My supercharged K8 project...

131751 Views 192 Replies 85 Participants Last post by D.Man, Feb 10, 2015

toro1

Discussion Starter · Mar 31, 2011

The bike pictured above is my bone stock K8. A friend gave me a fantastic deal on this bike last year, and it has just under 2000 miles on the clock. I love this bike for the same reasons everyone does -- incredibly smooth, extremely capable and controllable, great power, and fantastic ergonomics for a supersport machine. The local Dynojet 250i says it puts down 152whp (SAE corrected), which is actually more power than a full-exhaust, PCIII-tuned '04 ZX-10R produced on the same dyno.

Now, normally the next step would be to add an exhaust, change the gearing around, or add some braided lines, and while I'll eventually get to those mods, I have something different in mind right now...

It's a Rotrex C15-60 supercharger, right off the plane from Denmark. This little unit can support over 230whp, and that's the number I'll be shooting for with my little project here. Also, the impeller wheel used to be cast, but these new wheels are apparently machined out of billet.

Before you ask, yes, I am a power junkie. There's just no going back once you've ridden a boosted literbike...

You can see how small it actually is compared to the bike. Somehow, some way, it will fit in there...

After staring at this sight for a couple of days, I realized the only place to put this thing is in-between the engine and the radiator, just below the frame. I'd love to stick it up higher, but the frame would get in the way of the belt (which is a dealbreaker) and the radiator fan would also have to be relocated. Placing it lower eliminates these problems, but makes it much harder to hide the drive behind the fairings and also places the inlet of the Rotrex very close to the header. I also do not want cornering clearance to be compromised at all, so it will be in as far (and up as high) as possible.

If anyone is wondering how I plan on driving this thing, take a look at the picture above. The M10 bolt currently fastened into the end of the crank will be removed and a machined adapter will take its place (this adapter has to locate perfectly off the crankshaft for this to work). A pulley will sit on top of this adapter and then drive the supercharger via an 8mm synchronous belt. The supercharger bracket will either take the place of the stock cast cover or locate off of it -- I'm not exactly sure yet which way to go.

There's a lot of work left to be done, but I'm looking forward to it. I plan on tuning the ECU directly and, of course, it will run on pump gas. In the meantime, wish me luck, and stay tuned...

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toro1

Discussion Starter · #21 · Apr 22, 2011

mpp12 said:
Here in dominican rep. for some reason of the universe the K7 pumps have failed miserabily and my mechanic uses the K5 ones, since they are easy to find car pumps that fit. I think that mitsubishi lancer evo is the same or hondas.

If I where you I would use a external pump with a external presure regulator.

There is no other pump that fits like the K7 one.... they are small maybe that is the reason they are failing like that.

I wasn't aware of K7 pump failures. I have read of a few cases where the pickup filter became clogged over time and lead to poor performance, but nothing in particular was about the pumps themselves. What kind of failures were seen? Were the actual causes of failure ever determined?

mpp12

· #22 · Apr 22, 2011

you ride the bike and it simply lost performance, gradualy. until the problem became more aparent, at first was in hi load conditions.

the filter could be clean.... simply the pump itself was tired if you could say that word.

I think that people that run the bike on low fuel all the time (hi heat) and also the size of the pump fisicaly does not help.

The K7 was rated a bit more than the K5 and lighter but I think it came with a very negative price.... remember we ride here all the time, all year.

toro1

Discussion Starter · #23 · Apr 22, 2011

Gotcha. Thanks for the input. I want to run some tests on the stock pump to check on things like the temperature at various pressures and voltages, and then compare it to a Walbro. The older style pump housing always kept part of the pump submerged, but the newer style housing has a flat bottom and, as you said, could lead to much higher operating temps (and premature wear) if the gas is run down all the way.

mpp12

· #24 · Apr 22, 2011

Just put a K5 pump... more reliable.
you need to put the float in a diferent position in order to work.

The Ripper

· #25 · Apr 30, 2011

Update?

