Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Anyone with FI add a square top IM?

Thread Tools
 
Search this Thread
 
Old 10-16-2013, 10:06 AM
  #1  
Junior Member
Thread Starter
iTrader: (3)
 
tomiboy's Avatar
 
Join Date: Oct 2011
Location: Naperville
Posts: 372
Total Cats: 3
Default Anyone with FI add a square top IM?

I'm curious if you get the same gains with the square top on cars with FI

Thanks!
tomiboy is offline  
Old 10-16-2013, 11:28 AM
  #2  
Elite Member
iTrader: (1)
 
Full_Tilt_Boogie's Avatar
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 406
Default

Yes.
Full_Tilt_Boogie is offline  
Old 10-16-2013, 11:28 AM
  #3  
I'm a terrible person
iTrader: (19)
 
FRT_Fun's Avatar
 
Join Date: Apr 2009
Location: Arizona
Posts: 7,174
Total Cats: 180
Default

no never.
FRT_Fun is offline  
Old 10-16-2013, 11:59 AM
  #4  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Read the last few pages of Soviet's build thread.
Savington is offline  
Old 10-16-2013, 12:07 PM
  #5  
Junior Member
Thread Starter
iTrader: (3)
 
tomiboy's Avatar
 
Join Date: Oct 2011
Location: Naperville
Posts: 372
Total Cats: 3
Default

Andrew, can't seem to find it
tomiboy is offline  
Old 10-16-2013, 12:31 PM
  #6  
Elite Member
 
JasonC SBB's Avatar
 
Join Date: Jul 2005
Posts: 6,420
Total Cats: 84
Default

Also look for the FM dyno test on m.net. However they didn't rev it above 7200. Most of the gains are >6000 RPM.
JasonC SBB is offline  
Old 10-16-2013, 01:36 PM
  #7  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

basically you lose a couple wtq at various points in the lowend/midrange and pick up a BIG chunk of power and torque past 6500
18psi is offline  
Old 10-16-2013, 01:37 PM
  #8  
Supporting Vendor
iTrader: (3)
 
ThePass's Avatar
 
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
Default

how does this belong in the race prep section?
__________________
Ryan Passey
ThePass is offline  
Old 10-16-2013, 02:06 PM
  #9  
Elite Member
 
jacob300zx's Avatar
 
Join Date: Jul 2007
Location: Houston, TX
Posts: 3,201
Total Cats: 145
Default

He is obviously Richard Allistor or Dougie Sweetmaster
jacob300zx is offline  
Old 10-16-2013, 02:49 PM
  #10  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Originally Posted by JasonC SBB
Also look for the FM dyno test on m.net. However they didn't rev it above 7200. Most of the gains are >6000 RPM.
FM did a forced induction squaretop test?
Savington is offline  
Old 10-16-2013, 02:51 PM
  #11  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Originally Posted by tomiboy
Andrew, can't seem to find it
https://www.miataturbo.net/build-thr...ild-you-61522/
Savington is offline  
Old 10-16-2013, 02:51 PM
  #12  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

I don't think soviets thread really gives us any info specifically on the squaretop either - too many other changed variables.
18psi is offline  
Old 10-16-2013, 04:01 PM
  #13  
Junior Member
Thread Starter
iTrader: (3)
 
tomiboy's Avatar
 
Join Date: Oct 2011
Location: Naperville
Posts: 372
Total Cats: 3
Default

Originally Posted by ThePass
how does this belong in the race prep section?
You're right, it probably doesn't. I just do HPDEs. There are so many knowledgable people in here that I figured I'd get some solid answers. I just bought one, in the for sale section, a minute ago.

