Send an old piston to J&E and they will make a custom new forged one of the same dimensions, or even slightly lower compression if you want. (Lower compression height compromises strength, which is the reason the pistons were "bad" in the first place.
Secondly, the '99 pistons are the worst of the T7 pistons. The later ones got trapezoidal small rod ends, which allowed for beefier piston reinforcement. The compromise is that the my 2000+ con rods won't be as good for high revving.
All of the T7 pistons, rods, and crankshafts are lighter than the previous 2.3L engines. But a forged set of pistons shouldn't make anything much heavier, and if made out of the 4340 low expansion alloy, they shouldn't harmreliability any.
You could also sent a set to Mahle, but I'm not 100% sure if they do custom pistons or not. I know J&E does as I have a set in my friends 1990 Dodge Shadow.
Higher Compression = Taller piston = stronger piston = more likely to knock = compromise
Lower compression = shorter piston = weaker piston = less likely to knock = yet another compromise
You just have to decide which compromise you like best. 9000 Aero's are getting 500+ hp on 9.3:1 compression if your gas is good enough.
MAHLE would actually be the best for high revving. They use a lightweight, but strong, box-in-box design. I do not know if they make custom forgings though. Let alone at the relatively cheap prices J&E make them for.
If you have the money, see if MAHLE will make their box-in-box design for your engine. Your stock con-rods are both strong, and lightweight; combined with a lightweight forged and strong piston, it should make for a very nice engine.
If you have only roughly $1,000 look into J&E pistons. They make custom pistons for about $400-800 a set. Get them at around 8.4-8.8:1 if you plan to make big power on pump gas. Yes you CAN go higher than that, and still make lots of power, but it's easier with lower compression. If possible send the pistons to www.performancecoatings.com and get them tri-coated. (Ceramic on top, moly on sides, and dispersant on bottom.) That will make them even tougher to detonation.
The ECU should be able to handle the lower compression just fine. It won't significantly change airflow. You'll just notice a drop in fuel mileage when cruising, and probably some additional ignition advance during warm weather when the stock pistons were too high compression for that heat + pump octane combination.
It's more a question of how much KNOCK they can handle. Unfortunately the answer is almost none.
Anything you do which increases cyllinder heat will make the pistons weaker. (Aluminum gets weaker with higher temps.)
For safety I'd switch to the 82C degree thermostat from the 9000 Aero. That significantly reduced the tendancy of the ECU to reduce power from knock. Also I'd make some ducting to your intercooler (if you get a larger one, make sure that all of the air goes over it, and not just SOME, proper ducting), insulated all your intake piping, and do everything you can to reduce heat in the engine. Heat = knock = blown motor.
Then upgrade slowly by spending money on supporting modiications that reduce heat while saving for pistons. Once you have money for pistons and an upgraded ECU, then you'll be ready to make some SERIOUS power.
Also, the 06-cm exhaust housing from the 9000 Aero turbo will reduce heat in the combustion chamber by reducing backpressure. So too will headers. Headers have been shown time and time again to SIGNIFICANTLY reduce EGT, and thus cyllinder temps. CoolAr is bettAr.
Ok, well my stage 3 ECU should be in soon... so im thinking i need to reduce engine heat... I took out that shit insulation on the hood and the car actually seems ALOT colder... I also cleaned the air filter and took off my front licence plate and i notice my turbo does stay alot colder. But yeah.... once i have more money I guess pistons would be a good idea...
Trust me, more difference in detonation resistance than any other mod I've tried. If you can, have the dealer re-program the cooling fans to come on at 200F degrees instead of 212 as well.
Sorry I didn't emphasize that before, I was giving a total list. If you're going to do ONE thing, that is the one thing to do. That, and the duct tape over the gap between the top of the intercooler and the bumper. Costs like $2, and makes more difference than even I thought it would on hot days.
Taliafferro do. But they are $800 ... the 82C thermostat is $18 ...
Headers could still be better. I don't think the Taliafferro Saab setup is ideal ... but they are good. Make sure to combine them with the 06-cm exhaust housing. That's the REAL bottleneck. Even the guys working at the Saab factory in TrollHattan reccomend that for power above 270 hp.
The slight loss in spool up from the 06 cm housing should be compensated by the headers!
And don't forget the thermostat or so help me god I'll come over there and HURT you! lol kidding ... but seriously ... 82C is 180F degrees ... and the stock 89C is 193F degrees. It's a noticable difference! Cooler coolant = cooler cyllinder walls = cooler pistons = stronger pistons!!!
06-cm exhaust housing can be gotten of any used 9000 Aero turbo from 1994-1998. Even if the turbo is in bad shape, the housing should clean up nicely. Remember, you just need the exhaust housing ... and you'll need to use a grinder to port the stock manifold a little.
Check out this forum. ERP did it recently, and posted exactly how!
A turbo in bad shape, should be very cheap. Check e-bay?
The thermostat just requires the removal of 4 bolts, the $18 kit comes with a new rubber seal. I used Mopar RTV solicone (way the fok better than the crappy stuff at Autozone or wherever) just in case ... but the factory uses no sealant. So just clean up the surface of each.
If you can get any of their black RTV silicone from a dodge dealer go ahead. My best friend is a technician and this stuff doesn't even COMPARE to the stuff you buy anywhere else. It's so strong that it seals instantly, and it smells so strong that if you're not careful you'll get dizzy just leaving the cap off the tube sitting near you.