Hi all,
I currently race a gsxr in Australia in a post classic road racing series(PCRA of NSW http://www.postclassicracing.com.au/ )Ita a 1989 Gsxr 750 and have just fitted a 1st gen 1100 motor,Yosh exhuast,38mm slingshot carbs with stage 3 dynojet kit and Ul 98 race fuel running on 192 main jets.
Problems im having with it is getting the bike of the line at start as the clutch is just too grabby and wheelies at slightest chance(750 engine shot of the line like a rocket with no such problems)and secondly keeping it cool.
Ppl have said i should use a braided clutch line others said change plates even told to fit a 2 stage clutch,but ppl in aus know stuff all about early gsxr's here so thought id ask the guys in the know.
Also has anyone ran a second smaller cooler behind front fairing like the F1 racers of there time (see attached pic)and had any issues with oil pumps ect.
Any help or advice will be appretiated on this or anything else.
Thanking you.
If you're running the cable clutch conversion, you should be able to run heavy duty springs and good plates and slip the heck out of it to keep the front end down- just have to launch just beyond the torque curve, probably in the 6000 range. But with the 5-speed trans, keep the oil changed after every race to avoid clutch fibers plugging the oil pickup and burning up the engine. 6-speed setups can launch in 2nd gear with no problems.
Longer '90 1100 swingarm helps too, but then you negate the better handling of the 750 chassis. Playing with shock springs and settings can help too. Practice really is the key in my experience. Motul or other high quality full synthetic oil will help. Also, running the curved oil cooler from the '90 750 will help as well.
can't help you with 1052 clutch grabbiness, but on my mostly stock 749 trackbikes, i found out that the stock suzuki plates and springs worked better and lasted longer than aftermarket. what plates/springs are you running?
seems like you have good top-end. i am going to tryout some stock 90-92 750s 38mm carbs on my mildly built 749 with 1mm high compression pistons and such. what do you think of the 38's? what air filters are you running?
I ran the 38mm carbs on the 90 model 750 as they were standard for it,i put a dyno jet kit through it with a significant gain through the rev range but noticably top end.I was concidering flat slides but with standard motor didnt think it would be of value yet.But yes i would recomend them as my 750 held even with fzr1000's doen the straight.
After fitting the kit i was up to 137 mains up from 117,we put the standard springs back in the slides(as the dyno kit ones were too soft and touchy on throttle)rasised the needle 2 slots and got 106 rwhp with a nice smooth curve.Im running the 150mm long uni filters as i think it creates more air reserve air then the shorter pods and also advanced timing 5 degrees.
Im running the 90 model curved radiator with the 1100 and fitted a cooler behind fairing.
Also what oil viscosity do yous run,was told by shop to run 10w 50 but with the way the oil system works may not be letting full flow thru cooler with oil being to thick,could this be possible?
Im running stock plates,hydraulic line with motual 10w 50 in clutch with 14 /46 gearing(just hit redline at end of eastern creek straight)
The 1100 currently has 126 rw hp with 65pd torque not great but happy being standard but the power curve is just awesome over the 750.
P.s 86 gixxer ill get some pics up for you soon,cheers.
Gees, alot of people were stepping off their bikes, looks like they take it pretty seriously. Braided line will help with feel and control of clutch. Maybe it's just a case of getting use to the extra torque and clutch operation... I know I can thrash my 750 without too much fear of the front coming up high, whereas the 1100 really wants to rotate, and in the 750 package I imagine it's even more prone to this. Running an extra radiator is not a problem, just watch oil pressure and temperatures.
OEM Suzuki clutch parts are hard to beat overall, but I'd run Vesrah products just as well and have good luck with mixing Barnett springs with OEM/Vesrah stuff as well to get just the right feel.
Bottom line is practice and don't be afraid to abuse it off the line, use the clutch to control our wheelie, ride it like you stole it...
Here's some pics of it.
And yes they are starting to take this class seriously and as long as i can hand it to the fzr 1000's ill be happy as class ranges from 1982 to 1990 and them fz's are fast.
Think ill try the braided clutch line and try keep it out of the torque range,grow some balls and yeah ride it like i stole it lol.
P.s have you had problems with clutch slipping till bike warms up?could that be the 10w50 im running?
we run 10w40 in the 1216 drag bike with no problems! And NO synthetic!! it good for the motor but BAD for the clutches!! In the 1402 bike we run 15w40 rotella....yes diesel oil!!IMHO i would shit can the hydraulic and go with cable run factory clutches and steels you will get much more "feel' of the clutches engaging! and launch the baby at peak horse power at watch the rear tire blaze!!! and be sure to be layin down on the tank!
