jman77

Its been a long time since i was able to get back into the car scene (marriage tends to do that). I am now rdy to get back and have some fun. I dont have anything yet but im looking to get a junk yard LQ4 and throw a turbo on it. I dont know alot about the engines so i though i would ask the experts. Im looking to make 500 to 600 hp and break into the 9 if possible. What am i looking at to make upgrades on a junkyard block to withstand the boost and/or is a just a good power adder? right now im thinking about throwing it in a foxbody. thats all i have right now so any help would be great. Even if you want to throw in everything you would do to it if you had same set up would be nice. It will only be driven on streets on nice days and be taken to track alot. Im rdy to go fast so please help me out.

jman77

Or the other option is the LQ9 with nitrous adder. Ive heard more lean towards boost so whats your guys opinions.

lsx_production

I would lean more towards an lr4 for going boost. lq9 with nitrous is a good combo as well. you just need to decide which route you want to take, research, and go from there. do you have a platform (vehicle) picked out yet?

jman77

i think im going to go with a fox body. i havent looked much into the LR4 i was trying to get as cheap as i could and i know turbo and fuel systems will be expensive but trying to get by as cheap as can. what year and vehicles are LR4's in?

GMTheOnlyWay1

iTrader: (1)

Also possibly an LQ4 I believe they are slightly lower in compression than the LQ9 therefore better for boost

lr4 is also lower compression just less cubes and it comes in-
2003–2006 Chevrolet Express/GMC Savana
1999–2006 Chevrolet Silverado/GMC Sierra 1500
2000–2006 Chevrolet Tahoe/GMC Yukon

jman77

ya i think i want to stick with an LQ4. which comes in the 1500 and 2500 i believe and do they have the iron block? or what years are iron block. If im going to boost a junk yard engine what should i replace on the engine. i heard pistons and rods are weak links? L92 heads are big upgrade and what woud be a good cam to go with that? try to get as much info as i can.

TMTMTL

500 hp turbo ? too eZ. stock motor can do that

GMTheOnlyWay1

iTrader: (1)

Yeah LQ4's and LQ9's are both iron block aluminum head motors. Except for earlier Lq4's


LQ4 debuted in 1999
Displacement was/is 6.0L
1999-2000 had iron heads
1999-2000 had a crank adapter to mate the LQ4 with the 4L80 trans (not LS1 compatible)
Compression ratio was 9.5:1
Block was Cast Iron

In 2001 the LQ9 was introduced
Both the LQ4 and LQ9 shared the iron block and new 317 heads (similar as the 243, but with larger 76cc chambers), hence both are 6.0L
The LQ9 had 10.4:1 compression ratio, versus the LQ4's 9.5:1
No longer did either 6.0L require the crank adapter for the trans, now works with LSx applications.
In 2004/5 6.0L recieved improved rod design

In 2005 the LS2 block was introduced
It is essentially the LQ9 with an aluminum block
LQ9 still offer with an iron block.

jman77

ok so if i go with the LQ4 with iron block and put a turbo on it what would i need to upgrade in the motor to withstand 15 psi and what numbers would i roughly be looking at?

GMTheOnlyWay1

iTrader: (1)

I've Never Built a FI LQ4/9 but according to my research the Stock Bottom end seems fairly reliable to 600-800 rwhp numbers. But if your planning on picking up a Junkyard motor and are planning to disassemble it to hone/clean it up you might as well look into building your bottom end as well. Also what tranny are you planning to use?

I can give you a list of parts of how I would set it up if you'd like?

There is also a lot of builds on this site similar to what your wanting to do, take a look and get some ideas. That will also give you an idea of what kind of numbers you should be looking forward to.

jman77

tranny would be my next question. ive been doing more research and would prob have forged internals as well. ya i wouldnt mind hearing what you would do with your setup (tranny and all).

lsx_production

lq4 is about triple theprice of an lr4. its the only reason why imnot stuffing onein my fox. I ended up getting a 5.3 for less than a 4.8 so that is whatim going with... as far as tranny goes, I have a built t56 and hope to procharge this fox

jman77

so why you going with a supercharger instead of a turbo?

lsx_production

compactness and ease of installation. less custom work and power in the low rpm's

lsmustangx

Kind of a change of subject but how much PSI can you run on without needing an intercooler or meth on a lq4/9. Ill be running pump or race fuel. E85 isnt an option where im from.

Chawlz

Kind of a complicated question. The psi is just the restriction of air being forced into the motor, so better flowing heads, intake, exhaust, and cam would lead to lower psi building on a supercharger but still making more power...weather you need the intercooler or meth would also depend on iat's and quality of tune. They are both used to lower iat's and prevent detonation. But since you are planning on running a decent amount of boost its all going to get pretty warm. I personally wouldn't try to go over 450 whp without intercooler
Short answer: get one or the other or both as it will increase potential power and probably save your engine