oscs

iTrader: (19)

I would like to start off by saying this: If you do not own a turbo LS please keep your comments to yourself, im tired of internet experts. I will also say that YES i understand how much power i am trying to achieve.

The intended purpose of this post is to find out the best way to reach my goal of 700RWHP on pump gas utilizing my existing upgrades. I would like to do it relatively inexpensively and reliable.. although i am a gambler by habit and have been known to skimp here and there.

The car: 1977 datsun 280Z
Engine: LQ4 (100k)
Trans: T56
Safety: full roll cage/racing seats/5point/big brake kit in all 4 corners
Upgrades:

Fast 92 intake, BBK 92 TB, LS2 MAF, fuel system capable of sustaining 1khp, 46lb injectors,ARP rod bolts, LMR tuned, aftermarket fuel rail, TSP 228 .590 .590 114LSA (I think)

Now obviously the injectors will need changing and the trans will need a good talking too. The info im after is turbo specs for for my setup and any other helpful information from people WITH turbo LS's. take in mind the car weights 2700lbs with me in it. Also something to keep in mind is the fact that i will be running a 3'' exhaust off the turbo all the way out to the rear of the vehicle so it will be choked up a bit. This is a weekend car and i will be beating on it hard saturday and sunday. However i dont want it falling apart and id rather not have to tear it apart every weekend. My wife rides in it and i would like to take it to dinner, cars and coffee etc. I want the car to behave untill i mash gas.

With that said lets hear what has worked for you guys!

Fondle

iTrader: (4)

tc78 is what i run. i have a 5.3 with a custom ground cam with a fast 92/92 combo and make 700hp at 12.5psi

SPRAYED 01

iTrader: (22)

If this is not a track car and you want to keep the m6 trans id go precision 76mm gts turbo. It uses a 3 inch dp and is the most proven of the smaller frame turbos. It will spool instantly in that motor and easily hit 700whp

oscs

iTrader: (19)

76mm is the size ive been thinking about. Im not going to lie the ON3 76/.81 turbos are very tempting for the price but i just dont see them making 700 reliable HP

HRHohio

Too small of a turbine on the On3 76 for what you're looking to do, especially with that big LQ4. I would recommend this over the ON3 76:

http://www.ebay.com/itm/CXRacing-GT45-GT45R-Ball-Bearing-Turbo-Charger-80mm-wheel-T4-1-15AR-Big-Power-/181106806132?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a2ace8d74&vxp=mtr

SPRAYED 01

iTrader: (22)

You have to understand turbos to determine which "76" is good for you. They slap names on turbos that don't necessarily describe them accurately.

An on3 "76" actually has a 68mm turbine. A precision "76 gts" has a 75mm turbine. Worlds apart imo.

oscs

iTrader: (19)

I dont really have great understanding of turbo specs. I understand the intake turbine size and the differences between small and bigger AR's. im eager to learn though

shawnc16

Your best bet is a PT7675 or equivalent. The budget turbos (On3, TC76, etc..) have a small turbine wheel. It won't play nice with that 6.0. Also that 3" exhaust is a big limiting factor.

"MAC"

iTrader: (1)

I was thinking about going turbo on my 01 WS6 a good friend of mine put it to me like this; if its going to be a drag car then go for it if its going to be a DD then don't. The cost of the build and the cost of maintenance isn't worth the occasional street race that you may or may not get. and don't forget the fact that if you get caught by the police how much that ticket is going to cost and court fees as well. At the end of the day a its your decision and your money regardless make sure you post pics of the build if you decide to go turbo please.

HRHohio

I would disagree 100% with this. But that's just me. haha

I actually find that it made driving my car a more enjoyable experience, every time I get in it. Knowing that I can roll up to nearly any stock vehicle out there on the street and leave them scratching their heads in the rear view mirror (Mustang 5.0's, new Camaro SS's, Corvettes, a few exotics, and even some modified domestic and import cars that think they're fast.) Nothing worse than the occasional street race in a car that always loses. The feeling of a turbo building boost is like a jet taking off, faster and faster down the runway. It leaves you scared at times, but always with a smile. Something only a turbo car owner/driver can appreciate I guess.

