coolmanvette75

iTrader: (2)

Hey guys. After much deciding, I have decided to ditch my LT1 in favor of a budget junkyard 5.3 turbo build. Ive done a lot of reading and have come up with a rough list of what I will want to do. Any opinions and/or suggestions are much, much appreciated. This is my first turbo build so I still have a lot to learn.

Stock 5.3 Shortblock (trying to get an L33 but might just settle for an LM7)
ARP Rod Bolts
ARP Head Studs
LS9 Head gaskets
317's
Boost cam (suggestions appreciated)
LS6 Intake/TB
Bigger Injectors (suggestions appreciated)
Huron Speed Turbo Kit
On3 76mm (0.96 a/r)
3 Bar MAP

Still undecided on my fuel system. Car is a 94 Z28 and currently just has a Walbro 255lhp with a hotwire kit. Was thinking twin in-tank 255's but I'm not sure. I would be very satisfied with 600hp to the tire and 10s at the strip. It is an M6 car too...

ren987

iTrader: (4)

that is not a good turbo for a single set up. Your back pressure will be astronomical. With that being said it will work it is just not an optimal set up. The turbine wheels are 64.5mm. there are many better options out there for turbos but none will be as cheap.

godlyxdan

iTrader: (1)

People are making good power and having good results with on3 76mm as long as you're ok with their rep as Chinese made.

With that said I would say hell no to the 317 heads, they will lower CR WAY too much. All the way down around 8:1 which is too low even for boost. I recommend some 243, or 799 heads

ren987

iTrader: (4)

I have two of their turbos, I will never buy another regardless of peoples "good" results with them. I have no problems with mine but I also have a little bit of pride and don't like to be treated like dirt, the owner has no idea how to treat customers. 600rwhp will be nearly at the limit of that turbo and cubic inch you might be able to eek out a little more. The point is you can buy one that doesn't hold your engine back as badly.

godlyxdan

iTrader: (1)

Oh I'm not argueing that there's no better turbo to be had, there certainly is!! But they have become the go to turbo for budget builds so I would stick with it if it were me

coolmanvette75

iTrader: (2)

Throw out some other turbos! I am open to suggestions. Willing to pay a little more if I will benefit from it in the end...

godlyxdan

iTrader: (1)

Precision 7675 have proven themselves time and time again on 5.3s, for the extra coin the gains are phenominal

got-a-ls1

iTrader: (12)

7675 im a fan!

a4ls2goat

Or you can go with a gt45

denmah

iTrader: (2)

gt45 and if you want a larger exhaust housing borg warner s475 is a beast

Fb0dy0nly

iTrader: (10)

Are you kidding me? Search 76/5.3/5.7 combos on here and see just how many you get in return. Everyone runs those in single builds if they are looking for under 700whp for their stock shortblock. Its close to perfect size for a single on a stock ls block.

A 76gts will run about $1500 compared to the $300 china turbo and isnt going to benefit him power wise in any way on a stock shortblock as the turbo is in no way the limiting factor and it has the same size exhaust housing anyways (.96ar). Now if he had a forged/stroked ls1 or 6l, I would totally agree on going bigger.

All in all, make sure you do your hw OP...

a-low

iTrader: (26)

The s475 seems to be a real good turbo for the money and correct me if im wrong guys
but i think it'll support 700rwhp no problem.

got-a-ls1

iTrader: (12)

you do realize the a/r is a ratio and has nothing to do with comparing exhaust housings right? i mean a .96 a/r on a 65mm turbine isnt the same size as a .96a/r on a 116mm turbine. the on3 turbos have a small 65mm turbine or smaller? ebay turbos do work good from what it seems, but that small of a turbine is going to have some back pressure and choke on the exhaust side way before the compressor.. a pt7675 will take a 5.3 to around 900rwhp when youre ready for it. that said i think that on3 turbo may get you 600 rwhp but you will want more.

ren987

iTrader: (4)

some people will never understand the concept air and fuel in=air and fuel out. If it has no where to escape once you really start cramming air and fuel in it WILL NOT make more power lol.

coolmanvette75

iTrader: (2)

Yea I'm not looking to spend over a grand on just the turbo right now. This is a stock shortblock build. Not looking to produce crazy numbers. The GT45 seems to be fairly inexpensive (around $400). Opinions?

a-low

iTrader: (26)

If youre set nj a gt45 i just saw one on the classifieds for 250 shipped brand new just yesterday.

coolmanvette75

iTrader: (2)

Parts classifieds or eastern classifieds?

a-low

iTrader: (26)

Parts classified

Ferocity02

iTrader: (60)

That on3 will get you 600 rwhp. foose04 made 730rwhp through one at 18psi on his 4.8L w/ a 50 shoy. His was a Magnum 76 Q-trim but it's very close to the on3 unit. Yes your backpressure will be large, 2:1-3:1 probably. He wasn't making anymore power above 18psi. My build is very similar to yours, same turbo, same motor, cammed, w/ 799 heads, also aiming for 600rwhp.

Couple good threads from the truck side...
http://www.performancetrucks.net/for...m-next-508193/
http://www.performancetrucks.net/for...e-test-508336/

ren987

iTrader: (4)

Me and my friend built a kit for his 5.3 silverado using the on3 76 I know exactly what they are capable of and I personally have two on my car. I am telling you from experience that in a single application there are much better turbos out there, especially if you want a little wiggle room for growth in the future.