Ok, I know that it's somewhere on this site, but unless Im using the search option wrong....I can't find it and nothings in the FAQ for turbos.

I don't know what to look for when buying a turbo. I want to upgrade my TII but have no clue what is good for a quick street car.

Heres what I heard and dont understand

Theres cast iron and theres Steel...whats better?

Whats the 411 on these below?

A/R
Trim
"S"
"R"
ball bearing type
bridged?
"two runners seperate for a divided flange"

I want something that spulls up quickly and doesn't die out early. I do hear that a hybrid t3/t4 is good for that, but if so...I dont know why. Again, I am really trying to learn on my own, but Im stumped..please help!!!

 

t3/4 is too small. What psi are you looking at for the power?

 

I see alot of people run around 12-14psi. I come from a world of v8's so this is my first turbo'd car. I don't know what I need. I want good torque, farely balanced thru the RPM range....I want a fast street car!

 

Forgot one thing....if a t3/t4 is too small, what about a t4... A/R 60? Is this anygood?

 

I think the smallest you can get these days is the GT35R, from a spooling standpoint. If someone else knows something faster(besides the RX6a/b) please chime in. The RX6a/b turbos are not available anymore as far as I know. Also the bigger porting you get, the faster a larger turbo spools. So a large streetport with the GT35R will spool pretty quick and be losta fun. The biggest Q's is what are you willing to do; ie, sacrafice fuel mpg for a larger port, idle quality, money=biggest factor. Of course this is my opinion and others will tell you "go big or go home". What could help is make some friends with defferent setups, and get a ride watching what the car does. If you're super lucky they might let you drive... Maybe not...

 

Rebuild your engine first!


-Ted

 

Well that should be a given. I was just answering his turbo Q's. Besides if he gets it ported, he should/will have to rebuild it.

 

Alright,

1) A/R- It's a geometric property given for the compressor and turbine housings. A larger compressor a/r increases low boost performance. A larger turbine a/r increases spool up time, but increases volumetric effeciency. Check out what a/r's other people are running on their single setup to get a good idea of what you should have. (or you can do some math, but the forum is pretty useful)

2) Trim- Also a math thing, for both compressor and turbine. The larger the trim, the more air flow a wheel (compressor or turbine) can support. Compressor trim is found by taking the Inducer diameter squared over the exducer diameter squared and multiplying the answer by 100. Turbine trim is found the same way, except it's exducer over inducer. (BTW, exducer and inducer are the larger part and smaller part of the wheel blades.)

3) 'S' and 'R' - Depends what turbo you are refering too. 'R' Usually means ball bearing on garrett turbos.

4) Ball bearing type- the CHRA (center housing rotating assembly) uses ball bearings to support the turbo shaft (as opposed to less effecient journal bearings) This has a number of benefits, the most notable being decreased spool up time.

Hope this helps.

BTW, I'm excited about it so I just want to add that I just bought a T25 with 30K on it and ZERO shaft play (and absolutly no cracks around WG) for $140, Woooooooohoooooooooo. And I'm picking up my custom equal length manifold on friday, Hell ya.

 

Thanks guys for the replies. Just so you know, I am getting a rebuild. Im getting a 13b with the upgraded corner seals. 3mm apex and a stage 1 street port. I would like to get a stage 2 if its a big difference, but I live in California..so I dont know if it would be hard to smog. Im going to look into the cost of a gt35r, hopefully its not a pocket killer. I did see a cheap kit...its xs power, I believe its a t4 with a stainless exhuast and external wg for around $500-$600. If this was a good size turbo, I figured thats a nice price. Thanks again for the input!

 

Oh, since you're in cali, have fun with smog. Very few kits allow you to retain your airpump. You can use a remote mounted one that is electric from a corvette.

 

Ahhh....lovely! I guess I have to read up on that too, thanks!

 

all what you need to make a turbo II a faster street car is a turbonetics h3 compressor upgrade to make your stock turbo an hybrid $300 bost controler $20 and fuel pressure regulator $60
you can do low 13's @ 10 psi of boost

 

Either way, I think you're screwed as far as smog goes... I've fought like crazy to keep all my smog stuff, yet it seems even though my airpump will stay, my injectors are going to be too small to add enough fuel and therefore I either need to add injectors on the elbow or UIM, or upgrade to top feed secondaries, and ditch the ACV / Smog recirculation stuff... which any one of those options will make me fail a visual, not to mention the turbo alone would make any serious inspector suspicious...

-DC

BTW Working on putting a GT35/40 Kit on...