Supercharged!

[mattyv74]

I'm now pretty happy with my bike cosmetically and suspension wise. But now I want some grunt.
I cant afford a 9 engine, head work won't really do what I want for acceptable $, turbos are too lethal when they lag or boost-up mid corner, and NOS is just plain silly.
But we have some experience with supercharging.
A normal roots type blower would work but won't fit, but I've got both a T2 and a T3 turbo at my disposal. The idea is to rplace the exhaust housing of the turbo with a belt drive. This in turn would be run off the crank. The result would be a centrifugial blower. It would easyily fit and will boost straight from idle, so no dangerous lag.

Compression ratios, cam timing and ignition is sorted. But I still have two issues to figure:

1- Crank drive, I've never had the bottom end of one these apart so I don't know if the nose of the crank or the bearings will cope with the extra load of driveing the blower
2- Induction, I know it can run well with carbies, but blowers respond best to injection. How adaptable are the throttle bodies off the old GPZ turbos. I've got acces to a complete but smashed one of them

Does any body know of any resources that I can learn more from or know anybody who I could share ideas with? any of you guys?:mrgreen:

[Bluefly]

Lay off on the smiley's and get back to studying!!!!!

[mfzx6r]

Matt
No idea on supercharging but
That new Aust mag Moto 1 or what ever its called has two turbo bikes in it
and one is a zx12r.
The guy in it will have some idea and I'd give him a ring for info.
They did have to change to forged pistons on the zx12r after they melted
tho so supercharging may have the same affect

Grab the mag at the newsagent and have a quick look it may give you some insight.

mario.
What are you studying to be ?

[mfzx6r]

I know sorry but it aint my fault.
I submitted the first one and the error came up so I thought it will go through anyway so I went to the forum index and then to new posts since
and it showed bluefly's as the last reply so I did it again and same thing so I did it again and same thing so I gave up and when I had a look anyway even though it still showed that bluefly was the last reply to my shock/horror I overposted !

mario
Oh well now I'm getting closer to Yoda.

[mattyv74]

WooHoo! YOU TRIPLE POSTED. I'm glad I'm not the only one having the problem.

At the moment I'm studying Human Movement. At either the end of this year or another two years(depends on my marks), I'm planning on doing Physiotherapy. I'd like to get involved in sports physio and accident re-hab. So a blower will help the 7 keep up untill I can afford that 10.

[mattyv74]

They did have to change to forged pistons on the zx12r after they melted
tho so supercharging may have the same affect

That's a common problem with torbos because;
a) you burn a shit load of fuel, so it makes more heat.
b) The air gets really hot in the turbo, thats one of the reasons you use intercoolers. It's a bit hard to fit one in a bike though.

We've found that larger engines, upto 8litres, all need forged pistons. But often in really small engines, good cast pistons are fine. You actually make more horsepower with cast ones coz they are much lighter. But they tend to fail sometimes. Last time it happened to me we were doing 90+MPH in the boat. We ended up with oil on fire every where! and we got really wet when the we can to a stop too quickly and got swamped by our own wash. But that was OK coz it put the fire out.
Need to figure this out though. I like my nuts where they are thankyou

Heck, I've just hijacked my own thread.

[Smitty]

I'm now pretty happy with my bike cosmetically and suspension wise. But now I want some grunt. ..snip..Does any body know of any resources that I can learn more from or know anybody who I could share ideas with? any of you guys?:mrgreen:

Matt
you are mad...a 7 isn't quick enuf???
there isn't a street car on the planet that can keep up with you
and only 900 or litre bikes will be quicker than you as well....
oh well...
as someone who had a turbo bike..yep the ol' GPZ750r Turbo
great in a straight line...NOTHING came close....
ooopsy do ...when we talk braking and cornering
although I am sure the 7 would be better than an old 750r...

can I suggest you go back to studying instead of thinking bikes.....


cheers

[mattyv74]

Hmmm... begining to sound like bluefly.hahahaha
Nah, my last exam starts at 1:20 today and I'm no good at cramming.
But then IM ON HOLIDAYS AND CAN RIDE ANYTIME I LIKE WHILE YOU ARE ALL AT WORK . Might see if Rossi is up for a mid week stroll.

But seriously Yoda, any ideas?

[Bluefly]

Smitty1955 wrote:


can I suggest you go back to studying instead of thinking bikes.....

I'll second that. And when exams are over, think of girlfriend instead. MATT YOU ARE OBSESSED!!!!!
_________________
Bobbi
Black '97 ZX7R (aka RandyV)

[Smitty]

Smitty1955 wrote:


can I suggest you go back to studying instead of thinking bikes.....

