Creampuffs and Superchargers

[Bugeater]

All years with Non-forged pistoned will all need to replace them before use of a supercharger is recommended, correct?

This puts a pretty substantial increase in the DIY cost, I would
assume.

Is this a fair assessment?

 

[Gerald]

I would highly doubt it. I'm sure the DIY kits will only "scratch" the surface of power that can be extracted (though I"m probably wrong) so I would imagine no need to replace the pistons. But if your after S/C wizadry and true HP gain (600 rwhp +) for only a few thousand more, you might need to replace them. I"m most likely completely wrong about this.....


Gerald

 

[Chuck B 98 GTS]

I know DLM builds cars for many dealers that are brand new with the cast pistons. You can use the stock cast pistons but I don't think you can run high amounts of boost with them.

Chuck

 

[Bugeater]

The reason I wanted to confirm is that this was stated in
a conversation with Heffner regarding the cast pistons. He said
the danger is when hitting up against the rev limiter, the fuel shuts off creating alot of heat, under boost >>> piston failure.

He recommended against using the cast piston. I dont know if this should be interpreted as a must-change for all boost applications. We were talking the base system fyi (6psi).

Mr Heffner, Mr Levin...?

Just trying to sort out future plans...

 

[Gerald]

I would guess it's which tuner you choose to supercharge your car. I think Dan Blacks ACR is a 99 (Cast pistons) and he is pumping out nearly 620 RWHP, safely. There are many factors involved in extracting "safe" HP and many tricks with the computer, heads, etc. that are untilized..


Gerald

 

[Bugeater]

I believe 99's are forged.

 

[Jason Heffner]

Gerald, all 99 Vipers have forged pistons. I never said that you can't safely supercharge a cast piston engine. DIY systems from any tuner will most likely be in the range of 6 psi for cast piston engines. I seriously doubt if anyone would put 12 psi on a Viper without forged pistons. I have supercharged nearly four hundred cars, not all Vipers but the theory is still the same and most of them have cast pistons. I just want to make it clear that if you want the most durability out of your engine on a supercharged application, forged pistons are the way to go.

Doug, what is your policy as far as cast pistons go?

 

[Bugeater]

Jason,
Thanks for clearing that up! I interpreted from our discussion that there was high risk in not using forged for 6psi applications. As I dont plan on a 12 pound system up-front, so this is good news for me.

Question:
Whats the additional cost to upgrade from a base system to 12 pounds (w/forged) vs. total up-front install of 12 psi? For the budget-minded, is this still a cost-effective option?

 

[Gerald]

I knew I was wrong.... See? Shows you how much I know...NOTHING. I'll keep to one liners..

 

[Jason Heffner]

To go to a 12 psi system including keyed crank, forged pistons, new rings & bearings, blueprinted & balanced engine, complete fuel system upgrade, new injectors, programmable engine management system, all new gaskets & seals, 1/2" fuel rails would be an additional six thousand dollars installed, this would not be a diy system.

 

[Bugeater]

Thanks Jason.

BTW, I am checking out a GTS in Baltimore this weekend.
How far away is your shop? Would like to check it out...

 

[Jason Heffner]

Probably about 20 minutes.

 

[Doug Supercharged Vipers]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Bugeater:
The reason I wanted to confirm is that this was stated in
a conversation with Heffner regarding the cast pistons. He said
the danger is when hitting up against the rev limiter, the fuel shuts off creating alot of heat, under boost &gt;&gt;&gt; piston failure.

He recommended against using the cast piston. I dont know if this should be interpreted as a must-change for all boost applications. We were talking the base system fyi (6psi).

Mr Heffner, Mr Levin...?




<HR></BLOCKQUOTE>I would commend your mechanics decision to suggest alternative provisions, quite simply; Making it live.

Cast pistons can be utilized for performance building, but their integrity can be compromised in sever-duty applications. The high position ring land is subjected to extreme temperatures and microscopic pieces of piston material get hot enough to weld to the top ring. Once that occurs, the ring seal becomes degraded and power is lost. Detonation which involves too rapid a rate of energy release produces excessive pressures and temperatures in the combustion chamber; these high pressures and temperatures can damage cast pistons (yes, and brake away the ring land or flake off pieces of aluminum) in no time. It's not just the fuel cut off at 6,250 rpm that effects cast pistons, It's the byproduct of the "over-rev" that may cause the skirt on the piston to crack and work its way to the top, eventually catastrophic engine failure is inevitable.

Our policy on boost levels is not necessarily the boost level number, we refer to the "CFM" as part of the many mitigating factors along with the proper initial tuning to combat any ill-effects to the engine internals on a cast piston/supercharged application.

- I hope this was helpful.

Regards,
Doug