Ideas for a cost-effective computer for a basic turbo kit?

ColinL · 02-25-2001, 01:45 PM

Buy something from Australia, there is a lot to pick from. Do a little legwork.

Many Australian-made products available through US distributors are not as cheap as they should be considering the AUD / USD exchange rate.

Just my 2 cents...

* Registered users of the site do not see these ads.

Jessie James · 02-25-2001, 01:51 PM

Yeah, I've seen quite a bit of them down there, but of course, I never bookmarked them at the time (didn't think I needed it.)

So what about adding a hi-flow fuel pump instead - would that have the same results? Like a Walboro or the Holly that Shiv used?

Wouldn't a hi-flow pump be a better bet in the long run because they could be more "stock" in installation, and function like the RRFPR?

Then what about the MAP clamp I have been reading about - that would be required for a turbo, right?

8Complex · 02-25-2001, 01:54 PM

You'd need a fuel pump and a fuel pressure regulator, the regulator will block the higher pressure from the stock pump so you need to be able to put a new regulator in and adjust the pressure from there. A Cartech/Bell RRFPR works well.

Jessie James · 02-25-2001, 02:21 PM

Okay, so I found the Cartech.net website - nice - Then I noticed all the RRFPR seem to look the same. Does the MY00 Impreza have one already? If so, where is that thing?

Thanks - this info is really helpful.

AaronB · 02-25-2001, 05:52 PM

You want both a RRFPR and a hi flow fuel pump. I had just the RRFPR (actually a Vortech SFMU) and was only getting mid 60's out of my fuel pressure. I swapped in the Vishnu fuel pump and was getting over 90 psi with the same settings.

I have since backed it down to mid/high 70's under boost.

With just these two things your car will run pretty well at 5psi.

Aaron http://www.azscooby.com

Midwayman · 02-25-2001, 06:06 PM

Really? running out? Were you running lean? I understood that a fuel pump wasnt required until 7psi.

Jon Bogert · 02-25-2001, 07:57 PM

7psi is approaching the ragged edge for the stock injectors at ANY fuel pressure. I believe that you need a larger fuel pump--and higher fuel pressure--for anything over 2-3psi.

Of course, some people are more comfortable than others playing on the ragged edge...

Jessie James · 02-25-2001, 08:29 PM

Anyone seen one of those deals where you add a fifth (and sometimes a sixth) fuel injector to the system?

Any opinions on that, functionally. I know it'll be a deal to drill into the manifold, but what are the performance issues, if any?

Adrian128 · 02-25-2001, 08:57 PM

Microtech is quite popular here in Australia with people intalling turbo kits, or when they upgrade turbo systems. I am not too familiar with their computers, but I know the have a few different models. Some of them come with handsets for on the fly adjustments.

ImprezaRS dot com · 02-25-2001, 09:37 PM

RS25.com - As stated above, with a MY00/01 turbo kit you need a RRFRP, fuel pump, MAP voltage clamp as a minimum.

The JCS toque chip II includes the MAP voltage clamp, but also monitors speed and rpm increase over time (accelration) and adjusts fuel to achieve maximum acceleration - but once the injectors are wide open under boost, it is still up to the RRFPR to push more fuel through the stock injectors (since the MAP voltage is maxed out and clamped).

The stock injectors, with fuel pressure in the mid to high 70's will support about 7 psi and 240 hp, but the stock fuel pump can't push that much pressure unless maybe you put vice grips on the fuel return line

The stock 280cc injectors flow about 330cc at 80 psi (per Shiv at www.vishnuperformance.com ), and someone else calculated that this 1320cc of fuel was good for 240hp max.

You asked about accessory injectors. I have just now bought a used Simple Digital Fuel Injector kit (from Canada), being installed next weekend. This adds two 440cc injectors with a control module that adjusts fuel based on both BOOST and RPM. This will eliminate the need for a RRFPR, but still requires the high flow fuel pump. They cost $465 plus shipping when new for the whole kit with module and injectors. The beauty of this kit is the fact that it varies fuel delivery based on RPM as well.

This brings up a major point I am learning about the RRFPR on a MY00/01 - With the RRFPR the quantity of fuel delivered under boost at 3,000 rpm is the same as at 6,000 rpm if the boost (and therefore the fuel pressure) is the same! Think about it - the injectors are already as wide open as the MAP voltage clamp will allow. So 5 pounds of boost resulting in 75 psi fuel pressure pushes a certain amount of fuel into the motor, no matter what RPM you are at you get the same amount of fuel through the injectors. You cannot get less fuel at 3,000 rpm than at 6,000, unless you can decrease the amount of boost the RRFPR sees at lower RPM. So, you can tune it for good midrange power or good top end power, but not both. This is with a MAP based MY00/01 only, not the older MAF equipped models.

