New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

ecu question, warning : newb!

Thread Tools
 
Search this Thread
 
Old Jul 1, 2009 | 10:51 PM
  #1  
evoentertainment's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2009
Posts: 262
Likes: 0
From: San Francisco
ecu question, warning : newb!

Hi, Ive recently purchased my first rotary engine car. It is a 1988 TII. It is running on a rebuilt motor with FD internals, a hybrid turbo, 550 primary and 750 secondaries, running on stock ecu. What the prev owner said was since its on stock ecu I cannot pass 7psi since it has fuel cut off. He also included a stand alone megasquirt ecu, which he told me needs to be tuned before it can be ran in the car. The problem here is the nearest reputable tuner is about 450 miles from me. 450 miles that I do not want to travel lol. What he suggested was that I just purchased a rtek ecu, which he explained does not need to be tuned what so ever. So my question is what is my best options here? What should I do? Thanks in advance guys, also sorry for the noob questions!
Reply
Old Jul 3, 2009 | 08:55 AM
  #2  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
The RTek needs to be tuned like any other ECU, but is the easier option as it is plug and play. The Megasquirt is a much better ECU but would need to be fully wired.

I have to believe that within 450 miles of San Francisco there is at least one knowledgeable rotary person that can tune the car. It's not really rocket science. Check out the West Coast subforum.
Reply
Old Jul 3, 2009 | 10:17 AM
  #3  
Chillski's Avatar
Junior Member
Tenured Member 05 Years
 
Joined: Apr 2005
Posts: 12
Likes: 0
From: queens, ny
definitely keep looking man... i guarantee there is somewhere closer by san francisco that can tune ur fc3s. dont blow ur money on another ecu when ur still gonna end up having to go to a shop and get it tuned anyway.
Reply
Old Jul 5, 2009 | 11:18 PM
  #4  
RotaryRocket88's Avatar
Top Down, Boost Up
Tenured Member 10 Years
iTrader: (7)
 
Joined: Mar 2008
Posts: 8,718
Likes: 6
From: San Diego, CA
You can use an Rtek 1.7, if you leave the boost alone. If you start flowing much more than the stock turbo at high RPMs, all bets are off. But, it's still much better than using a stock ECU that thinks you still have four 550cc injectors. You're just dumping excess fuel in over 3800 RPM.

But eventually, you'll want to use the megasquirt. And you're going to need bigger injectors to give you headroom for whatever this hybrid is. Even a small hybrid will be limited at high boost by the modest injectors you have.
Reply
Old Jul 6, 2009 | 01:22 AM
  #5  
evoentertainment's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2009
Posts: 262
Likes: 0
From: San Francisco
first off, thanks for the input guys. the prev owner told me the way his setup is, the turbo and motor is good for max 12psi. I am considering about just getting a rtek 1.7 for now, boost controller, and boosting at 10 for the time being, until i figure, find a reputable tuner in near San Francisco. Everywhere ive tried so far said either no, or that they dont know how "good" the tune will turn out. any input would be greatly appreciated!
Reply
Old Jul 6, 2009 | 09:09 AM
  #6  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Remember, if the car makes 12 PSI on the wastegate spring, then then lowest boost you will ever be able to achieve with a boost controller is just slightly above 12 PSI.
Reply
Old Jul 6, 2009 | 09:33 AM
  #7  
evoentertainment's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2009
Posts: 262
Likes: 0
From: San Francisco
im at 7 right now without a boost controller and stock ecu. so do you think i ll be able to set it to 10 with controller and rtek1.7?
Reply
Old Jul 6, 2009 | 01:08 PM
  #8  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Yep, that should work. Just be aware that with a hybrid stock turbo and a boost controller, boost adjustment is going to be very non-linear due to the small wastegate. You will reach a point where it will skyrocket with only a tiny change in the boost setting.
Reply
Old Jul 6, 2009 | 01:23 PM
  #9  
evoentertainment's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2009
Posts: 262
Likes: 0
From: San Francisco
i see, then should i just get the rtek 1.7 and let it boost at whatever it boost at, and just forget about the boost controller? sorry for being sucha newb. =/
Reply
Old Jul 7, 2009 | 08:51 AM
  #10  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Using the boost controller is fine, it just takes baby steps. But yes, I think first you should find out what its natural boost is before you start running the controller.
Reply
Old Jul 7, 2009 | 01:32 PM
  #11  
RotaryRocket88's Avatar
Top Down, Boost Up
Tenured Member 10 Years
iTrader: (7)
 
Joined: Mar 2008
Posts: 8,718
Likes: 6
From: San Diego, CA
I wouldn't touch the boost without at least a wideband. Who knows how big of a hybrid this turbo is. If it's something like a 60-1 wheel, and you start running 10+ psi up to redline, the "stock" map on an Rtek 1.7 isn't going to be a good match.

For one, the base timing between 5.5-7k RPM (at 100% load) on the stock map is pretty aggressive (~25 to 35* lead). This only gets retarded an additional 1* per psi over 9psi of boost with the extra code pocketlogger adds in. The stock turbo power band is the only explanation I have for why the timing is this way. The stocker can't hold much boost beyond about 6k RPM, and torque dips significantly.

Then there's fuel. The 1.7 basically runs stock fuel levels because 25% is taken out up top to accomodate 720cc secondaries. Without adjustable fuel control & a wideband, you're just crossing your fingers it'll stay rich enough.
Reply
Old Jul 7, 2009 | 05:48 PM
  #12  
evoentertainment's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2009
Posts: 262
Likes: 0
From: San Francisco
i forgot to mention his previous setup was with a rtek 1.7, but then he sold it to purchase the megasquirt. Then he deceided to sell the car to me. So I pretty much have my eye set on the rtek, what info should i obtain from the prev owner? sorry im hekllal newb
Reply
Old Jul 7, 2009 | 07:28 PM
  #13  
RotaryRocket88's Avatar
Top Down, Boost Up
Tenured Member 10 Years
iTrader: (7)
 
Joined: Mar 2008
Posts: 8,718
Likes: 6
From: San Diego, CA
You should ask the previous owner for details on the hybrid turbo. Find out what was changed, and how large the compressor wheel is.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Skeese
Adaptronic Engine Mgmt - AUS
65
Mar 28, 2017 03:30 PM
CaptainKRM
2nd Generation Specific (1986-1992)
14
Aug 26, 2015 09:52 PM
Professorpeanutrx7
New Member RX-7 Technical
5
Aug 15, 2015 01:38 PM




All times are GMT -5. The time now is 04:14 PM.