Turbo recommendations

[ArizonaKid]

So I am starting to collect parts for a custom project, and I wanted to know what a good turbo is for a 225 slant six. A friend of mine told me to use a turbo sized for a motor about 2/3 of what I had, with that in mind I would need a turbo sized for about a 150CI/2.4 liter sized motor. I was hoping to go a remanufactured route, ($300) instead of a new, $700, turbo.

Would a junkyard turbo be trustable? because the pt cruisers had a 2.4 turbo. Keep in mind I don't know anything about turbos, this is my first forced induction project.

 

[RustyRatRod]

Try this.

 

[Brandon Weaver]

NO NO NO NO NO NO NO NO NO! And again, NO!

I have no clue where this '2/3' junk came from, but that's the most garbage I've heard. Also, any slant turbo article *I've* ever read was garbage, with no truthful/useful turbo sizing info. The best 'off the wall' guess I can say is look for something relatively the same as the engine you're building. Not sure if that makes any sense...

Basically, If you're wanting to look at it in 'simple' terms, a 3.8 Buick turbo.

The more you look into it though, you'll realize if you use the Buick turbo it is extremely inefficient, and don't expect very much out of it. Really, don't expect very much if you are just bolting on a turbo to a stock slant. To take full use of it, you need to do all the N/A type mods as well (better flowing head, proper cam, good rotating assembly, intake, etc.), plus your turbo stuff (turbo, aftercooler, blow off valve, wastegate, etc.)

You may be able to go the reman route (actually, I'd look into that too) but you still have to get the right turbo. You really just need to do a LOT of reading, especially on turbo sizing. Sorry, I can't point you out to a good site that introduces basic turbo stuff and theories. I'm afraid anything I pointed you towards would be way too much to take in at once.

Junkyard turbo: I'd treat stuff out of the junkyard about like I'd treat cheap chinese eBay stuff. I'd stay pretty far away. Just me. However, you'll see people that use chinese eBay stuff in their builds replace them shortly. Kind of seems to be a waste of money to me, especially risking detrimental failure. Ain't my money.

Also 'Keep in mind I don't know anything about turbos, this is my first forced induction project.' that's why you learn before you build :thumblef:

Best of Luck!

 

[UOP]

Something like this would work nicely, IMO. The turbine housing is a little big for what you're doing but it should still spool up nicely. Very common turbo for 4-6 cylinder turbo builds. It comes with both water and oil cooler ports, but only oil is needed. You can plumb it for water if you want though, the extra cooling certainly doesn't hurt.

http://m.ebay.com/itm/270940682667?nav=SEARCH

 

[Brandon Weaver]

What I don't understand with that turbo though, is what's the point of taking a t3/t4 turbo, and adding a t4 turbine to it? Seems backards to me, but I may be missing something. And other than a looser AR, the t3 is exactly the same as far as I can tell http://www.ebay.com/itm/CXRacing-GT...Parts_Accessories&hash=item43a9544582&vxp=mtr
And is there a map for either?

There is a slant that makes 250rwhp on 7psi using a gt35. Rear mounted. But it has quite a bit done to it. I'm not sure if I would trust CXRacing personally, just because I like more established companies. Have you had/heard many things about them UOP?

 

[ArizonaKid]

I'm pretty sure the 2/3 thing came from him grenading an engine or two, I figured it sounded like a general rule of thumb. I guess, thinking about it, a turbo sized 2/3 of the engine wouldn't be very efficient at its job.

 

[rkite]

2/3rds would give you instant response and low end torque but no top end. If you go too small it will be hard to control boost, the waste gate may not be able to keep up. Plus your intake temps will be high from a turbo which is too small.

The 2.3 turbo ford guys get used Holset HX35 turbos off of diesel trucks like the Cummins 5.9. They are a little on the large size for a 2.3 gas motor but should work on a slant six. The HX40 is another option it is the next size up. A rule of thumb for using a diesel turbo on a gas car you divide by 1.9. 5.9/1.9 = 3.1 liters gas. Course for turbos you go a little larger for high rpm horsepower and a little smaller for less turbo lag.

It takes a 2.3 turbo motor about 3000 rpm to fully spool an HX35 so there is a bit of lag. Having a turbo a little too large is not a problem as far as horsepower goes but there will be more turbo lag. The 2.3 guys get up to 400hp from a HX35.