Once we finish development on our ScoobyRacing boost referenced ITC, we will work on a boost controller. I mention this here because we are considering including a device to send less boost signal to the RRFPR at lower RPMs as well, thus allowing more precise fuel delivery with an RRPR installed. They could all work off the same pressure sensor in the ITC and piggyback to each other, thus reducing the costs!

I'll keep you posted on these new products in the near future.

Larry www.ImprezaRS.com

Jessie James · 02-25-2001, 09:42 PM

Larry, do you have a web address for that Simple Digital system you are mentioning? I would love to review and research what they are doing.

That fuel issue is a bummer! Not much good for turbos!

Thanks for the huge reply!

ImprezaRS dot com · 02-25-2001, 09:53 PM

I am working on getting the URL... It is not simpledigital.com, simpledigital.ca, or simpledigital.co.uk

Larry

Jessie James · 02-25-2001, 09:54 PM

Too cool - I really appreciate it. As you can tell I am in the process of educating myself as much as possible before I make the leap to do this turbo kit.

ImprezaRS dot com · 02-25-2001, 09:54 PM

It is www.sdsefi.com - thanks to MSN.com search...

Larry

PS: Then I searched my website and found it was already listed there as well!

Then I look at the website and am trying to find the injector controller and not the complete ECU system. I wonder if this is the right link...

[This message has been edited by ImprezaRS dot com (edited February 25, 2001).]

ImprezaRS dot com · 02-25-2001, 10:01 PM

Okay, try this http://www.sdsefi.com/eic.html

This is the kit...

Larry

Jessie James · 02-25-2001, 10:01 PM

Found it - http://www.sdsefi.com/eic.html

That's cool...

Jessie James · 02-25-2001, 10:16 PM

Heh - we both found it at the same time.

I actually had been looking at their systems for full control, but forgot about their EIC unit as a less expensive way to get started.

Have to send them a techy quesiton...

AaronB · 02-25-2001, 10:40 PM

I am very interested in seeing how your injectors work out Larry keep us informed

Jon Bogert · 02-25-2001, 11:20 PM

Quote:

With the RRFPR the quantity of fuel delivered under boost at 3,000 rpm is the same as at 6,000 rpm if the boost (and therefore the fuel pressure) is the same!

Larry, that can't be right. If that were true, the STOCK motor would be delivering the same amount of fuel at 6k as at 3k. At WOT the ECU follows it's WOT (no feedback) map, right? And this map certainly varies fuel delivery with RPM.

So, hypothetically, at 3000 RPM and WOT, the ECU tells the injectors to stay open 50% of the time, and at 6000 this increases to 80% of the time. The higher fuel pressure increases the amount of fuel that flows for any given injector on-time.

Am I right, or am I missing something?

Jessie James · 02-26-2001, 12:09 AM

Okay, I'm working on making a basic turbo kit, and would like to know if you have any ideas for a "Stage One" fuel computer for it.

What I mean by that is a computer that can be used in conjunction with the factory ECU to prevent running lean and fuel cut issues.

I've seen the JCSports torque chip, but JCSports can't seem to tell me anything about it other than the price and that they don't have any info on it.

I've also seen the Apexi S-AFC, but I would like to keep the price down somewhat lower than that, if possible.

If you have ideas, that would be great. If you have websites with product information (and wiring diagrams?) that would be even better. If you can point me to an outfit that sells them at the best price, that would be awesome!

Thanks!

8Complex · 02-26-2001, 12:26 AM

I think the Hyper-AFC is about $175 ($100 less then the Apex S-AFC). Beyond that, a rising rate fuel pressure regulator is probably your best bet, but still around $200.

8Complex · 02-26-2001, 12:27 AM

Just read that yours is a 2000... yeah, a S-AFC or Hyper-AFC won't work for you. The computer relearns the settings and it becomes useless between ECU resets. The RRFPR is the way to go in the 2000.

Jessie James · 02-26-2001, 12:38 AM

And that would be the only thing I need - no electronics? (To myself: "Sweeeeeeeeeeet!")

Can you tell me the names of one (or a few?) that would work well, and the manufacturers web site, or where I can get more info and prices? I'd really apreciate it.

