Monday, 31 December 2012

Kawasaki Z1R-TC - The Psycho Turbo Z

TURBO. For a certain generation who grew up in a time before forced induction became a “green” thing, nothing screams “Eighties Excess” and “Performance” like a turbocharged… anything. You are probably familiar with the early turbocharged cars that used forced induction as a way to squeeze extra power out of emissions-strangled motors of the Reagan era. Less known is a short-lived generation of production turbo motorcycles from 1982-85. The first shot in the 1980s turbo wars came from Kawasaki, who attempted to revive an ailing model by boosting it beyond all reason. And they beat the other manufacturers to the punch by introducing their turbo fiend at the end of the Disco era.

In the late 70s the Kz1000 was Kawasaki’s bread-and-butter superbike, a ‘litre four-pot brute that competed with the Suzuki GS and Honda CB for dominance on the street and track. It was a direct descendant of the legendary "New York Steak" 903cc Z1, the bike that had knocked the CB750 off its perch in 1972 and cemented Kawasaki’s reputation for high performance engines. Over the 70s the Z was updated gradually, eventually being punched out to 1016cc in the Kz1000, which would beget the Z1R in 1978 through a styling change, cast wheels, and the addition of a headlight fairing.

Unfortunately for Kawasaki in 1977-78 the big-Zee (Zed?) was getting behind the curve and was in dire need of an update. Kawasaki had long been seen as the purveyors of particularly fast, vicious machines that had more motor than frame. The H-series of two-strokes were a good example of the widowmaker reputation earned by Kawasaki sports bikes – monster motor, flexy frame and suspension, mediocre brakes. Go faster than everything else - at your own peril. The Z continued this tradition by stuffing a hot four-cylinder motor into an antiquated chassis, but the competition had caught up in the power department by the late 70s. Handling was always the weakness of the Z models, as period tests often pointed out. Zs were prone to instability and headshaking as well as rubbery handling, and attempts to stiffen the suspension just made the flobbery frame even more apparent. Tire choice was critical, as a set of mismatched profiles could cause serious wobble issues. The Z1R was no better in this respect, being mechanically identical to the Kz1000 - which now had 90 odd hp twisting the beams that were more or less unchanged since the Z1 hit showrooms in ‘73.

So what do you do when your flagship is falling behind the competition and spitting off riders due to an outdated chassis? If your first thought was “give it a shedload more power” then congrats, you are just as insane as circa-1978 Kawasaki USA. And you’d probably be the target demographic for the Z1R-TC, the angriest, most ferocious motherf***er of a superbike to hit the streets in the late 1970s.

The Z1R-TC was remarkably under-engineered and overpowered in just about every respect, and was so ridiculously over-the-top that it is scarcely believable that it was sold through official dealers. In fact it wasn’t really a production model at all, more of a dealer special put together to lure power-mad riders into Kawasaki showrooms in the USA and Canada and shift stocks of the languishing Z1R. It wasn’t the first or last example of the breed – the legendary Laverda Jota 1000 wasn’t a production model, it was a hotted-up 3C built by a British distributor. While the Jota would become mythical, the TC would fade into obscurity. Presumably after laying a big strip of rubber and then promptly melting a piston.

The TC was the result of slapping a turbo kit onto an otherwise standard Z1R. And I do mean slapping on. No internal modifications were made to the motor. No suspension change. No frame reinforcement. Just a turbo kit and about 10 lbs of boost knocking forty extra horsepower to the rear. Yep, the TC was rated for a staggering 130hp, in an era when a Ford 302ci V8 was wheezing out 140 hp on a good day. Power claims vary of course – boost pressure was variable and the wastegate was adjustable, so you could have gotten anything between 6 and 10 psi “as delivered” with the potential to screw boost into “expensive” territory with the flick of a screwdriver.

And it wasn’t just the horsepower tally that impressed, it was the way it made power that was truly breathtaking. By breathtaking I mean it would scare they everloving piss out of you with the most evil turbo lag this side of the ass-engined Porsche 930. Up until 4500-5000 rpm it behaved like a standard KZ. Then all hell would break loose and it would go tearing towards redline with a spurt of violent acceleration. Just like every other early turbo machine, in other words.

