Single Turbo RX-7's Questions about all aspects of single turbo setups.

For those running 1600 secondaries & power fc

Thread Tools
 
Search this Thread
 
Old Jun 10, 2008 | 01:38 AM
  #26  
siguy2k's Avatar
SLEEPER
Tenured Member: 20 Years
iTrader: (3)
 
Joined: Nov 2005
Posts: 1,145
Likes: 11
From: nebraska
Originally Posted by RX794
Myself and other notable members from this forum haven't used resistors with 1600 cc secondaries in PowerFC's for YEARS with no ill effects. THERE IS NO NEED TO USE RESISTORS WITH 1600 cc SECONDARY INJECTORS WITH A POWER FC! In fact, 1600 cc secondaries actually perform better without resistors inline because they will receive all of the amperage from the injector driver instead of it being diluted with a resistor being placed inline between the injector driver and the injector. 1600 cc injectors are usually rated at 4.4-4.5 ohms, this is within the range of a high resistance injector. Injector resistance grows the higher the duty cycle rises which will make it less prone to damaging the injector driver under load. If you're unsure of this, check your 1600 cc injectors with an ohm meter to make sure the resistance is between 4.4-4.5 ohms, if so just wire them up normally with no resistor inline, you'll notice not as much injector lag and improved stability without them.

ON A SIDE NOTE: You will gain injector performance with the FJO peak and hold injector driver in this type of application BUT it's not needed if you don't use the resistors as described.
Does this work for a FC with the pfc the same way? Ive never had problems with mine. I have 10ohm 10W resistors on mine.
Reply
Old Jun 10, 2008 | 05:11 AM
  #27  
PvillKnight7's Avatar
Rotary Freak
Tenured Member: 20 Years
iTrader: (16)
 
Joined: May 2002
Posts: 2,597
Likes: 3
From: Maryland
Originally Posted by JHew84
I was hoping other people would have already done the leg work so I wouldn't have to go through each distributors website to see if any of them sell them for cheaper than the $150 I've been seeing most commonly . I'll check HPF though.
how much is a pfc with resistors compared to an e6k?
is it worth the lack of speed?
at what power level is the trade off with the pfc? what about he e6k?
Reply
Old Jun 10, 2008 | 08:17 AM
  #28  
kenn_chan's Avatar
Savanna Rx-7
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: Jun 2004
Posts: 1,577
Likes: 12
From: yokosuka japan
Originally Posted by PvillKnight7
how much is a pfc with resistors compared to an e6k?
is it worth the lack of speed?
at what power level is the trade off with the pfc? what about he e6k?
I don't think that e6k was mentioned anwhere in there, I think he was talking about the difference in prices for the FJO setup. as he already has the PFC.


Smitter, it simply did not work and had a burned smell to it. vice messing with it and and damaging it we took it to a electronic repair shop up by Yokohama and they fixed it for like 7500 yen (70 USD give or take).

kenn
Reply
Old Jun 10, 2008 | 01:08 PM
  #29  
arghx's Avatar
rotorhead
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Aug 2004
Posts: 16,205
Likes: 461
From: cold
The type of resistor you use shouldn't make a huge difference (note that I said huge difference, there will be a manageable difference) in the way the car drives if you play around with the fuel map, lag ,and transition times. Yes, the injector driver would be ideal, but you can still iron out all the serious driveability problems of big injectors even with the 10W / 10 ohm resistors on a PFC. People have been doing it for years.

With my OEM 6ohm resistor pack I did a full recalc, rescaled my P rows, and basically redid my entire fuel map to compensate for the injectors, resistors, etc. It's not "perfect" but I don't have any scaling/transition problems or significant deviations in the intended fuel curve (such as serious rich or lean spots). When you switch to a secondary injector that is twice the size of the stock ones it's just going to take time to get it to run right, no matter what your setup (resistors, no resistors, no resistors + FJO driver).

Sometimes there's no silver bullet and you just have to do brute-force tuning: tedious datalogging and driving, adjustments based on a little bit of luck and guesswork (as opposed to having an Excel spreadsheet correction formula that should work yet doesn't 100% of the time). You may try a different lag or transition setting and then you have to play with the fuel map or something else. That's just the way it goes.
Reply
Old Jun 10, 2008 | 06:15 PM
  #30  
lib's Avatar
lib
Junior Member
Tenured Member 15 Years
 
Joined: Feb 2003
Posts: 40
Likes: 0
From: canada
i'm using 3ohm with no problems
Reply
Old Jun 11, 2008 | 12:53 AM
  #31  
Smitter's Avatar
Thread Starter
94 Single Turbo FD
Tenured Member: 15 Years
 
Joined: May 2006
Posts: 1,418
Likes: 1
From: Calgary, Alberta, Canada
Today i tried my pfc in a friends car, same result, the fuel injector drivers must be fried. 4.4 impedance injectors and 3 0hm resistors, by formula a safe combination.