Thanks to all
tomiboy is offline  
Old 10-16-2013, 04:10 PM
  #14  
Elite Member
iTrader: (33)
 
RotorNutFD3S's Avatar
 
Join Date: Jan 2007
Location: Newnan, GA
Posts: 2,518
Total Cats: 30
Default

I used one in the build I just finished but there were no before numbers, actually we're still waiting to get to the dyno for numbers at all. But what 18psi stated above about power seems to be the common result.
RotorNutFD3S is offline  
Old 10-17-2013, 04:31 AM
  #15  
Supporting Vendor
iTrader: (3)
 
ThePass's Avatar
 
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
Default

Probably hasn't been tried much because 0.5 psi more will do the same trick...
__________________
Ryan Passey
ThePass is offline  
Old 10-17-2013, 12:39 PM
  #16  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

For the most part yes, but once you approach the flow limit up top, .5psi more actually won't do the same trick, and/or this would be like uncorking "free" horsepower that is otherwise choked up
18psi is offline  
Old 10-17-2013, 01:02 PM
  #17  
Supporting Vendor
iTrader: (3)
 
ThePass's Avatar
 
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
Default

It's not free, it's $500
__________________
Ryan Passey
ThePass is offline  
Old 10-17-2013, 01:02 PM
  #18  
Elite Member
iTrader: (37)
 
EO2K's Avatar
 
Join Date: Apr 2010
Location: Very NorCal
Posts: 10,441
Total Cats: 1,899
Default

Originally Posted by 18psi
For the most part yes, but once you approach the flow limit up top, .5psi more actually won't do the same trick, and/or this would be like uncorking "free" horsepower that is otherwise choked up
Related: Has anyone actually put a number on this "flow limit up top" for the stock manifold? At what point does it choke under boost?

The way I read it quite some time ago, boost is actually a measurement of resistance to flow in the system. All other things being equal, 5psi on a BP4W with restrictive stock exhaust, log manifold & GT2560R is going to make vastly different power compared to 5psi on that same BP4W with a +1 valve ported head, tubular manifold, 3" exhaust... you get the idea.

Anything you can do to reduce resistance in the system will show benefits. With the squaretop vs stock, the question becomes "where do I see these benefits?" Is this is a street car that lives most of its time around 4k with occasional trips to redline, or does it spend most of its life around 6k for 20-30 minutes at a time BECAUSERACECAR?

The $400~500 pricetag of the squaretop might be worth it to the racecar guys but that same $400 buys you a lot of goodies on a street/hpde/autox build.
EO2K is offline  
Old 10-17-2013, 01:09 PM
  #19  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

Originally Posted by ThePass
It's not free, it's $500
haha ok valid point
Originally Posted by EO2K
Related: Has anyone actually put a number on this "flow limit up top" for the stock manifold? At what point does it choke under boost?

The way I read it quite some time ago, boost is actually a measurement of resistance to flow in the system. All other things being equal, 5psi on a BP4W with restrictive stock exhaust, log manifold & GT2560R is going to make vastly different power compared to 5psi on that same BP4W with a +1 valve ported head, tubular manifold, 3" exhaust... you get the idea.

Anything you can do to reduce resistance in the system will show benefits. With the squaretop vs stock, the question becomes "where do I see these benefits?" Is this is a street car that lives most of its time around 4k with occasional trips to redline, or does it spend most of its life around 6k for 20-30 minutes at a time BECAUSERACECAR?

The $400~500 pricetag of the squaretop might be worth it to the racecar guys but that same $400 buys you a lot of goodies on a street/hpde/autox build.
Exactly. I think most the street/daily driver VICS guys don't really even need this thing. Heck, even the VTCS guys don't really need one for the street (and one of the reasons I'm going to try using my vtcs mani at 1st and only switch to the squaretop if I'm unhappy with it). The track guys love this cause its OEM, bolts right up, and actually holds together unlike some of the honda mani's we've seen. And those running setups that make serious top end power obviously want it too because the stocker chokes up pretty dramatically (at least the vtcs does) past 300 or so.
18psi is offline  
Old 10-17-2013, 01:18 PM
  #20  
Elite Member
iTrader: (37)
 
EO2K's Avatar
 
Join Date: Apr 2010
Location: Very NorCal
Posts: 10,441
Total Cats: 1,899
Default

V: My offer still stands to loan you my spare VICS manifold when you get around to testing the VTCS vs Squaretop. I'd be nice to see all 3 on the same testbed with some 100kpa+ data
EO2K is offline  


Quick Reply: Anyone with FI add a square top IM?



All times are GMT -4. The time now is 02:16 PM.