Which Pistons to use? - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-19-2015, 10:27 AM   #21
Goin Innnnn!!!
iTrader: (7)
 
Chooofoojoo's Avatar
 
Join Date: May 2014
Location: Denver, Co.
Posts: 460
Total Cats: 40
Default

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!
Chooofoojoo is offline   Reply With Quote
Old 11-19-2015, 11:06 AM   #22
Elite Member
iTrader: (17)
 
Join Date: Aug 2007
Location: Fort Myers, FL
Posts: 2,790
Total Cats: 128
Default

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.



pdexta is offline   Reply With Quote
Old 11-19-2015, 12:15 PM   #23
Senior Member
iTrader: (8)
 
Join Date: Feb 2012
Location: Raleigh, NC
Posts: 617
Total Cats: 53
Default

Quote:
Originally Posted by JustThisGuy View Post
These are the steps I am following...(good ideas)
After hearing this I must warn you, you're well on the path towards being a successful, happy modded miata user.

You near NCSU I assume? I'm not far from there.
petrolmed is offline   Reply With Quote
Old 11-19-2015, 10:33 PM   #24
Newb
Thread Starter
 
Join Date: Nov 2015
Location: Raleigh NC
Posts: 15
Total Cats: 0
Default

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.
JustThisGuy is offline   Reply With Quote
Old 11-20-2015, 08:43 AM   #25
Junior Member
iTrader: (5)
 
Join Date: Oct 2014
Posts: 473
Total Cats: 23
Default

Quote:
Originally Posted by Savington View Post
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.
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.
90civichhb is offline   Reply With Quote
Old 11-20-2015, 06:13 PM   #26
Newb
Thread Starter
 
Join Date: Nov 2015
Location: Raleigh NC
Posts: 15
Total Cats: 0
Default

Quote:
Originally Posted by 90civichhb View Post
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.
You might be right, but that call will not be made for 2+ years due to money. If I (eventually) build a car in the 250+ wheel HP level and decide it is too much, all I have to do is turn the boost down and possibly retune if the turbo gets replaced with a smaller one for better response. The key is planning it all out. Currently I am slowly collecting all the necessary parts to install the 1.8, so that it will not sit for months after the final assembly before I can install it. After the 1.8 is in I might decide that it is enough power(for a while) and leave it alone and do the suspension. I don't know what will happen in the future but writing it all out and having a knowlegable group of people who have been down this road before is a great help.
JustThisGuy is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Chunk from differential, track day on Monday k1l4m Race Prep 21 03-16-2016 08:15 AM
Engine swap, now billowing smoke, do I need an oil restrictor? 6strngs DIY Turbo Discussion 15 10-27-2015 02:16 AM
turbo VVT, springs choice for stock redline alpinaturbo Engine Performance 8 10-19-2015 03:01 PM
Diff Companion Flange / Pinion Damper Knocking Little Badger Suspension, Brakes, Drivetrain 4 10-15-2015 01:18 PM
1.8 swap worth it on a budget? And correct me if my plan is mistaken. 1991 DIY Turbo Discussion 35 10-12-2015 04:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:28 PM.