turbo selection question

[f150intally]

http://www.precisionte.com

[emperor_lunchbox]

http://blaastperformance.com/t3t04e4870.html

This is the closest turbo I found!does anyone see any problems with this turbo as far as it being capable of around 400 whp and being a quick spooler?

thanks

[f150intally]

i haven't heard good things about the 57 trim. you should be looking at a 50 trim. that turbo will probably spool a little later than a normal 50 trim.

[DSMs_Suck]

Yup the 57 trim is a older wheel and not one of garrets better ones. The 50 trim is actually more efficent (peak) and has a wider band of efficency (the comp. map is nice and fat)... it is actually one of the "newer" t4 wheels.

If I were you I would say keep looking and get a 50 trim... If you don't mind a little worse spool a 56-trim is a BAD *** wheel =]

[emperor_lunchbox]

any other suggestions on where to look for either a 56 or a 50 trim.

[DSMs_Suck]

http://store.yahoo.com/cheapturbo/t3stkit.html

779 for a 50 trim (w/.63 ar) and a tial 38mm wastegate and shipping.

[emperor_lunchbox]

How do you convert bar to Psi?also is it possible to internally wastegate that turbo?I would rather not try to find or make two manifolds!either way i think ill get that turbo.

thanks alot.

[f150intally]

it may be difficult to get one internally wastegated. you should call them and find out the deal.

[emperor_lunchbox]

which would be more difficult:making a manifold built for that turbo and for the wastegate that comes with it?or to internally wastegate the turbo?

Does anyone here make manifolds?

[f150intally]

if they can get it great.. call them to see. i'm not sure what the market is like for aftermarket rb manifolds.

[BoostFab]

How do you convert bar to Psi?

1 bar = 14.5037738 pounds per square inch (PSI)

[emperor_lunchbox]

ok, now that I know how much one bar is equal to. my next question is which wastegate to order?the turbo starter kit comes with a wastegate and I get to choose the spring setting. it comes in 3,6,and 9 bar. If I plan on running about 20-23 PSI i suppose a 3 bar spring would suffice?I have no clue how that works!

[DSMs_Suck]

Ok alot of times yuo can get those setup for internal wastegates, just call the place you order from.

Also, that was .3 bar, .45 bar or .6bar... and that is a BASE Setting. A boost controller can raise the pressure if you would like. I would go with the .6 bar which is about 9 psi, maybe a .45 bar (about 6.5 psi). From there if you want more boost then get a boost controller and you can turn it up.. Although with a boost controller you can never turn it down.

As far as the manifold thing goes... Most people make an "adapter box" type thing. It basically spaces the turbo off the STOCK manifold a bit and also has a wastegate tube coming off of it so you can use an external wastegate.

[BoostFab]

my next question is which wastegate to order?

that is just personal preference. using an external wastetage require a wastegate flange on the turbo manifold. an integral wastegate is the way to go if you don't want any additional custom work.

i'm using the tial 38mm.

[emperor_lunchbox]

Where can i get an adapter box, or are those custom?

DSMs_suck:From there if you want more boost then get a boost controller and you can turn it up.. Although with a boost controller you can never turn it down.

what does "you can never turn it down" mean?I thought a boost controller would allow you to Control the Boost.

[DSMs_Suck]

Yup... you have it right.. When you get a turbo and you get a particular wastegate spring setting such as .6 bar (or ~9psi) that will be your BASE boost. I.e. you can not get the boost to go lower than this. A boost controller will raise the boost above this point, and possibly make boost a consistant level, however it can never turn the boost down below the base level.

This is because the wastegate works based on boost pressure. What a boost controller does is BLEED OFF a certain amount of that pressure, it can NEVER ADD to that pressure. So for example say you have a .6bar spring (again 9psi) and you set your boost controller to 15 psi, the boost controller will actually bleed off 6 psi (15-9) from the line that goes to the wastegate, so that your wastegate only sees 9psi and opens....However its impossible to set your boost to 7psi because that would mean the boost controller would have to bleed off -2 psi, which isnt possible by "bleeding" pressure.

Hope that helps

So basically what I am saying is if you do go with an external wastegate, pick the spring rate that you know you will never want to go lower than. IMO unless its a HUGE turbo .6 bar sounds good, because then you are running a nice 9 psi without the need for a boost controller.

Murray

[f150intally]

he meant that you can never use a boost controller to go lower than the spring allows.

if you have a .4 BAR spring (5.80 psi), then the boost controller can not go lower than the rated spring pressure. Thats why I always buy the spring that equals the lowest boost pressure i want to run. boost controller off = 5.8psi, controller on low = 12 psi, controller on high = 20 psi.

understand now?

[emperor_lunchbox]

i get it. That helped alot. Makes alot more sense now.Now is internally wastegated or externally wastgated better for performance?

also is there a difference in reliability?

[BoostFab]

why not start out using the turbo setup already equiped w/ your rb. all the addition custom work isn't necessary....

[DSMs_Suck]

Internal Gate:Pro: - For the RB no adapterbox or new manifold is needed. It will basically bolt right up- Costs less than external gate

Con: - More likely to have problems with maintaining the proper boost level on BIG turbos. (Sometimes they can't keep the boost level as low as you want, or sometimes they just have a problem keeping a steady boost level). - Can't "dump" the wastegate gasses whereever you want... if you care

External Gate:Pro: - Better performance, they in general can hold lower boost levels and always hold a steady boost line - You can dump the wastegate gasses whereever you want... again if you care

Con: - Cost. The wastegate itself costs more and for the RB you will need a new manifold or adapter box

Basically, the external gate is a better wastegate solution than an internal gate, except for the fact that it costs more money. As far as reliability in terms of failure rate (i think this is what you mean) they are both about the same, and in general wastegates (when hooked up properly ) are reliable.

Murray

[emperor_lunchbox]

does anyone know where I can get an adapter box or a custom manifold for an external wastegate?

or does anyone make them?