Ok folks, I've been digging around. trying to come up with a value piston for a relatively tame build. what I want to do is run 7psi(ish) on a single turbo through 317 heads on an lq4 using an LS9 cam, stock crank, and stock rods. the main hitching point for me is the pistons.. now the main point is detonation resistance / strength, now with an "old school" non computer controlled engine, I can completely understand the need for a forged piston. however, with modern engine control, a good tune, and good fuel, is a forged piston a necessity? I keep looking at smaller displacement OE turbo mills, which I can assume run hyperutectic pistons because of emissions (loose piston to wall clearance at startup, cold start noise, etc, etc,) which are putting out over 100hp per liter. apply that math to a larger engine, and thats over 600hp. so what am I missing here? do the oe engines not use a hyper piston? or because of the bore size, its a physically smaller piston? (edit, I know some of the real "thumping" turbo mills are direct injected, lets leave those ones out) whats the deal?

also I'm not against running forged slugs, with that it will leave the short block open for much more power, but at my budget and time frame, might never happen, so what I'm looking for is advice, has anyone successfully run a hyper piston on a mild boost build, has it lasted? and of course suggestions on a moderately priced forged piston? I know this is pretty open ended, and there are 10 billion variables, that when one goes askew a piston goes byebye.. but none the less, advice? and we can save the "don't run hypers, they will not last" if ya haven't tried it, leave it be, I've read that a 100 times, as well as many people running them in boosted applications successfully.. but I want real world advice on this...

 

more ramblings on this.. all the gen 4's save for the ls9 use a hyper piston right?, now, with aluminum block, the heat dissapation is better right? so say using a stock 4th gen with an added STS turbo kit or a procharger might not be a good "real world" example but none the less, i know there's more than a few folks with otherwise stock engines running these setups, they also have higher compression ratios thus pushing the envelope.. or say adding a supercharger to a stock lq4 in a truck, that's another example. do these setups cause premature failure? or what?

 

I don't think a forged piston is a necessity at only 7 psi. People have made over 1000 on a stock junkyard 5.3.

 

I think even a quick search would have answered your question 100 times over.

 

If you know what you are doing and don’t get stupid, you will be fine.
Otherwise, you will lift a ring land.

 

you are over thinking this there is no ls based engine in good working condition that can not live a long life on 7 psi boost. I run 17 psi on my 200k lq4 and it don't blink an eye. 4 years now.

get a good sound running engine and boost it if the tune is good it will live a long time. jmho.

 

I cant figure out these questions..... cant people use google and read? Are these people lonely and just want to talk? Do they think that they are the only one ever to think of this stuff? Is it some form of automotive masturbation? I just dont know

 

I've been reading google, engine masters, and print, as well as talking to tech support from the manufacturers for about 2 years now, confirming what I've read, and found from real world examples because the answers are all over the place... so far we've got boosted on 200k 7psi is fine for hyper, and a good tune, which confirms what I thought.. problem is in hot rodding trends follow unnecessarily some times because of "old school" rules of thumb. tell someone 20 years ago that a manufacturer produces a 200+ hp turbo 4 cylinder that works well and is reliable.. and doing it with under 2 liters.. just to think back 125hp was normal for a 1.6L engine just a scant 15 years ago.. now the little dinky econoboxes are pushing what the v8's of the 70s were hard pressed to make.. there's a reason for that. trying to understand how to make it work for me for as cheap as possible....

 

Ie opening up the ring gap...

 

When you want to know how much a specific engine will handle, look up info on that engine, not engines in general.
This will give you a bit of insight, although its a little outdated now.
https://ls1tech.com/forums/forced-in...end-lsx-s.html

7 PSI is child's play for these engines.

If everything goes as planned, the 3 engines I have together right now will all break 1000 HP on stock short blocks on the dyno this year.

 

ive tried.. turbo lq4 only gets a couple of hits.. and when i do, its on a full throttle dyno flog with people who know what their doing.. and all out hp goals.. I don't really know where to look, to be honest.. folks round where im from are still spending buku bucks on cammel hump heads and think hp tuners is from hewlett packard... (no lie.. just got that 2 days ago) I'm in the dead zone for power, and just trying to make up for lost ground... going to read up on that thread.. thanks for the insight

 

Ok, will allowances given for regional disparity in common knowledge I will lay it out for you...... DONT worry about the damn pistons, rods, rings, bearings, springs, intake, exhaust pipe size, throttle body size, cam, pushrods, lifters, coils or fuel rails. GET a Stock motor that you know runs, get the motor bolted into your ride. GET on sloppy mechanics and learn you some turbo plumbing techniques with Ebay junk. THEN learn how to tune it with whatever ECU you happen to use (This is the most important thing, LEARN TO TUNE!!!!!) DONT worry about the motor, the turbo makes the power, all the engine has to do is hold together (LEARN TO TUNE!!!). 6.0, 5.3, 4.8, 5.7, LS1, LS2, LQ4, L33, LQ9, it doesn't really matter, they will all make enough power to boot any 3500lb **** box into the 10's bone stock.