ImprezaRS dot com · 02-26-2001, 10:57 AM

Hmmmm, Lemme think about this.

We're talking about MY00/01 here only. Normally the MAP sensor will see increasing vacuum at higher rpm on an NA car right? And, it only has fuel table values for up to about 2 pounds of boost (4,000 feet below sea level). Once the MAP sensor sees over 2lbs of boost, and sends more than 4.7 volts to the ECU, the ECU goes nuts not knowing what is going on. The JCS torque chip II limits the MAP sensor to 4.5 volts.

So, if we have a voltage clamp that prevents the ECU from seeing more than 4.5 volts from the MAP sensor, then the ECU will use the fuel tables for that MAP value. And, as RPM rises the fuel injectors would open more. And, you would be correct.

However, my understanding is that the injectors are wide open at this point, and there is actually pooling of gas next to the hot intake valve which is being vaporized to be used with the next time the valve opens (per Shiv again). So, if the injectors are wide open at 100% duty cycle, then they cannot adjust the fuel based on RPM. The question is, with the voltage clamp at 4.5 - 4.7 volts, what is the injector duty cycle and is the ECU still controlling the injectors because we are at <100% duty cycle under boost?

Larry

Jon Bogert · 02-26-2001, 11:18 AM

All I'm saying is that the stock ECU map must have provisions to supply adequate amounts of fuel at all loads at all RPMs. It may, for reasons of performance, dump extra fuel in at at WOT at 3000RPM, but it still needs to be able to supply enough at WOT at redline, too, right?

If you accept that, you would HAVE to tune the RRFPR to keep the motor alive at redline at full boost.

02-26-2001, 12:09 AM	#20
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Ideas for a cost-effective computer for a basic turbo kit? Okay, I'm working on making a basic turbo kit, and would like to know if you have any ideas for a "Stage One" fuel computer for it. What I mean by that is a computer that can be used in conjunction with the factory ECU to prevent running lean and fuel cut issues. I've seen the JCSports torque chip, but JCSports can't seem to tell me anything about it other than the price and that they don't have any info on it. I've also seen the Apexi S-AFC, but I would like to keep the price down somewhat lower than that, if possible. If you have ideas, that would be great. If you have websites with product information (and wiring diagrams?) that would be even better. If you can point me to an outfit that sells them at the best price, that would be awesome! Thanks!

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02-25-2001, 01:45 PM	#1
ColinL Scooby Guru Member#: 114 Join Date: Jul 1999 Chapter/Region: MWSOC Location: Wichita, KS and Whoring, OT Vehicle: '03 Evo, Rice White '01 Erion CBR 929	Buy something from Australia, there is a lot to pick from. Do a little legwork. Many Australian-made products available through US distributors are not as cheap as they should be considering the AUD / USD exchange rate. Just my 2 cents... * Registered users of the site do not see these ads.

02-25-2001, 01:51 PM	#2
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Yeah, I've seen quite a bit of them down there, but of course, I never bookmarked them at the time (didn't think I needed it.) So what about adding a hi-flow fuel pump instead - would that have the same results? Like a Walboro or the Holly that Shiv used? Wouldn't a hi-flow pump be a better bet in the long run because they could be more "stock" in installation, and function like the RRFPR? Then what about the MAP clamp I have been reading about - that would be required for a turbo, right?

02-25-2001, 01:54 PM	#3
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 16 WRX (white) 04 FXT (red)	You'd need a fuel pump and a fuel pressure regulator, the regulator will block the higher pressure from the stock pump so you need to be able to put a new regulator in and adjust the pressure from there. A Cartech/Bell RRFPR works well.

02-25-2001, 02:21 PM	#4
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Okay, so I found the Cartech.net website - nice - Then I noticed all the RRFPR seem to look the same. Does the MY00 Impreza have one already? If so, where is that thing? Thanks - this info is really helpful.

02-25-2001, 05:52 PM	#5
AaronB Worst Mod Ever Moderator Member#: 369 Join Date: Oct 1999 Chapter/Region: SWIC Location: Phoenix, AZ Vehicle: 19 CTS-V, 18 XC90 17 GTI	You want both a RRFPR and a hi flow fuel pump. I had just the RRFPR (actually a Vortech SFMU) and was only getting mid 60's out of my fuel pressure. I swapped in the Vishnu fuel pump and was getting over 90 psi with the same settings. I have since backed it down to mid/high 70's under boost. With just these two things your car will run pretty well at 5psi. Aaron http://www.azscooby.com

02-25-2001, 06:06 PM	#6
Midwayman Scooby Specialist Member#: 1997 Join Date: Jul 2000 Chapter/Region: MWSOC Location: Des Plaines, IL Vehicle: 2006 Acura TL 6spd STMGM6 alumni	Really? running out? Were you running lean? I understood that a fuel pump wasnt required until 7psi.

