I want to turbocharge my streetported 12a with a mikuni carb. I've done some searching and found most people are using a turbo out of a 2nd gen. But I've found a turbo XS turbo with 60 on the compresser side and 1.10 on the exhaust side. Here's the link: http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

Would it just be easier to use the 2nd gen turbo because it already has a properly sized wastegate?

 

I don't have a direct opinion, since I'm an N/A guy, but to answer your question: whenever something is already done for you, it will always be easier.

 

I say stick to the TII stock units.... It would be easier to run overall. And a few other reasons to stick with the S4/5 units:

1) Turbo XS is junk
2) You'll need an external wastegate for that turbo = more $ out of pocket
3) You'll need a matching manifold = more cash out of pocket
4) 1.1 exhaust is HUGE for a little 12a and will spool very late
5) 2g S4/S5 is about the perfect size unit for a 10psi 12a, and wastegated in that range to-boot (actually WG'd around 6-7, but will boost toward 10 with your custom exhaust)
6) Turbo XS is junk
7) Did I mention Turbo XS is junk?

 

Shane has covered the subject very nicely.

If you go with a 3" exhaust, you will need to port the wastegate, which is covered in the 2nd gen section.

And the XS Turbos are junk. Do a search in the single turbo forum. there are pics of a couple of nasty failures.

 

very nice!! i wish all the newbs learned as quickly as this guy! 10++

 

Ok thanks, that really answer my question. So I guess I'll stay on the look out for TII units. What size intercooler piping and the intercooler should I get. I was thinking about 2.5 for the piping and for the intercooler I should just use the biggest I can fit.

 

hey sand121 i would goto with the TII turbo..you can get alot of help and info about the turbo from the 2nd gen guys(you willl need to port the waste gate) also timmybighands did a nice little write up how to get a TII manifold on a 12a click me there are lots of guys using this turbo its good for 200-250 hp good luck keep us updated

cheers PaTricK

 

dont neccesarily get the biggest you can fit.

bigger=heavier
bigger=more pressure drop
bigger=longer lag

If you dont need it that big, dont get it that big. Check out some other people's setups, especially ones that are setup similar to how you want yours. Lots of people like the NPR intercooler.

 

2-1/4 is a good size, quick spool up and not too restrictive^^^^ he's right on!^

 

Thanks I'm learning alot from you guys. Another question I have is should make a carb hat for the mikuni or should I make a y-pipe and have it go into the carb. Where should the blow-off valve be, as close to the carb as possible?

 

the BOV question is argueable. some people tell you to put it as close to the turbo as possible since that is what it is protecting. Dumb if you ask me. What happens is that when the throttle blades close boost begins to build up and then goes back and causes compressure surge and that's bad for your turbo. If you put it as close to the throttle lade then it catches the reverse puse of boost as soon as it starts and vents the next incomming air towards the blades. With it close to the throttle it will vent off the excess pressure and still leavesom boost in the charge pipes and intercooler for faster spool and boost right when you get back on throttle. As opposed to right on the turbo when it will vent once the air opposit the throttle blades is comming back at the turbo. and vent most to all the boost out of the charge pipe and intercooler. It's louder closer to the turbo though. That's why you see it there lots... If this is confusing it's cause I'm drunk...

 

A cookie from Scott....

A cookie from Robert...

A cookie from Patrick... If you guys keep that up, I may find myself in a sugar-induced coma from all these cookies.

But seriously, I'm glad you asked instead of buying a $100 turbo. You can use just about ANY intercooler you want. Personally, I've opted to use the stock TII unit. It flows well enough for a low-boost application like I'll be doing <10psi, and you can easily convert it to a small front mount. I'll try to do a small write-up on that with some pics soon.

I'm also using 2.25" intercooler piping to keep the air-velocity up a bit. No need for 3" IC pipes, as your not going to boost so high... I tell myself regularly - "KISS" your turbo project, that's "Keep It Simple Stupid". Going WAY overboard and adding unnescissary junk only makes for more headaches. Doing it right is one thing, going overboard on useless stuff like 3" IC pipes is another.

Good luck with your project - I hope you'll post your progress.

 

Agreed