Thickness under the crown - VOTE IF YOU ARE IN THE PROBE GB!

[Doward]

Just as it says!

I, personally, feel the .230 is MORE than adequate.

From thinnest to thickest of the aftermarket pistons:

.160" under the crown - Wiseco pistons (over 730rwhp recorded on these via 7MPower.com)
.230" under the crown - JE Pistons (over 620rwhp recorded on these via 7MPower)
.260" under the crown - Ross Pistons (none of the top 10 @ 7MPower recorded using Ross pistons)

For comparison - an LS2, with a 4.06" bore, Probe uses a .180" under the crown. Running a 102mm turbo, they ran 1100rwhp through it, when the tossed a rod through the block.

Remember, these are FORGED pistons - not cast.

To me, I look at what is out there - from .160" to .260", and the middle is .210"

.230" is, to me, perfectly fine. Extremely robust, and will handle anything thrown at them.

BUT - I told Shawn I would put this to a vote in the community. So here it is.

.245" or .230" thickness? It's an extra 4 grams of weight for the .245"

 

[screaminglemon]

i vote .245" i feel 4g is nothing for a bit more peace of mind. just remember, these are supposed to be designed for daily driver punishment. these are not race pistons were every gram counts. and even with the extra weight, at 304 grams they will still be the second lightest piston available.

 

[Doward]

Precisely. I'm not sure why everyone seems to think that a 300 gram piston is light -

JE makes quite a few 83-84mm pistons that are 220-250grams - 300 grams is a good bit heavier!

 

[born2drv]

.230 I say, more then enough! 4 grams is 4 grams!

By the way I have a jewelry scale which weighs to +/-0.01 gram, you know I'll be weighing these right????

 

[supraguy@aol]

Don't care, you guys decide, but do it fast, so that we can get these pistons in our hands!
:aigo:

 

[Doward]

LOL! I figure these 2 weeks that everyone is buying in, would be the prime time to 'fine tune' these pistons

 

[starscream5000]

More meaty, the better peace of mind I have .

 

[Doward]

If the Wisecos will do 730+ rwhp with a .160" crown thickness, I think the .230" is a good compromise

 

[starscream5000]

I don't care about massive amounts of power, if I wanted a race piston, I'd buy one, that's not what this group buy was originally set around, but that's what it's turning into...

 

[Ckanderson]

If the Wisecos will do 730+ rwhp with a .160" crown thickness, I think the .230" is a good compromise

Very true. why have more material then you need?

 

[Sar-Supra]

I don't care about massive amounts of power, if I wanted a race piston, I'd buy one, that's not what this group buy was originally set around, but that's what it's turning into...

I second that. I need a set of streetable pistons and not a set of race pistons. If it´s going in this direction I´m out.

 

[Doward]

The JEs are race pistons (with no skirting, they will 'rock' in the bore)
The Wisecos are race pistons (with minimal thickness under the crown, they won't last if your tune isn't really good)
The Ross are ridiculously overweight, imho (and put way too much stress on the rod at ~7000 rpm). This group buy was never intended to make a Ross piston for $340.

If you want a Ross piston, buy a Ross piston!

If you want a piston that takes the best of the race pistons, the best of the street pistons, AND IS HALF THE PRICE OF EITHER - then get in on this group buy!

Also, the slug itself has little bearing (unless you don't have any real skirting, lol) on how well it lasts - the rings are what wear, not the piston! That's why the 1.2/1.5/3.0 ring pack, instead of the 1.0/1.2/2.8 ring pack.

Do you want a piston with JZ strength and reliability? That's what these Probe pistons are.

 

[Doward]

I don't care about massive amounts of power, if I wanted a race piston, I'd buy one, that's not what this group buy was originally set around, but that's what it's turning into...

Not true - when did JE make their pistons? Did they compare the combustion chamber in the head vs what's in the piston?

Technology has come a long way since the late 80s, early 90s. Improved machining, and better technology has allowed a lightweight piston, with better quench/swirl properties, in a bulletproof package.

If these were going to be race only pistons, they'd be a 250gram slug with no skirting (a lightweight JE)

The crown of the Probe's is stronger than stock.
The skirts are thicker than stock.
The material is better than stock.
The machining is better than stock.

These pistons offer something NO OTHER PISTON ON THE MARKET does (in my opinion) - it gives us the best of the pistons out now, with newer technology. I told Shawn from the start, these are meant to handle 600rwhp all day long, on the street, for 100,000 miles.

They'll do it.

 

[starscream5000]

Not true - when did JE make their pistons? Did they compare the combustion chamber in the head vs what's in the piston?

Apparently they didn't, neither did any of the other big wig companies based on what they produced, or there is another reason for not designing the piston like Probe has that hasn't been brought to light.

 

[tte]

Any of you guys measured the thickness of the mkiv pistons or thought why Toyota designed it that way.

I am sure MKIV pistons can handle 600 hp.


cheers,
Roy

 

[IJ.]

These pistons offer something NO OTHER PISTON ON THE MARKET does - it gives us the best of the pistons out now, with newer technology. I told Shawn from the start, these are meant to handle 600rwhp all day long, on the street, for 100,000 miles.

They'll do it.

You might want to qualify that this is "Your Opinion" as you have no real data other than what the guys are telling you and won't know for sure until you have run a set at 600rwhp for xx.xxx miles...

I know you're enthusiastic about all of this but you really need to throttle back on the claims until you actually know how they'll perform.

 

[Doward]

You might want to qualify that this is "Your Opinion" as you have no real data other than what the guys are telling you and won't know for sure until you have run a set at 600rwhp for xx.xxx miles...

I know you're enthusiastic about all of this but you really need to throttle back on the claims until you actually know how they'll perform.

You're right, I am excited... the ball buster (to me) of it is, that this is the last piece of my own puzzle.

Believe me, if there were anything I didn't like about these pistons, I'd be the first on the phone raising hell over it

When I first brought all this to light, the general idea was a set of JEs with longer skirt lengths. Something akin to the Wisecos, but without the increased compression. Something as strong as the Ross, without the weight.

It's all an art of compromise. The biggest thing in my head, is I do NOT want to see something come to market, that we already have! That would be pointless, in my opinion.

I'm very excited to get these pistons going! I'm even going to pull the head back off come December, after I've put a few thousand miles on them, to inspect the piston itself.

What is that they say about compromise? It's an idea makes nobody happy :biglaugh:

 

[Doward]

Apparently they didn't, neither did any of the other big wig companies based on what they produced, or there is another reason for not designing the piston like Probe has that hasn't been brought to light.

It's called laziness. :3d_frown:

 

[IJ.]

Apparently they didn't, neither did any of the other big wig companies based on what they produced, or there is another reason for not designing the piston like Probe has that hasn't been brought to light.

"Might" make a miniscule difference to economy and detonation resistance but there's nothing earth shattering to be had in gains due to the CC design.

 

[tte]

I thought since this is the first time Probe is doing a piston for the 7m, it would have been a good idea to have a set of pistons made, put in a motor, all the tuning done and put out 600rwhp.

Use the 600rwhp daily for some period of time.
Run some tests, or pull the head off or whatever needs to be done to test it and post the data

What do you think?:icon_bigg

Cheers,
Roy