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

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Old Oct 25, 2003 | 05:04 PM
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Engine Management

Hi Guys, I just found this site today. Yes, I'm a newbie

I'm hoping to get some help from some members with experiance with this car.

I have an 87 Turbo that I just got up and running in the last week. It's has stage 2 portwork on a 91 motor using one piece seals, using the 87 ecu and wiring. Other upgrades are a Greddy intercooler, racing beat exhaust, light flywheel and 6 puck clutch, HKS PFC F CON Controler and Greddy boost controler. The car uses the stock turbo.

I ran the car on the dyno on tuesday. It put 268 horse to the wheels at .7 bar at 5200 rpm.

There are several problems:

After 4500 rpm the fuel/air mixture goes from 12.5:1 up to 14.9:1 at 5100 rpm. We didn't run the car beyond this range for safety reasons. These were 4th gear runs.

At cruise, the air/fuel raito gauge is showing full rich and the gas milage is around 11.5 mpg.

Any feedback about making this system work or experiance with other engine management systems for the RX7 turbo would be greatly appreciated.

I'll post some pictures next week. Look forward to talking with some other gen 2 folks out there.

Thanks
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Old Oct 25, 2003 | 05:06 PM
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Check out microtech, its the most bang for the buck stand alone ecu.
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Old Oct 25, 2003 | 05:53 PM
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Yeah as said the Microtech will be a very good choice....but if a standalone is out of range for you right now, you could look into the S-AFC it does a good job for what it is. Also what type of fuel pump and injectors is in the car? If its still the stock system you will need to upgrade.
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Old Oct 25, 2003 | 06:22 PM
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I find it hard to believe a stock turbo would produce that kinda numbers.
What kinda dyno?


-Ted
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Old Oct 25, 2003 | 06:32 PM
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I'd be happy if my car put out that much with 1.0 BAR.
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Old Oct 25, 2003 | 07:37 PM
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The fuel pump and injectors are stock. The dyno is a mustang dyno using win pep software at the carb connection in Kirkland, WA. I'll post the dyno sheets on monday.

Who makes the S-AFC?

What's the wed address for Microtech?

Any recomendations on injectors and fuel pump?

Has anyone herd of the Wolf standalone system? I have herd that they are comming out with a plug and play for the RX7?

Thanks for the feed back
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Old Oct 25, 2003 | 07:50 PM
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apexi makes the s-afc you can look at it at www.rx7store.net
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Old Oct 25, 2003 | 09:38 PM
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the first thing you need is a bigger fuel pump and injectors. you're not gona get any more fuel outa the stock ones with any other ecu.

I also don't belive it's the stock turbo making that kinda power...

Last edited by Scott 89t2; Oct 25, 2003 at 09:55 PM.
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Old Oct 25, 2003 | 10:18 PM
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Originally posted by Jeff Butler
What's the wed address for Microtech?
There isn't one that I know of, but here are some vendor sites for the Microtech products:
http://br7racing.com/
http://microtechefi.com/
http://www.a-spectuning.com/

Originally posted by Jeff Butler
Any recomendations on injectors and fuel pump?
Walbro (cheap) or Bosch (better quality) fuel pump if you just want something for now that will work well, SX or Aeromotive if you want something that will handle future upgrades. SX has an excellent fuel pressure regulator. You may want to move up to 4x680cc or 4x720cc injectors. If you only drag race, then you can run large secondaries with your stock primaries. However, if you want more streetability, you should keep the flow rates the same or at least close between the primaries and secondaries. RC engineering has a worksheet for same-sized injectors. Your BSFC will be somewhere around .64, maybe higher if you are running a rich AFR and/or overspeeding the stock turbo.
http://www.rceng.com/technical.htm#WORKSHEET

Originally posted by Jeff Butler
Has anyone herd of the Wolf standalone system? I have herd that they are comming out with a plug and play for the RX7?
I have one, as do most of my friends. It's a good EMS.
http://www.wolfems.com.au/home

Sorry, Wolf does not make a plug & play EMS for the 86-92 RX-7 at this time, and probably will not ever make one due to the old nasty original wiring and sensors in the car, and the overall lack of demand.

