantage really is they need slightly more static negative camber to work and with modern tires, that’s not such a disadvantage.

        1. Mike if you are referring to the 2019 (or even the 2018) GT3R it has rear engine and the tranny sits in the front of the engine. It’s not mid-engine.
          Only the RSR has the engine in front of the tranny, like the Cayman and therefore mid-engine. Both the GT3R and the RSR have double wishbone up front but multi-link in the rear.

      2. yeah but isn’t the whole GTx thing basically a race car for the street? And if they’re gonna go through the trouble of developing a double wishbone setup for the race car, why not put it on the street car too?

        I know there are lots of well handling McStrut cars, but they’d be even better with double wishbone… and this part might just be in my head or coincidence in the cars I’ve driven, but double wishbone cars tend to have better steering feel for me

        1. The versions that have double wishbone are turnkey racecars. I believe they are primarily for IMSA.

          “Porsche announced the new 911 GT3 R customer race car, which slots in above the 911 GT3 Cup and below the factory race team’s mid-engined 911 RSR. The new Porsche 911 GT3 R can be ordered immediately for 459,000 Euro plus country-specific VAT and will be delivered from December 2018. All technical details and data are provisional until the final approval is received through FIA.”

          Awhile ago, my parents were shopping for a used car. It was between the Camry and the Accord. My mom actually choose the Accord. I asked her why, and she said, “The car just felt better to drive.” When she told me that, I realized it was because of the double wishbones, over the strut suspension of the Camry. She doesn’t know anything about suspension, of course, but she still made the best choice in terms of handling. I thought that was really cool.

  11. Speaking of Porsche fan boi’s. I got a lot of Boxter and 996 911 owners mad with my article ragging on the M96 engine. They don’t understand facts!

          1. yeah, its no Honda K or F… its really hard to be impressed by any NA 4 banger after driving those 2…

          2. I think SBGarage is working on one… either that or they’re just posting really suggestive pics on their instagram

          3. It’s a little frustrating that they’re never going to be embraced like the Ks were – the slightly older Duratec I4 has some configurations that aren’t that far off the Ks. Inertia though… nobody cares so there’s gaps in parts availability that you need to fill with custom stuff, which means nobody much does them, which means nobody cares.

          4. @Dan
            as the owner of an NC Miata which has an MZR, which is a Duratec with variable cam timing… its really a far cry from a K… the only way to get any decent power out if it is with boost. If you wanna stick to NA you gotta dump a crap ton of money into it. Mountune builds the engine in the BAC Mono which makes 305 crank hp and that engine costs 30k. 4Pistons sells a K series that makes 360 crank hp for 1/3 that cost. For 10k dumped into an MZR/Duratec, you’d be lucky to make 250. The only advantage I’ve found with the MZR is that there’s a relatively cheap drysump oiling system available for it. And I think its a bit lighter than the K and a little shorter.

          5. @bob

            I roadrace an NC too, albeit in classes that are close to stock. That’s kind of my point – so it turns out if you dig into things, the best head for the family is Ford only, and the 2.5 crank isn’t great at high RPM so you basically need to build a configuration never offered or throw a forged crank at it. Then you’re into rods and pistons that aren’t shelf items and custom cams, plus machine work, plus manifolds aren’t shelf items.

            All this stuff for the K-series is off the shelf, proven, mixing and matching the right parts, so yes cheaper. Though looking at Mountune’s site it’s a little unfair comparing the price per performance of a Honda longblock for whatever application not constrained by rules to the price of a complete mapped engine with intake and exhausts build for a spec class with sealed engines.

          6. @Dan
            there are off the shelf pistons and rods for the 2.5 MZR, but as far as I know you only 2 options, maybe 3. There are also a few off the shelf cam options, and there are a couple manifold options from Dynotronics (generally makes good stuff but generally very optimistic with his power claims) and XeroLimit. Availability is a little spotty on the manifolds cause not many people buy them so they’re not regularly in production. So there are some decent options that are affordable for the MZR, but they’ll get you to what a stock K with bolt on’s or maybe mild cams will do.
            While I agree comparing K engines to Mountune engine’s isn’t really fair in terms of price, but thats part of the problem isn’t it? There are lots of options for a built K… there’s only a handful options for the MZR in the US. Europe has a few more options cause this engine is raced more, but price to power is still pretty close to what Mountune charges. No matter how you slice it price to hp will always be in the K’s favor, usually quite significantly.

