1SLOWC6

Recently I Talked To Vette Shop They Told Me That A Stock Short-block Can't Handle The Power If You Have A Supercharger, Cam And Heads! Is That True Or Should I Be Looking To Get A Bulit Short Block? I Want About 6 Psi From The Superchager

Thanks For The Help Guy's

LS1LT1

Properly tuned and with an intercooler a stock LS2 bottom end can certainly take 6psi and a properly matched H/C package with no problems IMO, at least on the short term.
Thrash the car hard with redline shifts every weekend for 200k miles straight without changing the oil and no, it might not wear quite as well as say a bone stock LS2 would.
For higher boost though built/forged is always better.

yell03

I also have spoken to a major performance shop about the C6 stock block.

In their opinion the LS2s and LS1s are junk.

In fact, the LS7s are not much better, yes they have better rods, but their pistons are still garbage.
Cast pistons are just not made to handle Forced Induction.

That is why all the kits come with only 6# of boost for a STOCK block.

Why doesn't GM use Forged Pistons then?

For a production car the tolerances are much better with cast pistons (less oil consumption), plus cast pistons are lighter meaning better economy and better performance in stock form.

If you go Forced induction your car will probably be fine unless you get greedy and up the boost.

I had a 2000 Mustang GT with a Novi 2000 supercharger.
On stock boost it made 340rwhp SAE and was fine.

But, I got greedy and upped the boost to 13# and added an intercooler for safety resulting in 385rwhp SAE on a safe 11.5 a/f tune.

All it took was one very COLD morning and a romp on the throttle, I heard a slight rattle of detonation and backed off.

Too late, my #8 piston shattered.

The car was still making 350rwhp+ with only 7 cylinders.

Howard

cmb13

Talk to Jeff (jschilit) or Rick (sickrick)....their engines are doing fine, but everything else seems to need strengthening. New clutch, rear end brace, and more. Both have h/c and superchargers.

1SLOWC6

Well Thanks For Your Help Guys I Suppose I Will Be Getting The Supercharger Soon Also Saving Money For A Built 427 Shortblock

vettl83

For what it's worth my racing partner runs a Pro Charger on his LS6 using 6 lbs. of boost. The car is bone stock except for the Pro Charger and has been run in competion for two seasons without any issues. The only problem I've seen is he has assasinated more cones on the auto-x courses than he used to. However, no problems with open road racing or one mile shootouts.

schilitj

I have a 05 C6, Z51, MN6 with the following:

Procharger D1SC Supercharger
AFR 225 Heads
Cam 224/230 581/592 114 LSA
Corsa Sports
Dynatech Supermaxx Headers
Callaway Shifter
160 Degree Thermostat
Tuned

It puts out:

HORSEPOWER
TO THE CRANK = 690 TO THE RW = 586.1

TORQUE
TO THE CRANK = 595 TO THE RW = 506.1

Absolutely no problems. Took it to the track and had a pro drag racer take it down. Too much power for the stock clutch, only did a 12.27@121.6mph. Putting a competition clutch in and then back to the tract. Looking for a high 10 second run at 130+mph.

Jeff

Dgatto

schilitj

Your car looks just like mine

Tommy D

A stock block with a conserative tune, should be fine. If you go looking for every bit of horsepower....... that LS2 will become a boat anchor very shortly. Unfortunately, stuff tends to happen so when it does you can replace it with forged internals.

IF YOU WANT TO PLAY YOU HAVE TO PAY

schilitj

How true, how true. And you can say that again: How True

SpinMonster

Amazing that it is as easy as that for the expensive lesson to come to pass.

yell03

SpinMonster -

I remember a while before that I swore I heard something shoot out the exhaust, but the car ran fine afterwards.

Maybe a spark plug electrode???

FI is alot of fun, but it can have consequences if you get greedy.

My 1992 Mustang with a mildly built engine (forged rods and pistons) had a Powerdyne at 5# of boost when I bought it.
It made about 410-420rwhp and ran the 1/4 in high 11s@116-118.
But, I got GREEDY....
I swapped to a Vortech.
No problem, on the same tune the car ran PERFECT and ran a 11.8@122on a 2.0 60' at the track.

BUT NO, I NEEDED MORE....
So I bought a Powerpipe to get an extra 1-2# of boost for $100.
The car now needed a new tune.
So I decided to pulley down also.
So, after $4000 in work to compensate for the extra 2-3# of boost the car came out with 461rwhp SAE.
1st time at the track I got two passes, the 1st run started great, lifting the front left tire with a 1.66 60', but it got squirelly and only ran a 11.6@123+.
Second run, eased out with a 1.81 60' on the DRs and ran a 11.2@124.56, but blew a Headgasket. I did not know it was not o-ringed when I bought it.
Later on after trying to get the thing running, I replaced the headgaskets, but a poor adjustment resulted in THREE cracked roller rockers also.
I sold the $20,000 project for $6000

Sorry for the long story, but the point is....

