Your opinion, GT12 or GT14

[Sleepr DSM]

Disclaimer: There are hard line folks on this site. If this is an ignorant post, delete it. If I'm posting in the wrong place, please move it. If I'm offending anyone, I'm sorry. I'm looking for suggestions from knowledgeable people who aren’t vultures about criticizing people who know less than they do.

I've been researching this for days. I'm getting a dual ball bearing GT30 series turbo. I'm set on a GT series 56 trim compressor wheel.

But, I can't decide between these two turbo's. (below) Can you guys help me decide. I KNOW that the majority of DSM owners run relatively small turbo's, so most of the responses may point me to the smaller turbo... Regardless, I'm still looking for your input. What would you go with.
I have stand-alone fuel management, 8.5 to 1 compression, 703cc injectors, a built bottom end, and a front mount intercooler in 3 months. My application is a daily driven car with AC, going to the track once a month. Lag has never bothered me in any turbo car I have ridden in. (up to 60-1 on a B18C-1 GSR)
I know.... why the hell can't I just pick one for myself?

From the many dyno charts I have studied on the net over the last few days, I'm guessing the GT12 will have what I call its M.B.P. (massive boost pull- or hit) from 3500 to 4000. I am guessing the GT14 is going to hit from 3800 to 4300, to as late as 4000 to 4500.

If some of the numbers below seem wrong or unlikely let me know.
What is your guess on spool? What would you go with?

Gt12, rated at 500 HP. I understand that if I subtract a hundred from those horsepower numbers, I’ll be closer to what I’m likely to achieve someday with every supporting Mod. = )
Part Number: 700177-0012
Turbine
Turbine A/R: Unknown
Size: 60mm GT30
Turbine Outlet size: 55mm
Turbine Trim: 84
Compressor
Compressor A/R: Unknown
Size: 76mm TO4S
Compressor Outlet: 57mm
Compressor Trim: 56

GT14 rated at 600 HP
Part Number: 700177-0014
Turbine
Turbine A/R: .70?
Size: 60mm GT30
Turbine Outlet Size: 55mm
Turbine Trim: 84
Compressor
Compressor A/R: 1.06
Size: 82mm GT40
Compressor Outlet: 61mm
Compressor Trim: 56

 

[GSX4LIFE]

the 12 will spool quicker. The 14 will make more power. Take your pic. I have the GT30 56 trim now. I like the GT40 56trim much better.

 

[candela]

I'm guessing the GT12 will have what I call its M.B.P. (massive boost pull- or hit) from 3500 to 4000

You are definetly right about that. I have a dyno appointment in 3 days to get my car settup the right way, but since Ive installed my turbo (see pics below) its been pretty fun and Ive made quite a few passes with my logger. As pointless as this seems Ive only been running the turbo at about 12psi (mbc backed out) so it really doesnt have much advantage over either of my previous settups right now...however after only a couple of hard pulls Ive been noticing that I definetly get that 12psi before 4k rpm. The boost threshold is relatively early at about 2k rpm, but it seems like full boost/power comes on within a split second (which Im sure will be fun tuning on the dyno). Ill definetly be able to give a really good reveiw of this turbo in general after i go to the dyno and get my way with it.

not to difficult to install at all. Only tediously annoying part was bending all the lines/denting the water pipe to fit. Other than that a little clocking, and inginuity will get it done pretty easily. I originally didn't even want this turbo, but its just kinda what I ended up with. You didnt really state your goals in the end, but Im willing to bet that this turbo should get me at leist 325-340whp range on 91octane in a few days. Im pretty confident in it and feel its enough turbo (ofcourse the rest of your settup plays a good role in everything as well) to get me some good numbers Ill be happy with. Look for a review in about a week or so

 

[candela]

BTW- what ever happened to you getting the G50? I assume this is what your thinking of getting on replacement of Mikes new 'custom cast" 50 trims that hes been waiting for He's a good guy to deal with, a lil' difficult sometimes, but Im sure you'll be happy with what you guys decide in the end...

38mm flapper

 

[peregrine]

why dont you take the middle ground and go with the gt13? thats what id do. i talked to mike extensively about the gt12 and then the gt13 and decided that the 13 was more to my liking.

 

[Sleepr DSM]

The efficiency of the GT series 56 trim. I am impressed by that wheel.

 

[Sleepr DSM]

Anyone else have any input on this?

 

[Sleepr DSM]

 

[eclipse90gsxt]

I'm in the same boat as you dude, I am either getting the GT-12 or Gt-14, can't decide. It would be on a stock bottom end for now, so low boost. I am building an engine over the next few months. I have every supporting mod except for the internals for the engine.

ANy help would be awsome, IDK, I can't decide either.

 

[CanadianTSi]

Holy Back from the dead batman!

 

[laggin3]

Hahaha no kiddin! Sleepr has a 3052 now and hes pretty damned happy with it. He spends more time on Talk now though.

 

[candela]

Wow I cant beleive I found this post... I usualy don't hit the boards much anymore but what do you know. Its funny ot see what you typed so long ago. That turbo now belongs to boostinAWD.

Well anyway for those that care... that turbo was outstanding. 11.6@120 I had lots of fun with it and pulled great number numerous times. If anybody is interested for details feel free to PM or reply.

 

[BoostinAWD]

Yep shes mine, bought it a year ago and have yet to use it. That's all gonna change in about 2 weeks.

4bolt rear /w lsd, welded center diff, and a new eprom on the way.
I'm also in the process of building an intake mani, velocity stack style. Gonna be fun.

 

[definitiveno]

I know this is old but I just bought a gt14 and I'm not sure if I did the right thing. Candela were you talking about a gt12 13 or 14?


I have an automatic with a high stall TC but I still worry about response.

 

[definitiveno]

nevermind, you were talking about the gt12. What psi were you running when you 120 and what have you done to your head if any thing?