[92xjunker]

Here are some pics, I decided to modify the rear fairing on the turbo side to allow me to mount it all back up. I was tired of running around with the wastegate all exposed and the bike slightly naked on the not so sexy kat frame.

Originally I drilled a nice 2.5" hole but i was slightly off and had to dremel it out for it to fit, I will prob have to go back and clean it up but it looks good. So the bike is 98% complete, now all i have to do is modify the oil fill cover plate for the turbo drain oil AN fitting.

Sry but no video yet of it riding, today was the first nice day that I didnt have any plans but work so I was able to get this done. I'll figure out the video situation soon.

ALso I think I figured out why this thing feels so much peppier or quicker in the lower RPMS. Increased back pressure in the exhaust will increase low end tq and I think the turbo exhaust inlet is a restriction lol. The turbo exhaust inlet was super tiny like 1.25"-1.5" compared to the 2" piping that I used for the exhaust (stockish size). So I think that is causing back pressure thus increasing my low end tq.

Nice build... but, you should do something with the turbo inlet, It sticks out too far. throws the bike way off. looks like a crash bar, Maybe a steel plenum or tighter bends, being that I can't see in person it may be how it has to be? As for the turbo sizing, If you reduce the inlet pipe and open the turbo inlet, you can increase your exhaust velocity, which will help your low boost issue and help with spool up efficiency.

[91_gsx600F katana]

thanks guys.

I'll see what I can fab up to make for a boost leak tester.

craven, the ports your looking at are the wastegate (large hole on the left side) and the small hole on the top right is the 02 bung which at the moment has a plug in it.

I know the exhaust hole is rather small on the turbo and I did contemplate porting it when I got it. I think what detered me was getting shavings in the brand new turbo lol, sure I could have put a wad of paper towels in it but then again I didnt know what I was doing with the exhaust etc so I left it alone. Now I should be able to port it if I pull it out again. Also I remember that the casting was not as thick as I would like it to port it enough, prob like 1/4" thick roughly at the corner bend, so grinding it out would weaken the flange mount which currently is used to mount the turbo (not something I would want to weaken too much).

92xjunker, the turbo inlet is what it is. I couldnt tuck in closer as I needed room for the Vband otherwise when I put the fairings back on it would cover the vband which means I wouldnt be able to remove the exhaust or fairing easily. At the same time mounting the fairing would be super hard. I could have went with a more modded fairing that would just slip around it (maybe 2 pieces) but I was going for decent looks there. Once you figure out how far the Vband must be then you have to route the exhaust to the vband, which in this case is one serious bend (90*+) and to not hurt flow I wanted it to be as smooth as possible (No hard right angles). There is absolutely no other way to get the exhaust in closer than it is WITH the Vband flange LOCATED WHERE IT IS. With that being said I could make it cleaner or closer to the bike by deleting the vband completely and welding right to the turbo flange. Complimented by a 2 piece fairing would allow me to run the exhaust closer by about 3" roughly but then I wouldn't have any room for the Waste gate (which is tucked in behind the fairing at the moment. Remember the waste gate much attach the exhaust before turbo to exhaust after turbo which means to remove the exhaust from the header to the turbo would require removal of the waste gate to the exhaust every time I need to pull the exhaust. My way just makes my life easier as its removes without taking 40% of the turbo apart.

You might ask, well how many times will you have to remove the exhaust once its completed. My answer would be every 3-6,000 miles for an oil change! the V&H header collector is directly below the oil drain plug, so I would have to remove the header back exhaust to perform an oil change. WHich is the main reason I picked this design. Also the exhaust prob sticks out about as much as the stock exhaust and is tucked up behind the the riders leg.

[ManQu]

I would do a rolling road session at a tuners ,they will be able to tell you whats going on and when and at what speed....

[crazycraven420]

I would most definitely do something with the exhaust to turbo transfer, maybe just a reducer even so you dont have to compromise the turbo inlet. With a naturally aspirated intake that would kill flow so im sure its affecting the turbo from fully spooling

[91_gsx600F katana]

Picked up some parts today to make my own turbo boost leak tester. SHould be able to pressurize the charge pipe and plenum together to check for leaks. Im sure I got a million pin holes lol.

I will prob pull the exhaust and grind out that turbo inlet for a smoother transition as well.

Contrary to popular belief header/exhaust size is less important on a turbo setup, and undersized is usually better. This is compared to a NA motor which are 2 completely different animals. Just like how forced air induction changes a heads/intakes flow characteristics, hell even fuel jets flow a hell of alot more when under pressure.

Here is some good info on exhaust sizing etc for turbo applications. Quoted right from the site

Pipe Diameter?

Another very common question is what pipe diameters to run?

There is no simple answer to this either, although I will use a simplistic rule "smaller than you think is necessary". Most people want to go big on the pipe, and there is nothing wrong with that. Going too big on the pipe, for the most part, isn't a huge negative.

The only situation I stress on this is exhaust header pipes. IE primary pipes. Go small. Very small. I've played with different sizes and have never ran into a small pipe that was *too* small. Regardless to HP!

