2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

BNR Turbo Now, Fuel later?

Thread Tools
 
Search this Thread
 
Old Mar 30, 2004 | 03:49 PM
  #1  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
BNR Turbo Now, Fuel later?

Well, right now I have enough money to send my turbo to bnr and have it upgraded to the stage IV. ITs money left over from the rebuild at the rotary specialist shop, the guy that is rebuilding it is also streetporting the engine and told me that if I get the turbo before he finishes, he will install it at no charge, my question is, can I set my boost controller to about 6 or 7 psi and keep my stock fuel mods until I can afford an injector/pump/computer upgrade. Right now the only fuel mod I have is an HKS FCON which can be tuned to run rich. I also have a greddy profec b spec II to control the boost.

Basically, I wanna get the big stuff on already, and add the injectors, pump and standalone later, can I do tat as long as I mellow down the boost......way down?
Reply
Old Mar 30, 2004 | 03:54 PM
  #2  
bryantho's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Jun 2003
Posts: 75
Likes: 0
From: WA
Yeah, that sounds reasonable.

Different compressor maps might tweak the tune a bit, but as long as you have enough fueling for 6-7psi, you should be fine.
Reply
Old Mar 30, 2004 | 03:54 PM
  #3  
Rxmfn7's Avatar
Do a barrel roll!
Tenured Member 20 Years
iTrader: (4)
 
Joined: Oct 2001
Posts: 7,529
Likes: 2
From: Lower Burrell, PA
Id think you should be ok if you only run stock boost levels. Be aware though that you cant turn boost down with the boost controller, only up. Meaning, if you have a free flowing exhaust , and intake, your boost levels will be much above stock levels, necessitating more fuel. If you put the stock intake and exhaust back on, you should be ok. Be aware though that the stage4 turbo at 7psi is flowing more air than the stock turbo at 7psi, so I would advise at least getting an upgraded pump to start off.
Reply
Old Mar 30, 2004 | 04:04 PM
  #4  
bryantho's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Jun 2003
Posts: 75
Likes: 0
From: WA
Originally posted by Rxmfn7
Be aware though that you cant turn boost down with the boost controller, only up. Meaning, if you have a free flowing exhaust , and intake, your boost levels will be much above stock levels, necessitating more fuel. If you put the stock intake and exhaust back on, you should be ok. Be aware though that the stage4 turbo at 7psi is flowing more air than the stock turbo at 7psi, so I would advise at least getting an upgraded pump to start off.
Huh? Okay, that's confusing.

1. The BNR turbo's have larger waste-gates. They can divert more exhaust gas around the compressor, thus they have better control over "boost creep."

2. If he has a manual boost controler, he can set it to turn on at 7psi. Meaning, the boost controller will see 7psi in the manifold, and vacuum actuate the waste-gates. So you can turn the boost “down.” Since the BNR turbos have better waste-gates, this should work better than stock.

3. Yes, the stage4 is a different compressor, and may flow denser air at 7psi. But isn't that what the AFM and air temp are for? The ECU will compensate for air charge temperature and mass.

Did I miss something?
Reply
Old Mar 30, 2004 | 04:11 PM
  #5  
Rxmfn7's Avatar
Do a barrel roll!
Tenured Member 20 Years
iTrader: (4)
 
Joined: Oct 2001
Posts: 7,529
Likes: 2
From: Lower Burrell, PA
Yes, you are correct. I wasnt arguing with you. A few things though, BNR does port the stock wastegate larger. However, with intake and exhaust mods, I still highly doubt that it is sufficient to hold 6-7psi of boost, with a open exhaust and intake. I remember reading about a forum member who had even ran an aftermarket 35mm wastegate off the BNR stage4, and still couldnt hold boost under 12psi. Thats a huge *** compressor
Reply
Old Mar 30, 2004 | 04:19 PM
  #6  
bryantho's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Jun 2003
Posts: 75
Likes: 0
From: WA
Ahh, okay.

Revised:
Stock vs. BNR. The BNR wastegates can and will divert more gas around the compressor. But whether or not that's enough to keep him from creeping past 7psi is another question.