I'll second that. And when exams are over, think of girlfriend instead. MATT YOU ARE OBSESSED!!!!!
_________________
Bobbi
Black '97 ZX7R (aka RandyV)

oh 2 postings of sig.......nice.....

and there is no way I am gonna get involved in this one...
guess I will keep the answers to bike matters....

[icebreaker]

What pulley is going to run the supercharger???

[Smitty]

..snip..
But seriously Yoda, any ideas?

Matt you said.... But we have some experience with supercharging. A normal roots type blower would work but won't fit, but I've got both a T2 and a T3 turbo at my disposal. The idea is to rplace the exhaust housing of the turbo with a belt drive. This in turn would be run off the crank. The result would be a centrifugial blower. It would easyily fit and will boost straight from idle, so no dangerous lag.

Alrighty....
putting on modifiers hat (and having played with turbos and superchargers on cars)..
here we go...
mate...
won't work...using a turbo body with belt drive!
why..???
the fan in the turbo body is short (length wise)and requires
VERY high revolutions to compress the air (or air fuel mixture)
whereas
a supercharger has a long(ish) body and a different fan (called a screw..but you knew that) that uses its length to compress the air...
really..
its all a matter of physics....
superchargers are normally driven (rotated) at around the same speed as the engine (underdriven at maybe 80% of engine speed or overdriven at up to 120% of engine speed) but a turbo requires rotational speeds of up to 40,000 rpm to work (or up to about 6 or 7 times engine speed) to compress the air...due to the small volume of its body..
all to do with the volume available to compress air... and metallurgy says
you could not rotate a supercharger screw at 40,000!!!..it would come a part...blammm
and you would also have a problem getting a belt (or chain) that would stay on or stay together at those sort of revs...
so no...a belt driven turbo ain't gonna work...
supercharge it...with a belt driven off...? what??? thats a problem...
or turbocharge it....
BUT
put the turbo body as close as you can to the exhaust port
gets rid of lag...you see....
they don't do this normally with cars... (cept SAABS and Porsches)
and you get lag...'specially in a Vee engine
SAAB put the turbo body about 20-30mm from the zorst port
(as part of the zorst manifold..and so do Porsche)...no lag
BUT..lots of heat..so you need an intercooler
with its plumbing issues....
a turbo with an intercooler would be an easier proposition on a bike
..as has been done....
oh...and you REALLY do need fuel injection...not carbs....
you can do it with carbs...but it will have to be a drawthrough setup
(carbys external to the pressurized system)...
don't even think about a a pressurized system on a bike...
where are you going to put a pressurized plenum...with all the carby throttle controls....
FI is best.... as I said....

mate
does that give you something to think about....

cheers

[mfzx6r]

Matt
After reading Yoda's reply it just seems too much hard work.
This is what I'd do if I realy wanted to keep my zx7 and blow away/suprise other bikes I'd just fit a worked early model zx9r motor
in the zx7r frame simple. It works and its been done lots of times and all the hard work nutting it out is done for you. Hell there's even a few with
VFR single sided swing arms fitted.
Its all been done and its very trick looking.


mario

[Smitty]

Matt..snip..
I'd just fit a worked early model zx9r motor in the zx7r frame simple.
mario

hmmm...
like it... its simple...
just like the Holden V8's I throw into early model Toranas..
everyone says...where the phaarrrk did he go...?
NOTHING beats 'more cubes..'!!

[mattyv74]

Thanks Yoda, thats the beuty of these forums coz you bounce ideas around.
I agree with what you've said above.
Injection is the way to go.
A roots or screw type blower is too large and requires too much force to be able to drive. A 3/71 screw blower takes 180hp to turn it at 6000rpm. Wont work.

I have seen the modified turbo done on one of my old customer's boats. Will try to find some pics for you.
He was running a T07 on 374ci cleveland. His main problem was keep the belt on it at 7500rpm (these are not cheap motors).
The solution he came to was to run a step pulley system. Two 200% stepups,2:1 driving 2:1 this gave a total overdrive of 400%.
If I can generate enough rpm for the compressor it will work. The issue is getting drive.
Use of a surpintine belt will put too much load on the front main. A gilmer belt will be needed. Similar width to those used on mechanical fuel pumps on Kieth Blacks and Rodeks.
The challenge is to keep the high speed belt (the one on the compressor shaft), is as as short as possible to minimise whip and stretch.
By running an over size compressor, we can absorb some inefficiency of slightly lower rpm if that means keeping the whole show together.

The worst thing you can say to a hot rodder is "that can't be done"
We"ve put a tunnel rammed LS7 454 in a ford Anglea before.
Both our Hot rod and my brothers Charger will beat his mildly worked ZZR1100 to 200km every time.
I never said it would be easy. We'll through some ideas around on the next ride if you like. Is that the longest post ever?