02-25-2001, 07:57 PM	#7
Jon Bogert Scooby Specialist Member#: 1133 Join Date: Mar 2000 Location: SE PA Vehicle: 09 GTR, 02 996 C4S 95 993 C4, 71 911, 04 STI	7psi is approaching the ragged edge for the stock injectors at ANY fuel pressure. I believe that you need a larger fuel pump--and higher fuel pressure--for anything over 2-3psi. Of course, some people are more comfortable than others playing on the ragged edge...

02-25-2001, 08:29 PM	#8
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Anyone seen one of those deals where you add a fifth (and sometimes a sixth) fuel injector to the system? Any opinions on that, functionally. I know it'll be a deal to drill into the manifold, but what are the performance issues, if any?

02-25-2001, 08:57 PM	#9
Adrian128 Scooby Specialist Member#: 3346 Join Date: Dec 2000 Location: Sydney,Australia	Microtech is quite popular here in Australia with people intalling turbo kits, or when they upgrade turbo systems. I am not too familiar with their computers, but I know the have a few different models. Some of them come with handsets for on the fly adjustments.

02-25-2001, 09:37 PM	#10
ImprezaRS dot com over boosted again Moderator Member#: 1458 Join Date: May 2000 Chapter/Region: RMIC Location: Colorado Springs CO USA Vehicle: 2017 WRX Limited 15 Forester XT, 21 Ascent	RS25.com - As stated above, with a MY00/01 turbo kit you need a RRFRP, fuel pump, MAP voltage clamp as a minimum. The JCS toque chip II includes the MAP voltage clamp, but also monitors speed and rpm increase over time (accelration) and adjusts fuel to achieve maximum acceleration - but once the injectors are wide open under boost, it is still up to the RRFPR to push more fuel through the stock injectors (since the MAP voltage is maxed out and clamped). The stock injectors, with fuel pressure in the mid to high 70's will support about 7 psi and 240 hp, but the stock fuel pump can't push that much pressure unless maybe you put vice grips on the fuel return line The stock 280cc injectors flow about 330cc at 80 psi (per Shiv at www.vishnuperformance.com ), and someone else calculated that this 1320cc of fuel was good for 240hp max. You asked about accessory injectors. I have just now bought a used Simple Digital Fuel Injector kit (from Canada), being installed next weekend. This adds two 440cc injectors with a control module that adjusts fuel based on both BOOST and RPM. This will eliminate the need for a RRFPR, but still requires the high flow fuel pump. They cost $465 plus shipping when new for the whole kit with module and injectors. The beauty of this kit is the fact that it varies fuel delivery based on RPM as well. This brings up a major point I am learning about the RRFPR on a MY00/01 - With the RRFPR the quantity of fuel delivered under boost at 3,000 rpm is the same as at 6,000 rpm if the boost (and therefore the fuel pressure) is the same! Think about it - the injectors are already as wide open as the MAP voltage clamp will allow. So 5 pounds of boost resulting in 75 psi fuel pressure pushes a certain amount of fuel into the motor, no matter what RPM you are at you get the same amount of fuel through the injectors. You cannot get less fuel at 3,000 rpm than at 6,000, unless you can decrease the amount of boost the RRFPR sees at lower RPM. So, you can tune it for good midrange power or good top end power, but not both. This is with a MAP based MY00/01 only, not the older MAF equipped models. Once we finish development on our ScoobyRacing boost referenced ITC, we will work on a boost controller. I mention this here because we are considering including a device to send less boost signal to the RRFPR at lower RPMs as well, thus allowing more precise fuel delivery with an RRPR installed. They could all work off the same pressure sensor in the ITC and piggyback to each other, thus reducing the costs! I'll keep you posted on these new products in the near future. Larry www.ImprezaRS.com

02-25-2001, 09:42 PM	#11
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Larry, do you have a web address for that Simple Digital system you are mentioning? I would love to review and research what they are doing. That fuel issue is a bummer! Not much good for turbos! Thanks for the huge reply!