 

Learning how to tune is good advice.

But learning how to tune IMO is not good advice on an investment that you just dropped $5 - $10 K on.

The money for your own tuning software IMO is better spent if you find and can rely on a good tuner who will examine you what you have and then tune accordingly. Then you will be safe. Also, not paying $600 for tuning software will pay for a tune, or upgrade your fuel injectors, or upgrade your fuel pump.

Finding a reliable tuner can be disappointing in and of itself. So imagine you trying to learn by yourself when there are so many hacks out there who call themselves good tuners but aren't, even though they have been doing it for years. Those who say it is easy - it's not.

IMO with a turbo or charger, you will have to have access to a dyno as well. I think you will be hard pressed to learn how to tune a turbo or procharged car using a data logger and learn as you go.

You will find your engine reaches 6500 rpms pretty quick only to find it went lean and just detonated - oops. So you probably want to leave that part to someone who knows what they are doing.

Five to 7 lbs of boost in most cases is safe with a perfect tune on a stock LS1, but not if your injectors aren't up to task, or the fuel pump isn't adequate to supply enough fuel, or your air supply temps are too high. These can cause your engine to go lean and toast your engine even at 7 lbs of boost.

A good tuner will ask those questions before even starting.

Finding a good tuner:

Drive-ability tuning is what takes the most time. My experience with so-called tuners is that they don't want to deal with time. IMO if it costs $5- $600 for a tune, then you should get at least 5 hours of time from your tuner. But some just want to strap your investment on a dyno, make 500 rwhp, take your money and send you out the door. And of course, you are jumping up and down because your car just made 500 rwhp on the dyno.

Then later when you get it home and drive it,you find it won't idle, shifts terrible, spews gas out the exhaust and drive-ability sucks.

So it all boils down to the tune along with the right parts as so many say no matter who you ask or where you go.

Learning how to tune is nice, but to start find a good tuner first.

If you want, then later, you can buy some tuning software, data log, examine the logs and tables, read, read, read and get to understand what will destroy your investment or let it live.


Good luck.

 

You will learn more about what it takes to make a engine run and perform properly by tuning yourself than you ever will by buying expensive parts and paying someone else to make it work. Only thing your going to hurt is the engine by screwing up the tune, most of the money in a turbo setup is in all the crap bolted to said engine.
Its the whole give a man a fish argument. Learn on junk yard stuff then youll have a idea of what you need when the time comes. Many people figure out that a 600-700hp street car is no joke, and stock motor parts are just fine.
But then again some guys love to talk about how much they spend on stuff.

 

I read the OP's question as what he has to do or not do to a stock engine so it will be reliable and NOT grenade if adding a turbo or supercharger

I gather the OP doesn't have deep pockets, so the OP wants to do it right the first time out the gate and not make mistakes as he learns. None of us want to destroy an engine only to learn that's the price we pay if mistakes are made.

My pockets aren't deep enough to blow up a turbo'd stock engine as I learn how tune it even if it is stock. My suggestion to the OP is that a $500 tune by a professional might save a $3500 stock engine from destruction as opposed to the OP learning how to tune it himself.

I agree totally that learning how to do it yourself or by example for most is the best way to learn. But it can be very expensive if the engine grenades. If it blows up, well that's a big price to pay in lieu of getting a professional to help you.

I agree too, that 700 rwhp is no joke. But it can also break many parts real fast or even get you killed. Going from driving a 300 rwhp car to 700 rwhp is a giant learning curve if you want to stay alive or not hurt someone else while you learn.

 

My bone stock short block LQ4 got me a 10.3 at 130 with twin 61mm’s, before I snapped my drive shaft. only thing I changed in the motor was the cam and springs to match everything else is stock down to the truck intake. It made 540 at the tire on the dyno.

 

Do this^^^^ ignore dland sounds like he's still stuck in 2002 when making 500hp was unicorn type ****.

 

Hi All, so this once I agree !

I WILL STATE the cost difference to UPGRADE to a Forged RaceTech Piston is ONLY $200.00.
They will be liter with no re-balance required, thus SAME COST. (-200.00 balance cost).

Thus fitment of the CORRECT piston, a choice, could cost LESS.

They will be +.004" (or choice) so NO BORE COST, just the normal "ball buster"
The +.00x size will OPEN UP rings gaps, thus no file fit required. (easier installation)

So I ask, "Would it be better to install a stronger part if it saves money" ?

Lance

 

I’d just use the stock parts.
I think it’s a very good idea to disassemble the engine, clean all the parts, gap the rings and put it back together putting all the parts back where they came from.
At least this way you know you didn’t start with an unknown turd that was destined to break.

 

If a piston/wrist ping/ring pack assembly is notably lighter than the stock stuff, not balancing it would be a bad idea.