When I bought the car it was VERY FAST and totally reliable at LOW BOOST.
Just turning up the wick a little bit resulted in catastrophe.

Howard

glass slipper

Relatively speaking (in terms of the HP they have to handle), the LS7 rods are not stronger. They are lighter (being titanium) which reduces the stress on the rotating assembly. Titanium is stronger than steel pound for pound, but on the basis of cross-sectional area, steel is stronger than titanium when talking about yield strength. In other words, if the rods are the same exact size, the steel rod will be stronger. If they are the same weight, the titanium rod will be stronger. But you can only make the titanium rod so big before you run out of room inside the engine. That's why when making big HP increases for the LS7, engine builders replace the titanium rods with forged 4340 steel rods as there is simply not enough room for a titanium rod that will handle the power.

GM uses cast pistons for three reasons: lower emissions, better MPG, and more HP. It has less to do with the weight of the piston and more to do with the density of the piston which affects its' thermodynamic properties. Forged pistons are more dense which increases heat transfer. Since HP is heat (1 HP=746 watts, ever grabbed a 60 watt light bulb?), forged pistons transfer more heat/HP. Given identical engines, cast pistons will make more HP than forged pistons...until they crack/shatter. Forged pistons will tolerate detonation much better than cast pistons but because of its' increased heat transfer, they have higher emissions and lower MPG.

Forged pistons can have the same oil consumption as cast pistons as that is dictated by the oil control rings and the 2nd compression ring (not many people know the 2nd compression ring serves double duty to remove the metered amount of oil left by the oil control rings).

And one final component to worry about is the cylinder liners. GM uses grey cast iron which, like the cast pistons are strong, but very brittle (not ductile). If you build the bottom end to handle a huge increase in HP and neglect the liners, they will split open the first time the engine detonates (like cast pistons). Darton has cast ductile iron sleeves to finish off a bullet proof short block.
http://www.darton-international.com/ductile_info.htm
The graphite flakes of grey cast iron act like stress risers giving cracks a place to start. The spheriodal (nodular) graphite in cast ductile iron eliminates the stress risers increasing strength and ductility significantly. I'm sure you've heard of cast nodular iron crankshafts...this is where it gets the "nodular" part of its' name and why it is much stronger than a "regular" cast iron crankshaft and almost as strong as forged cranks.

Tommy D

Howard.......how true

I started with paxton, I had the second bracket produced that was supposed to correct the slipping belt problem (1991). That bracket had free trips to California it went back so many times. Tuning was non existant The MAF was like a big cork in the intake. Fuel delivery left a lot to be desired, so when the headers started turning cherry red and the exhaust temp went off the scale....... more gasoline.

I finally gave up and got a Vortech. Not enough power, so I went to the smaller pully. I upgraded everything I could but who knew Ford 302 blocks were only good for 500 HP. One boat anchor later, I built a 306 with forged internals and girdle but the AOD two piece input shaft said bye bye. I got a GER AOD & converter and the car remained that way as my daily driver until I sold it this April.

(yup also gave it away...... sold it for 6,500 the car cost 14,800 new with aproximately $ 11,000 in parts and many, many hours of my hard work)

BTW the first run with street tires was 13.80 at 108 smoking the tires down the entire lenght of the track the second run I mounted drag radials and ran 11.43 @ 117 and was asked to leave and not return until I installed the required safety equipment. AH yes as my wife laments "BOYS AND THEIR TOYS"

yell03

There is definitely a lot of history with 5.0s & Mustangs with the NJ and PA crowd isn't there?

Lately I am starting to favor NA to FI.

Recent cars that started to sway me toward NA were my Viper (approx.410rwhp), my 99 Ram Air TA (330rwhp), and now my 2006 C6 (370rwhp).

For a street driven car on street tires there is only so much power you can use anyway, 425rwhp is pretty close to the the limit.

The NEW Z06 at 430rwhp is a good example.
If it weren't for MASSIVE 325 rear rubber, a killer suspension, and Active Handling it would be uncontrollable.

My Viper was downright dangerous on stock tires on the 1-2 shift.
There were no electronic safety nets on that car and sideways was always a stab of the throttle away.

Howard

Tommy D

Howard


Absoutely, I guess a whole bunch of us came from the Mustang camp. I have been told that I have gone to the "dark side"

But it always starts the same "not enough horse power" and before you know it you can't drive it on the street without drag radials. Just like joke about the guy with a Supra. What does the 850 HP Supra and a stock Supra have in common......... They both run 13 second quarter miles.

I have promised my wife no modifications....... I'm shopping...... looking...... drooling and maybe in the market for HP tuners before I start to play. I do all my own work which is great because it takes me forever to do anything and I have to always have a extra set of hands around so we will see....... I promised myself that this car would be drivable on the street with the stock rubber.

yell03

Tommy D -

I love that Supra joke, first time I ever heard it

Howard

k0bun

I made that same promise to myself and my fiance'.

Wayne O

Everyone....good thread up and down!

To glass slipper....great information! I appreciate you sharing your expertise. I learn something new everyday! Thanks.