need help concerning rrfpr's - 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 10-03-2006, 08:37 PM   #1
Newb
Thread Starter
 
Join Date: Mar 2005
Posts: 6
Total Cats: 0
Default need help concerning rrfpr's

i have a 1.8 bp that i will be using the 323gtx fuel, ignition, and knock controller on it. 323 gtx has 300cc injectors at about 40 psi of fuel pressure.

couldi use an rrfpr to run a t3/t04e 50 trim .48 a/r turbine stage 1 exhaust wheel at say 6 - 10 psi?
if so, what rising rate?

also, is there a size range to upgrade to larger injectors and still run the stock ecu?

if i went to a larger injector would i have to lower fuel pressure at idle?
khrys771 is offline   Reply With Quote
Old 10-04-2006, 12:12 PM   #2
Newb
Thread Starter
 
Join Date: Mar 2005
Posts: 6
Total Cats: 0
Default

no one knows?

currently my 323 gt has a 1.6L B6T gtx motor and with a vj11 probe turbo on it, it gets an afr of 11.8 at 17psi of boost.
khrys771 is offline   Reply With Quote
Old 10-04-2006, 02:40 PM   #3
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Yes, you can use an FMU to increase the fuel pressure. Not exactly sure what rate, but you typically want to shoot for around 100psi. 300cc injectors can support around 255BHP at those levels.

Since I have a 1.6 with a flapper AFM I could adjust the tension to idle at 14.7 AFR with 305s. Not sure where the limits of the 1.8 ECU is.

Fuel pressure at idle should only change to shoot for a target idle AFR.

You'll probably have an easier time adjusting with a BEGi FPR, a wideband and a fuel pressure gauge.


With that said; On my 1.6 at 9psi of boost, with 305cc injectors, with a 6:1 rise, I'm at 12:1 AFR (around 100psi of fuel).
Braineack is offline   Reply With Quote
Old 10-04-2006, 03:32 PM   #4
Newb
Thread Starter
 
Join Date: Mar 2005
Posts: 6
Total Cats: 0
Default

well i'm not going to be using a 1.8 ecu. i will be using the gtx ecu, so i wont have to worry about timing and knock. 300cc or 305cc whatever it is, they are stock injectors on the 323 gtx, it also uses a flapper afm.

i looked at the begi unit but am unsure which is the right one i want, i also plan on getting a plx m300 wideband to check my afr.
khrys771 is offline   Reply With Quote
Old 10-04-2006, 03:46 PM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

My injectors are 30% bigger than stock and I'm running them with the OEM ECU, so it can be done. Anything bigger may just require take some tinkering with your AFM.

There are two BEGi units, the first is the most common, the rising rate. This can only adjust the base idle pressure ABOVE that of which the OEM FPR regulates. On top of that you can adjust you rate of gain anywhere between 1:1 and 12:1.

The second is the multi role. This takes the place of the OEM FPR. So base idle can be set anywhere you want it to go. And like the other unit your rate of rise can be fully adjusted.
Braineack is offline   Reply With Quote
Old 10-04-2006, 06:28 PM   #6
Newb
Thread Starter
 
Join Date: Mar 2005
Posts: 6
Total Cats: 0
Default

after looking on bell engineerings site, are the fuel psi numbers on the charts adding to stock fuel pressure, or are what the fuel pressure will be in the fuel rail?
khrys771 is offline   Reply With Quote
Old 10-05-2006, 12:46 AM   #7
Senior Member
 
Join Date: Dec 2004
Posts: 1,450
Total Cats: -1
Default

I guess we'll assume you're referring to this page?: http://bellengineering.net/Pages/pro...struction.html

If so, then the first graph shows estimates for total pressure required on a naturally-aspirated car, the second graph is "...the amount of increase required" (last sentence in the paragraph before the figure) and the third figure is "...a typical guide to fuel pressure vs. boost pressure." In other words, that's the total amount of rail pressure.

These are all estimates and can be wildly different from kit-to-kit.
bripab007 is offline   Reply With Quote
Old 10-05-2006, 01:21 AM   #8
:(
iTrader: (7)
 
Join Date: Jul 2006
Location: nowhere
Posts: 8,281
Total Cats: 2
Default

well if you have the 323 ecu and afm then you could probably throw in some 400's and get the multi roll frp from begi they are currently out of stock but they are expecting some soon 10 atleast but 3 have already been sold or so stephanie tuner told me so good luck. btw the stock pump will max out at 85 psi period a walboro 190 hp or a peiburg will let you run 100+ psi fp.
magnamx-5 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MS PNP requires reading and following directions??? satisfied MEGAsquirt 141 10-06-2015 11:44 AM
Wtb: Rrfpr jaywood WTB 2 08-31-2011 09:46 PM
Hesitation while in boost Qckslvr General Miata Chat 17 08-24-2009 04:04 PM
what parts do i no longer need? drftem2 MEGAsquirt 2 10-18-2008 05:02 AM
Piggyback VS Bandaids s10383 DIY Turbo Discussion 16 05-25-2007 03:42 AM


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 02:26 AM.