Pistons... - 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 07-02-2009, 11:30 PM   #1
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,327
Total Cats: 1,926
Default Pistons...

M-Tuned rods have been ordered. Next step, pistons.

Wiseco 79mm, 8.5:1, $460: Rice Engineering

Supertech 79mm, 8.8:1, $440: Belfab Racing

Discuss.
Joe Perez is offline   Reply With Quote
Old 07-02-2009, 11:43 PM   #2
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Only appreciable difference joe is that you can run slightly less clearance with the supertechs vs the wisecos because of alloy differences. The cr ratio difference as you know is negligible.

I personally am a huge fan of wisecos, but having seen the supertechs in person I can say that they also look like great pieces.

I don't think you can go wrong either way.
neogenesis2004 is offline   Reply With Quote
Old 07-03-2009, 12:01 AM   #3
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,578
Total Cats: 40
Default

I have nothing to contribute other than wondering what's in store turbo hardware wise Joe.
kotomile is offline   Reply With Quote
Old 07-03-2009, 12:08 AM   #4
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

My guess is that he might just want to turn up the boost and still be reliable. After all these posts of bent rods it makes you wonder when your straw will be drawn.
neogenesis2004 is offline   Reply With Quote
Old 07-03-2009, 12:20 AM   #5
Junior Member
iTrader: (5)
 
Join Date: Mar 2008
Location: Dallas
Posts: 131
Total Cats: 1
Default

I chose the Supertechs because of their expansion qualities and price point.

p.s.: that bore/compression ratio is still on backorder from Belfab. Shouldn't be too much longer.
juxt3r is offline   Reply With Quote
Old 07-03-2009, 12:24 AM   #6
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

They can be bought elsewhere.
neogenesis2004 is offline   Reply With Quote
Old 07-03-2009, 12:31 AM   #7
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

call me crazy but wiseco offers a 79.5 and, lets be honest, you wont be re-boring your block for larger pistons in the future. take the minor bump in displacement. 1660cc

had I not picked my pistons up 2nd hand, I'd probably get the 85.5's for the 1.8...1951cc without a stroker! so what if the cylinder walls are foil thin?
y8s is offline   Reply With Quote
Old 07-03-2009, 12:56 AM   #8
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,327
Total Cats: 1,926
Default

Quote:
Originally Posted by neogenesis2004 View Post
Only appreciable difference joe is that you can run slightly less clearance with the supertechs vs the wisecos because of alloy differences.
I've heard this as well, and I wonder if there is any actual documentation to back it up, or whether it is marketing hype? If true, then it is certain a strong argument in favor of the Supertechs.



Quote:
Originally Posted by kotomile View Post
I have nothing to contribute other than wondering what's in store turbo hardware wise Joe.
For the moment, I intend to retain my current turbo and manifold. I've got some long-range plans that involve experimenting with various modes of WI, and I don't want to wind up destroying my engine in the process. I went ahead and ordered the rods now on account of the group buy.



Quote:
Originally Posted by juxt3r View Post
p.s.: that bore/compression ratio is still on backorder from Belfab. Shouldn't be too much longer.
I am in absolutely zero hurry. It'll be months before I have a chance to actually install any of this hardware.


Quote:
Originally Posted by y8s View Post
call me crazy but wiseco offers a 79.5 and, lets be honest, you wont be re-boring your block for larger pistons in the future.
I'd actually be more inclined towards the 78.5s, which are also made by both Wiseco and Supertech. An extra 0.5mm bore diameter (79.5 vs. 79) buys you a whopping 27 cc (1.6 cubic inches), or an increase of 1.6%. I'm much more concerned about wall thickness, given that the B6ZE is already overbored 7mm beyond the original 71mm of the B3.
Joe Perez is offline   Reply With Quote
Old 07-03-2009, 01:22 AM   #9
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

It is indeed legitimate. Although the amount is small. I am talking 0.0005-0.001" type of difference. Still that can be the difference between cold slap and no cold slap. Depending on your power level your safe bet on clearance with these pistons is around 0.0035-0.004". Just remember that if you run too much clearance no one will know, run too little and everyone will.

Additionally, The alloy differences also correlate to the ability to withstand pre-detonation. The "softer" alloy of the wisecos can withstand a bad tune more so than the supertechs will be able to because they are "harder". Regardless both will be many times stronger than the stock hyper eutectic pistons.
neogenesis2004 is offline   Reply With Quote
Old 07-03-2009, 10:38 AM   #10
Junior Member
 
Join Date: Jan 2006
Location: Toronto
Posts: 182
Total Cats: 0
Default

Between Wisecos and Supertechs, I had no real preference. I'll never approach the limits of either.

Not to get into the CR issue again, but I had a long talk w/ Marc at ETD Racing before buying my Supertechs (9:1, 84mm.) He strongly suggested close to stock CR (which is 9.5:1 for the 1.8L.)

Regarding bore diameter: the change in piston area is so small that the additional power would be in the order of 2%.