How did such an amazing monstrosity ever see the light of day? The TC was the product of a specific set of circumstances that will likely never be seen again. Alan Masek, a former Kawasaki USA general manager who had helped with the original Z1 project, had started a company called the Turbo Cycle Corporation in California to offer American Turbo-Pak bolt-on kits for power-hungry riders. ATP was the go-to for go-fast parts during the golden era of Japanese superbikes, and offered turbo kits for Z1s, CBs, CBXs, and of course KZ/Z1s. Masek made an arrangement with Kawasaki in North America to take stock pastel-blue Z1-Rs, install the ATP kit at TCC, then have the completed “Z1R-TC” sold through Kawa dealers without a warranty. The bike would be a flagship performer that would garner attention for the brand until they were able to replace the ageing KZ, but without the liability headaches that you’d expect from bolting a big ass compressor to bike with an inadequate frame. It would also help to shift some of the unpopular Z1Rs that were stagnating in the showrooms. The bike was technically an aftermarket special produced by TCC, which absolved Kawasaki and the dealers of any warranty claims (and allowed for a lack of compliance with EPA measures…). Buyers were required to sign a legal waiver and forfeit the standard warranty.

The TCC modifications were straightforward. A complete exhaust system with a cylindrical header was connected to a Rajay turbocharger that was situated just behind the engine, where the standard bike’s carburettors sat. An adjustable wastegate metered pressure in the system (which could easily be knocked up with a screw adjuster on the bottom of the ‘gate), which pumped into an inlet manifold running a single 38mm Bendix carburettor fed by a high-flow fuel pump. Finally, a boost gauge was tacked onto the steering head. Price for the completed machine was $5000 USD, vs the Z1-R at $3695.
Aside from the TCC fettling the bike was standard. You got an air-cooled four with double overhead cams and 2 valves per cylinder. Bore and stroke was 70x66mm, compression 8:1. Frame was a steel tube cradle design with Kayaba suspension front and rear. Wheels were cast alloy with cross-drilled disc brakes front and rear. Transmission was a 5 speed with chain final drive. With the turbo plumbing the wet weight was a shade under 560 lbs. The signature Z1R bodywork was retained, and even the paint was left stock aside from the addition of a couple of TC badges on the side panels.

Media test bikes were modified to cope with the boost. Valve and clutch springs were upgraded. The pressed-up crank pins were welded together to prevent crank twist under load. Performance was stunning, - at 10lbs of boost magazines could knock out quarter miles in the high 10s at over 120 mph. It was scarcely believable at the time. Don’t forget that this kind of performance was in a bike that was known to have poor handling and braking, now made even more interesting with the addition of a ridiculous spike of power at the top of the rev range. 

A problem for real-world owners was that those reinforcements made on test bikes were extra-cost options on the “production” models. In addition to internal strengthening the compression ratio should have been lowered, and the ignition retarded, to prevent detonation and piston ring failure. Owners quickly found out why they had to waive their warranties. Running anything over mild boost would shatter rings and melt pistons in short order (sometimes as little as a few hundred miles!). If you missed a shift and over revved, easy to do when the boost came on hard at 7000 rpm before the 8500 redline, you’d get valve float and smash the pistons into the valves. And that’s if the crank didn’t twist or spin a rod bearing under the extra load.

Just makes you want to ride one even more, doesn’t it? 

The 1978 TC earned a reputation as a fearsome, barely controllable brute that was king of the quarter mile. Just the sort of reputation that sells bikes – motorcyclists have always been a weird lot of madmen, and when you tell them something is just “too fast” and brutal you can be sure they will be lining up to buy it.  Of course some of the legend is just that - legend. "My best friend's third cousin's uncle got this turbo bike that will do 200 miles per hour and power wheelie in 5th gear. It's a secret prototype you won't find in the catalogues because its too fast, he bought it right from the factory. Swear to god guys, it's the truth."

