DIY Turbo Discussion greddy on a 1.8? homebrew kit?
Sponsored by:
Sponsored by:

Worth doing ITB + turbo?

 
Old 05-01-2018, 01:56 AM
  #1  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default Worth doing ITB + turbo?

I have a set of 4AGE ITBs + manifold and stacks from when I was going to go built N/A... I just bought a GT2554R turbo (I know, small, but I wanted a fast spool and know I cant trust myself with a 250whp+ Miata), and have the manifolds and everything coming shortly - is it worth it fabbing up a single "collector" tube for the ITBs to use in conjunction with the turbo? Or will it just prove to be more of a hassle than it is worth, despite having the "coolness" factor? I was thinking that with the small Garrett, it might be some really great throttle response when tuned properly
503 is offline  
Old 05-01-2018, 09:18 AM
  #2  
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 10,263
Total Cats: 1,606
Default

More hassle than worth, unless you value cool enough to flip it the other way.
concealer404 is online now  
Old 05-01-2018, 09:54 AM
  #3  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 76,380
Total Cats: 2,295
Default

do it, and tell us if it was worth it. no one ever does....
Braineack is offline  
Old 05-02-2018, 07:47 AM
  #4  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

I suppose we will see if I still have the ITBs once everything gets here and I get the turbo installed, should only be a few weeks... I was moreover wondering if the ITBs themselves will really provide any gains in terms of top end that would make it worth the hassle, or if I'd be better off going for the squaretop/skunk mani and TB for a similar end result

A bit off topic, but will the RX8 yellow injectors be enough to max out a GT2554R? I was told to just go with the Flowforce, but there is someone near me who has barns filled with rotary parts and can get me a genuine set for ~$70 so I don't want to spend five times as much if it won't get much benefit, for now
503 is offline  
Old 05-02-2018, 08:36 AM
  #5  
Junior Member
 
Join Date: Jan 2016
Location: Akron, Ohio
Posts: 313
Total Cats: 40
Default

You are not including the cost of cleaning those injectors. Let alone if they will flow anywhere near each other. Injectors are not something that is worth risking even on a low budget build. Especially when we have someone who offers a fantastic product and is a great contributor to the community.
Joseph Conley is offline  
Old 05-02-2018, 08:46 AM
  #6  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

My understanding was they were good sets that are cleaned, that he had set aside for full overhauls on the wenkels - but, you are right, I'd have no cards or anything on them. The $250 difference goes a long way towards other things on the car, though
503 is offline  
Old 05-02-2018, 09:23 AM
  #7  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The non-murder part.)
Posts: 29,086
Total Cats: 2,846
Default

I'm with Brainey on this one. A lot of folks talk about it, but I can't recall seeing one actually finished. I doubt you'd see any gain on the dyno, and am highly skeptical about quantifiable gains in throttle response. Still, it'd look cool.

What's the plan for engine management?
Joe Perez is offline  
Old 05-02-2018, 09:24 AM
  #8  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

I have a MS3X, but I really don't know where I would start with tuning it
503 is offline  
Old 05-02-2018, 09:57 AM
  #9  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The non-murder part.)
Posts: 29,086
Total Cats: 2,846
Default

What was your original plan (back when you first acquired the ITB setup) for obtaining a stable MAP or airmass signal?
Joe Perez is offline  
Old 05-02-2018, 09:59 AM
  #10  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

The manifold has barbed nipples on each throttle body - I was going to take a steel line, and run it to a piece of tubing that was tapped for four barbs + another barb on the end, then capping the other end and welding it shut.

I also bought a TPS
503 is offline  
Old 05-02-2018, 10:01 AM
  #11  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The non-murder part.)
Posts: 29,086
Total Cats: 2,846
Default

Originally Posted by 503 View Post
I also bought a TPS
This is a 1.6 engine?
Joe Perez is offline  
Old 05-02-2018, 10:02 AM
  #12  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

BP4W
503 is offline  
Old 05-02-2018, 10:18 AM
  #13  
Senior Member
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,356
Total Cats: 68
Default

“Worth it” is a very subjective thing. Many of our spouses would argue none of this nonsense is “worth it”

That being said the overall power difference will be minimal compared to a properly setup intake. You have even have better off boost torque with the 99 vics manifold and skunk TB. What you will gain is lean in throttle response. Most notable off boost. It’s up to you to decide if the costs and trouble are “worth it”.

k24madness is offline  
Old 05-02-2018, 10:26 AM
  #14  
503
Junior Member
Thread Starter
 
Join Date: Apr 2017
Posts: 79
Total Cats: -1
Default

Yeah, I've stopped telling people about my cars and bikes because they look at me like I'm crazy.