Side note: I don't think the OP is asking to be talked out of it... I think he's asking "which turbo" to go with. lol

"MAC"

iTrader: (1)

lol yea i saw what he had said and was like thats too much to read but I hear what you are saying on the turbo 600+ hp should always be fun I just know i would dog the crap out it everyday and more than likely kill my self tryn to do something stupid like going 200mph lol

HRHohio

Lol. No worries. Your friend is right about one thing, they are expensive to build and maintain. But the reward is OHHH Sooo worth it! Hahaa

(Hope I can always keep the rubber side down too.... )

oscs

iTrader: (19)

Thanks for turbo suggestions and yes you guys are right I will not be talked out of it. Keep the turbo suggestions coming. Anyone concerned about the bottom end holding together at this level? How about springs? I know those will need to be done. I've also heard the 317 heads are a good platform for turbo, they jut need to be cleaned up a bit, is there any merit to this? Also if and when I d swap heads what is a good head gasket to run?

Any lq4 turbo guys out there with suggestions before I start ordering parts.

oscs

iTrader: (19)

How big of a limiting factor are we talking about here? In HP numbers what do I stand to loose running a 3" DP outback VS. A 4" dump out the side fender.

LS1 240sx

iTrader: (1)

BAD!


take my car for example, its 240sx chassis with 5.3 and 317 heads strapped with a GSP T76 (pretty much same as on3) but i found out that my t76 has 65mm turbine which I see on3 having as well. On the dyno after 6k to 6200rpm my power dove down 200whp within 500rpm (6800rpm).


Back Pressure!!! results..... I lifted my heads while forcing air into my coolant chambers shooting coolant out of my radiator reservoir tank and a rod knock to top it off. Now imagine a that same on3 76 on a 6.0. Ill put it this way if you dont mind setting your rev limiter to 5500rpm then go for it cuz after that RPM I bet you will create some serious back pressure.

Now I have to change my block, HG, Head studs, and deck the heads because of this small turbine bullshit. Im going cxracing 80mm.

GL but STAY AWAY FROM THE ON3 T76!!! lol

geoff17

An lq4 with proper upgrades will hold a decent amount of power, 700 shouldn't be a problem. On mine I did ARP rod bolts, ARP head studs, LS7 lifters, LS9 head gaskets, custom grind boost cam, valve springs, and hardened pushrods. Never touched my 317 heads. And as others have said make sure you at least go with the better turbos that utilize at the min of a 75mm exh wheel, esp with a 3 inch exhaust you need to relieve the back pressure. Currently I have a tc76 which is 76/68 and until I yank that off and put something better on, it will not be pushed harder than 10psi.

shawnc16

HP #'s depends on the setup and what turbo you run. A 3" DP limits turbo selection as well. 6.0 with the PT7675 3" DP will meet your goals but you'll run into high back pressure if you seek more out of it.

RedRocketZ28

iTrader: (19)

FWIW I made 606/570 with an on3 76mm on my LQ4. This was on 14 lbs. as well. The power did dive off after 5500 rpm or so. You being an M6 would probably get close to 700 rwhp with even an on3. I switched to a Turbonetics 7875 and on 15 lbs. made 677/626. Power falls off after 5700 rpm but holds it a little better. This was all done through an unlocked 4L80e, but the newest dyno #'s were through a 9 inch instead of the 10 bolt.

On another note, through my 3" exhaust, on 10-11 lbs. my car trapped 136 and doesn't weigh anywhere near yours. I guess where I am going with this is that you could always start out with a cheap turbo, get your setup working, get bugs worked out, etc., and switch to a better turbo later on. On3 is coming out with a 7875 turbo this Fall/Winter that might be worth looking into. I had no problems at all with my on3 turbo and my biddy will be running it on his Silverado shortly.

necrocannibal

iTrader: (5)

Well I have a Twin Turbo car that I have had since about March and have only driven 3 times because of stupid issues I cant seem to get worked out like the plug boots being so damn close to the manifold it melts them after a few pulls. Another issue is I get a good puff of blue smoke a lot of times when I stop. The car likes to run a little warm, was overheating but now it is better but still too warm for me. The car has a terrible exhaust leak somewhere that all of the exhaust side is going to have to be taken apart and seals replaced and on my way back from a friends house the steering column stared rubbing against the drivers side manifold when I am turning.

When I can drive it it is fun as hell but all of these little issues add up annoyance and money wise and I am starting to regret the turbos and wishing I had gone blower instead.

oscs

iTrader: (19)

Lot of REALLY good info here guys. I think I'm just gong to spend the money on the right turbo first thing. Seeing as that is the main factor here I prefer to get it right. If you guys could do it again what are the exact specs you would request for this setup? 75-76mm turbine, what about inducer/exducer on both sides? Besides quick spool is there any advantage to a smaller AR? I was thinking .96 but open to all opinions.