Bob Shammas's FJ1314 Turbo

It's great to get feedback from FJer's hitting this site. Some sharing their experiences, others just gathering more info for that 'next project'. It was then, great to hear from Bob Shammas from Michigan USA.

Bob has two FJ1100's, both boasting 1314cc conversions. He then went on to casually mention that one of his FJ's was also turboed, with a host of other modifications to boot.

Naturally, I couldn't let Bob off the hook that easily and asked whether he would be prepared to write an article on how the project came into being. Fortunately, for us he agreed and what's more in fine detail. Bob's own words are highlighted in mauve to ensure they're not mixed with my drivel!

Want to mess with this !!??

A quiet tootle around the woods !!

A machine on a mission !!


Hi Barry,

Cool site! (Nice start Bob, I'm a sucker for compliments!) My name is Bob Shammas and I live in Michigan in the US. I just saw your site for the first time. I have two '85 FJ1100s. Both are 1314cc, one turbocharged, the other normally aspirated. I built the first one for myself, then built the other for a friend with the idea of turbocharging that one too. He lost interest and I ended up with the bike.

I can offer a few observations about my experiences with modifying these bikes. The normally aspirated bike just has the big piston kit and suitable jetting, Everything else is stock as far as power making, with the exception of a 4 into 1 pipe. Of course the trans. is undercut and I used heavy duty cylinder studs and nuts. I was really surprised at the improvement the big kit made with no headwork or cams. The FJ is heavy in the front and normally won't wheelie. With this bike (stock gearing), just whack the throttle open at 4000 rpm in 1st gear. The bike lunges forward and then sends the front end skyward to the point you have to back out or shift early. It's pretty fun and impressive. Should be a good sport tourer. I just picked this one up so I haven't had it on the dyno or even ridden it much, but I can update you if you want.

The turbo bike is in another league. I geared that one 18/38 - as tall as I could get. It's a simple draw through turbo, but works pretty well. The stock motor made 210 HP at 20 psi boost. The 1314cc motor makes 238 Hp and 160 at 20 psi boost. I normally run no more than 15-16 psi boost or it's just unrideable. Part of it is the swingarm which twists so bad so as to point the bike to the right. The other part is 140mph unsolicited wheelies. I have a new 4" extended, heavily braced swingarm I'll be trying when the weather breaks. Seven psi will leave a ZX-11 with a 40lb lighter rider in the dust. So far the motor has been very reliable. I use a Falicon billet clutch basket, Barnett clutch spring conversion, and MRE lockup clutch. R&D motorsports undercut all five gears (under heavy boost it would pop out of first gear too). I run two stock oil coolers, the second mounted on the chin fairing so as not to block airflow to the head or cylinder.

Hope I'm not boring you too much. Let me know if you want more info.



No chance of boring me Bob, I'm getting excited already. (Don't worry it doesn't last long....Debbie Edwards).

So then I asked for the full low-down and Bob kindly obliged...........


The Building of an FJ Turbo

By Bob Shammas

Ann Arbor, Michigan, USA

January, 2000



As a dedicated motorcycle nut and a mechanical engineer, I had always enjoyed building fast bikes. I had been dragracing 2-valve Kawasakis for a number of years, one of them a blown-alcohol 1394cc Z1. At 220 lbs I always needed more power in my streetbikes to stay ahead of the lighter guys out there. Nitrous worked, but had its drawbacks with filling bottles and keeping bottle pressure up in the cold weather we often get here in Michigan.

I first got the idea to buy and build this bike when I was at my friend Jerry Berreth's cylinder head shop in Iowa. Jerry's personal 1985 FJ1100 that he had purchased new was sitting there under a sheet. It had 11,000 miles on it. He had an old ATP turbo kit for an XS1100 sitting on the shelf and we knew the header matched up to the exhaust ports of the FJ. It was just your basic draw through system with a Rayjay F40 turbo. After some discussion regarding the fact that Jerry never rode anymore, I purchased the bike and turbo kit. The bike has been sort of an ongoing project ever since, with several distinct phases as follows:


Phase I

Work began in the Fall of 1996 with modest intentions. The first job was making it fit and trying it out. I had to modify the sub-frame to get the intake in and the exhaust out. This was a simple evening job with my mig welder, once I knew what I wanted. Turbo pipes were cut and welded to fit, and the exhaust angled down and behind the left leg to a slash cut dump pipe. The intake was in a similar position on the right side. I used a large Gates rubber elbow and added a big K&N cylindrical filter for plenty of flow area. The intake spigots were modified for the different bolt pattern of the FJ. I also installed a remote oil filter in-line to the turbo, as I took unfiltered oil from the oil filter cover to feed the turbo. If one were to buy a kit already made, most of this step would not exist, so I am not spending much time on it.

