GPZ Turbo project rego'd

[Benz]

Here's my gpz turbo now fitted with a gixxer '98 front and '91 rear end.
The motor is off getting an 810 Wiseco kit, new gearbox,and reconned head. Should be good for about 140 horses, and 140nm torque, I'm hoping. Obviously the front wheel is yet to be sorted, and I'm thinkin I'll just drop the complete front end in from my L Gixxer, as I want to retain the original GPZ speedo/dash, I'll need to have a speedo drive I can adapt to suit, the '98 forks and spindle don't help here.
Yeah, I know, what's the fairing doing on it[^]!! It's staying,and although it was a bastard to make it fit the usd's,I'm happy with the outcome. Bike will sit about 50mm lower at the front, making the fairing that much lower , and the arse end will be about 40mm higher than stock, with 17" wheels both ends it should settle into a nice nose down, arse up look.
I need to get hold of a pair of clipon risers, as I can't use the renthal bars method, as I want to mount the original indicator/idiot lights in that space.Problem there is everyone wants a friggin fortune for them
There's also the problem with the footpeg mounts, they rub against the larger swinger, and there's still plenty of other mods to go, but the beast will be on the road/track soon enough[8D]

[Gix11]

Looks like it's coming together nicely mate. The USDs really give it some body don't they? Are you keeping the side fairing half way down your engine cradle as well? It's just begging to lose that nose fairing mate. As soon as the flat bars go on it might change your mind. If you can pull the invisible front wheel off I reckon you're onto something mate.

[Benz]

Yeah Si,
I'm gonna try and keep all the original fairings, the alloy brace, and lower pan [obviously not in the photo!] included. It's a part of the bike that separates it from the N/A models, and buffed up will look schmick.
I put the tyre in there to gain some perspective, to see if the usd's would give me clearance for the turbo, and it looks OK.
Sure would be a lighter front end with the 'invisible wheel' but I think there could be problems slowing down[)]

[Slingblade]

those perspex wheels look amazing

Looks good mate. Your right Si it is always amazing how a set of USD'S and 17 incher instantly modernises the look of any aged bike. Imagine how good a condition those fairings would stay in hanging on your wall???

It will look great either way.

And with flat bars you'll have much better control of all those ponies on the road.

[cutcat]

Benz, how hard was the swingarm conversion?

[evad]

Looking sweet Benz, what FI are you running? Stock with race mode enabled?

[Benz]

The swinger changeover was pretty simple. The internal pivot spacer from the GPZ is swapped into the Gixxer arm [after destroying a pivot bearing on each]then you can use the original GPZ pivot bolt, the gixxer pivot bearings are virtually the same size,2x1mm spacer washers either side, and its in.
The Gixxer lower link has to be slimmed a little but will fit the GPZ mount.It fouls on the rear of the frame mount, so I tapered it a little on the linisher, and its free. There's also the problem of footpeg mounts.fouling the arm's movement. as to what I'm doing there is still a mystery
Ozcat sent me some extended dogbones, which are on the bike now, so they set the rear ride height, at this stage. I may make up some adjustables, so I can fine tune it later...
Stock fuel injection[dfi],race mode enabled, adjusted with a 5k pot,a malpassi adjustable fuel pressure regulator,adjustable boost controller from 8-16psi, with an uprated Ht10 to Ht 12 turbo[mazda RX7 internals]. It's not a fullon drag setup, but should make for a rush of a roadbike. The extra compression from the wisecos,[from 7.6 to 8.5/1] and another 74cc should give it good kick in the pants down low, and it was always fun on boost, so I should just get more betterer fun

[evad]

Are you on 750turbo.com? I see that Lorcan is getting 238 hp out of his now and over 200mph so the motors can definatly put out some horses. Should be a fun bike when its done

[Benz]

I joined 750turbo.com early 2002?, when I first bought the bike as a barely running mess from the local wreckers. It looked like someone had blasted it with a shotgun, there were that many dents in the bodywork. It got a complete [less motor]rebuild then , and it ran strongly , until the gearbox shit itself, and started jumping out of second. Okay [^]it was about 60 ft and 1.9sec out when it first jumped outa gear.......so I can't complain. Then the turbo shit itself, so it was rebuilt bigger and much better, spools up a heap faster with the larger compressor wheel.
I'm not lookin for big horsepower really,[sure..!] but I DO want a heap of torque, so we're goin small turbo, fast spool up[]

[cutcat]

Hey Benz, I am way impressed and thanks for the detailed review of what you have done. Can you explain about the race mode enabled box? and what fuel pressure are you running at max boost?

[Benz]

I'm not sure of my fuel pressure,and with the 810 kit , it will have to be reset anyway. This time around I'll have a F/P guage on board.....and setup on a dyno.
Race mode [on the turbo motor DFI only] is enabled by disconnecting two wires and inserting a 5KA potentiometer between them, to adjust fuel delivery +/- 20%over the entire map. It's a bit crude, and affects idle, usually making it a heap rich, so the throttle position indicator must be backed off a little.....easier said than done, as it's incredibly sensitive.The best part of race mode is it removes the 'overboost'settings, so you can dial up more pressure, and not have the bike cutout at max torque, somewhere around 6.5K revs [family jewels slam into tank, then once throttle is reduced, power is restored, and you're at the back of the seat,fighting to regain control!]Race mode also keeps delivering fuel on a trailing throttle, so when you accelerate again, there is less lag. Not very enviromentally responsible..., but helps keep the exhaust flaming.......
You can find out more details from 750Turbo.com, where I got most of my info. Lorc has a FAQ section, it's in there.

