S/C boost relation to octane requirements?

[rxrider]

That is what I'm thinking machzrobbie.
It may not be detonation causing it at all.

Stigapex, I would go With a set of JE pistons on the rebuild.
The Wiseco's have a problem With weak wrist pins.

 

[Riceburner]

X 3

Newer not necessarily better. [ At least where high boost entered in to the equation.]

 

[Stigapex]

New engine bought in.
JE pistons, carillo rods, 10mm head studs in order from Ulmer

 

[machzrobbie]

I really like the CP carillo pistons Hurricane had made that use stock apex rings, have used them in a couple motors and they make good power

 

[Stigapex]

What will be the difference beetween carillo and JE pistons

 

[HURRICANE]

We had the Carrillo pistons built stronger to stand up to high load conditions.We also had them made to be used with Yamaha rings for factory oil control.The pistons are a direct fit with 10-1 compression

 

[Stigapex]

Wrist pin not broken, can't se any damage in the other pistons and rods

I don't know what have caused the broken rod

 

[machzrobbie]

Can't see you other pistons close enough but have a good look - this is one of the pistons I've removed that had cracked

 

[Stigapex]

The three pistons that is not broken have the same crack, and the one that is broken, is broken in the crack. Add some picture of the bearings also

 

[Riceburner]

Stig,

How much boost were you running?
When I installed the AEM Tru Boost controller i had to lengthen the Wastegate Rod 12 turns from shortest at Sea Level. I was making close to 19 lbs with the rod 4 turns out. I only ran there for 2 seconds so hopefully my motor is ok.
I havent checked Max Boost at 100 % on the AEM so not excactly sure what it is now. I run the AEM most of the time @ 60 % which is 12 lbs ish. Off is 7 PSI & 50% is 10 ish psi.

Dave

 

[machzrobbie]

Thats definaltly the piston that broke, same as my buddy stone's motor when it let go - the new style pistons definalty aren't as good for boost. I'm curious too, how much boost do you normally run.

 

[Stigapex]

I also use the AEM tru boost controller. Set to 45%, and that's 19 psi in my setup. I normally run at 19 psi. The engine have 3200 miles with turbo, and before that 1800 miles without turbo. Never longtime run at wot, only 8-10 sec.
I've also added an ignition module, see pic under for ignition.
I can understand that my engine would blow with so much boost for 3000 miles, but a friend of mine with the same sled blow his engine after 700 miles, and he almost never run with so much boost. His setup was a MCX315, 16psi. Maybe 50 of the 700 miles was with 19 psi setup.

I removed the mcx dumpvalve in the intercooler, and changed it with another. Then I had to turn down 10% at the aem tru boost, to come down to the same boost. It was a lot of leak in that dumpvalve

 

[Stigapex]