Once the bike was running, I learned several things:

1) An FJ makes the most awesome deep, bellowing sound with a turbo and a dump pipe - much better than a KZ, GSXR, ZX, whatever.

2) The thing took forever to warm up and carbureted very poorly off idle with the supplied Zenith 38mm carburetor. I couldn't even get boost for a couple of miles in cold weather.

3) 6 psi boost slipped the clutch right to redline.

4) A Barnett clutch spring conversion cured the slippage.

5) Up to 12psi boost was used in this form and was exhilarating on the highway to say the least. Very promising. I was excited!


This'll keep your leg warm !!

Should suck your right leg off !!

No point painting those buggers !!

Phase II

Satisfied that the project was worth continuing with, I then tore everything down to do a complete turbo engine. Specifications of the new engine follow:


 All other internal parts including the bearings were in good condition, so I left them alone. The rings were fine and the bike never smoked, so I kept the original ones also.

 Riding the beast in this form in spring of 1997, I wasn't afraid to let it see some boost. 15psi was good for about 175 Hp at the rear wheel. I kept 110 octane race gas in it for the first season since I was in the experimental phase still. An early dyno chart is shown below. The bike was in the midst of a misfire problem that occurred when significant boost was reached (12-15psi), and the ability to use the full rpm range was compromised. Just when it was about to really make big power, BANG! This was very disappointing and aggravating. It was eventually traced to the spark plugs as stated in the notes below the chart.

 The best run in the chart above was a 4th gear blast. While rpm isn't shown on this chart, the power began to climb steeply at about 6000 rpm. As I recall 100 Hp is reached at about 6500-6800 rpm here. In 5th gear with the engine typically cutting out at 9500rpm, the wheel speed was still over 170mph.

 I would sum up the most notable things I learned in this phase as follows:

 1) Early on I switched to a Mikuni HSR42 carb and this changed the bike entirely: Easy starting, good idle, smoothly pulls away from stops, etc. Highly recommended! Just know that you'll have to rejet it entirely if you buy it from Mr. Turbo. A #17.5 pilot and 0.125" main jet (drilled as large as possible) worked for me. It wouldn't even accept full throttle with the supplied jetting..

2) Disconnect the vacuum advance on the stock ignition - it'll only give you trouble

3) Plugs only last about a day at high boost unless you keep the gap under 0.020". This was responsible for my high rpm misfire on the dyno sheet above. Once you make this simple change, normal reliability is returned. You'll put a couple sets in a season, of course. I use NGK D9EA plugs.

4) The clutch again slipped above 15psi boost (175 Hp)

 After installing an MRE lockup clutch I could venture beyond 15psi boost and get wheelies instead of clutch slippage. Second gear is good for over 100mph with the 18/38 gearing, and it WILL wheelie at the top of 2nd gear on flat ground. Third and 4th gear wheelies may occur depending on the grade of the road.

 Another trip to the dyno netted 210 Hp at 10,300 rpm with 20psi boost. We found that it only liked a few degrees of timing retard. We actually hit 200mph wheel speed on the dyno and the dyno shut down due to overspeed. This was with the rev limiter disconnected to allow the engine to hit over 11,000 rpm. At this time I am unfortunately unable to locate that dyno sheet.

 The bike was rideable this way, as it "only" made 125 of torque and didn't hit until high in the rpm band. That was one of the downers. With the Rayjay F40 turbo on it, no significant boost occurred until about 5500-6000 rpm. I needed more displacement!! Another downer was that the transmission started ratcheting in first gear, similar to the well-known 2nd gear problem, under high boost. Still, at this point the bike had proven its reliability enough that I did some touring on it. I rode it up to the UP of Michigan, over the Mackinac Bridge, through Paradise, and to Tahquamenon Falls.


Phase III

This was the winter of 97-98. I decided that 1314cc were needed, and I wanted to go to pump gas full time for 1998. Besides, after a summer of pounding on the poor thing, and with the transmission problem, I needed to split the cases once again to fix the trans. and take a look around.

