Suggestions for a turbo charger

[squid]

Hi guys. There's just too much for me to choose from, so I thought I'd ask for your opinions. 

I have a Kat with EFE engine that's prepared for forced induction - in fact has been used in drag racing. This year I was running it naturally aspirated, but thought about fixing that. Internals are standard EFE with reinforced gearbox. The head's been heavily ported, the combustion chambers reworked and the story goes it's got slightly hotter cams too. Ignition is Dyna S and it's running on standard carbs, both of which I intend to keep. 

The goal is 200+ hp and enough reliability that the bike's actually usable. The thing is there's an infinite number of turbos, and everybody seems to have their own opinion. For instance I thought about using a TD04, but then I was told "using a turbo that small you'll just melt the head" and "with that low oil pressure you'll need a ball bearing turbo". 

So what do you guys think? 

[vizman]

I'd say ideally you'd want stock/mild cams in a turbo motor... crank welding.....I'm not sure about 200bhp on standard pistons....oil pump....

...and I'm guessing blow-through if your wanting to keep your carbs

I'm sure loopie or duck n' dive could answer this.

[squid]

Yeah crank's welded. As I said the engine's been used in a drag racing bike, it's fully prepped for power levels above those I aim to reach. And I've heard from several sources (including the original builder) that standard EFE pistons are good. Oil pump's got GS750 gears already.

[Arttu]

Even with the GS750 gears the oil pressure will be too low for journal bearing turbos (except old Rajays). However, there are some tricks to make more pressure for the turbo. So either use a ball bearing turbo or pay some special attention on oil system.

200hp should be pretty easy. Stock EFE pistons are forged so they should stand some reasonable boost without problems. If you don't know the compression ratio I recommend checking it first. I would aim to around 8.5-9:1. If you can keep proper AFR and ignition timing you should be able to use over 1 bar boost with that which should produce over 200hp easily.

[busa ash]

Sounds good , good luck with your build 

[squid]

I tried to read all I could find, but holy crap there's so many options and me with no engineering degree am just getting more and more confused. So I decided to  take the easy route and get a kit from Proboost. The bigger one. Gonna take oil feed to the turbo straight from the pump. Maybe that's good enough for a journal turbo. 

Arttu, no idea about CR as I haven't had the engine open yet, and the original builder didn't remember it either. I suppose it might be even lower than that taken that the combustion chambers are opened up. It's an old Any10 race engine, so I suppose they've had an idea what they're doing when building it. 

[Arttu]

Whaat? What Proboost kit you exactly got, do they have a kit for EFE? Any way, no need to gamble with oil pressure. For journal bearing turbo you need to make a take off plug that goes in place of the oil light switch. The idea is that the plug takes all the oil flow coming from the filter, bleeds oil to the engine through a restriction hole and feeds the turbo before the restriction. This increases pressure high enough for the turbo. I can dig up dimensions for the plug a bit later on. Or you can ask from Proboost, they should know.

Who's engine it is, Rampe's? Well, based on my experience you newer should suppose anything when it comes to second hand engines It can quickly get expensive with turbos. But of course you can always take a risk and see what happens, your call. You have been warned  

  

[squid]

Yeah, gonna open it anyways, replace whatever needs replacing. Yeah, Rampe's old engine, he said it's in race spec apart from the pistons which he claimed would be good for up to 300 or so hp - but he didn't remember a lot about the exact spec. And no worries about the plug, I have a guy who's worked a lot with these engines helping me and he's gonna make a new adapter thingy for different plumbing to feed the turbo. And in addition to that, I'm gonna feed the head from the side gallery. 

Proboost say the Bandit kit is bolt-on for EFE and Katana too.

[Arttu]

Yeah, gonna open it anyways, replace whatever needs replacing. Yeah, Rampe's old engine, he said it's in race spec apart from the pistons which he claimed would be good for up to 300 or so hp - but he didn't remember a lot about the exact spec. And no worries about the plug, I have a guy who's worked a lot with these engines helping me and he's gonna make a new adapter thingy for different plumbing to feed the turbo. And in addition to that, I'm gonna feed the head from the side gallery. 

Sounds like a plan  And feel free to ask if you face any problems. I have been playing with these engines for some time and done quite a lot investigations on different aspects relating to turbo use. So there is a good change that I can give some answers right away.

I'm not sure if stock pistons can stand 300hp but it's possible. My previous engine had stock internals except the clutch and it run without problems for quite long time at 0.8 bar boost and about 200hp.

Proboost say the Bandit kit is bolt-on for EFE and Katana too.

Very likely true since carb and exhaust port spacings are the same. Of course there might be some smaller issues but probably nothing critical.

[homer]

For journal bearing turbo you need to make a take off plug that goes in place of the oil light switch. The idea is that the plug takes all the oil flow coming from the filter, bleeds oil to the engine through a restriction hole and feeds the turbo before the restriction. This increases pressure high enough for the turbo. I can dig up dimensions for the plug a bit later on.

Dig up those dimensions. There might be someone else who like to see them