preliminary DIY setup without FPR? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 10-17-2006, 10:29 PM   #1
Elite Member
Thread Starter
iTrader: (5)
 
Atlanta93LE's Avatar
 
Join Date: Sep 2006
Location: Marietta, GA
Posts: 2,198
Total Cats: 1
Default preliminary DIY setup without FPR?

So I put the Braineack's theoretical fueling equations into Excel to play around, and if what I see is true...

One could get some 295cc injectors and make them work with an RX-7 AFM on the stock pump, FPR, and ECU for 170hp at 8psi? Doesn't make sense to me, but the equations show that, with 48 rail psi from stock fuel supply equipment, 292cc is what's needed to make 170 hp.

If Braineack can get his 305cc injectors running with stock ECU, I imagine 295cc would work also.

So why wouldn't this work? Thanks

Last edited by Atlanta93LE; 10-17-2006 at 10:30 PM. Reason: spelling
Atlanta93LE is offline   Reply With Quote
Old 10-17-2006, 11:40 PM   #2
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,247
Total Cats: 291
Default

Ponder this: If AndyFloyd is running 330s on the stock ecu, why wouldn't it work?
m2cupcar is offline   Reply With Quote
Old 10-18-2006, 08:14 AM   #3
Elite Member
Thread Starter
iTrader: (5)
 
Atlanta93LE's Avatar
 
Join Date: Sep 2006
Location: Marietta, GA
Posts: 2,198
Total Cats: 1
Default

But is he using an AFPR/FMU? I bet so...

I notice you have a red 93LE interior in your car. They're pretty nice, aren't they? And in Atlanta, too! Good choice.
Atlanta93LE is offline   Reply With Quote
Old 10-18-2006, 09:48 AM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,910
Total Cats: 1,793
Default

The 170HP number would be at the crank, so figure maybe 140rwhp. So figure with 295cc injectors you'd be good for about 4psi without an FMU.

What's stopping you from getting one in the first place? the price? I'm selling my Vortech unit with all the discs.
Braineack is offline   Reply With Quote
Old 10-18-2006, 11:07 AM   #5
Elite Member
Thread Starter
iTrader: (5)
 
Atlanta93LE's Avatar
 
Join Date: Sep 2006
Location: Marietta, GA
Posts: 2,198
Total Cats: 1
Default

Makes sense now that I think about the HP value being at the crank.

Right now I'm playing/planning to see which direction I should go...I'm looking to find a cheap initial setup that will allow me to slowly upgrade without ditching initial parts.
Atlanta93LE is offline   Reply With Quote
Old 10-18-2006, 11:13 AM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,910
Total Cats: 1,793
Default

Even with engine management a FMU isn't a bad idea since you can pump up the fuel pressure and extra some extra room to play with on your injectors. Say 240rwhp on 1.8 injectors with EMB. But i'd consider the BEGi unit then, if planning on boosting past 10psi, lots more room for adjustability.
Braineack is offline   Reply With Quote
Old 10-18-2006, 11:44 AM   #7
Senior Member
iTrader: (6)
 
Join Date: Mar 2005
Location: Sammamish, Washington
Posts: 1,396
Total Cats: 0
Default

I was able to run 3.5 psi with a T3 60 trim with the stock 1.8 injectors and no rrfpr. It had dutycycle headroom as well because I hit a 10:1 mixture a few times under boost while tuning. I was using the Walbro 255 Hp as well though so my fuel pressure was a whopping 4 psi higher.
Kelly is offline   Reply With Quote
Old 10-18-2006, 12:27 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,910
Total Cats: 1,793
Default

right in line where I figured.
Braineack is offline   Reply With Quote
Old 10-18-2006, 12:51 PM   #9
Senior Member
 
Join Date: Jan 2005
Posts: 737
Total Cats: 0
Default

Quote:
Originally Posted by Atlanta93LE View Post
But is he using an AFPR/FMU? I bet so...

I notice you have a red 93LE interior in your car. They're pretty nice, aren't they? And in Atlanta, too! Good choice.
Yes, Im using an FPR but thats doesnt mean that you cant get these to idle and run perfect as long as you keep boost VERY low and dont exceed about 140whp. My FPR does nothing to help it idle, thats all in the AFM spring adjustment...the FPR just gives the extra pressure when I need it. I know for a FACT that 295's will idle just fine...you might have to fiddle with it but it will work.
F20turbo is offline   Reply With Quote
Old 10-18-2006, 12:55 PM   #10
Elite Member
Thread Starter
iTrader: (5)
 
Atlanta93LE's Avatar
 
Join Date: Sep 2006
Location: Marietta, GA
Posts: 2,198
Total Cats: 1
Default

So this might be a dumb question, but let's say that a turbo had a 7psi wastegate. Upping boost is easy. But what about decreasing max boost? I presume a new wategate would be needed...is this right?
Atlanta93LE is offline   Reply With Quote
Old 10-18-2006, 01:05 PM   #11
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,910
Total Cats: 1,793
Default

You can port the inlet, which will push more boost against it and open it quicker.

OR

You could try an "un" helper spring. Basically a springs thats constantly putting load on the swingarm to pull open. Say attach a bracket to the firewall and connect a spring from that to the swingarm.
Braineack is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 12-15-2017 09:00 PM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 01:25 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM
Low oil pressure after 1.8 swap and new turbo setup JesseTheNoob DIY Turbo Discussion 15 09-30-2015 03:44 PM


Thread Tools

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 06:48 PM.