 Everything again looked great. The stock pistons were in excellent condition. All bearings were in the same visual condition they were in the previous year, and no excess play was noted in the rod bearings. Those stock rods are massive, beautiful pieces and can withstand large power levels without any problems as long as they are not over-revved.

 I chose a Wiseco 1314cc, 10.25:1 kit (the only CR available) and bought the heavy wall hard chrome wrist pins. These are really good and Wiseco has their act together on wrist pins now. This piston kit is nice because you end up with a 0.100" cylinder wall thickness which is good for long term durability. A 0.050" base gasket was used to reduce compression and squish. I could have gone with an even larger gasket, but I wanted to keep the compression as high as tolerable to improve off-boost performance. Lynn Nyler at Performance Cycle in Toledo, OH bored the case, sleeved the block, and bored the cylinders. With the big pistons and heavier pins, I decided to stick with the stock rev limiter from this point forward. This limits top speed to an actual 185-190mph with 18/38 gearing, but this was judged to be adequate for street use.

 The transmission was sent back to R&D to go over and undercut first gear this time. I also found that second gear had been pressed on too far and burned up the thrust washer. I replaced the washer and pressed the gear onto the shaft, leaving 0.005" clearance to the next gear.

 Thanks to Terry at T&A Custom Cycle in Belleville, MI for coordinating a lot of the machine work and getting most of the parts for me.

 When it was time to start the bike, it wouldn't. I found that with the new displacement, the idle screw on the carb had to be turned all the way in just to make it idle at 1000rpm. The engine also turned over much slower on the starter.

 Once running, it was a whole new bike. The engine pulled like a freight train off the bottom with a strong surge through the midrange. Boost built strongly from 4000 rpm, and a guy could be happy running less than 6000 rpm all day and only a few pounds of boost. I can't say enough about how much nicer the big bore bike is for true street riding. Even if you never turbo your FJ, go with the 1314 kit. I did find that on 93 octane, once fully heat soaked, the detonation limit was only 6-7psi. The FJ is very good at audibly notifying the rider of detonation before any damage occurs. While 7psi was enough boost to leave a ZX-11 with a lighter rider far behind, I needed more on pump gas. I also found that hot starting was a problem with the big displacement unless the battery was completely new.

A water injection system was fabricated. A small Honda Spree oil tank was mounted in the chin fairing and filled with a 50/50 mixture of water and methanol. A small windshield washer pump was mounted to the tank, and an automotive oil pressure switch was mounted to the intake manifold. At 6psi boost, the pump turns on, shooting the anti-detonant through a Mikuni pilot jet into the intake charge. This system raised the detonation limit on pump gas to 10-11 psi - probably a good 170Hp at the rear wheel or so.

 With a little race gas added to the tank and 15-16 psi, the bike was just awesome to ride. The torque was fantastic, and it would twist the swingarm so badly as to point the bike off the right side of the road. I would actually have to hang off to the left, just like a funnybike. Getting to 10,000+ rpm in high gear doesn't take long, and the guys riding behind you often have trouble believing that you just went that fast in front of them. I never stayed at that speed for long.

 Another trip to the dyno was made on race gas. This time, 20 psi netted 238Hp and a whopping of torque. Both numbers peaked early so it seemed that fuel delivery was a problem and more power was within reach. Extrapolating the curve indicated that more like 255 HP should be possible at that boost level. The dyno chart follows:

As you can see here, peak power was only at about 8800 rpm, and peak torque at 7200 rpm. With lower boost levels (up to 18psi) the power peak was right at 10,000 rpm. Still, look at the numbers and think about this: At 5500 rpm it's broken 100 Hp and roughly 100 of torque. That's almost as much Hp and about 40% more torque than a stock FJ makes at its respective peaks. By 6000 rpm it's making 135 Hp and 120, 6500 get's you 175 Hp and 140, you break 200 Hp at 6800 rpm with 150, at 7200 rpm you have 220 Hp and a huge 160 of torque. The Hp continues up through the peak and never drops below about 220 Hp until the throttle is chopped at 10,500 rpm. The midrange portion of the curve is the most impressive to me and must be experienced to be believed. Again, the early peak torque and power I believe are due to insufficient fuel system capacity. I've since increased the fuel pump capacity from 20Gph (really only good for 200HP) to 30Gph, and I've played with a boost compensating fuel pressure regulator to increase the fuel pressure as boost increases. I have not been back to the dyno since. I only rode the bike in 20psi trim once. Remember this is a stock-chassised bike with no swingarm extension. In 3rd gear, geared for over 130mph, the bike simply tried to go over backwards with no warning. In 4th gear (good for over 160mph), it stood up and carried the front wheel down the road. The boost needle went from nothing to 20psi almost instantly. It was downright scary. I went home and turned the wastegate down to a more realistic 15 psi (200 Hp or so @ 10,000 rpm). Even at that level, first and second gear full throttle usage is simply a matter of knowing when to short-shift to keep it semi-controllable.

