kz 650, garrett turbo, need jetting help

trx250r wrote:

Well see I'm learning stuff already. I'd say they are, I just built a manifold that sits where the air box used to be, the turbo boosts directly into that manifold so I'd assume they are being pressurized, unless I'm missing something or am missunderstanding what your asking, which is entirely possible. This is my first attempt at a turbo on a bike. I'm used to working with turbos but normally on 7000 plus cubic inch v-12 engines with 10 inch pistons running on natural gas, so a little out of my rhelm here.

Which turbo are you using?
You have to run boost pressure to the bowl vents.
How much is what you are going to have to figure out.
You will need an electric fuel pump and boost referenced pressure regulator.
Jetting will be close to what the bike needs without the turbo.

Oh damn, dude thank youso much for taking me back to the basics, this is stuff I know and should be thinking of on my own but it just didn't even dawn on me till now. I deal air fuel ratios all day on the waukeshas and caterpillars I work on for a living. And thanks for complimenting the size of my balls, lol. This is just the way I do things, jump in head first and figure it out. Guess I'm a sick individual on that note.

It's all starting to make sense now. Looks like I'm gonna be doing some more parts scavenging. The turbo is a Garret T3 series. Any recommendations for a fuel pump and pressure regulator? How should I go about getting the boost into the bowl vents, can I just plumb it in through the drain hoses or do I need a larger port or to put it in somewhere else? You guys are awesome on here!! I really appreciate all the help. I really should have thought of most of this stuff sooner but I sometimes I just get a little ahead of myself.

Please, more pics. Did you build a custom manifold to feed the turbo?

Yes I did build a custom exhaust manifold using pieces from the original pipes, it went amazingly well. Here is a picture of it pretty much done, all I had left to do at this point was weld the flange to it. I'll try to take and upload some more detailed pics of everything later today.

Any concerns about the varied lengths of the exhaust runners? That seems a lot simpler than making a downwards facing manifold with equal length runners but I wonder what the difference would be...

I'm curious as I'm hoping to start a turbo project in the next couple years and haven't seen many people tackle it.

How did you connect the oil lines to the turbo?

What's the specs on the turbo (beyond being a T3) and what was it off of?

trx250r wrote:

It's all starting to make sense now. Looks like I'm gonna be doing some more parts scavenging. The turbo is a Garret T3 series. Any recommendations for a fuel pump and pressure regulator? How should I go about getting the boost into the bowl vents, can I just plumb it in through the drain hoses or do I need a larger port or to put it in somewhere else? You guys are awesome on here!! I really appreciate all the help. I really should have thought of most of this stuff sooner but I sometimes I just get a little ahead of myself.

what did the turbo come off of and what size is impeller and other parts?
for fuel pump a small 12v holley pump with adjustable regulator should be fine as long as youre not running too much boost

NO, I don't have any concerns about the varied exhaust runner length. I've built auite a few different exhausts for various different bikes of mine over the years and some cars too, and I've never really seen much of a difference in the systems due to varied runner lengths. That said, if your going for max horsepower, as in even a 1 or 2 horsepower increase is important to you, then yes it would be worth your while to balance and tune your exhaust. But I've even talked to some engineers about the implications of it on the street and even they say far to much weight is generally put into it.
I just drilled a hole in the oil passage plug that is right ahead of the points cover. I did some hunting around on here and noticed a lot of guys talking about a lack of oil pressure but I'm getting 60 lbs. of dead head pressure there and 30 to 40 lbs of flow pressure there so I'm not concerned. If for some reason it is under oiled though oh well, I only paid 50 bucks for the turbo and more are readily available at the salvage yard. For the return I tapped a hole in the front of the oil pan. It seems to be working fine so far but I'll monitor it in the future to be sure. Ran stainless tubing for all oil lines, 1/4 inch supply and 3/8 drain.
The turbo actually came off of a Volvo 4 cylinder. There is usually plenty of them in the junk yards and rarely is it the turbo that puts them there. They usually end up there cause of a bad transmission so you can be pretty confident the turbo will be good. Like I said earlier it's a Garret Turbo, model # is TB0326, if you just google Garret TB0326 you'll find all kinds of info on them. The waste gate setup on them is nice and easy and dumps at 7 psi which I thought was a pretty good starting point.
All that said, I got a carter 10-14 PSI fuel pump today, and a holley regulator. Drilled and tapped the cap on the reg so that I could hook up a boost reference line to increase fuel pressure with boost, presurized my float bowls, and guess what, I put about 20 miles on the bike! Mind you it needs some fine tuning, but it works, and man is that thing ever one pissed off machine. It's a whole nother when that boost hits!! I'll be back to working on it later this week and will keep you all posted on progress with the fine tuning. And more pics, I promise.

Awesome... :woohoo:

If you get a chance, I'd love to see the exact spots you chose to tap the holes for the oil lines as well as the manifold you build to replace the airbox.

And a video...

trx250r,

In addition to this site, you may want to spend some tome over at zrxoa. Several guys there have built turbo bikes. Even thought they are 4v water cooled engines, I bet they could lead you in the right direction on pumps, valves and such and may even be able to point to potential problems.

Lookin forward to pics and videos

Any progress on the turbo??