Are u more likely to fry the drivers redlining the car as opposed to granny shifting it @ 5000rpm?
i believe i damaged the ecu when hitting the rev limit @ 8500 rpm
Reply
Old Jun 11, 2008 | 05:50 AM
  #32  
rxrotary2_7's Avatar
Lives on the Forum
Tenured Member 20 Years
 
Joined: May 2001
Posts: 5,097
Likes: 1
From: southern NJ
as already stated, a driver box would be ideal and not a band-aid,
yes you can run without resistors as proven by many people over time,
but to answer the original question... try this online calculator for getting the right resistors in a system.

http://www.injector-rehab.com/kbse/resistor.htm
Reply
Old Jun 11, 2008 | 07:35 PM
  #33  
Smitter's Avatar
Thread Starter
94 Single Turbo FD
Tenured Member: 15 Years
 
Joined: May 2006
Posts: 1,418
Likes: 1
From: Calgary, Alberta, Canada
i'm shipping the ecus into apexi to see wtf is wrong, its gotta be the injector drivers. while i wait 3 months to get the results, i have purchased another pfc and am gonna pick up the fjo driver.
Reply
Old Jun 11, 2008 | 08:01 PM
  #34  
Rx72Heaven's Avatar
Rotary Enthusiast
Tenured Member 05 Years
iTrader: (2)
 
Joined: Sep 2006
Posts: 1,350
Likes: 0
From: Vancouver, BC
cool man so whens the car going to be on the road?
Reply
Old Jun 18, 2008 | 02:18 PM
  #35  
Smitter's Avatar
Thread Starter
94 Single Turbo FD
Tenured Member: 15 Years
 
Joined: May 2006
Posts: 1,418
Likes: 1
From: Calgary, Alberta, Canada
Got my new power fc today, plugged it in and just as i suspected the Car ripped like it did before. So this solidifies that my 2 power fcs both have fried secondary drivers. Running with 7.4 ohms of resistance.

I emailed Steve Kan to get his recomendations and he said that the power fc circuits can only with stand 1.5 amps of continuous load, Not 2.0 amps that many have told me. That explains it. That being said, he recommended a minimum resistance of 8.7 ohms.
Reply
Old Jun 19, 2008 | 11:03 AM
  #36  
cewrx7r1's Avatar
Eye In The Sky
Tenured Member: 25 Years
iTrader: (2)
 
Joined: Feb 2001
Posts: 7,943
Likes: 133
From: In A Disfunctional World
I have seen different resistance listed for the Bosch injectors over the years.
If using resistors, be sure to measure the injectors first before going any further.

My Bosch 1600/light gray tops were slighlty over 5 ohms.

Below is something posted by another member.
************************************************** ********************
After much searching and head scratching, I think I finally deciphered this mess. I think that all 1600cc, or more exactly, 1680cc/160lb Bosch injectors are originally made for one purpose: to flow CNG on vehicles purposely made from the factory to run on this fuel. They were made for 2 engines, a 4.6L modular V8 from Ford that was fitted on their Crown Victorias and a 5.2L LA small block V8 from Chrysler that was fitted on their Ram vans. Thus we have 2 sets of part numbers, which are:


Ford injectors (should have a Ford logo embossed on them):

Bosch part # 0 280 150 839, Ford part # XL3E-C5A. Light green top (aqua).

Bosch part # 0 280 150 846, Ford part # F5TE-B5A. Light gray top (white).


Chrysler injectors (should have a Chrysler pentastar logo embossed on them):

Bosch part # 0 280 150 837. Brow top.

Bosch part # 0 280 150 843. Blue top. Both share Chrysler part # 53030518.
************************************************** *********************
I´ll rather not mix part numbers. It has been suggested on this forum (search around) that the Chrysler injectors have faster reaction times, and there is also talk about different resistance readings (i.e., ohms) between different part numbers. And there might even be volume differences, too, as the Chrysler ones were meant for a 5.2L engine and the Ford ones for a 4.6L. As I said, my rantings are not based on any factual evidence other than my 843s have 5.3-5.6 ohms resistance cold and they flowed at 141.2 and 142.8 at 18ms or roughly at 90%.
************************************************** *************
Don't forget the 0 280 150 846 that has a 4.7 ohm coil and white top.
Reply
Old Jun 24, 2008 | 12:42 AM
  #37  
EZFD's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Jul 2005
Posts: 520
Likes: 0
From: Lancaster, NY
10 ohm 10 watt here with no problems after 2 yrs.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
Jul 1, 2023 04:40 PM
Clacor
Single Turbo RX-7's
0
Aug 14, 2015 09:17 AM
gabescanlon
Interior / Exterior / Audio
1
Aug 11, 2015 05:59 PM
Wolf_
Single Turbo RX-7's
3
Aug 11, 2015 04:23 PM




All times are GMT -5. The time now is 09:08 PM.