250 of the original powder-blue models were made with moderate success; sales would improve in 1979 with the introduction of the TC2. This is the most recognizable TC, with black paint set off by striking Molly Design neon graphics that make it look like a turbocharged surfboard. ’79s were still based on ’78 Z1-Rs (including a few unsold TCs) as Kawasaki had discontinued the slow-selling model that year. The TC2 incorporated a better 4-1 header, improved lubrication, and a milder 6 psi boost setting (still adjustable by the owner for maximum grenade potential, though). Turbo lag was reduced, as was overall power, but reliability was improved. The proper internal reinforcements for any sort of longevity were still optional.
250 TC2s were made before California laws changed and the party ended. From 1980 on no production vehicle could be sold with exhaust modifications, so the TC became verboten. Shame too, because sales were picking up in 1979 as the legend grew. It wouldn’t be until 1982 that another production turbo bike would be available, when the legendarily ugly but well engineered Honda CX500 Turbo “Plastic Maggot” hit the market. It would be followed by a short trend towards turbocharged middleweights - which would all be discontinued by 1985 due to high cost, high complexity, and insurance blacklisting. The Z1R-TC beat them all to market, and trumped the later bikes for outright performance (at the expense of any form of longevity). The TC has become a rare collectible; with only 500 examples in the US and Canada, and with a reputation as a violent street brawling brute, it’s little wonder than Z1R-TC values are rising steadily and available bikes are getting snapped up by enthusiasts “in the know” about Kawasaki’s off-the-record psychotic turbo bike. It's the truth guys, my aunt's boyfriend's half brother's best friend said so.                   

Interesting Links and Image Sources
Some awesome period images of a 1979 TC2
Molly Designs California
Motorcycle Classics on the Z1R-TC
A 1979 TC2 for sale 
A curious rant from someone who claims to have had all the "correct" info about the TC in a stockpile of documents which he destroyed because no one offered to buy them


  1. Hi Jason – I actually owned one of these monstrosities (not my third cousin’s neighbor) back in 1980. (scroll down a bit)

    Your description of this machine is dead on man. Dead on.

    The one thing no one seems to mention about the Z1R-TC is that an electric fuel pump was needed to purge the Bendix carb. The 2 years I rode my ’78 TC the fuel pump “burned out” 3 times requiring replacement. Excessive heat was cause. The fuel pump was located under the seat (next to the removable kick-start pedal) and the heat from the Turbo just seemed to fry those poor suckers.

    Great article man. Brought back many memories – if not “happy” ones…


    1. Thanks so much for sharing your thought! I always enjoy hearing from actual owners, rather than going by the usual heresay and the opinions of so-called "journalist". Obviously I've never had the chance to ride a TC but I tried my best to convey the experience without falling into the problems of a "third cousin's neighbour's" fifth-party retelling. I've shared your site and your thoughts on the TC on the OddBike Facebook page.

  2. Possibly the most comprehensive and accurate info on the TC on the web, and yes I do own one with only 2800 miles which will be featured in an upcoming magazine article June 2013

    1. We're looking for Z1R-TC owners who could serve as technical references for the inquiries we receive on our website. The archives for these bikes were destroyed so there's not much information on them. Go to our website and contact us if you're interested. Thanks.

  3. Hey Anonymous - please let us know when your Z1R-TC article is published. All I have is an old "Polaroid" of mine... Would be nice to see one that is still alive and breathing (both motorcycle and rider).



  4. WoW ive just ridden my first TC and guess what
    it now lives in my shed lol
    just one question
    is it common for them to run like a pig at low revs/off boost ???
    i now they chew spark plugs like there is no tomorrow
    actual any sort of information on these animals would be greatly apprectiated


  5. Wow how good a story you have written!
    I have one ,and how true , when I first rode it I had to challenge life once more!
    I survived .... The TC never . Lol
    But $400 later with a rebore and set of low comp pistons , copper head gasket and farrrk wow
    It's scary all right , you can't change gears quick enough , it's like traveling the time warp ... Or what I imagine it to be like .
    It has just done 10k I like to ride it ! But I can't control my self so I just look at it now
    I did abstruse it not long ago for $30 k
    I'm glad it never sold it's worth that just to look at it
    Mine still has the exhaust regulation sticker on it
    Which I have never seen on any others for sale
    Loved your story! Keep up the good work
    Mick Perth wa

  6. I have a ZR1TC without an electric fuel pump. when I get an electric pump, does anyone know what the pump pressure should be set at?

