Probe Forged Pistons: You want 'em? GB!
- Thread starter Doward
- Start date
Yeah, I'm not cool with the 9:1 for a street driven PUMP GAS turbo car.
So what's the verdict on the rings? 1.2/1.2/3.0s? 1.2/1.5/3.0s?
After further thought, the 1.2/1.5/3.0 (aka JZ) will probably be better - ring #2 acts to scrape the oil from the cylinder wall, and prevent it getting into the chamber, yes?
The 1.2 top ring would be lighter, to prevent hammering of the ring at higher rpms, as well. a 3.0 low tension oil ring would be fine, I think.
I want some opinions from you guys!
BTW, between here and SF, I've got about 23 sets wanting to get ordered
So what's the verdict on the rings? 1.2/1.2/3.0s? 1.2/1.5/3.0s?
After further thought, the 1.2/1.5/3.0 (aka JZ) will probably be better - ring #2 acts to scrape the oil from the cylinder wall, and prevent it getting into the chamber, yes?
The 1.2 top ring would be lighter, to prevent hammering of the ring at higher rpms, as well. a 3.0 low tension oil ring would be fine, I think.
I want some opinions from you guys!
BTW, between here and SF, I've got about 23 sets wanting to get ordered
When will these be ordered? If it's going to be longer then 2 months before I get them from today's date, then I may need to remove my name off the list. Thanks.
6-8 weeks would be awesome. We gotta get the ball rolling on this and a fire under Probe's ass(as wierd as that may sound).
Sounds good Doward... Just give me a heads up when you are ready to make this official... Hell, I may buy some for a "future" project...
Tuesday I'll be talking with Probe's engineer to see what he/she thinks, then we'll get the group buy rolling next week. We're looking @ 6 weeks for them to build the pistons.
So what are we finalizing that we want from these pistons?
Here is what I have so far -
Long skirts, to keep rocking down.
Good weight compromise between lightweight, hi reving and heavyweight, take anything you throw at it (between a JE and a Ross - about 320-330 gram weight would be nice, imho)
1.2/1.5/3.0 rings. The 1.2 top ring will keep hammering to a minimum, and the 1.5 will keep the combustion chamber clear of oil - this is stock JZ size, guys.
Basically, if you want an all out race motor - go JEs (super thin rings, super light) - if you want a stock motor, go with stock cast pistons.
If you want to DRIVE your 600rwhp Supra daily, then you want these pistons we are designing.
Sound good?
So what are we finalizing that we want from these pistons?
Here is what I have so far -
Long skirts, to keep rocking down.
Good weight compromise between lightweight, hi reving and heavyweight, take anything you throw at it (between a JE and a Ross - about 320-330 gram weight would be nice, imho)
1.2/1.5/3.0 rings. The 1.2 top ring will keep hammering to a minimum, and the 1.5 will keep the combustion chamber clear of oil - this is stock JZ size, guys.
Basically, if you want an all out race motor - go JEs (super thin rings, super light) - if you want a stock motor, go with stock cast pistons.
If you want to DRIVE your 600rwhp Supra daily, then you want these pistons we are designing.
Sound good?
well what i was trying to state in my previous post is i would not like the pistons to be 9:1 cr but closer to stock so that if you have to shave a lot off the head as i did and block. Even with a 2mm head gasket it comes out to 9:1 cr. if my ross pistons had not been 8.5:1 (i think) i would have a lot higher final cr especially if i had to start with a higher cr piston.
are these pistons going to be 8.4 or 8.5 cr? that way we can use them with a thicker hg to keep the cr down or use a thinner (1.2, 1.4) to raise the cr.
i have not been able to control my boost very well yet but i have hit 12 to 14 psi on 9:1 cr with my aem with no problems. usually boost 9 to 10 psi regularly just got to watch that timing an a/f.
are these pistons going to be 8.4 or 8.5 cr? that way we can use them with a thicker hg to keep the cr down or use a thinner (1.2, 1.4) to raise the cr.
i have not been able to control my boost very well yet but i have hit 12 to 14 psi on 9:1 cr with my aem with no problems. usually boost 9 to 10 psi regularly just got to watch that timing an a/f.
interesting stuff here. i might pick up a set, but that depends on final spex and C/R....personally i'd like to see something more like 9:1....
Doc, you might want to look into the Wiseco's, if you're wanting 9:1 These are aiming for 8.4:1 after 'normal' machine work.
These are aiming for 8.4:1 after 'normal' machine work.
1) Doward
2) S turbo 87
3) zachm611
4) TobyCat
5) mark3monster
6)MassSupra89
7)Born2drv
8)90T04
9)woodytsi
10)bmoss85
11)LilMissMkIII - pending shipping price to Aus
12)screaminglemon
13)bustedknuckle
14)starscream5000
15)knight202
Id like to run with thicker rings for some added life time. as far as scirt length and such, im not really up on all aspects of pistons and all, but reading what has been said, going with the longer skirts would be good.
Hopefully things are rollin soon, hows things coming Doward
Chris,
2) S turbo 87
3) zachm611
4) TobyCat
5) mark3monster
6)MassSupra89
7)Born2drv
8)90T04
9)woodytsi
10)bmoss85
11)LilMissMkIII - pending shipping price to Aus
12)screaminglemon
13)bustedknuckle
14)starscream5000
15)knight202
Id like to run with thicker rings for some added life time. as far as scirt length and such, im not really up on all aspects of pistons and all, but reading what has been said, going with the longer skirts would be good.
Hopefully things are rollin soon, hows things coming Doward
Chris,
Tuesday I'll be speaking with Probe's engineer - but until then, I think we have a small problem.
*every* aftermarket ring I've found is either a 1.0/1.2/2.8mm pack, (too thin for a DD, imho) or 1.5/1.5/4.0mm (I don't like the ring weight for a 7500+rpm 7M)
So... we might be looking at a custom ring set - 1.2/1.5/3.0. I'm going to ask about that on Tuesday, and see how much of a price that is going to be. If it's too big of a price change, then I'll see about a 1.2/1.2/2.8mm (if that's possible) - otherwise, 1.5/1.5/4.0 it will be, most likely.
*every* aftermarket ring I've found is either a 1.0/1.2/2.8mm pack, (too thin for a DD, imho) or 1.5/1.5/4.0mm (I don't like the ring weight for a 7500+rpm 7M)
So... we might be looking at a custom ring set - 1.2/1.5/3.0. I'm going to ask about that on Tuesday, and see how much of a price that is going to be. If it's too big of a price change, then I'll see about a 1.2/1.2/2.8mm (if that's possible) - otherwise, 1.5/1.5/4.0 it will be, most likely.
I'm good for the 1.2/1.5/3.0 John. Was there ever a description of how good of an allow they will be using? I know the type of alloy itself was mentioned, but how does it stack up the competion?
Coating the pistons is great! I'm going to have mine coated all the way around anyways. How much space will probe want in between the cylinder walls and piston with the alloy they are using?
Coating the pistons is great! I'm going to have mine coated all the way around anyways. How much space will probe want in between the cylinder walls and piston with the alloy they are using?