BTW, the "plug & play" term is not actually correct with respect to any of the current standalone EMS products on the market. Rather, they are more like "plug & tune". There are some piggyback chips and reprogrammed ECUs that are true plug & play, but they do not have anywhere near the capability of a full standalone EMS or fuel computer.

My recommendation would be to use whatever EMS or fuel computer your local tuner uses, and see if he will give you a package deal or a rate reduction on tuning if you buy the EMS from him. Good products under $2,000 (alphabetical order) include the Haltech E11, Microtech LT8, and Wolf3D 4.0. The S-AFC is also OK, but does not have the capabilities of the previously-listed items. Before you ask, no, the AEM Plug & Play and the Apexi Power FC will not work in a 2Gen RX-7. Also, in case you were wondering, the AEM business in Australia that makes the Wolf is not the same as the AEM business in the US that makes an EMS for the 3Gen RX-7. Yes, it is confusing.

See our ECU forums for more info:
https://www.rx7club.com/forumdisplay...ne=&forumid=37

Also see RETed's site for good overall information on the TII:
http://fc3spro.com/sitemap.html

Originally posted by Scott 89t2
the first thing you need is a bigger fuel pump and injectors. you're not gona get any more fuel outa the stock ones with any other ecu.
I have not been able to confirm this, but supposedly the stock ECU only allows for about 63% injector duty cycle. I hate referencing internet heresay, but I think it is still worth considering. Anyway, the engine is going to run like garbage if bigger injectors are installed without some type of fuel computer. I think that an EMS is a good first step because it allows the monitoring of the systems (duty cycle, AFR, MAP, IAT, etc.) so that the rest of the system can be planned based on this information. If an EMS is out of the budget, then I think it's still good to install the fuel computer before, or at the same time as, the larger injectors. The fuel pump can be installed at any time as long as the fuel pressure regulator can handle it. Come to think of it, the fuel pump may be a better first step than an EMS given the poor grounding and old age issues with the stock pump.
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Old Oct 26, 2003 | 01:00 AM
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Originally posted by Scott 89t2
the first thing you need is a bigger fuel pump and injectors. you're not gona get any more fuel outa the stock ones with any other ecu.

I also don't belive it's the stock turbo making that kinda power...
As far as I know it's the stock turbo. The engine came from Japan and is a 91. Maybe the turbo is different than the U.S. spec?

Thanks for all the feed back, especially Evil Aviator. You put some time in to that one.
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Old Oct 26, 2003 | 01:08 AM
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Originally posted by Jeff Butler



What's the wed address for Microtech?


http://www.microtechefi.com/
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Old Oct 26, 2003 | 01:37 AM
  #12  
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nearly 270 rwhp to the wheels...on a mustang dyno...at only .7bar??

Take pics of the turbo....

14.9:1 - I'm surprised it didn't ping or knock at that level. Like others have said you need a bigger fuel pump and at that level of power you're maxing out your stock injectors. Evil answered the EMS question with in depth detail, and the choice of which stand alone to go with is for you to choose based in my mind primarily on money and whatever your local tuner is comfortable with.

edit: Maybe it is a stock turbo and the enormously high power level comes from the engine running so lean. The leaner the a/f ratio the more power can be made. If the motor was at 14.9:1 and didn't knock it would definitely add some power.....who knows though a hybrid like one that came on vosko's old t2 is likely as well.
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Old Oct 26, 2003 | 01:28 AM
  #13  
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that's some crazy numbers for only .7 bar, I'm having some trouble believing that's the stock turbo
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Old Oct 26, 2003 | 01:36 AM
  #14  
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Well I will put money on the fact that its at least a hybrid. If its a jspec, then he got whatever came over with it more than likely. But anyway it goes, thats great numbers for .7 bar.
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Old Oct 26, 2003 | 10:13 AM
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So what kinda power does the stock turbo make?

I'll shoot some pics of the turbo on monday and post them with the dyno sheets.

I think the boost was creeping just over .7 bar when we stopped the dyno run. The alarm is set @ .8 and had not gone off.
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Old Oct 26, 2003 | 12:12 PM
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Originally posted by Evil Aviator

I have not been able to confirm this, but supposedly the stock ECU only allows for about 63% injector duty cycle.
he listed an f-con at the top though which is probbaly maxing his out. so at this point an EMS woudln't do any good without injectors and / or pump as well.