See Steddy Win

· #26 · Apr 30, 2011

INTERESTING build.

With where the supercharger has to be placed, you could have went with a really, nice, small turbocharger and not worried about heat soaking the living hell out of compressor side.

A centi super will come up a lot more controllable, but one thing you're going to have to keep in consideration is the amount of revs versus the pulley you're going to be running.

:lol

Not to mention the amount of cyl pressure a supercharger adds versus a turbo. With a smaller turbo you probably could have ran a non intercooled set up, been reliable, and made the power you are aiming for at a lot safer cyl pressures. Superchargers make some SERIOUS heat.

Granted this isn't a roots style blower, but still, I take it a uber rich AFR will be your means of intercooling or are you aiming to run an air-air set up?

:lol not to mention a by-pass system to keep surge under control.

Very interested.

Good luck.

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toro1

Discussion Starter · #27 · May 2, 2011

Steddy, this is not my first Rotrex-equipped bike. I've been personally running my stock-internal, non-intercooled, pump-gas powered VFR on 10.5psi since '07 without a single issue to speak of. As you said, tuning is key, but the boost curve of a centrifugal supercharger is just about as good as you can get for running safely on pump gas. This bike won't be pushing that amount of boost, but I do plan on it maxing out the C15-60.

I will be utilizing a vacuum operated Bosch bypass valve to limit surge. To tame the exhaust heat, I plan on wrapping the entire unit with Thermotec shielding, and also plan on running a separate oil cooler for the Rotrex itself.

You just cannot beat the tuning benefits and controllability that a supercharger provides, and though it can be tricky to implement, I love the challenge (and, of course, the end result).

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Mike Edwards

· #28 · May 2, 2011

mpp12 said:
you ride the bike and it simply lost performance, gradualy. until the problem became more aparent, at first was in hi load conditions.

the filter could be clean.... simply the pump itself was tired if you could say that word.

I think that people that run the bike on low fuel all the time (hi heat) and also the size of the pump fisicaly does not help.

The K7 was rated a bit more than the K5 and lighter but I think it came with a very negative price.... remember we ride here all the time, all year.

It has nothing to do with the pump and everything to do with the filter. Unfortunately by the time you realise the filter needs changing it is too late and it has backed up and blocked the rest of the pump also.

We have never been able to get a pump working as well after filter problems as it did before.

Either check regularly or just get another K7 pump from eBay, they are fairly cheap.

Mike Edwards

· #29 · May 2, 2011

toro1 said:
Since I know the output of the stock pump cannot support 250-260 crank hp, some upgrading will need to be done. I yanked the stock assembly to see if it's possible to shoehorn in a Walbro, but there's just absolutely no way.

Simply crimp the pressure regulator and you will be surprised at just what a stock pump is capable of.

toro1

Discussion Starter · #30 · May 2, 2011

Mike Edwards said:
Simply crimp the pressure regulator and you will be surprised at just what a stock pump is capable of.

I very well might end up doing just that. I still want to thoroughly test it, though, before deciding which way to go.

Maj750

· #31 · May 3, 2011

There is a bosch that is closer to drop in fit ,
info here http://www.suzukihayabusa.org/forum/index.php?topic=144442.0

With a fairly good filter on my 08 busa i still could only get 300hp of fuel flow at the 65 psi base pressure i needed to start with, i'm going to revisit the intank pump idea but remove the filter and build a 3/8 stainless hardline to replace the filter and run an external filter and reg

toro1

Discussion Starter · #32 · May 3, 2011

Thanks for the info Maj. That Bosch pump is still the size of the older design, though -- the K7 & K8 pump is an entirely different animal. I realize I can replace the housing with one from an earlier bike, but my goal is to use as many of the original parts as possible.

T.R.E

· #33 · May 3, 2011

toro1 said:
but my goal is to use as many of the original parts as possible.

Hi Toro,now that you mentioned it,are you are going to use ecueditor to flash the stock ECU since it can control fuel vs boost,retard the timing etc etc?

