Gen 2 Cream quot Puffed quot

**Voros_Siklo** · 11-24-2019

Good evening,

About a week and a half ago, my Gen 2 had a very loud engine knock when accelerating off of the onramp to get up to speed as it was a short merge. Being as my Gen 2 was a '00 model with a supercharger, I had assumed that the pistons were upgraded to forged parts. Turns out that it was still using the Hypertech cast pistons. I now have 2 failed pistons and damaged valves. Valves are being replaced with SS sets and awaiting an update as to the state of the cylinder walls.

I am debating whether or not to keep the supercharger on the GTS as I do not want to go through another instance of piston failure. Not sure about the boost levels or fuel flow rate as the documents provided with the vehicle does not list those figures.

I would like to know if there are any forged piston sets that someone could recommend that has had experience with a supercharged set-up? Looking for something that will be relatively reliable but won't break the bank.

**dave6666** · 11-24-2019

I ran an 8# boost on a cast piston engine for nearly 10 years. It's all in being tuned correctly.

**Fatboy 18** · 11-24-2019

What boost were you running on your creampuff? As Dave said, it's all down to the Tune.
6lb boost is fine on a creampuff, any more than that it might be worth swapping out pistons.
I have a brand new set of forged pistons up for grabs if needed.

**Martyb** · 11-24-2019

Originally Posted by dave6666

I ran an 8# boost on a cast piston engine for nearly 10 years. It's all in being tuned correctly.

Dave hit the nail on the head, the tune is beyond critical. There are a few guys running about 1000hp on creampuff engines with cast pistons, and have been doing so for many years. I know of one that was a turbo can and the other was a supercharged car with nitrous. Spend the money on a good tune it will pay off in the long run.

**99RT10** · 11-24-2019

Just upgrade the pistons to give you a better part and able to absorb a tune that might be off. Find a better tuner and up the boost,

**Voros_Siklo** · 11-25-2019

Unfortunately, the documents that came with the vehicle didn't have the tune information. It only came with the parts list and the three dyno runs with the HP and torque listed only. Unfortunately, the place that had performed the work has since been liquidated. I will be able to find out more about the tune as work progresses on the repairs. I believe that the boost was between 4#-6#. Also, always used Chevron's 91 octane and never on fumes. Never used octane boosters.

I think I might have missed a shift but made sure not to pass the 5.5k mark. As soon as the snake's heart is back in order, will definately have the tuning checked out.

Any recommended manufacturers for the forged pistons?

**M5toViper** · 11-25-2019

https://exoticengine.com/

Check them out

**MH60M** · 11-25-2019

Originally Posted by Voros_Siklo

Any recommended manufacturers for the forged pistons?

I'd just hit the Roe Racing website for better pistons....They're probably the manufacturer of your Supercharger anyway.

**ellowviper** · 11-25-2019

A couple of considerations.
1. Been there with my 01 Supercharged creampuff and like you, busted a ring land due to a malfunction in my tune (not the tune, but the VEC malfunctioned). Hurt the head but the cylinder was fine.
2. Replaced all cast pistons with Diamond forged form ROE racing. My shop charged $10 each to remove from stock rod and press the new piston on the stock rod. Can't use full floating pins since 00-02 rods use the .945 wrist pin and those are a press fit into the rod. Pistons are set-up for full floating wrist pins...its the rods that forces you to use a press fit.
3. No need to rebalance the engine if you just swap to a forged piston on the stock rod. Been running high boost (13+ psi) for 50k miles with this set-up no problem.
4. You can do this with the engine in the car...really you can...to include cylinder prep and associated tasks. Its easier out of the car (done that too)...but most folks don't have the equipment to remove.

**RT SERPENT** · 11-25-2019

Running Diamond Racing Forged pistons for 10+ years.

While the tune is critical and some folks have run very reliably on cast pistons, I would still recommend forged.
You rarely get a second chance with a cast piston... Any detonation, due to an infinite number of reasons,
and your cast piston is usually toast. Why take the chance.

**Fatboy 18** · 11-25-2019

Many years ago there were a bad batch of VEC Controllers which caused a few engine failures. Vec did replace many of them under guarantee but a few slipped by the net and once the Guarantee ran out it was tough cheese

**Voros_Siklo** · 11-26-2019

Well, knowing my luck, if it is a VEC mine probably fell through. I should have my name changed to Murphy...

**ellowviper** · 11-26-2019

Originally Posted by RT SERPENT

Running Diamond Racing Forged pistons for 10+ years.

While the tune is critical and some folks have run very reliably on cast pistons, I would still recommend forged.
You rarely get a second chance with a cast piston... Any detonation, due to an infinite number of reasons,
and your cast piston is usually toast. Why take the chance.

Its not all about detonation....but under boost, your EGTs rise well above design limits which cause your rings to expand and "pop" your ring lands. The cast pistons let the factory run really tight ring gaps (great for controlling blow-by/emissions) but are not good for boosted applications. actually quite the opposite...boosted applications, all things being equal, require larger ring gaps just for this reason. A great way to control this is to use water injection...thus why I'm an avid believer/user of a good water injection system even with forged pistons. I run a tight ring gap even at 13+ PSI boost since I run a big shot of water injection. Just another point of fact when it comes to how you want to mitigate issues in the future. Manage combustion temps and you won't be popping ring lands. Its also great for controlling detonation too....