So what kinda power does the stock turbo make?
.7 bar on the stock turbo would push around 200-220 at the wheels. 1 bar maybe 250
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Old Oct 26, 2003 | 01:52 PM
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Originally posted by Jeff Butler
The fuel pump and injectors are stock. The dyno is a mustang dyno using win pep software at the carb connection in Kirkland, WA. I'll post the dyno sheets on monday.
That makes it even more hard to believe. The stock fuel injectors and fuel pump barely can support 250hp to the FLYWHEEL, let alone rear wheel power...

You sure it wasn't a "2" instead of a "7"?


-Ted
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Old Oct 26, 2003 | 04:27 PM
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Ok, so I have some pic's of the car, work in progress, turbo,(the stamp marks on the turbo that I'm trying to show are T90) and the dyno sheets.

I don't know how to attach the pic's with the replay, can some one fill me in?
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Old Oct 26, 2003 | 04:31 PM
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If you got the hosted somewhere, you can just type [ I M G ](put URL here)[ / I M G], without the spaces and the Forum will auto load it in your post.

Else, there's a "Attach file:" option right below the reply box that allows you to upload files.


-Ted
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Old Oct 26, 2003 | 04:50 PM
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Hey Ted,

I attached one jpeg file and got this error. What's up?

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /newreply.php.

Reason: Error reading from remote server
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Old Oct 26, 2003 | 10:04 PM
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Originally posted by Scott 89t2
he listed an f-con at the top though which is probbaly maxing his out. so at this point an EMS woudln't do any good without injectors and / or pump as well.
Thanks, I missed that. In that case, I guess an S-AFC wouldn't be much of an upgrade.

Originally posted by gsracer
The leaner the a/f ratio the more power can be made.
That's not necessarily true. Moving away from the best power AFR, either leaner or richer, will reduce the power. However, I do not know of any case where the best power AFR was not richer than the best economy AFR. See the graph at the bottom of this link for a generic example of how this relates to an internal combustion engine:
http://racetep.com/halmeter.html

Originally posted by MrBob 86
http://www.microtechefi.com/
I didn't realize that is the official Microtech web site. It's nice to see that the website has progressed so well in the last few months.

Originally posted by Jeff Butler
Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /newreply.php.

Reason: Error reading from remote server
I think the new server is having some temporary difficulty with that function. You may just want to put the pictures on a web site and post a link here. Many of the free web sites do not allow direct links to pictures, but you can get around this by posting a link to the web page instead. For example, rather than posting actual pictures, I can post the link to the web page with the picture(s):
http://www.geocities.com/evilaviator/axia

Fortunately, this forum's photo gallery IS working. I know, because I uploaded a picture a few days ago. It may take a day or two for your uploaded pictures to get approved, but it does work.
https://www.rx7club.com/photo/index.php
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Old Nov 3, 2003 | 02:24 PM
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Alright, im posting these pix for jeff. I havent riden in the car since the motor got replaced but...heres some pix to tide you over and hopefully give some more responces.












Thanks
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Old Nov 3, 2003 | 02:31 PM
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I have a really hard time believing that the stock turbo and fuel system will make those numbers safely. It is possible that the turbo has been modified. Either way, you're at the danger zone with fuel. I wouldn't push the car until you can deal with it (at the very least, a fuel pump upgrade).

BTW, Japan and US engines had the same turbo.
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Old Nov 3, 2003 | 02:49 PM
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Originally posted by Aaron Cake
I have a really hard time believing that the stock turbo and fuel system will make those numbers safely. It is possible that the turbo has been modified. Either way, you're at the danger zone with fuel. I wouldn't push the car until you can deal with it (at the very least, a fuel pump upgrade).

BTW, Japan and US engines had the same turbo.
Did you look at the AF ratios?
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Old Nov 3, 2003 | 02:53 PM
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He said it's leaning out top end...Not unexpected. Something has to be wrong with those numbes though...Stock turbo making that power at > 11 PSI?
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