Just my opinion as always, but even the biggest, baddest 1000 hp bike, I wouldn't run bigger than 1.5" primaries. I have experimented with pipes as small as .8" ID and found no notable disadvantage. I normally run 1.125" ID pipes, simply because they are easily purchased in my area.

Cold pipes, I base my size off of the turbo outlet. If the outlet size is 1.5", then step it up to 1.75" just to play it safe, but that'll be more than enough.

The only exception to this rule would be the exhaust pipe, assuming you run more than a dump pipe. There is no such thing as too big in that catagory. I run at LEAST 2" on all my systems, preferably 2.5", and even then I'll run dual 2.5" if I can work it into the system.

Any back pressure after the turbo is robbing the turbo efficiency. Every single quarter of psi is lost hp. So make it as absolutely free flowing as possible.

Header Types?



The two biggest types of headers used is "log manifolds" and normal headers types. Log manifolds have the different cylinders feed into a common log at indirect angles, and usually have the turbo feed at another indirect angle. Where as the normal header type will look more like a stock header with a collector conforming with the flow anges into one outlet, that then feeds directly into the turbo.

There is no question that the latter is better. But its not a huge difference. If you don't have the fabrication cability, or the realistate to make a nice collector, don't stress it. It'll still spool just fine. Your effeciency might be slightly lacking, it might spool slightly slower, but it'll be slight.

Always try to make things flow into each other as smoothly as possible, but if you have to make a hard transition, don't let it keep you up at night. It'll still work just fine.

[crazycraven420]

Always try to make things flow into each other as smoothly as possible

Just sayin I think by cleaning up that junction an addressing any pinholes will make a pretty noticeable difference. A reducer would funnel all the air at a higher, more direct rate.

[92xjunker]

As for the turbo sizing, If you reduce the inlet pipe and open the turbo inlet, you can increase your exhaust velocity, which will help your low boost issue and help with spool up efficiency.

I know my turbos What size is the exhaust pipe, bigger than the intake by 1.5? a rule somebody once told me, I use it as a base rule.

[91_gsx600F katana]

Thanks guys, I decided to tear it apart today and start all the work. If Im going to enjoy this I want to enjoy it fully!

Craven, I did what you said and obivously I thought it was a good idea lol.

92xjunker, Exhaust pipe is stock/aftermarket size, Basically thought that making it the size of the exhaust would be a smart idea. Basically its 2" OD tubing at 16 gauge, expanded to like 2.25" to attach at collector. Turbo exhaust (undertail) is the same 2" tubing as it fit very snug in the exhaust outlet flange. Intake pressure tubing is 1.5" OD tubing. So 1.5X the intake 1.5 = 2.25" which is what the exhaust should be. So it might be alittle undersized but the 2" exhaust pipe is much much much larger than the turbo inlet hole size, which was more like 1.5"-1.25"DIA (as you could see in the pics). the exhaust tubing is larger than the flange hole as well by 1/8" roughly as well which you could see in the pic I uploaded before.

THis is what I did today. I used the carbon outline of the ID of the exhaust pipe/flange on the turbo as my guide and ported the turbo casting to the carbon mark. I tried to smooth the transition enough so that it would flow better while not making the casting too thin. About an hour later I ended up with a much smoother transition. Then I went and smoothed/ported the exhaust flange so it matched the ID of the exhaust pipe to the turbo inlet. So now its a much smoother transition and should speed up velocity into the turbo.

Please see pics of the ported to non ported flanges and how it all matched up in the end. I think this will help with spool... dont u? lol

Now I noticed that the Wastegate must have been opening as it has carbon on the exit into the exhaust. Which means that I was reaching 4psi in the exhaust from excessive back pressure or I was hitting the actual 4psi boost. Which means that my boost gauge might not be reading accurately or too much backpressure causing it to open and me to not reach full boost.

I havent tested the pressure side for boost leaks yet. I hope to be able to do that tmrw.

[crazycraven420]

looking good man, that should hopefully help it at least spool a bit sooner if you are indeed hitting 4 psi as planned.

[91_gsx600F katana]

Well I must be hitting 4psi In the exhaust or somewhere as the wastegate must have opened for it to have carbon on the exit. But now that I think about it.... the exit on the wastegate is open to the exhaust at all times so carbon could have been pushed in from the exhaust flowing past it. So maybe I'm wrong. All I know is that I got only 2 psi boost on the gauge during WOT so either Im not spooling (turbo to big) or exhaust pressure too great pushing open the wastegate to vent exhaust not allowing turbo to spool fully, or pressure side there is a leak, or boost gauge isnt reading accurately, could be the boost block causing bad boost readings or the 6ft of copper tubing giving a lower reading idk.

So addressing the exhaust flow into the turbo as been accomplished. I will check for boost leaks then maybe figure out a way to test boost gauge (which i dnt think is the problem).