Keep up the good work! :cheers

See Steddy Win

· #34 · May 3, 2011

toro1 said:
Steddy, this is not my first Rotrex-equipped bike. I've been personally running my stock-internal, non-intercooled, pump-gas powered VFR on 10.5psi since '07 without a single issue to speak of. As you said, tuning is key, but the boost curve of a centrifugal supercharger is just about as good as you can get for running safely on pump gas. This bike won't be pushing that amount of boost, but I do plan on it maxing out the C15-60.

I will be utilizing a vacuum operated Bosch bypass valve to limit surge. To tame the exhaust heat, I plan on wrapping the entire unit with Thermotec shielding, and also plan on running a separate oil cooler for the Rotrex itself.

You just cannot beat the tuning benefits and controllability that a supercharger provides, and though it can be tricky to implement, I love the challenge (and, of course, the end result).

:twothumbs

Hey I wasn't a doubter by any stretch of the imagination...more curious than anything. Forced induction on a motorcycle engine isn't overly common, unless the thing is a straight drag bike USUALLY.

Can't wait to see the finished project

toro1

Discussion Starter · #35 · May 4, 2011

T.R.E said:
Hi Toro,now that you mentioned it,are you are going to use ecueditor to flash the stock ECU since it can control fuel vs boost,retard the timing etc etc?

Yep. Actually, while I have downloaded and played with the ecueditor software, I'm going to be working with Guhl Motors for the tuning. I've spoken to Don and he really knows his stuff, so I think I'll be able to do exactly what I want with the stock ECU.

I'm thinking about generating a couple different maps (that can hopefully be assigned to the stock ABC power switch); one which will allow me full power for hooligan antics and general around town riding, and one which will allow full throttle while keeping the front end on the ground (the best that it can, anyway). The timing and secondary throttle plate control on a per gear basis should be the key to making it work...

T.R.E

· #36 · May 4, 2011

toro1 said:
Yep. Actually, while I have downloaded and played with the ecueditor software, I'm going to be working with Guhl Motors for the tuning. I've spoken to Don and he really knows his stuff, so I think I'll be able to do exactly what I want with the stock ECU.

I'm thinking about generating a couple different maps (that can hopefully be assigned to the stock ABC power switch); one which will allow me full power for hooligan antics and general around town riding, and one which will allow full throttle while keeping the front end on the ground (the best that it can, anyway). The timing and secondary throttle plate control on a per gear basis should be the key to making it work...

I don't know about ABC,but you can easily make 2 sets of maps including fuel,ignition,secondary plates etc,and change between them on the fly by grounding or not pin 66 via a toggle switch...

From what I've read on other discussions,setting the injectors to spray on 50-50 basis gives you the most amount of fuel you can get out of the stock injectors,and if combined with an increased fuel pressure ( 4 bar? ) you might not need to change the stock pump...

Anyway,keep up the good work! :cheers

toro1

Discussion Starter · #37 · May 17, 2011

I was able to mill the pulleys for the bike this past weekend. First, I had blanks CNC turned by a local shop to my specs. Then, I made a fixture to perfectly locate the blank and mounted that into my CNC mill:

Finally, I created a program to machine the pockets, set the tool height, and presto:

The machining process for the the supercharger pulley is the same, and once I get the teeth cut in both pulleys (for a Gates PowerGrip GT2 belt), I'll send them both down for hard-coat anodizing. This hard-coat will keep the relatively soft aluminum surface from wearing over time as it is basically as hard as diamond.

More good stuff still to come once I find some time...

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piester

· #38 · May 17, 2011

can we see some close up shots of the pulleys? i love it ha

toro1

Discussion Starter · #39 · May 17, 2011

I'll post some more pics once I get the teeth cut -- it looks like jewelry afterwards.

piester

· #40 · May 18, 2011

toro1 said:
I'll post some more pics once I get the teeth cut -- it looks like jewelry afterwards.

thats why i asked

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