Texas_WS6

iTrader: (9)

I ordered my first turbo today. I am building a rear mount system for my 346 using the GT-K 850 with a .81 AR. Going to pull the MS3 out and install a new 232/232 114 custom ground cam. No other major engine changes to the present 346 planned at this time. Hope to be finished by October. I am wanting to remove my nitrous, but still make the power I did with the nitrous but with the turbo instead. Starting in Jan, I am going to start the replacement engine wich will be a LSX block punched to 4.125. Using the 4 inch stroker shaft I have had in the new box for 2 years now (I got off track by buying a 2007 Victory Jackpot ). So the goal was to select a turbo and a cam that will work best on the 427, but will still be able to give me 500 rwhp on the present 346 and make the 346 street manors better then the ms3 cam. So what do you think? Am I on the right track with this turbo selection and cam selection? I am presently running a 4000 staull with 3.73 gears and am hoping to reduce the converter staull and change the rear gear back to the 3.23 or even go into something lower like 2.?? (I am not sure what the other gear ratios are).

98transguy

iTrader: (7)

i have a feeling u are going to regret not getting a bigger turbo. that gt-k 850 is only rated at 850hp. i am guessing that it is going to fall on its face behind the planned 427.

BigJls1

He could go to a .96 housing later. rear mounts dont need a monster turbo. I say good choice and plan on an easy turbine housing change when you go 427. now get to fabricating.

Texas_WS6

iTrader: (9)

You are right, I will be limited with the 427, but I really do not want to make any more power then that. I have spent alot of money on the transmition mods and I am sure it will be very hard for it to stay together at 850hp. I do not want to loose the A4 so going to a stronger trans is out of the question. Yes I can change the AR in the future too. The over all goal is limited to the fact that I will not back half the car, or remove any of the stuff like A/C, radio, power stearing, power brakes, loose the A4 and what not. It has to have good street manners. The idea behind this car is to build a car that can run low 11 at 3500 feet elevation, inhanced road handling to run in the open rode 200 mph class we have anually here, and if I ever get lucky, take the car to the Bonneville Flats to see what the max mph is. Build an American muscle car that will defeat a $300,000 Europian car at his own game. Just a dream I have.

I hope this turbo will put me on the right track.

DrTurbo

iTrader: (3)

A TC76 would have been a better choice. It spools just as fast and makes more power as well. Plus a good bit cheaper as well.

Texas_WS6

iTrader: (9)

How much cheaper? What makes a TC76 make more power over the GT-K 850? Whats funny is one distributor says a Super T76, another says a T76, another 72 compressor, another a 60, another the GT-K 850. So much info and diversity, its almost like picking a cam. Don't get me wrong, I am not flaming, just stayting "too many choices". I just hope the GT-K 850 will do what I want it to do, with both engines. As for price, I gave $1350 for the turbo. All the T76 were quoted to me at a higher price. I did not get a quote on those turbos from my local supplier though. I bet he could have beat them. Once he gave me the price on the turbo I realy liked, I bought. Well, it's my luck. What would the TC76 cost me?

frcefed98

iTrader: (16)

Just under a grand for a TC76, with a MPS wheel just over a grand.
TC76
P-Trim
$999
MPS trim
$1099
BB 1399

Its rated at "1000chp" so it should be good for 800 to the wheels if you pushed the **** out of it.

Nice lil turbo, spools fast as hell even with a .96a/r

Don't need a 427/turbo combo to run a low 11 at your elevation.

I ran 11.10's@124-125 here in Albuquerque (5800ft, DA usually upper 7K's) with a measly ol forged LS6, 348ci running a ATI SDCE D1-SC step with FMIC, 3800 stall, 3.73's, mid lengths, cats, full catback, and a few suspension pieces....nothing spectacular by anymeans.

Texas_WS6

iTrader: (9)

Isn't the GT-K a ceramic ball bearing?

DrTurbo

iTrader: (3)

Mucho hype over BB's. Don't get caught up in all that.