[Benz]

Here's the LHS, old huge rubber topped chunk a steel GPz peg and frame mounted gearchange gone, replaced with Gixxer peg/shift combo. I welded the geep mount to the gsxr peg, and fitted to the rear hole of the geep peg, Now sits 20mm higher, 20mm back. Still rough, there's plenty of tidying up to do yet...

[Benz]

Still got to find a place for the switch, and a spring, and obviously got to mount the actuator to pedal, but there is clearance, and the ugly cylinder mount has been ground off, making for a more balanced look, I hope....
This way you don't have to space the mounts to clear the swinger, and pegs are up and back, and shitloads lighter. Plenty to do yet, but I'm getting there.

[fimpBIKES]

piss the switch+spring off mate,
stu sells a little switch that replaces one of the banjo bolts


saves a lot of fucking about

[shift1313]

the bike is looking good. I remember when i threw my upper on just for kicks. Mine looked bad on there because the front was so much lower. I dont think i have any pics of it unfortunately. I see you are working out your footpegs just fine. I had the same problem and actually left a nice little chunk on my swingarm with the rear mastercylinder pivot. On your suspension linkage did you not have any clearance issues running straight to the swingarm? I had some straight linkage on my bike and the rear end sat really sqwatted.
http://filebox.vt.edu/users/maperez/...kage3small.JPG
What rear wheel are you running? if you are running a 5.5" you are going to have some fun lining up your sprockets. I think i moved my rear sprocket in towards the wheel a bit to get things right. I think HPU still offers an offset 530 sprocket for the turbo model up front. When i pulled the spacers out of my gpz swingarm it didnt destroy any bearings but mine slide in perfect in place of the inner spacer on the gsxr arm. The only part thats kinda funny is the small steped spacer the gpz arm uses. I used it on my bike but im going to make a replacement to the bearings get loaded properly.

I cant wait to see more pics of your bike, good luck with it.

[Benz]

Thanks Fimp, I've sent Stu an email, that switch will make things a lot easier, as there is precious little space left..... and I've still got to get a return spring on somehow.
Matt, my GPz arm would not give up its spacer without destroying a roller bearing, maybe it was the crap on the outside of the spacer that prevented it from sliding out.....who knows, I've replaced them now anyway.
There doesn't seem to be any hangups with straight links, but I will have fun getting the chain to pass over the top of the arm as it is, so there may be issues still to work out.I am considering trying to reverse the arm, so the linkage mount will be on the bottom,the '91 gixxer arm does look like it's symetrical, just haven't put a tape to it to find out for sure, but it would solve any clearance issues with the linkages.I'll go with it as it is, until the motor goes in, and look at it from there. I have used the gixxer bottom pivot, it looks like you went with the original, which is a different configuration
You're right about the weird little spacer from the Geep, I left mine out for now, but will have to do something about it when the bike is torn down to bare frame for a repaint
HPU is off my list, too many sus sales to guys on 750 turbo.com to deal with Mike. I'll probably just weld another cog to the original, and get about 8-10mm extra width, maybe lathe the outer face of the cushdrive[another 8mm there] and reverse the rear cog, good for another 2mm. I had to do something similar on the Katana dragbike, worked well.

[RussVC]

Hey Benz try Afam in Japan for a 530 offset sprocket, 3500yen which works out to $37-50 plus postage, I'm currently running a 630 chain on my Katana with 5.5" and 170 rear combo but will be upgrading to 530 stuff soon. http://www.afam.co.jp/E/menu_index/offset.htm

[trx900]

benz I have been keep in my eye on this post and I really like how your bike is coming along, as I used to own one of these bikes in 1987 it was my first big bike I traded my rz350 in on it, keep up the good work and I look forward to seeing it when it's finished.

[shift1313]

hey benz, the arm is not symetrical, and it looks like your using the same brake caliper as me, but mine has a machined channel inside the arm for the orig caliper to slide in. I had to make a spacer for the left side of my wheel so the nuts on the sprocket didnt hit the swingarm. I know for a fact there would be clearance issues on the flip side as well. I had to make a chain roller for the lower part of my frame(old center stand mount) so my chain didnt hit the lower frame when the chain slapped around on decel. I might have to revisit that as well. Also im pretty sure the 750 and turbo motors were in the same location so on your rear with a 5.5" wheel you are going to have to shim your front out a very decent amount. I made a 5/8" offset sprocket and machine the cush drive up a bit and that wasnt enough. When i was riding the bike i had some chain misalignment that i didnt like. Thats one of my projects today is to figure out what to do about that. I want it right this time. If the motor was so wide it shift it over 1/2" to help out but that causes problems with ground clearance, weight distribution and getting the header on. If you want me to try and snap some pics to show you what your working with id be glad to. The chain slider that goes over the front of the arm(stock gsxr) rubs the geep frame. atleast the 95 unit does. I actually had a 92 unit on there for awhile(same as yours) and it lined up fine, weird. I think it was the difference between a 5" and a 5.5" rear rim.