I feel the need, the need for more speed!
On this page have I tried to give a guide to engine tuning.







































Stage I
The first things to do when tuning your engine is to improve the "breathing" of the engine. You do this by change the exhaust and airfilters. On the first generation GSXR you must change the whole exhaust as it is manufactured in one piece and therefore a slip-on is not possible. Next is the airfilter, change it for a highflow replacement. To ditch the airbox and replace it with individual filters can give jetting problems and I don't recommend it. When you have replaced the exhaust and airfilter you must probably do some jetting work. The easiest way of doing it is to install a aftermarket jet kit which usually gives a good result straight out of the box and has also the advantage of improving the throttle respons. You may also considering an ignition advance unit which alters the ignition by about 5 degrees. The advance unit gives usually a small increase in midrange HP. You can easily make yourself a free and adjustable ignition advancer:-) Look at the bottom of the page for instructions. If you do all of the modifications above you should end up with an increase of 5-10 HPs over the entire RPM range, an improved throttle respons and a much nicer sound. See the dynosheet for an example of an stage 1 tuned 1986 GSXR1100.

 

Stage II
Not enough power yet, of course not. Then there's time for some serious engine tuning. The goal is still the same, to improve the "breathing" of the engine. To get more fuel/air mixture in and out of the engine you must port the engine head. Porting enlarges and reshapes the in and out channels in the head to improve airflow. The combustion chamber can also be reshaped to improve airflow and combustion. Porting the head gives mainly topend HPs but with a good porting job you will see increases in the whole RPM register. Next is to skim the head. That is to remove a thin layer of metal from the sealing surface on the head. That increases the compression ratio of the engine which means more power:-) Head skimming gives mainly midrange HPs but also a little on top. One word of caution about head skimming. You must carefully calculate the compression ratio so it's not getting to high which can seriously damage the engine. How high compression ratio you can run depends on what fuel you plan to use. With 98 octane fuel you can run about 12.0:1 safely. Another thing to check is valve to piston clearance. One thing to remember when skimming is that the camshaft timing is altered. To restore this you must have adjustable cam sprockets. You can buy these but it's easy and free to modify your own. See bottom of this page for more info. The adjustable camsprockets can also be used to fine-tune the power delivery of the engine but that is best left to a professional engine tuner with a dyno bench. Next obstruction of the airflow is the carburetors. The first generation of the GSXR1100 (1968-88) has small 34 mmm carbs. Replace these with carbs from later GSXR models or aftermarket flatslide carburetors. The advantage of flatslide carbs is much increased airflow and greatly improved throttle response. Another thing to consider is replacing the ignition coils and wires with some high energy aftermarket stuff. This to better coupe with the increased compression which makes it harder to light the air/fuel mixture. All the above modifications should give you an increase of 10-20HPs over the whole RPM range. See dynosheet for an example of an stage 2 tuned 1986 GSXR1100.

 

Stage III
Now your getting serious. The aim is still the same, get more air/fuel mixture in and out of the engine. The next step is to change the camshafts and valves. The tuning camshafts have a different profile which enables the valves to lift more and stay open for longer. This increases topend power for a sacrificial of the bottom end. Increasing valve diameter also increases airflow. One of the most cost effective way of increasing HP and torque is to go for more CCs. A 10% increase in volume gives about 10% higher torque and 5 % higher HP. If you go really big (1255 or larger) the the crankshaft and rods are in danger. The crankshaft could be cracktested and polished and the same goes for the rods. They can also be replaced with aftermarket parts. One thing to be aware of with increasing volume is engine overheating. But the air/oil-cooled GSXRs seems to cope with almost anything without any problems. The above modifications can give anything between 10-50HPs depending on camshafts and engine volume. See dynosheet for an example of an stage 3 tuned 1986 GSXR1100.

 

5 Reasons to Big Bore
1) More skull-batering power
2) Wheelies? Thatīs torque for you
3) Impress mates with your bigger equipment
4) You wonīt have to sell your bike for something bigger
5) Itīs better than spending it on drugs

5 Reasons Not to Big-Bore
1) You might ruin what was a perfectly good engine
2) It might blow up and kill a load of penguins or something.(eh?)
3) If you donīt tell your insurance company, youīre probably not insured...
4) Itīll cost steaming wads of dosh better spent on tires
5) Maybe drugs are a better investment

The reasons are taken from Superbike magazine July 1996.