Also becareful when getting sound turbo advice. Alot of folks sell turbos out of catalogs.......find people that manufacture them and deal with ALL the different turbo brands. Some brands are better then others, and some can be made even better.....

Also yes they are around 1000 for the TC76.

BigJls1

Dude you got this turbo and it will work so get on with it. There will always be "better choices" in everything. post some pics of the build.

DrTurbo

iTrader: (3)

Its not really a question of better choice. For a 427, its more of what it needs. A 72mm turbo will not feed a 427.....plain and simple. Heck a TC76 is small for a 427 as well.

smokinHawk

iTrader: (48)

why upgrade to the 427 when you dont need it, a 346 engine mated to the right turbo will fill your goals just fine.
if you want to throw some money away just cause, give some to me........

Texas_WS6

iTrader: (9)

Thanks Dr, Turbo, I do see your point. I spoke with Turbonetics again today and the have assured me the GT-K850 will do what I want it to do. They did say I will need to change the turbine housing from the .81 to a .96 (Ithink that was the number) once I install the 427. Please remember all I am shooting for with the 427 is 850hp on a daily driver. Any more then that and I will be spending more time fixxing the trans, rear end, and buying tires then driving the car. Yes, a 346 with the right turbo will do that too, but a 427 will do it and will have better street manors. This is a street car, not an all out quarter mile car. It is too late to change the order, I ordered it last Monday. Like I said before, it seems like turbos are like cams, tons of options, so many it gives me a headache.

Thanks for all the input guys. Dr. Turbo, do you think the GT-K 850 I ordered will feed the 427 to 800 - 850 crank hp?

bboyferal

iTrader: (9)

LOL

Too true.

JZ 97 SS 1500

iTrader: (2)

That turbo will NOT make a sustained 850hp on a 427. On the dyno you will see a quick peak at around 4500-5000rpms and then boost and hp will drop like a rock. The backpressure will be 3:1...minimum at 850hp level. Your going to have a tough time keeping head gaskets down. Ask tried and true guys on here like Nasty, Mightymouse, Harlan, PSJ, Cablebandit and others how tough it is to keep the heads down with 2:1 backpressures. Sorry to say, that is bad info they have given you.....

frcefed98

iTrader: (16)

Oh well we tried. One thing why didn't you go with the GTK-1000?

But i'd still go larger on the turbo, T4 flanged 88 on a rear mount set up...might be a better choice??

Nothing is too late, either have em take it back, cancel the order or sell the turbo when you get it in your possession and upgrade to one more suited to your goals.

If you do anything, listen to JZ and Dr. Turbo, they really know their **** about anything that has to do with a turbo.

BigJls1

it is [B]rear mount [/B] so alot can be learned from this guys setup, there is not alot of info on how rear mounts act with 850 hp. You must size the turbo smaller for the rear mount.

Texas_WS6

iTrader: (9)

Not sure what you mean.

I will call tomorrow and see if I can change to a different turbo. Which turbo would then be good for the 427 and still be good for the 346 but not over kill on the 346?

Texas_WS6

iTrader: (9)

Looks like you might sell turbos, what kind do you suggest and how much. With only the necassary items. If ball bearings are not needed you know. I hope you can beat the price I have paid for the one I already ordered.

BigJls1

with all these guys talking about you need a bigger turbo. I disagree I have done three custom rear mounts setups. Your problem is not going to be the exhaust backpressure build- up as was stated by someone that 3:1, no way, your problem will be trying to fit an intake pipe to flow 60 or 70 lbs and hour and not hang 3" below your car. Alot of folks will dump info on you but they are useing front mount turbo knowledge. You have will be suprised how different rear mount technology is. keep what you have. and use 2.5 ehaxust for now and the .81 housing. then when you go 427 I say go 3" exhaust and at least the .96 maybe even an 1.15 housing. You will need 2.5" or even 3.0" intake pipe, good luck fitting that maybe you can go with (two) 2" pipes to flow enuff and still have ground cleareance.