02-25-2001, 09:53 PM	#12
ImprezaRS dot com over boosted again Moderator Member#: 1458 Join Date: May 2000 Chapter/Region: RMIC Location: Colorado Springs CO USA Vehicle: 2017 WRX Limited 15 Forester XT, 21 Ascent	I am working on getting the URL... It is not simpledigital.com, simpledigital.ca, or simpledigital.co.uk Larry

02-25-2001, 09:54 PM	#13
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Too cool - I really appreciate it. As you can tell I am in the process of educating myself as much as possible before I make the leap to do this turbo kit.

02-25-2001, 10:01 PM	#15
ImprezaRS dot com over boosted again Moderator Member#: 1458 Join Date: May 2000 Chapter/Region: RMIC Location: Colorado Springs CO USA Vehicle: 2017 WRX Limited 15 Forester XT, 21 Ascent	Okay, try this http://www.sdsefi.com/eic.html This is the kit... Larry

02-25-2001, 10:16 PM	#17
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	Heh - we both found it at the same time. I actually had been looking at their systems for full control, but forgot about their EIC unit as a less expensive way to get started. Have to send them a techy quesiton...

02-25-2001, 10:40 PM	#18
AaronB Worst Mod Ever Moderator Member#: 369 Join Date: Oct 1999 Chapter/Region: SWIC Location: Phoenix, AZ Vehicle: 19 CTS-V, 18 XC90 17 GTI	I am very interested in seeing how your injectors work out Larry keep us informed

02-26-2001, 12:26 AM	#21
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 16 WRX (white) 04 FXT (red)	I think the Hyper-AFC is about $175 ($100 less then the Apex S-AFC). Beyond that, a rising rate fuel pressure regulator is probably your best bet, but still around $200.

02-26-2001, 12:27 AM	#22
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 16 WRX (white) 04 FXT (red)	Just read that yours is a 2000... yeah, a S-AFC or Hyper-AFC won't work for you. The computer relearns the settings and it becomes useless between ECU resets. The RRFPR is the way to go in the 2000.

02-26-2001, 12:38 AM	#23
Jessie James Scooby Specialist Member#: 2072 Join Date: Aug 2000 Chapter/Region: MAIC Location: Out of my mind	And that would be the only thing I need - no electronics? (To myself: "Sweeeeeeeeeeet!") Can you tell me the names of one (or a few?) that would work well, and the manufacturers web site, or where I can get more info and prices? I'd really apreciate it.

02-26-2001, 10:57 AM	#24
ImprezaRS dot com over boosted again Moderator Member#: 1458 Join Date: May 2000 Chapter/Region: RMIC Location: Colorado Springs CO USA Vehicle: 2017 WRX Limited 15 Forester XT, 21 Ascent	Hmmmm, Lemme think about this. We're talking about MY00/01 here only. Normally the MAP sensor will see increasing vacuum at higher rpm on an NA car right? And, it only has fuel table values for up to about 2 pounds of boost (4,000 feet below sea level). Once the MAP sensor sees over 2lbs of boost, and sends more than 4.7 volts to the ECU, the ECU goes nuts not knowing what is going on. The JCS torque chip II limits the MAP sensor to 4.5 volts. So, if we have a voltage clamp that prevents the ECU from seeing more than 4.5 volts from the MAP sensor, then the ECU will use the fuel tables for that MAP value. And, as RPM rises the fuel injectors would open more. And, you would be correct. However, my understanding is that the injectors are wide open at this point, and there is actually pooling of gas next to the hot intake valve which is being vaporized to be used with the next time the valve opens (per Shiv again). So, if the injectors are wide open at 100% duty cycle, then they cannot adjust the fuel based on RPM. The question is, with the voltage clamp at 4.5 - 4.7 volts, what is the injector duty cycle and is the ECU still controlling the injectors because we are at <100% duty cycle under boost? Larry

02-26-2001, 11:18 AM	#25
Jon Bogert Scooby Specialist Member#: 1133 Join Date: Mar 2000 Location: SE PA Vehicle: 09 GTR, 02 996 C4S 95 993 C4, 71 911, 04 STI	All I'm saying is that the stock ECU map must have provisions to supply adequate amounts of fuel at all loads at all RPMs. It may, for reasons of performance, dump extra fuel in at at WOT at 3000RPM, but it still needs to be able to supply enough at WOT at redline, too, right? If you accept that, you would HAVE to tune the RRFPR to keep the motor alive at redline at full boost.