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Have anyone installed a lt4 s/c on our SS? I have a lsa already installed. Want more boost without breaking crap.
 

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LT4 blower is actually smaller. Not sure how it would even perform on an LS3 with port injection. Not to mention, I doubt it bolts up.

If youve already got an LSA, makes a lot more sense to port that blower or use a smallet pulley, or both if you want more boost. However, I dont think a stock LS3 can handle more than 10 psi. So like the previous person said, build up whats underneath.
 

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>10 psi boost and a stock LS3 is Russian Roulette. Already a mismatch Solid boost and a factory GM tolerances good NA engine, but not built by GM for boost. If you've got a Colt or Webley 6 shooter throw a bullet/round in, pull the trigger odds are published online especially, you might just be fine. Probability states you will mostly be fine....The internet posts all the success "my stock LS held boost turbo Supercharged, Centrifugal, or Positive displacement". Low boost stock NA engines win. At low boost high gain low risk. That's not gambling. It's not gambling with LS1s and LS truck motors (many are iron) when the junkyard has dime a dozen replacements. High boost blow up, junkyard hand over small change, even fun.

A used LS3 costs a bit more like real money still. For a while. The last Commodore is becoming a junkyard car in Australia already, but they are charging...

When it's my wallet >10psi boost LS3 you're now a casino high roller. Take a whole engine approach, whole LSA, whole LS9, whole LT4. Or build it, that means check it yourself, trust your builder/machinist and forged parts supplier = stress.

Forums and e-knowledge is still useful valid https://www.lsxmag.com/tech-stories/engine/preparing-your-ls3-for-surviving-boost
almost 9 year old article. Close to a decade later it might still be only mostly right. Cue posting exceptions....Probability can be cruel when you pull the trigger at >10psi boost

In laconic Aussie speak there are Wednesday and Friday engines. Ironically in LS3s A Wednesday engine may have perfect tight ring gaps that close with heat and high cylinder pressure >10psi, and a bad Monday or Friday engine, or even an abused engine loose enough to handle >10psi boost....heat and cylinder pressure.

As I'm planning over 10 psi I'm worried regarding - the nodular cast LS3 crank over forged crank, H beam rods over premium I beam, may be false economy. Plenty of stress comes with the tuner offering to turn up the boost, timing, injectors and fuel system. Or do you as in Kenny Roger's "know when to walk away or when to run" at a HP Limit.
 

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An LS3 with LSA blower, cam, and headers will have reduced boost pressure. Is it safe to say that boost drops down to approximately 6lbs?

What I've been debating when I have my LSA blower, cam, headers installed is going with the ATI balancer with the 10% overdrive supercharger pulley. I believe that combo will keep boost at 10lbs or less. I don't want to blow the engine up, but if there's room to safely increase boost I'd like to take advantage of it. Worse case, I go more conservative with the 5% overdrive supercharger pulley.
 

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10lbs of boost, (depending on volume of air) will not blow up a factory motor unless you do something like not provide fuel or not calibrate your setup.

I dont run an lsa, but i do run a 2300 js maggie, at 12psi @ 600whp and not breaking a sweat going on 70k bang shift miles.

Just do it right the first time and be done with it.
 

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An LS3 with LSA blower, cam, and headers will have reduced boost pressure. Is it safe to say that boost drops down to approximately 6lbs?

What I've been debating when I have my LSA blower, cam, headers installed is going with the ATI balancer with the 10% overdrive supercharger pulley. I believe that combo will keep boost at 10lbs or less. I don't want to blow the engine up, but if there's room to safely increase boost I'd like to take advantage of it. Worse case, I go more conservative with the 5% overdrive supercharger pulley.
I run a stock LSA lower and a 2.55” upper. I see 9.99lbs at 6,800 rpm with a cam, LT headers, full exhaust and mild port work on the snout and blower inlet.
 

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An LS3 with LSA blower, cam, and headers will have reduced boost pressure. Is it safe to say that boost drops down to approximately 6lbs?

What I've been debating when I have my LSA blower, cam, headers installed is going with the ATI balancer with the 10% overdrive supercharger pulley. I believe that combo will keep boost at 10lbs or less. I don't want to blow the engine up, but if there's room to safely increase boost I'd like to take advantage of it. Worse case, I go more conservative with the 5% overdrive supercharger pulley.
It all depends on the upper pulley. If you have a 2.55 upper with the 10% lower pulley, expect about 12lbs or so...
 

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Im @ 14psi, great tune, plenty of fuel zero issues on SBE LS3. Its less about a boost # and more about HP when it comes to engine life. What hurts people in builds is garbage supporting mods, 3rd rate injectors not using good brands like Injector Dynamics. Not giving it enough fuel, with something like a DSX aux pump, Fore, etc. Not installing things correctly ( your diy guy or some shade tree mechanic). Choosing a good tuner ( not a "he makes the most power" ) look at the company, the size and growth of the company, the units the company puts out and see what customers are saying about them. What does the shop look like? Could you eat in there or does it look like they struggle to make a living? A way a shop handles its space reflects a lot on the quality of staff, workmanship and ownership. Look at STG, Houston House of Power, RPM, Livernois etc. They keep a great clean shop, solid ownership, proven history and they don't do rinky-dink throw together crap.

My current build: Whipple 2.9, 3.25" pulley, Longtubes no cats, ID1050X injectors from injector dynamics, DSX Aux fuel system, DSX Flex fuel kit, Ported OEM throttle body, Stock bi-modal mufflers resulting in about 13-14 psi daily driven without any issues and Tuned by The one and only Chuck Anders at Houston House of Power.
 
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