i know nothing about picking a turbo, 3500

[merlot566jka]

well its a built 3500, spins to 6800 rpm. want full boost at 3400 rpm, want to start off with about 8 psi.

i dont want to research to figure out which hybrid is the best, i dont know how people even do it. there are so many maps, and when your plotted on the map and find a good turbo, you look around and they are all hybrids. it doesnt make any sense to me. if i want a turbo, i want a part number thats going to work and i expect that part number to be that turbo.

picking a turbo is like going to the dealer for a chevy truck, and getting a truck with toyota rims, ford engine, and dodge bed. sure its a chevy, but who the hell really knows what it is???!

[ezrollin]

That's the way it is,because there's no one turbo perfect for a given engine,It's where you want your power and there are so many variables even within a given engine size. Just because an engine is a hybrid doesn't necessitate a diff. turbo,it's based more on cubic inches,max. rpm;comp/ ratio and hp desired.

[1988GTU]

It also is based on how you want your powerband to be. Some people want sudden power like an on/off switch while others want it to glide in the power so you dont break axles or smoke up the tires.

[merlot566jka]

i meant hybrid turbos, not engines.

id rather have gradual power.

[Joseph Upson]

i meant hybrid turbos, not engines.

id rather have gradual power.

Start with a turbo that has a turbine housing a little larger than what you need for your power level. As for wanting gradual power increase, you already have the foundation for it with the 730 ecm and TGP code which allows you to set the boost level you want for a given rpm which means you have to choose a wastegate with a low boost spring and use the TGP boost control solenoid to vary the boost level. 3.63 psi is the lowest I'm aware of wastegate wise so you can increase from there over the rpm range.

Check out what they say about wastegate choice:

http://www.turbosmart.com.au/index.php?s=faq

These guys have some nice prices;

http://www.ssautochrome.com/

[ForcedFirebird]

60-1 [/thread]

Seriously, Joseph is correct yet again. I happen to have a 3.63PSI spring if you need one. It fits the Tial and Tial clones.

The only thing I don't like about using such a low sping, is there seems to be complaints of spiking when using a boost controler to more than double the spring weight (PSI). ie I know of a 3800 using a 7psi spring and is seeing major spikes when turned much past 12psi - some spikes as high as 25! I personally can't confirm, but its a repetitious problem. I blew my motor at 6psi.

I used one of the ebay turbos in the link above (along with some other friends), and it worked fine. I chase the to4e because of the iron heads and flow issues, but am planning on using a pair in the future (near, I hope).

All I can say is tuning, tuning, tuning. Don't let yourself get lean.

[Joseph Upson]

60-1 [/thread]

Seriously, Joseph is correct yet again. I happen to have a 3.63PSI spring if you need one. It fits the Tial and Tial clones.

The only thing I don't like about using such a low sping, is there seems to be complaints of spiking when using a boost controler to more than double the spring weight (PSI). ie I know of a 3800 using a 7psi spring and is seeing major spikes when turned much past 12psi - some spikes as high as 25! I personally can't confirm, but its a repetitious problem. I blew my motor at 6psi.

I used one of the ebay turbos in the link above (along with some other friends), and it worked fine. I chase the to4e because of the iron heads and flow issues, but am planning on using a pair in the future (near, I hope).

All I can say is tuning, tuning, tuning. Don't let yourself get lean.

Glad you mentioned that, I was planning on purchasing the 3.63 springs for a less aggressive boost level for starters in place of the 8 psi springs but I'll look into the 5 psi instead. I'm also curious to hear how the wastegate sounds.

I had a delimma initially because I couldn't remember what size wastegates I have since it matters for the spring size then I happened to find one of the boxes and discover they were 35 mm instead of 38mm which I believe still takes the same.

[Guest]

gt35R

Or if you don't want to pay for the ballbearing,

Precision sc6152E w/ .63 exh Thts what I am using 7 psi by 2800 rpm on a 3.4 iron head, will support 33 psi and 625 hp. Way more then enough for you, and ona 3.4 its very efficient at 14 psi.

sc61 is same as 35R but different exh housing, and no ball bearing. about $400 cheaper too.

[RedZMonte]

60-1 or T04E. Im using a turbonetics T04E super 60 P trim and it is MUCH cheaper then a GT turbo. I would use a Garett or a large brand name turbo. none of the Ebay china built junk. If you want a faster spool then i would run a large 60-1 HiFi (T3 exhaust) or a T3/T4 hibred

[Wiz85]

Like I have said to 2003cav's posting, go to Garrett's website (most helpful tips) and on their 2007-2008 catalog on the 53rd page, it shows all of their turbos and as closely matched turbo to an engine's power goal , displacement, etc.

Basically some of the things to think about are trim options (trim is the ratio between the impeller and turbine). It's best to match the trim to the N/A power of the motor.

1. A larger trim on a relatively small particular size compressor/turbine housing, it's going to spool faster, but not a lot of top end boost.
2. A larger compressor/turbine housing with a relatively small trim will spool slow at low rpms, but yield lots of boost at top end.
3Trim lets you know how fast it spools.
4.Size of housing determines how much boost.

Now a too large of a trim and housing, you get horrible lag and less boost than expected.

[merlot566jka]

wow, thanks everyone. i know now, what i did before. i know what the effects of too big or too small a turbo. i know how to set up a turbo, i know almost everything i need to know.

what i dont know is the TURBOS. i dont know what a t3 flange on a 60-1 with a .63a/r is. to me there is two turbos stated in that, with an a/r ratio (a/r of what, the hot or cold side???)

[Wiz85]

A/R is the cross sectional area (A) divided by the radius (R) of the compressor or turbine housing. You will have A/R's for both compressor side as well as the exhaust side. It explains it here on this link:

http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html

[ForcedFirebird]

Like I have said to 2003cav's posting, go to Garrett's website (most helpful tips) and on their 2007-2008 catalog on the 53rd page, it shows all of their turbos and as closely matched turbo to an engine's power goal , displacement, etc.

Basically some of the things to think about are trim options (trim is the ratio between the impeller and turbine). It's best to match the trim to the N/A power of the motor.

1. A larger trim on a relatively small particular size compressor/turbine housing, it's going to spool faster, but not a lot of top end boost.
2. A larger compressor/turbine housing with a relatively small trim will spool slow at low rpms, but yield lots of boost at top end.
3Trim lets you know how fast it spools.
4.Size of housing determines how much boost.

Now a too large of a trim and housing, you get horrible lag and less boost than expected.

Where did you find this info? Each wheel (compressor and turbine) has a trim. The trim is the division of the inducer divided by the exducer depending on if you are calculating the trim of the turbine or compressor depends on which is the in/ex-ducer (small or big side off the wheel). The restriction on the turbine is what determines how fast you spool, the compressor size is what determines where the surge limit max and min are.

Here is a direct quote from the Garrett site...

http://60degreev6.com/forum/showpost.php?p=329245&postcount=50

[ForcedFirebird]

Some educational reading for everyone...

Turbos 101 (basic)
Turbos 102 (advanced)
Turbos 103 (expert)

[merlot566jka]

^ thanks, too drunk to read it, but its in my favorites, ill read it at work in the morn