[crazycraven420]

exhaust pressure too great pushing open the wastegate to vent exhaust not allowing turbo to spool fully

So addressing the exhaust flow into the turbo as been accomplished. I will check for boost leaks then maybe figure out a way to test boost gauge (which i dnt think is the problem).

that's what I was thinking, im wondering if a heavier spring in the wastegate is actually a bit better. That way its not unintentionally leeching out though hopefully the ported inlet will help

[Christ]

Quick test for the wastegate - Lock it shut. Remove the actuator from it completely, and wire the bastard shut as tight as you can get it.

One pretty common issue with the chinese copies is casting quality/milling quality. The wastegate [if it's an internal one] probably isn't sealing anyway, allowing some blowby. Try to clean that up and get a flat, positive seal, and then wire it shut and see if you build any more boost. If you don't, it's not the wastegate.

[91_gsx600F katana]

Craven, thats basically what Im thinking, perhaps there is too much backpressure and a heavier spring will allow more pressure before it opens thus allowing more exhaust and boost. Well see what happens after everything I just did.

Christ, I will prob have to do that if this doesnt work, I would be really afraid of more than 6-7psi boost tho as thats about all the stock motor can take.

So today I spent alot of time on the bike and got alot done. Basically pulled the whole pressure side and set it up with my homemade boost leak tester. Which consists of stuff from home depot, Cast Iron reducers from 1.5" OD all plugged into each other with teflon tape down to 1/4" NPT which has the nipple for the compressor. Rubber end caps with a 2" ID to fit all over the carb ports on the plenum and then a 1.25" coupler which actually has a 1.5" ID to fit the Iron fittings to the pressure pipe. All connected together and tight, blocked Pitot tubes and actually decided to add a fuel pressure gauge so I could see exactly how much PSI was in the system so I could tailor it to my setup. It worked beautifully and with too much PSI the rubber caps shot off like a shotgun and scared the crap out of me a few times.

THis is what I found out. The single spring in the BOV with 3psi boost would not seal and there was a slight leak from the BOV valve (this is without boost on the BOV nipple which would help seal) But It leaked right away and would lessen if I blew on the BOV nipple bit still wouldnt seal. SO I decided to swap it out for the larger stiffer spring, it helped but still leaked around 4psi. So then I swapped in both springs which would allow it to seal to about 7/8psi when I got to 10psi the BOV leaked and applying mouth pressure to the BOV nipple helped seal but wasnt perfect. Once I got around 4psi and got the BOV sealed with 2 springs I sprayed windex around the welds and BOV etc on the whole pressure side including plenum. I had a bunch of pin hole leaks around the BOV welds, and some on the tube welds. Good news is that the plenum is fully sealed except around the pitot tubes which had some pinhole leaks as well. SO I decided instead of welding the holes which I figured out on the fuel line petcock setup I made would never fully seal around the thin wall steel tubing (pitot tubes) and I didnt have alot of room around the BOV flange to get a good weld anyway which is no doubt why I got some pin hole leaks in the first place. I Decided it was a good idea to try RTV!!!! Woohooo. I covered all the areas and let it dry and came back a few hours after work and tested it. No leaks!!! And this thing is basically sealed to about 7-8psi without Boost/pressure on the BOV nipple which would increase sealing. So I think its good to go.

Note to ppl who buy the ebay BOV's... they say they can handle 25+psi.... ha I just proved that wrong and 10psi is not even close!

I put everything back on the bike and got most of the bike back together. I wont be able to test anything till prob fri or the weekend as we are suppose to get lots of rain the next 2 days.

So those are my results. If I end up not getting the 4psi with the BOV with 2 springs, ported turbo exhaust and all that I prob will get a 6psi WG spring and see if that increases it. Otherwise It could be leaking boost around the carbs to intake boots or the boots to cyl head and I would never be able to know or test it.

lets hope for the best!

Here are some pics of the homemade boost leak tester and the finished exhaust, which you can see will hopefully flow alot more exhaust as its not really a restriction anymore

[91_gsx600F katana]

Quick test for the wastegate - Lock it shut. Remove the actuator from it completely, and wire the bastard shut as tight as you can get it.

One pretty common issue with the chinese copies is casting quality/milling quality. The wastegate [if it's an internal one] probably isn't sealing anyway, allowing some blowby. Try to clean that up and get a flat, positive seal, and then wire it shut and see if you build any more boost. If you don't, it's not the wastegate.

The Internal wastgate has been disconnected and its fully blocked. The exhaust flange I welded steel on the back side that pressed the internal wastegate flap right up against the casting so it seals tight. The external one is not the cheapest, its the one from wyntom or something and its one of the better chinese ones and like double the cost of the cheaper ones. Ive heard good things about the wyntom ones. So if i dont get more boost and if I put a heavier spring in the WG and I still dont build boost then prob its something else. and Im leaning towards the turbo is too big which I knew from the beginning. Its only gotta last the season then im swapping in a 750 or 1100 ASAP!

[thebird_19]

Good to hear. I jb welded my pin holes. Sounds like your bov was your biggest problem and the other leaks just didn't help things.