On the other hand, I think it might be safe to assume that if he's not creeping now, then he shouldn’t be creeping more just by changing to the turbo.
Reply
Old Mar 30, 2004 | 06:07 PM
  #7  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
so theres no way to hold the boost at 6-7 psi except putting stock intake/exhaust back on. Hmm.....those are long gone, guess ill be paying a visit to the rex junkyard for some stock echaust/airbox parts. Thanks for your help guys.
Reply
Old Mar 30, 2004 | 06:08 PM
  #8  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
so theres no way to hold the boost at 6-7 psi except putting stock intake/exhaust back on. Hmm.....those are long gone, guess ill be paying a visit to the rex junkyard for some stock echaust/airbox parts. Thanks for your help guys.
Reply
Old Mar 30, 2004 | 06:13 PM
  #9  
Rxmfn7's Avatar
Do a barrel roll!
Tenured Member 20 Years
iTrader: (4)
 
Joined: Oct 2001
Posts: 7,529
Likes: 2
From: Lower Burrell, PA
You could always just drive lightly...try not to boost much until you get your fuel system taken care of..
Reply
Old Mar 30, 2004 | 06:30 PM
  #10  
Digi7ech's Avatar
I break Diff mounts
Tenured Member 20 Years
iTrader: (1)
 
Joined: Jun 2002
Posts: 4,403
Likes: 4
From: Avondale, Arizona
BTW don't foget that 6-7 psi on a larger CFM compressor is more than 6-7 psi on a stock hitachi.
Reply
Old Mar 30, 2004 | 06:38 PM
  #11  
Silverfc88's Avatar
Rotary Freak
Tenured Member 15 Years
iTrader: (7)
 
Joined: Nov 2002
Posts: 1,790
Likes: 3
From: Travis AFB, CA to Okinawa, Japan
I'm running a BNR stage 1 and I'm running about 10psi of boost on it with 720's on top and on the wideband I'm running maybe 11.5-11.8's for A/R's and if I turn the boost up to 11-11.8 I can see it blipping to 12.1 for A/R's at higher rpms and thats with the injectors turned up to almost +25%. I'm looking at more fuel now to run 12 safely. Maybe adding a single 550 with an AIC at around 10psi of boost and more.

Something to think about when you do your fuel setup, maybe 2x680 and 2x720 or 4x720 should be good for that hybrid.
Reply
Old Mar 30, 2004 | 06:54 PM
  #12  
NZConvertible's Avatar
I'm a boost creep...
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 15,608
Likes: 8
From: Auckland, New Zealand
You're going to run a heavily modified turbo with the stock pump?! That's just plain nuts man. The chances you being able to keep boost that low are slim to none (you can't just "turn boost down" to whatever you want), and no fuel controller in the world will help you once the stock pump reaches its safe limits. If you can afford to have your engine and turbo rebuild and modified, then you should at least be able to afford to put a decent pump in as well to hopefully keep it alive.
Reply
Old Mar 30, 2004 | 07:00 PM
  #13  
MtnRacer's Avatar
infini guru
Tenured Member 15 Years
 
Joined: Nov 2001
Posts: 1,183
Likes: 0
From: Sunnyvale, CA
This a terrible aweful bad idea. Fuel first. Always.

Steve
Reply
Old Mar 30, 2004 | 07:44 PM
  #14  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
ok ok, so fuel first then, what is the recommended setup, maybe a walbro 255 pump, what else do i need?
Reply
Old Mar 30, 2004 | 08:02 PM
  #15  
MtnRacer's Avatar
infini guru
Tenured Member 15 Years
 
Joined: Nov 2001
Posts: 1,183
Likes: 0
From: Sunnyvale, CA
Injectors, an SAFC or something like that, and a good tuner!

Steve
Reply
Old Mar 30, 2004 | 08:10 PM
  #16  
iluvrx7z's Avatar
Senior Member
Tenured Member 10 Years
 
Joined: Sep 2001
Posts: 297
Likes: 0
From: puerto rico/connecticut
A boost controller can not lower boost, only raise it. Do a search, there are plenty of explanations why.

