Which Pistons to use?
#21
I was/am in this current position. University student building for boost.
I'm 2 years into my project now. My roadmap was this :
-Read/search/peruse these forums with a tenacity for acquiring knowledge. There is so much information picked up by reading build threads small to large. I have a bookmark folder where I bookmark posts with little tidbits or "I should do it this way" inspiration.
-Install + learn to tune with Megasquirt. Don't cheap on this. Even with Naturally Aspirated you want MS3. Trackspeed sells the MS-Labs MS3 basic, Brain will build you a MS3x, if you're handy you can knock one out yourself with a very short parts-list.
-Build motor on the side. I socked money away and ended up building my motor right from the start. I did the billet pump, forged rods + pistons, bearings, studs, coatings, port work, valves, springs, etc. Being patient was key here. Took me 6+ months to acquire parts for motor, and 2 moths for machine work and for me to build it. Good winter project. Caveat emptor : If you ever anticipate going turbo down the road on this built engine... go with low compression pistons. This was my major mistake. I built 10.5:1 and am now in a pickle due to my boost goals.
-In the following spring I swapped it in, along with a 6-speed and a bunch of supporting mods such as clutch, injectors, bushings... all the "while I'm in there" bits.
-Fast forward 8 months and I am now 99% complete with parts hoarding for turbo (which is a metric ****-tonne of small bits, fittings, planning and cost). This is my winter project to pull the motor, install everything, and hopefully win. I've driven over 8k+miles on my built motor this summer. It's been freaking awesome. Don't rush things. If I have to wait another 6 months to install my turbo, oh well. Premature ejaculation of whipping a cheap turbo setup together leads to sadness.
Do it once, do it right. Amortize the cost out. Live within your means first, and by doing so: respect the reasonable WHP 'recipes'. Savington is very much right. Between 250 and 300 is a no-man's-land of power goals. You stay within stock-block capabilities, or go for allofit with a built motor. Re-evaluate your goals, and if you continue to keep coming back to the same goal then go for it! Just remember, it will cost more than you think, it will take longer than you think, but in the end it will be what you want!
I'm 2 years into my project now. My roadmap was this :
-Read/search/peruse these forums with a tenacity for acquiring knowledge. There is so much information picked up by reading build threads small to large. I have a bookmark folder where I bookmark posts with little tidbits or "I should do it this way" inspiration.
-Install + learn to tune with Megasquirt. Don't cheap on this. Even with Naturally Aspirated you want MS3. Trackspeed sells the MS-Labs MS3 basic, Brain will build you a MS3x, if you're handy you can knock one out yourself with a very short parts-list.
-Build motor on the side. I socked money away and ended up building my motor right from the start. I did the billet pump, forged rods + pistons, bearings, studs, coatings, port work, valves, springs, etc. Being patient was key here. Took me 6+ months to acquire parts for motor, and 2 moths for machine work and for me to build it. Good winter project. Caveat emptor : If you ever anticipate going turbo down the road on this built engine... go with low compression pistons. This was my major mistake. I built 10.5:1 and am now in a pickle due to my boost goals.
-In the following spring I swapped it in, along with a 6-speed and a bunch of supporting mods such as clutch, injectors, bushings... all the "while I'm in there" bits.
-Fast forward 8 months and I am now 99% complete with parts hoarding for turbo (which is a metric ****-tonne of small bits, fittings, planning and cost). This is my winter project to pull the motor, install everything, and hopefully win. I've driven over 8k+miles on my built motor this summer. It's been freaking awesome. Don't rush things. If I have to wait another 6 months to install my turbo, oh well. Premature ejaculation of whipping a cheap turbo setup together leads to sadness.
Do it once, do it right. Amortize the cost out. Live within your means first, and by doing so: respect the reasonable WHP 'recipes'. Savington is very much right. Between 250 and 300 is a no-man's-land of power goals. You stay within stock-block capabilities, or go for allofit with a built motor. Re-evaluate your goals, and if you continue to keep coming back to the same goal then go for it! Just remember, it will cost more than you think, it will take longer than you think, but in the end it will be what you want!
#22
There's always going to be a wide range of opinions on what you can and can't do at power levels commonly known to break stock motors.
I had a spare '95 block, I pulled it apart, installed Eagle Rods, a new headgasket, and put it all back together. No block hone, and I reused the stock pistons, rings and bearings. I swapped that bottom end in with the stock '99 head and GT2871. I daily drove the car for several years over 300whp with that setup, put about 40k miles on it before some guy ran a stop-sign and hit me right in the driver's door totaling the car.
People will tell you that you can't do that, but I had good results with it.
I had a spare '95 block, I pulled it apart, installed Eagle Rods, a new headgasket, and put it all back together. No block hone, and I reused the stock pistons, rings and bearings. I swapped that bottom end in with the stock '99 head and GT2871. I daily drove the car for several years over 300whp with that setup, put about 40k miles on it before some guy ran a stop-sign and hit me right in the driver's door totaling the car.
People will tell you that you can't do that, but I had good results with it.
#24
looks like I am headed in the right direction, but first things first,
I have just found a problem with the subaru (head gasket leak) so the Miata will be serving as a daily until the subaru gets fixed(between thanksgiving and winter break)
This project will be put on hold for a bit. If I have time over winter break I may start a (slow)build thread so y'all can follow along and give me more useful advice.
I have just found a problem with the subaru (head gasket leak) so the Miata will be serving as a daily until the subaru gets fixed(between thanksgiving and winter break)
This project will be put on hold for a bit. If I have time over winter break I may start a (slow)build thread so y'all can follow along and give me more useful advice.
#25
For the same money you are about to spend rebuilding your engine, you can put together a barebones turbocharger setup on the stock '95 block that will make ~200whp without much trouble. 280whp is in the no-man's land of Miata powere, where you are only 30-40whp past what the stock internals can handle, but the cost of making 280whp is about 2x the cost of making 200-220whp.
If I were in your shoes, I would re-evaluate your goals.
If I were in your shoes, I would re-evaluate your goals.
After putting some time in a 250+ whp miata on 225 RS3's and revalved HDs I think it's too much power for 90% of what you will be doing. I know many won't agree with that but on the autocross course and the tight roads we have here in East Tennessee I found it troublesome. You also have to worry about transmissions at those power levels.
200-230whp is a great balance for a modified Miata chassis. I feel like anything over and you need some Hoosiers or other DOT/R tire to really enjoy what the car can offer.
#26
This.
After putting some time in a 250+ whp miata on 225 RS3's and revalved HDs I think it's too much power for 90% of what you will be doing. I know many won't agree with that but on the autocross course and the tight roads we have here in East Tennessee I found it troublesome. You also have to worry about transmissions at those power levels.
200-230whp is a great balance for a modified Miata chassis. I feel like anything over and you need some Hoosiers or other DOT/R tire to really enjoy what the car can offer.
After putting some time in a 250+ whp miata on 225 RS3's and revalved HDs I think it's too much power for 90% of what you will be doing. I know many won't agree with that but on the autocross course and the tight roads we have here in East Tennessee I found it troublesome. You also have to worry about transmissions at those power levels.
200-230whp is a great balance for a modified Miata chassis. I feel like anything over and you need some Hoosiers or other DOT/R tire to really enjoy what the car can offer.
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