    1. 4.5b lbs is the correct pressure and you can still buy a facet pump thru NAPA. Mr Z1R TC

  7. Paul on our Facebook page suggested this "Contact RAIDER MOTORSPORT Coffs Harbour NSW Austarlia are on facebook."

  8. i use one that self regulates but you want 3lbs no more than 8lbs you will flod if your pump doesent shut off you need some kind of fuel return so the pump doesent overheat and melt. turbo

  9. Thanks for the information. Is your pump a factory pump? If not, can you tell me the manufacturer, model or name of the fuel pump you use? I need to get a new one and have not found where I can get one.

  10. Hi I'm BOB DUFFEY & I bought the 1979 Z1R-TC brand new & still have it, along with both owner manuals & color flyers from Kawasaki.
    It is all true & then some, LOVED it then & more now. Want something really WILD - search ( fastest man on 2 wheels backwards ) IT WAS A REAL THRILL ! ! The last line on the factory pamphlets was great, it said
    ( It is for the person who wants to say ( I've got it & you don't ). How funny but true. I have all the articles that were in magazines back then even the one where they compared the 911 turbo to the Z1R-TC with INDY racer Danny Ungyess (spelling) GREAT ARTICLE the results U won't believe.
    THANK U THANK U THANK U for a great recap.

    1. Saw you at Norwalk in 80's. IDBA event. Was amazed. Have a 76 ltd with atp system on it. Motor built right. 10 flat @ 146 around 20 pounds boost. I still think about those day when nobody around here could touch me. Old times good times. Still have the monster to. Lot of chrome to. The harley guys have told me it's the best lookin jap bike they ever saw.

    2. Hi Bob,

      I have Z1R-TC with under 7k on it. I got excited watching American Pickers recently when they were at your place and I saw your TC in the background. They want rarities, I can't beleive yo guys didn't give it any airtime. Not even a mention. Whats up with that?


  11. We're looking for Z1R-TC owners who could serve as technical references for the inquiries we receive on our website. The archives for these bikes were destroyed so there's not much information on them. Go to our website and contact us if you're interested. Thanks.

  12. Sorry for the delay. Yes, I have both kinds of original pumps. The earlier TC's with the log-pipe style exhaust came with a Walbro/Autopulse Series 2100 bellows style pump. Unfortunately the rubber bellows of this pump degrades if there is any alcohol in the gas, so I use airplane fuel for TC with that pump. The later TC's ("Black Molly" version) with the sypder style exhaust pipe used a Facet brand "cube" style pump #40176. It can be purchased at NAPA auto parts supply - NAPA #BK 610-1077, Mftr Part #NAP12SV, $65 in 2012. I hope this helps. Mr. Z1R TC

  13. Hi
    I dont have a zr-tc but I have a 1981 kz1100 I plan on outfitting with a twin turbo setup once I upgrade the engine a but to handle the power.

  14. We had one of the Black Molly TC's in our showroom back in '79. (Vista Kawasaki in Nashville) Being the service manager, I got to ride it once. Compared to the "superbikes" of the day, nothing came close. Pulled harder in 3rd and 4th gear than a new GS1000 did in 1st. Powerband like a toggle switch. Throttle roll-ons in 3rd gear up were the most rewarding. Hit about 5k on the tach and see the boost gauge jump about the same time your arms got straightened and your butt headed southward on the saddle. By the time you realized what had happened it was time to upshift and repeat. Pulled clean to 9500+ rpm in 5th and still accelerating, but you knew you had to get out of it or grenade it.