            You’re definitely right, the optimal combination is a mix and match of parts mostly limited by that long stroke 2.5 crank.

          7. @bob

            So the best head off the shelf is the Ti-VCT Focus head with the DI holes plugged – unported it’s pretty close to the good K heads though I don’t know if it’ll go as far with porting. And the Ranger 2.3 crank works up to a point… but now you’re into custom rods and pistons, and any cams to make really good power are custom, and I think only Esslinger has manifolds off the shelf to fit that head. I found out about that combination from Esslinger actually, who build those to compete against K24s in a Midget class not allowing porting.

            The K sucks the air out of the room though is my point. My point is the MZR isn’t that bad, not that it beats the K. There’s lots of engine platforms that people build that are worse, but the MZR came out in this country in a time when there were Ks so it didn’t gain the critical mass. It’s akin to looking at LS/etc swaps… at a given power level there will always be a “best” bang per buck.

          8. @Dan
            does the Ti-VCT Focus head bolt on to the MZR? even if it does, I’m assuming the NC ecu with Ecutek wouldn’t be able to run the VCT and it would require a standalone, right?

          9. @bob

            Yeah, it bolts to the block. Esslinger is doing it in mechanical methanol injected form so I don’t know about ECU solutions. I’m probably doing one as a dyno mule at some point, but first I have to get the dyno going, you know?

          10. Want to do an article on the MZ engines? I know almost nothing about them and this is all too good information not to document somewhere.

          11. @Mike
            awesome! can’t wait! I volunteer my NC with the seized engine as a test bed! (on the off chance you actually need a car to test this in, the offer isn’t a joke. unless it comes with a 5 figure bill attached, then its a joke).

          12. @Mike
            I have too many irons in the fire to do a good job right now – family stuff meant that I didn’t get my engine dyno up and running last year, and I don’t want to try to sound authoritative when I’m so far just doing a wider than normal amount of research. I at least want to do head to head flow tests of the decent heads. Basically though the MZR is mostly hampered by cams and intake manifold. Mazda and Ford didn’t have something VTEC-like to throw at the cams so all the performance versions went turbo.

            I’m actually in the CAD stages of doing a GT-3 Mazda, I’ve been meaning to drop you an email to ask what it would cost to sanity check the suspension geometry.

  12. RWB’s 993 is just a 993 gt2 evo copy with few inches extra on each side and some horrible side skirts and a cheap black strip of rubber called a front chin/lip whatever and like two or three canards and winglets. The best in using the sealant to hide the misalignment fitment issues between the flares and fenders or quarters and where ever else… Yeah this one has a bit or a lot more mechanically than the usual RWB. Most have some half dead or dead tired underpowered dud for what they call an engine for the vehicle. Please explain the fascination about this dude, someone even built a fucken museum for him and the cars.

    For what he charges, I’d tell him to go remake the kit/molds where the parts fit nicely (get a accurate/nice cutting/drilling fixture made for your parts dude, go look at like techart or ruf on fitment) and no grinding and/or sanding finished painted part (what the point of paint something then?) and go have some moulding or custom rubber in place of your hokey sealant/silicon all around the car. I know what RAUH means. but seriously =| really?

    1. Completely agree. This customer is paying big bucks for this full build. Ohlins TTX 46 aren’t cheap, and so are those forged Brembo mono block brakes…and let’s not talk about the rocker-arm suspension design, cool shit but expensive. MoTec dash….and possibly a MoTec ECU and a fully motorsport harness…..AND it will have billet uprights….great stuff for sure! THEN they sourced RWB for the body kit? The paint should be applied AFTER everything fits nice and tight.

      Anyway, what about the front air-jack support welded onto the front crash beam? Not the best location if you asked me. Porsche welds the support for the front air-jack onto the chassis down low in between the shock tower, away from areas where it could get damaged.
      Eager to see this thing on the track though!

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