Dan
Reply
Old Mar 30, 2004 | 08:23 PM
  #17  
deltr0n`'s Avatar
Track Junkie
Tenured Member 10 Years
 
Joined: Oct 2002
Posts: 1,277
Likes: 0
From: Los Angeles
its common sence to get fuel first! its NOT very smart to upgrade a turbo without already having fuel mods, matter of fact thats the stupidest thing ive ever heard. but thats just me, if you want, go ahead and do it, but why cant you just use that money to go all out on your fuel mods, and then worry about the turbo later, you can push a reasonable amount of power with a ported motor, and upgraded fuel!

i hit 15 pounds with my mods, and once i get my fuel pump and rising rate regulator, im pretty sure ill have somewhere near the 250rwhp range if not more at 15lbs.

im gonna go with a comp pump from teamfc3s store, and a bell regulator from Bell Engineering (only the best) that right there will get you enough for plenty of power, then im going to redo the fuel lines and make the rails parallel.

Last edited by deltr0n`; Mar 30, 2004 at 08:43 PM.
Reply
Old Mar 31, 2004 | 07:18 AM
  #18  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
So, let me get this straight, I have a portd wastegate and a stock turbo. If I do a streetport on my engine and upgrae my pump and injectors, I can safely run 15 psi on my stock turbo? Will I really be making that kinda of power? Deltr0n, you also said a bell regulator from BEGI, Im not too sure what that is for, would I still need a fuel computer? Is my HKS FCON enough or do I nee an SAFC?
Reply
Old Mar 31, 2004 | 07:35 AM
  #19  
deltr0n`'s Avatar
Track Junkie
Tenured Member 10 Years
 
Joined: Oct 2002
Posts: 1,277
Likes: 0
From: Los Angeles
well if you got the 720's you need a way to manage them, and thats even MORE power, actually i forgot to mention this, i will also be running 720 secondaries. of course the stock injectors might max out, thats why you need 720's but once you get the 720's you HAVE TO have something to control them (SAFC or standalone)

the bell regulator is a rising rate fuel pressure regulator, meaning as boost levels go up, so does your fuel! letting you boost more. but im pretty sure with just the regulator and pump, you can support 15lbs, cause i know our cars stock can handle 10, and with that pump and RRFPR, that should be PLENTY fuel.

Last edited by deltr0n`; Mar 31, 2004 at 07:43 AM.
Reply
Old Mar 31, 2004 | 07:45 AM
  #20  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
so the pump, the regulator, the 720 injectors (4 of them right?) and an safc. Hmmmm............probably gonna go with the fmic as well, so that all I have left to upgrae it the turbo, alright man, perfect. Thanks alot for your help
Reply
Old Mar 31, 2004 | 08:31 AM
  #21  
Bukwild's Avatar
Rotary Freak
Tenured Member 15 Years
 
Joined: Apr 2003
Posts: 2,702
Likes: 1
From: DC Area
fuel first for a rotary
Reply
Old Mar 31, 2004 | 10:57 AM
  #22  
sub9lulu's Avatar
Rotary Freak
Tenured Member 20 Years
iTrader: (7)
 
Joined: Jun 2003
Posts: 2,739
Likes: 2
From: FL
2 of them 720's in the secondary u should be good
if u got $ u can get all 4
get the Rtek7 too , built in FCD sounds pretty good for 100 bucks
Reply
Old Mar 31, 2004 | 11:01 AM
  #23  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
so stock injectors and secondary 720's? is this enogh for 380-400rwhp?
Reply
Old Mar 31, 2004 | 01:03 PM
  #24  
Digi7ech's Avatar
I break Diff mounts
Tenured Member 20 Years
iTrader: (1)
 
Joined: Jun 2002
Posts: 4,403
Likes: 4
From: Avondale, Arizona
Umm I don't know about keeping the 550's for primaries.

It might not be enough for a 400rwhp set up.

J-Rat is getting the BNR and he is goin 720 Primaries(I think) and 890 secondaries.

Anyways. It's better to run rich than lean. Too lean == new engine go bye bye.
Reply
Old Mar 31, 2004 | 02:36 PM
  #25  
MazdaRx7Racer4Life's Avatar
Thread Starter
I AM A THIEF!! READ THE FEEDBACK SECTION!
Tenured Member 05 Years
 
Joined: Aug 2002
Posts: 86
Likes: 0
From: Miami, FL
So 720 primaries, 890 secondaries, comp tech fuel pump, rtek7 chip, bell engineering regulator......safc?? I don't think I can control 890's with the safc, I think it has to be 720's all around. What do you think
Reply



All times are GMT -5. The time now is 01:54 PM.