New to Miata tuning - is the VICs going to give me benefit over a gutted square top in a FI application like this?
503 is offline  
Old 05-02-2018, 10:27 AM
  #15  
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,931
Total Cats: 312
Default

Originally Posted by Joe Perez View Post
What was your original plan (back when you first acquired the ITB setup) for obtaining a stable MAP or airmass signal?
Im not sure is MS supports it but some EMS have a way of doing alpha-n blended with MAP. Its "the" way to do ITB + Boost, apparently.
Full_Tilt_Boogie is offline  
Old 05-02-2018, 10:34 AM
  #16  
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 10,263
Total Cats: 1,606
Default

MS does support that.
concealer404 is online now  
Old 05-02-2018, 11:27 AM
  #17  
afm
Senior Member
iTrader: (3)
 
Join Date: Nov 2015
Location: Berkeley, CA
Posts: 832
Total Cats: 295
Default

Originally Posted by Full_Tilt_Boogie View Post
Im not sure is MS supports it but some EMS have a way of doing alpha-n blended with MAP. Its "the" way to do ITB + Boost, apparently.
MS has a couple strategies like that:
  • "Hybrid Alpha-N," which is what happens if you pick Alpha-N while leaving the default setting of "Multiply MAP" on. This uses TPS as a load axis but incorporates MAP into the fueling calc. The TPS-indexed table entries are VE, and the VE value gets multiplied by the (usually cycle-averaged) MAP value.
  • ITB mode uses a calculated load value for the VE tables that is a nonlinear function of both MAP and TPS, which is influenced by MAP more at low loads and less at high loads. This is meant for better drivability on N/A ITBs, and most normal strategies for this mode would not work for boost, since it actually phases out the influence of boost on the load axis as you hit higher rows.
afm is offline  
Old 05-02-2018, 11:27 AM
  #18  
Elite Member
iTrader: (14)
 
Join Date: Jan 2007
Location: Murfreesboro,TN
Posts: 1,585
Total Cats: 97
Default

Not worth it. Not first hand, but second hand experience. A buddy of mine did it on his car and he spent a lot of time fine tuning everything just to make it drivable for very little gains. Its been almost 10 years and he still complains about how hard it was to tune the throttle tip in because there are so many variables that had to be tuned to make it work. Not just ECU adjustments, but he played around a lot with vacuum chambers to get a consistant MAP reference and brake pedal (before converting to manual pedals). Based on his recommendation, for a simple car to tinker with, leave the ITBs to NA use and single throttle body for boost.
Midtenn is offline  
Old 05-02-2018, 11:41 AM
  #19  
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,931
Total Cats: 312
Default

Originally Posted by afm View Post
MS has a couple strategies like that:
  • "Hybrid Alpha-N," which is what happens if you pick Alpha-N while leaving the default setting of "Multiply MAP" on. This uses TPS as a load axis but incorporates MAP into the fueling calc. The TPS-indexed table entries are VE, and the VE value gets multiplied by the (usually cycle-averaged) MAP value.

This was what I was thinking of. No personal experience but I talked with a tuner a while back who was tuning my buddies Evo using this strategy with AEM Infinity. The "fuel" map was very flat and weird looking because it was being scaled with MAP in another table.
Full_Tilt_Boogie is offline  
Old 05-02-2018, 11:42 AM
  #20  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The non-murder part.)
Posts: 29,086
Total Cats: 2,846
Default

Originally Posted by 503 View Post
BP4W
Gotcha. I was a little mixed up when you said you'd purchased a TPS; usually that's something that B6 people say (since the 1.6 engines didn't have a "real" TPS), but I forgot about ITB.



Originally Posted by Full_Tilt_Boogie View Post
Im not sure is MS supports it but some EMS have a way of doing alpha-n blended with MAP. Its "the" way to do ITB + Boost, apparently.
MS does support Alpha-N, but it gets hairy when you add forced induction to the mix. At that point, you're better off running straight MAP, which is its own can of worms with an ITB setup. (You need to construct a plenum chamber for the MAP signals themselves, which the OP has apparently already considered.)
Joe Perez is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Mr. Mattman
Build Threads
252
02-24-2017 12:53 PM
Pinky
DIY Turbo Discussion
48
02-28-2014 02:19 PM
JimmyKrackCorn
Supercharger Discussion
10
11-19-2010 08:58 AM
rtb
Hydra
2
08-08-2010 04:58 PM
WonTon
General Miata Chat
75
04-19-2010 09:43 PM


Thread Tools
Search this Thread
Quick Reply: Worth doing ITB + turbo?


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.