Custom pistons for my goals

[mitecl96]

OK first off I'll start of by saying I searched. Really wish I didn't. The stupid things I have read SOME 420a guys say. I can see way not many people take us serious. I will say I am committed to my car as bring a dd. I will buy a GSX later when I have the space and more income to make it the way I won't.

In the end I want a reliable dd making around 300 HP. My goal to make this is to turbo of course. The build is going to be done in stages. My first stage is going to be starting soon which is to have megasquirt as a complete standalone. Going to be running MS3 with the MS3x board. Going to run coil over plugs and have sequential spark and fuel.

The next step is where I need help. It is to build the block to hold up to what I need done. I have this mostly figured out. I just need to build the bottom end. The top end I've been told and read it should be fine with 300 HP just to freshen it up.

I'm going to use eagle rods but my question is I do plan on turboing the car but will be later on down the road. I know right now the only compression ratios I have to choose from is either 8.8:1 or 10.5:1. I don't want low compression because that will suck without a turbo. I know high compression will give me more engine power but is harder to tune when turboed and have to run e85. I still want to run regular gas 91 as it will be a daily driver and will sometimes have to drive 1000 miles to visit family.

So I was thinking to get custom pistons that make stock compression so the engine will still drive like normal and can handle the power when turboed. How much or custom pistons going to cost me and has anyone done this? I had a friend tell me why not buy the high compression pistons and have the shave the piston head to lower compression. I have heard of this but I don't know about this, I wouldn't want to spend money on pistons and then have them ruined.

I also want to add that step 3 is to turbo the car. The turbo I plan on using is a turbonetic T04B stage II super-v .48 A/R that will be water cooled. I am not sure about how much psi I will be running because not sure how much is needed to make my power goal.

Sorry if to much information just want to make sure you all have as much information to better help me.

 

[jayson427]

Shaving the head will rise compression not lower it. With Ms 91 octane on 10.5 compression is very possible. It's not the best fuel but it's been done many times. Custom pistons will run about 75-125 dollars more then a set off the shelf.

 

[arrowhead]

He said shave the pistons not the head, which is an option but a remote one.

Dont know what gaskets are available, but you could vary a 1/2 to 1 point with the gasket alone.

 

[Brax93]

For custom pistons I think its going to run me about $480 what I was told...I think Im going to go with 9.5 its in between 8.5 and 10.5 so I think its a good number to go with... Good luck with the build and tell me how how MS install goes!

 

[mitecl96]

Shaving the head will rise compression not lower it. With Ms 91 octane on 10.5 compression is very possible. It's not the best fuel but it's been done many times. Custom pistons will run about 75-125 dollars more then a set off the shelf.

I know its possible but isn't boost another factor in that. I still don't know what psi I will have to run with that turbo to get my goal.

He said shave the pistons not the head, which is an option but a remote one.

Dont know what gaskets are available, but you could vary a 1/2 to 1 point with the gasket alone.

I'll have to look into that. I know I need a thicker head gasket because the block and head need resurfaced.

For custom pistons I think its going to run me about $480 what I was told...I think Im going to go with 9.5 its in between 8.5 and 10.5 so I think its a good number to go with... Good luck with the build and tell me how how MS install goes!

Now I remember it was your thread I seen that on. Who told you that price? And what brand you going with. I know the two man ones or wiseco or je. I read that wiseco would be better because or there sleeve coating for a daily driver and have less of piston slap not sure if this is a 100% true. Good luck with you too need anything else about MS just pm me.

 

[jayson427]

My comments were talking about a turbo car. Slow2gen runs a s25 at 25psi on 10.5 compression but I think he runs e85. But you could totally run 91 with a meth kit and get it done. More and more guys are running higher compression with their turbo set ups. It just needs to be thought out big time. Like static compression, drive pressure ect.. All those things really make a difference. If you can find someone that knows a lot about the mathematical side of it that will take you to a reliable goal.

 

[Fotowntalon]

With fuel and tuning out there, running higher compression turbo builds is more realistic everyday, but of course lower compression is always safer. As with just about everything in cars, there is no "right" answer, all give and take.

For changing your compression ratio, your friend and Jayson and Arrow are all right. Shave the pistons to lower compression, or shave the head to up compression, thicker head-gaskets will lower compression. Hell you could go with a slightly shorter rod to lower compression (have the piston sit lower in the whole) but then would be using a custom rod, just throwing out ideas =P.

At the end of the day, making a single change to a shelf item piston adds about $50, I quoted Brax, and can get the same thing made for you. I quoted him Wiseco's (includes the skirt coating and rings/pins/locks), but I can also get JE's is you prefer, although I have always been a fan of Wiseco's for the reasons you listed.

Then of course $480 is just the base price for standard pistons with a single change. You can always get fancy and add gas porting, (to horizontal, or lateral or both) ceramic top coatings, extra piston lightening, and Wiseco's Armor Plating (which would increase the durability of the ring grooves and help prevent micro welding).

I guess what I am trying to say is with pistons you get get very fancy (fancy another word for options+$$$) or just standard deals with a CR change.