    I ended up building 2 more KZ-1000 turbos for customers that year. About $2500 (including teardown and crank welding, clutch work, etc.) for the 8psi version, or $3000 if you went obscene with 7:1 Wisecos and a jaw dropping 26 lbs. boost. - Doc

    1. Hey All,

      I saw that Bike in Nashville, You had a Blue Z1R and told us to come back next week and there would be a Turbo Bike. It Came with the Turbo installed, a box of parts and the pipes, The price was pretty high but the lack of a Warranty that killed the sale.

  15. I have a 74 Z1900 with the TC kit on it and other goodies. Its a custom bike that Im trying to get info on. bike runs great but needs the carb rebuilt. Would like the whole thing gone through to make sure its safe. Ive never ridden it and it has been sitting for 20 some years. I have all the Ray Jay documentation from American Turbo Pak.

  16. My brother had one new when I was about 13 he was about 29.He added alcohol injection and an air shifter to it. I use to ride on the back, I remember being in a pair of cutoff shorts, no shirt, no helmet (in Connecticut), and him saying hold on tight... tighter... tighter and when that turbo kicked in, WOW is all I could say. that thing hauled @$*., Crazy fun. Over the winter months he tore it down most of the way and I had the privilege of detailing every nut and bolt. I miss him and that bike. RIP brother. Love and miss you.

  17. My brother had a new one back when I was about 13 an he was about 29. He added alcohol injection, solid rear struts and an air shifter, probably some other things I can't remember. I use to ride on the back quite a bit. I remember one time being in cutoff shorts, no shirt, no helmet (Connecticut) and no glasses, on the highway and him saying; hold on tight. I squeezed. he said tighter. I squeezed harder, he said tighter, I squeezed even harder; then the turbo KICKED in. I remember looking over his shoulder, my eyes were bouncing all around, and seeing the speedo around 140mph. All I can say is WOW. I never felt anything like that since. Crazy fun.
    Then in the winter months he tore it most of the way down in his apartment downstairs room and I had the privilege of detailing every nut and bolt for it. Man I really miss him and that bike.
    RIP brother, miss and love you.

  18. I've owned a z1rtc for over 20 years. I put 2 to 3 thousand miles a year on the bike. After a few sets of pistons I now have the boost set at around 8 lbs. Have been challenged several times by other bikes and some cars, but if I'm rolling in 2nd or 3rd gear it's going to be tough to get around the z1. Getting the bike repainted this winter, it's a black molly.....68 year old Richard

  19. I have a 1980 KZ1000A4, American turbo pac kit. I just did the top end again about 400 miles ago. APE did all the top end work. I got the HSR 42 carb from Mr. Turbo. the HSR 42 is the way to go. the bike gets you going so fast, so fast. Love the bike, I will never sell it!

  20. I just found and purchased an almost all original ZR1-TC with only 2200 miles, the paint seems to be the only thing changed from original. It's been under a tarp for most of it's life. Everything is there, no nuts or bolts have ever been tampered with. I'll be restoring it over winter and interested in finding any shop manuals for it, The tires are rotten and appear to be original as well.

  21. I have one all original sitting in my garage with less than 600 miles. I also bought a HSR 42 mm carb from Mr Turbo, i took off the original Bendix and put the Mikuni on. Its like the bike is fuel injected now.

  22. This is an awesome article, I was one of the mechanics that actually did the Turbo mods right on the docks at San Pedro, ca. The original model was Turbo charged right there on the docks, we would un-crate them install the turbo charger, wastegate and plumbing, test ride, drain fluids and re-crate them back up for the showroom floors! The Company was "American Turbo Pak" out of Orange County, best part was we got to test ride these beasts!

  23. I had the pleasure of owning a couple tc pure beast .All the negative comments are true .I disagree with the outdated comment.
    After I bought my first z1 from the calif.chp for 245 dollars I loaded my boat anchor of a honda 750 with a 836 kit in it and pushed it over a cliff in the pacific ocean goodridence .I blew up every motor I had with a tc on it mostly because the oil would lose viscosity I beat the s_ _ t out of my zees.they would beat everything on the road till 1980 .Ya the laverda, ducks ,nortons would kill in the turns but thats it .every bike after the z was a copy meaning 4 cylinder twin cam .we all owe kawasaki a big thank you for there zees
    SF Bay area