A further improvement at the end of 1998 was the addition of a second stage to the wastegate. This made the bike much more usable. I knew they existed and after thinking about it for awhile, realized that I could make a second stage by applying switched, regulated boost pressure to the backside of the wastegate to augment the spring pressure. One could set the boost to 7-10psi for the first stage, and then increase it to 15psi or whatever at the touch of a button. This made it much more rideable in the lower gears, and a base setting which was pump gas friendly could be chosen, saving the second stage for those times when the tank contained spicier mixtures.

 I also added a second stock FJ oil cooler to the bike to reduce oil temperature in town and during slow riding. This was mounted on the chin fairing and plumbed in series with the original one. A large decrease in oil temp was realized by this modification (roughly 30-40F), and the detonation limit was improved since it is proportional to oil temperature.

 The bike was ridden this way in 1999. The biggest complaints at this point were hot starting, a lack of stopping power, and limited cornering clearance. I always rode this bike to the edges of the tires. I had to be careful when hopping off of my wife's '99 ZX-9R and onto the FJ because I would tend to go into corners WAY too hot.

 Power seemed to be eroding at this point, and a leakdown test uncovered some leaky valves and what seemed to be head gasket leakage between cylinders. After all, with two seasons of pushing the envelope on this thing I wasn't surprised it needed freshening up.


Just slot this bit in here  !

Flight Deck!

And a bit in here !

Phase IV

The present. Winter Y2K. I have now installed a 4" extended, heavily braced swingarm (pictured above) to both control wheelies and keep the bike pointed straight. I also decided that the hot starting problem had to go. The engine was freshened up (valve job), and a 0.100" base gasket was installed to further reduce compression. The pistons looked like new, and the wrist pins really held up well. Some improvements were made to the intake manifold to increase efficiency. The bike has not been ridden this way yet. I am also in the process of updating the bike to 17x3.5" and 5.5" wheels so that modern tires and brakes can be installed. I have a complete ZX-11 front end that will be grafted on. It looks like a simple stem change is all that's needed.

 If further reductions in compression are required to get the bike exactly where I want it, I may also go with some additional headwork to try to make more power with less boost. I was very impressed with turbocharging my ZX-11, as only 12 psi boost were required to make 265 HP on that engine (granted with EFI and intercooling). That is another story entirely, however.

 I've considered an air shifter and possibly a nitrous system to provide intake charge cooling and to aid as an anti-detonant. Power levels of well over 300 HP would no doubt be achievable. Still, I really have no use for that kind of power in my application, as I actually ride this thing, don't really want to stretch and lower the bike to the point it's useless in the curves, and have no desire to be a dyno hero.



I've really enjoyed the FJ turbo. The project has taught me a lot and has not disappointed me. I was going to sell the bike this year and buy a ZX-12, but decided to keep it. It's too much fun whizzing past these new bikes with the dinosaur's front end in the air. Making a measly 160Hp at the rear wheel like these new Hayabusas and ZX-12s is extremely easy with a big FJ turbo and can be done on pump gas. With a 1314cc package, you won't be left waiting for the boost to hit, either. Handling and braking will be areas to work on, however.

 Let the FJs ride on!!


Questions or comments? e-mail me via Barry Edwards.

© Bob Shammas 16 Feb 2000

Important Note:- All information detailed above has been observed during the course of race-bike preparation only. I in no way recommend anyone to follow such a course, or accept any responsibilty for any accident, loss or other misfortune befalling anyone doing so. ANY WORK CARRIED OUT ON YOUR MACHINE, SHOULD ONLY BE DONE BY A QUALIFIED MECHANIC/ENGINEER.


The Shammas Clan !!

Bob Shammas is a Senior applications Engineer for the NSK Corporation (so nothing wrong with Bob's balls :>). He works from their corporate office at Ann Arbour.

I would like to thank Bob for taking the trouble to mail me this great article and allowing me to publish it on the FJ Modifications Site - Barry Edwards.



What a piece of kit !!!