I am in the process of a new build. I need to buy new pistons due to having to go .020 overbore. What are the preferred pistons and why? I will be using Oliver rods. I have heard that the stock oem pistons are best because many after market pistons cause piston slap. I plan to keep power below 250hp.
Preferred Pistons
- Thread starter jwehrheim
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Metallic36
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- 2003 Mazda6 3.0L Speed Yellow
You will have to do something to the stock pistons to make them work with aftermarket rods. If you do the build right, you won't have issues with certain aftermarket pistons. If you are going .020, I doubt you're going to find stock OEM pistons to work with that. I have the CP pistons, as well as more people on here. The Arias pistons tend to have issues with the oil squirters (clearance, I believe) and there have been a few built blocks go bad because of that. Just type in the name of a piston brand on this site, and you'll find many threads with info about each type. I believe piston slap can be caused from not warming up a built engine prior to driving it.. not particularly the fault of it being "aftermarket" pistons. If you let the car warm up first and the pistons expand, then you're fine.
Metallic36
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- 2003 Mazda6 3.0L Speed Yellow
Then you have to figure out which compression ratio you are going to go with. That depends on how much boost you're wanting. For what you're going for, 9:1 would work, but for higher boost and more power, the 8.5:1 works. Just be sure you don't get that boost urge. (drive2) Once you start, you won't stop. Kinda like pringles. Unless you have good self-control..
i like speed
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Metallic36
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- 2003 Mazda6 3.0L Speed Yellow
Well, I wouldn't think you'd lose power, but you're going to have to build your car along with your motor unless you do the simple upgrade of customSMIC, hardpipes, and an AFC or Unichip, I guess you could run stock with a built engine, but at the moment I'm a bit scared to boost at all because I don't have my ems yet (Unichip tuned, anyway). I believe when Sam and Victor built Victor's MSP, they did 9:1 c/r. I went with the 8.5:1 just because if I did want to boost a lot, I'd be screwed if I went with the 9:1, might as well stay stock! But there's tons of other stuff you have to consider if you're going to build your engine, you can't just put in a forged engine and call it a day. You have to think about the type of intake system.. whether you're going to upgrade your SMIC or go with a FMIC. Then, you have to get a boost controller if you're going to be boosting over stock psi, then with that you need some type of EMS, then you need to get a wideband to make sure you're not running too rich or too lean, then you have to think about an exhaust so your engine can breathe, then you have to weld your LSD so it doesn't snap in half.. I dunno.. I'm one of those people that basically go along with: "If you're going to build it, BUILD it." You may not think you want to boost more than stock now, but just think ahead.. are you planning to keep this car or resell it later on? Are you going to be able to be satisfied with stock boost Fooorrrreeevvvveeeerrrrrr? And one more question.. why are you building it if you're staying stock?
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Metallic36
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Sam told me once that he had several engines come to him that needed rebuilt, and they were all using Arias. I had planned to go with Arias, but after that I chose the CP pistons because a lot of people on here have had good success with them.
I bought this car for my son. I bought it for $4,500 with only 56,000mi, but they guy threw a rod. This is why I am doing a build. Need to rebuild anyway and with the stock rods being so pathetic, why not spend the extra money for better rods. I have to overbore the block I bought, so I need to buy pistons anyway. I have no idea how much or the plans to build up the motor at this time, but if I do not lose power by going 8.5:1 CR, then it makes sense to go this way, doesn't it? That way if I decide or a new owner decides to build up the motor, the bottom end is taken care of.
If it is a bad idea or I will lose power, let me know? If I have to change the ECU mapping with 8.5:1 CR, let me know that too.
Thanks
If it is a bad idea or I will lose power, let me know? If I have to change the ECU mapping with 8.5:1 CR, let me know that too.
Thanks
Metallic36
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- 2003 Mazda6 3.0L Speed Yellow
Good deal you got on it.. I'd go with 8.5:1, that way if you do sell it, to me it would give the buyer more options to up the boost. With 9:1 it seems limited. It's kind of a bummer when you see "MSP with Built Motor!" in the title, then you check and it says 9:1. I dunno, just seems pointless to me. There's a lot of people on here that have gone with the 8.5:1 and also you'll need some sort of EMS, whether it be a Unichip or SplitSecond AFC.
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if by victor you mean pirana, he did not have a built motor, his project was to run that much power without upgrading internals....he never opened his crankcase
however you might have confused sam's with victors, cause sam just got done doing a built motor in his spicy (well, painted spicy)
also, you can run lots and lots of boost on 9:1 compression, its just a matter of tuning it properly...you wouldn't necessarily be screwed with 9:1 boost-wise because 9:1 is already a very low compression (and part of why our motor stock only kick out 98 whp without a turbo)...I'm running 9:1 right now and it takes to 10psi on a gt2860r no problem, I have also seen a spicy msp in so-cal thats running 8.5 psi on a t3/t4 no problem with an unbuilt motor (261whp was the last dyno iirc)
the lower the compression, the better for boost, however 9:1 is already a really low compression and will take to boost....that rule of thumb was meant for motors that run high compression stock, like the rsx type-s with ~11:1 compression
you can run PLENTY of boost on 9:1 compression, Ive run as much as 17psi before....however because I'm not yet tuned it was running way lean......you can look at it the other way as well though, nsn motorsports did the turbo mp3 before with a t3/t4 kit in it running only at 13 psi which kicked out over 300whp....you need to balance the amount of boost with your power goal, if you want power higher boost isn't the way to go unless it flows a lot of air at that psi, it all depends on your turbo your gonna use....however, you can run 9:1 compression on any boost level, no problem
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Metallic36
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I dunno.. I was just thinking of how Victor's car was when I met Sam at NOPI in 2007. IIRC he was forged, with a stock turbo. Maybe not then. I was surprised that it was the stock turbo. He was explaining to me how Victor's car had the 9.1:1 c/r, unless he was talking about a different one. http://blazinmsp.com/mods.aspx Sam could probably tell you about the difference between the c/r's and the benefits of both.
shane02pro5
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90% of the forged FS motors have gone 8.5:1. The difference in power with compression can be made up with advanced timing down low. I have no advanced timing from stock and 8.5:1 and I have no problems getting up and going! 8.5:1 just gives you a bit extra buffer!
^^
agreed it is an extra buffer, but not exactly necessary
just point out since she said that it was a shame when she saw a built msp with 9:1 that it's not really
(lol, defending my car =P)
now that is quite strange, because I could recall reading on here many times how he was running stock internals.....however they could have been old posts before he forged (dunno)
agreed it is an extra buffer, but not exactly necessary
just point out since she said that it was a shame when she saw a built msp with 9:1 that it's not really
(lol, defending my car =P)
now that is quite strange, because I could recall reading on here many times how he was running stock internals.....however they could have been old posts before he forged (dunno)
Metallic36
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- 2003 Mazda6 3.0L Speed Yellow
LOL well, just as a buyer's standpoint aka my own opinion though, if I was looking to buy one that could boost A LOT.. Sam did tell me that the 9.1:1 was suitable, but I just went with the 8.5:1 to have that added padding for when I did feel like boosting more. I guess I just feel better about myself with 8.5:1 hehehe.