 

 

TURBO
If you want to do 200kmh(125mph) wheelies then turbo is the way to go. To get more power from an engine you have to get more air and fuel in to it so way not force it in. The turbo is a turbine that's driven by the exhaust gases and forces in more air. A turbocharged engine can easily make over 250HP. But without modifications to the internal bits (rods,crank,clutch,etc.) it wont hold itself together for a long time. Itīs not cheap either, but if you look for the ultimate in power there is now other way. In the 1998 Brute Horsepower Shoot-out at Daytona Mr Turbos Kawasaki ZZR-1100 made 494,4HP at the back wheel, beating last years Suzuki GSXR1100 which only made 429HP. The ZZR is clocked at 230,7mph(369kmh). Now that's a seriously fast bike and its only possible with TURBO.


190 REARWHEEL HP!!
190Hp GSXR The picture on the left shows the TTS modified GSXR1100W. With 1251cc, 190bhp and 106.1ft-lb torque it's really loony. Here is the recipe:
Bore the cylinders 4mm to accept 79.5mm pistons.
Stroke the crank 3mm now you got 1251cc.
Drop in Carrillo rods.
Gasflow the head.
Fit in Stage 2 Yoshimura cams and valve spring kit.
Keihin 41mm flatslide carbs with open bellmouths.
Youshimura 4-2-1 pipe.
Compression 12.8:1
Now you got your self a monster bike. When Performance bike magazine tested it they was a little disappointed at first as the painstakingly setup carbs has made the Gixer a pussycat. But only when you want it to be. "So what happens when the wrist and tendons move in anger? the GSX-R fucks of, that's what." They tested the bike on a very soggy Mallory park at the same time they tested a hot 400 and the drivers got weary frustrated that they couldn't catch it on the track, simply because they couldn't use full power without fear of lobbing the GSXR. "For the long right hander of Gerrards it was wheelspin in second and back off, onto the straight and more wheelspin, into third and more back end fishtailing." source 1997 Performance Bike magazine. Text inside "" are quoted from the mag.



Adjustable Ignition Advancer
To make your own ignition advancer is easy and it's FREE.

Step 1: Remove the lower fairing and front/right engine cover.
Step 2: Remove the rotor by removing the bolt in the center with a 6mm hexagon wrench.
Step 3: Remove the 3 screws holding the ignition plate and loosen the plate.
Step 4: Enlarge the bolt holes in clockwise direction.
Step 5: Reinstall the plate and rotor (rotor bolt torque 25-34Nm 18-25.5lbft).
Step 6: Twist the plate in counterclockwise direction and tighten the 3 screws.
Step 7: Reinstall the engine cover and fairing.
Step 8: Go for a testride.

Click on pictures for more info.
CoverIgnition adv
So, how much should you enlarge the holes and twist the plate? Well the advance should be 3-5° and 1° is almost exactly 1mm on the edge of the plate. So enlarge the holes about 5mm. The best way to find the optimum setting is to dynotest the bike and try different settings. The advance units you can by have usually a fixed setting of 5°. Be weary carefully not to over do it and listen for engine "pre detonation" which usually occurs at low RPM, high gear and high load. On an otherwise low tuned engine you could expect about 1-2 Hp in the midrange.

Adjustable Cam Sprockets
Well the deal is the same here, just enlarge the holes. The material is quite soft so its easily done by hand. You should enlarge the holes about 5mm in each direction. Way to do it in each direction? That's because when you have assembled the hole thing you almost certainly discover you have enlarged them in the wrong direction so do both directions. DON'T forget to loctite the bolts holding the sprockets when reassemble, you don't wana lose these. Why then you ask? Well if you skim the head the camshafts moves closer to the crankshaft and the cam chain gets a little "longer" so to say. The extra slack is reduced by the cam chain tensioner but that causes the cams to "twist" in relation to the crank so the timing gets screwed up. To restore it you must twist the sprockets on the cams. You can also use adjustable or slotted sprockets to "move around" the HP and Torque peeks of the engine that is however a much more advanced exercise which requires a little experience. I may in the future do a complete guide to camshaft timing, if I get the time.


Winter Riding!

Snow and ice outside? That's no reason to park your GSXR. Put studded motocross tires front and rear, dress warm and go for a ride. Thanks Anders for the info and awesome pictures. Top speed on ice with studded tires is about 215kmh(135mph).


 

 

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