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Discussion Starter #1
Has anyone grenaded their cast pistons with a Maggie and other mods...running near 500rwhp? I'm trying to decide if I should build the bottom end up before putting ported heads, cam and a maggie on.
 

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VDiddy said:
Has anyone grenaded their cast pistons with a Maggie and other mods...running near 500rwhp? I'm trying to decide if I should build the bottom end up before putting ported heads, cam and a maggie on.
I have a book "How to Build High Performance LS1/LS6" that says that our cast eutectic aluminum pistons can handle just over 500 hp.

Tony
 

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Discussion Starter #3
Thanks 2004ctsv....I appreciate the reply but am always skeptical of things in books and prefer firsthand experience. I heard about that book by the way and it looks like a really great investment...not to mention some good bathroom reading. :)
 

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The book looks pretty good. Much ofwhat he says is sound from the engineering side.

I was stuck for a couple weeks on and off in the great metropolis of Texass City. I needed some light reading in between plant trials. This book convinced me that I can install the s/c I just bought.
 

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2004ctsv said:
I have a book "How to Build High Performance LS1/LS6" that says that our cast eutectic aluminum pistons can handle just over 500 hp.

Tony
Is that rear wheel or crankshaft? I'm guessing crankshaft, but...

If crankshaft, I find that interesting, as a maggie is advertised to add 130rwhp/torque. That would, in theory, equal ~535 crankshaft HP, which exceeds what they are recommending...
 

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rp64ctsv said:
Keep it under 8lbs and you will be fine.
Wouldn't it be more appropriate to measure the actual HP/torque (cynlinder pressures) of the motor? For instance, if the motor was under, say, 15lbs (I know, it's not reasonable, but bear with me), yet the motor only generated 300hp, wouldn't you think that the pistons could take that?
 

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Luna. said:
Wouldn't it be more appropriate to measure the actual HP/torque (cynlinder pressures) of the motor? For instance, if the motor was under, say, 15lbs (I know, it's not reasonable, but bear with me), yet the motor only generated 300hp, wouldn't you think that the pistons could take that?
Way over my head-good q for an engineer.I feel a maggie is more forgiving than a spool when it comes to forced induction.I just feel V8s and high boost don't go well together without forged internals.No way I wan't cracked pistons on my car,and I believe they will under high boost.
 

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Luna. said:
Is that rear wheel or crankshaft? I'm guessing crankshaft, but...

If crankshaft, I find that interesting, as a maggie is advertised to add 130rwhp/torque. That would, in theory, equal ~535 crankshaft HP, which exceeds what they are recommending...
It doesn't specify. But they do recommend holding to the 5-6 ponds of boost. For higher pressure, they use the iron LQ9 engines.

With our high comp ratio, I'll stick with the pulley provided for a while.

Tony
 
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I have run 10psi on stock cast pistons on another car with no problems. It is the detonation, not boost that breaks things. Run the wrong ratio of timing and A/F and things will break even on forged parts.

Norm
 

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V-Max said:
I have run 10psi on stock cast pistons on another car with no problems. It is the detonation, not boost that breaks things. Run the wrong ratio of timing and A/F and things will break even on forged parts.

Norm
Yeah, you're absolutely right, and I've seen 10# on stock engines alot, but I was running A/F of 9/1 - pig rich, and conservative timing. Cracked #7 piston on a 33 degree night, after about 5 min. of driving. Maybe I had a crack in it from something previous, or maybe it's just my shit luck. Don't know. Either way, it won't happen again:cool2: .

Mark
 
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Here is a classic example of when someone goes beyond bolt-ons and the operating conditions change, possibility outside the range that Bob @ EPP tuned it for on the dyno. You really need to run a datalog for a complete season before putting the notebook away. My project ran a compression ratio lower than the V and without knock sensors. Enough datalogging and I can see when oxygenated winter fuel is switched over in N. Ohio and which gas stations 92 octane is not on par with the others. :)

Most detenation happens during throttle transition and even driving style plays a role. It takes allot of time to catch lean areas of the map, whether it is timing or A/F. Most anyone can tune at steady state like WOT like some shops(which I hope EPP didn't do as they have a load type dyno like a Mustang).

Impressive power though!

Norm
 

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V-Max said:
Here is a classic example of when someone goes beyond bolt-ons and the operating conditions change, possibility outside the range that Bob @ EPP tuned it for on the dyno. You really need to run a datalog for a complete season before putting the notebook away. My project ran a compression ratio lower than the V and without knock sensors. Enough datalogging and I can see when oxygenated winter fuel is switched over in N. Ohio and which gas stations 92 octane is not on par with the others. :)

Most detenation happens during throttle transition and even driving style plays a role. It takes allot of time to catch lean areas of the map, whether it is timing or A/F. Most anyone can tune at steady state like WOT like some shops(which I hope EPP didn't do as they have a load type dyno like a Mustang).

Impressive power though!

Norm
I'm quite sure my driving style was the issue. Missed a shift and bounced off the rev limiter when it actually happened. Like I said though, I'm forging and lowering compression ratio. Shouldn't happen again:thumbsup: .

Mark
 

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Ouch! Mark, I didn't hear that happened until just now. I enjoyed the build on your car, you are definitely going down the right track now though..
 

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Mark,I'll be in Lawrence 1-9&1-10 maybe we can get a beer?
 
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