Last edited by OLDSKOOLDOILKOOLD; 07-25-2010 at 10:49 AM.
thanks for the fotos. one of my bikes also smokes on downshifts as well. i used to get black flagged, but they know me now. need to get the engine a rebuild, but still runs great.
thanks for the 38mm carb comments; i am going to try them out. fwiw: factory pro runs 147.5 mikuni main jets without the airbox for the 749.
i highly recommend mikuni RS carbs! i have a set of RS 36mm with 130 main jets and they ROCK! instant throttle response!
i also run synthetic rotella diesel oil with good results. i forgot the weight, but 15/40 or 15/50 sounds about right.
"And yes they are starting to take this class seriously and as long as i can hand it to the fzr 1000's ill be happy as class ranges from 1982 to 1990 and them fz's are fast."
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FRZ-1000 and fast brings one name to mind for sure here in the midwest USA, Fritz Kling- wicked fast rider and ballz fast bike. Some of the best local racing for sure pitted him against Steve Patterson and his big GSXR-1100 at Grattan & IRP in the early 1990s....
We ran 20w50 Kendal in our modded oil pumper race bikes, have used Rotella in many HD builds too.
Sorry guys the smoke from the bike is from a previuosly blown motor useing that same pipe filled of brocken piston and oil from a valve dropping.
Is a cable set up for the clutch easy to get?
Ive been told to go a 4 into 2 into 1 exhaust system to use the great torque these have instead of 4 into 1<im unsure as Yoshi woulda made one if so.
Sorry about the poor pics as im getting ready for a race this weekend,ill get some pics up later this week with all the little shrouds and peaces i have made and fitted,I.e carby shroud,headstem shroud for cooling under tank ect..
Thanks guys your help has been appreciated as we are currently the fastest racing oil cooled gixxer in Oz and just need that little bit more to hand it to them other smelly bikes of the late 80's, espeacilly the yamahahahaha FZ1000.
Cable conversion is straight forward, believe it is in the 'sticky' files and also on the oldskoolsuzuki site. Well worth the effort, especially on a race bike.
From my 7/11 experience, the newer (probably post 1995) Yosh systems outperformed the early build Yosh stuff both in feel and on the dyno. Had good luck with Hindle/Sudco as well. Probably depends more on the tracks you race as I'd imagine peak power would be just as good as some midrange from a 4/2/1 setup, although the 4/2/1 generally tucks under the engine better for additional clearance.
Hey.. Talking about racing on the old oilcooled machines, i just wanted to show some pics of my brother and me, racing the old bikes on a track, they seemed to take the "abuse" allright. But it's hard work to throw these old machines around the track, also the fairings seemes to hit the pavement a lot if one don't hangout a bit..
Knutstorp and Anderstorp in Sweden last year. It's me on the red/white and custom paint(neither of the plastic is for the road), and my brother on the Blue/white..
Edit: Sorry, but i cant help you with the problems you have..
Now preparing my bike for Vintage racing Mosport Aug 13-15. Unfortunately they want me to take off lots of road stuff ... I prefer "clubman" racing.. i.e. riding to the track, racing and riding home. However I guess my times would improve if I had a race fairing, new Ohlins, race goodies -- but spending a lot of $$$ is contrary to my nature. In the 60's I raced a '62 Manx that was new. This GSXR reminds me on the strength of that racing package. We didn't realize in those days how cheap we could race those Manx .. just tires, oil, gas, transport, a motor rebuild every few years !! So I am looking to race the GSXR like the Manx with minimum changes to the stock package. I find that careful preparation goes a long way to good results at racetrack, moreso than racer bits that eat up the budget.
I race WERA vintage 6 and 7 in the states on 7/11's. I have two 86 750 framed 1100's and run the hydraulic clutch. The only time I've experienced any symptoms of what you described is when I used a barnett clutch and springs. I've found that the stock clutch plates and springs provide the best feel and last the longest so I quit trying to save a couple of bucks and only use these. My smaller 1100 is a 1052 base with 1127 crank and slingshot cams it makes 135 hp on the dyno. My big motor is an 1127 bored 1216 ported with web cams and heavy springs. Stock compression and runs on pump 93 octane and puts out 158 at the rear with 89.2 ft/lbs of torque from 5800-9200 rpm. I raced in 100 degree weather last weekend and when I got back to my pits I shot the motor with a heat gun and it was at 288 degrees F. I also run the curved radiator and only use Klotz 10w40 as this was recommended by the cam manufacturer. What temperatures are you getting when you get in the pits and has the additional radiator dropped the temp.
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