Maybe Marc will chime in w/ some advice.
fluke is offline   Reply With Quote
Old 07-03-2009, 11:13 AM   #11
Junior Member
iTrader: (5)
 
Join Date: Mar 2008
Location: Dallas
Posts: 131
Total Cats: 1
Default

Quote:
Originally Posted by neogenesis2004 View Post
They can be bought elsewhere.
True that. IPP still offers these for $400.
juxt3r is offline   Reply With Quote
Old 07-03-2009, 11:32 AM   #12
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,327
Total Cats: 1,926
Default

Quote:
Originally Posted by juxt3r View Post
True that. IPP still offers these for $400.
Without rings, which are $80 extra. The others include the rings.
Joe Perez is offline   Reply With Quote
Old 07-03-2009, 03:33 PM   #13
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by neogenesis2004 View Post
Only appreciable difference joe is that you can run slightly less clearance with the supertechs vs the wisecos because of alloy differences. The cr ratio difference as you know is negligible.
I also chose them for expansion qualities, but I think piston "slap" is in the hands of the machinist. I agree that comp ratio difference is negligible in terms of drivability...however I disagree in respect to spark advance. I'd go with the lower ratio to add spark angle for all that yummy torque, especially if you're going to surface the head.

I can't wait to see how much torque you can make out of that little 1.6 with low-comp.
hustler is offline   Reply With Quote
Old 07-03-2009, 04:06 PM   #14
Junior Member
iTrader: (5)
 
Join Date: Mar 2008
Location: Dallas
Posts: 131
Total Cats: 1
Default

Quote:
Originally Posted by Joe Perez View Post
Without rings, which are $80 extra. The others include the rings.
Ugh...my bad. Thought the item title stating "w/ Rings" implied they came with...
Oh well.
juxt3r is offline   Reply With Quote
Old 07-04-2009, 01:32 AM   #15
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Emilio sells the supertechs on his website Joe. $440 + shipping.
neogenesis2004 is offline   Reply With Quote
Old 07-04-2009, 02:11 AM   #16
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,370
Total Cats: 1,332
Default

Joe, unless you are deadset on keeping your GReddy manifold, think about building a 1.8. You can get a longblock with crappy rings for next to nothing, and the 240cc displacement increase is impossible to ignore. Just grab an ETD manifold if you want to keep your GReddy turbo.

I did Supertechs and I have no regrets. 84mm 8.7:1. Car is a little sluggish off boost, but once the turbo is spooled it yanks plenty hard. You can't ignore the torque numbers that low-comp motors are producing.
Savington is offline   Reply With Quote
Old 07-04-2009, 03:43 AM   #17
Junior Member
iTrader: (10)
 
Join Date: Jan 2008
Location: SF Bay Area
Posts: 291
Total Cats: 0
Default

If I had to do this over again I'd get zero gap rings. Either piston set is acceptable.
bryanlow is offline   Reply With Quote
Old 07-04-2009, 10:46 AM   #18
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by Savington View Post
ve no regrets. 84mm 8.7:1. Car is a little sluggish off boost, but once the turbo is spooled it yanks plenty hard. You can't ignore the torque numbers that low-comp motors are producing.
you need to tune your **** off boost. This is another reason why I like my large a/r turbine housing.

Its nice to see that you've finally come around...half way at least.
hustler is offline   Reply With Quote
Old 07-04-2009, 11:52 AM   #19
Junior Member
iTrader: (1)
 
Join Date: Jan 2008
Posts: 161
Total Cats: 0
Default

Are you planning on doing a worklog when installing the pistons?
psiturbo is offline   Reply With Quote
Old 07-04-2009, 01:05 PM   #20
Boost Pope
Thread Starter
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,327
Total Cats: 1,926
Default

Quote:
Originally Posted by Savington View Post
Joe, unless you are deadset on keeping your GReddy manifold, think about building a 1.8.
Not happening.

For starters, I don't want to spend the extra money on another longblock, manifold, etc. By the time you factor everything in, it's probably an additional $1k.

Second, I'm pretty sure my crank timing wheel would hit the swaybar with the longer engine.

And third, I just don't need the displacement.


Quote:
Originally Posted by bryanlow View Post
If I had to do this over again I'd get zero gap rings. Either piston set is acceptable.
Hmm. I remember Total Seal rings being popular on ACVWs way back when, but it never even occurred to me to see if they were still around. A gapless second ring is in the maybe pile.


Quote:
Originally Posted by psiturbo View Post
Are you planning on doing a worklog when installing the pistons?
You're asking this of the guy who does a comprehensive writeup every time he farts?
Joe Perez is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MSM - Spark Plug Ground ate my Piston - ISO Advice on Comp / R&R OEM (on the cheap) justanothernic Engine Performance 2 04-18-2014 10:09 AM
Opinions on the look of my pistons Zaphod DIY Turbo Discussion 11 02-01-2013 10:48 AM
head gasket for 85.5mm pistons UrbanSoot Engine Performance 11 04-09-2009 10:49 PM
car is being mucho gay. MiazdaBLUE General Miata Chat 5 06-21-2007 11:43 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 10:34 PM.