Project Thread Project SC400TT

[cribbj]

Gang, it has been several weeks since I updated you on the mechanical aspects of my project…So here's an update of my progress… I have resolved the fuel pump wiring. Instead of running two separate fuel pump outputs and leads from the SM4, I decided that I would only use the main default output to run both pumps simultaneously. The default fuel pump output on the SM4 is now connected to both pumps and I split the trigger wire to both relays (one to each pump), and it is working perfectly. Both pumps stay off until I turn on the key, then the ECU primes both pumps and shuts them off until I start the motor. I think the secondary output that was reprogrammed lost its programming, perhaps after the ECU was re-flashed. Anyway, I will always run both pumps instead off staging them. Probably safer anyway. Now I have only to complete the installation of the water/meth injection, and connect the boost gauge. Btw, the base map is running well, and should be good for non-boosted driving. It is still a bit rich, but I will lean it out am little this weekend. I adjusted the idle set screw because the idle was very low (450 rpm), once I did that, it stopped idle hunting. I'm planning to drive the car this weekend. Final tune should be within a few more weeks. If the drive goes well this weekend, I will drive it over to Tampa for the final wet sand, buff, and repaint of the front fender.

Ryan

Ryan, be careful running both those simultaneously, all the time at 12v. You're going to be bypassing an incredible amount of fuel at idle & cruise. Be sure your return line is up to it, and your tank venting is too. You're going to have "a lot" of vaporisation.

If your return system isn't man enough to handle all that fuel, it'll cause a restriction, which will cause your FPR to go nuts, and you'll be running rich at idle and cruise. If you lean it out to compensate, then you'll be too lean under heavy boost = very dangerous.

You know that I'm a Kenne Bell BAP fan, and for me, that's the best solution, however failing that, if you've run out of outputs on the Autronic, you could always trigger the 2nd pump with a simple Hobbs switch set to 5-10 psi.

 

[SC400TT]

Ryan, be careful running both those simultaneously, all the time at 12v. You're going to be bypassing an incredible amount of fuel at idle & cruise. Be sure your return line is up to it, and your tank venting is too. You're going to have "a lot" of vaporisation.

If your return system isn't man enough to handle all that fuel, it'll cause a restriction, which will cause your FPR to go nuts, and you'll be running rich at idle and cruise. If you lean it out to compensate, then you'll be too lean under heavy boost = very dangerous.

You know that I'm a Kenne Bell BAP fan, and for me, that's the best solution, however failing that, if you've run out of outputs on the Autronic, you could always trigger the 2nd pump with a simple Hobbs switch set to 5-10 psi.

Thanks John. I appreciate the information.

That may explain why I am running about 10.5 on the AFR, when I should be at 14 or leaner at idle. I am using the stock hard return line with a hard line AN fitting connecting the -6 SS hose coming out of the FPR. I know I need to vent the fuel cap, as I have eliminated the charcoal cannister, and blocked that off. John, do you know of any particular type of vented Fuel cap I should look for? Any other suggestions are greatly appreciated.

I left that second trigger wire attached to the SM4, so I could look into reprogramming that output again, if I decided to go back to the staged pumps.

When I was originally working this out, I connected the reprogrammed output to the fuel pumps, and everything worked properly, until I connected the PCS transmission controller, and left it connected to the main harness. The the pumps then grounded out and ran contiunuously, even with the key off. There should be no correlation between the secondary fuel pump output on the SM4 as it is not connected to the PCS, but directly to the SM4. I could not determine why this was happening. I must also note that at that time, I had not yet connected the default Fuel Pump Output lead to the pumps, so that is what I did yesterday, while disconnecting the secondary output from the SM4, and everything worked correctly. The fuel pumps stayed off until the turned the ignition on, then the SM4 sent the signal to prime them for a moment, and they shut back off. I then started the car, and the pumps came back on and ran continuously.

Again, as I noted, I disconnected the lead from the secondary output to the pumps, and just left it there so I can still come back and change it if I decide to. Some are greatly concerned about staging the pumps due to a potential failure of the secondary pump to come on at high boost, thereby creating a lean condition at high boost, which would be dangerous indeed. The thing is, I believe the Autronic can see this failure, and I believe it can put the motor into a limp mode if this happens and save the engine.

Thanks,

Ryan

 

[cribbj]

I would keep the charcoal canister - it serves a very useful purpose, and doesn't detract from engine performance. You definitely don't want the tank sealed, because the combination of bypassing too much fuel, and vaporising it, will cause pressure to build in the tank, and again, your FPR is going to go nuts. That return line "must" have an atmospheric return, and if it doesn't, it's going to cause the FPR to raise the backpressure on the fuel system by the same amount. If you don't already have one, I'd highly recommend you get a fuel pressure gauge so you can monitor what's going on at the rail.

Toyota normally vent the Supra canister to the intake manifold with a VSV, but what I've done with mine is vent it to the intake manifold via a check valve, and that keeps the garage smelling OK. The check valve opens under engine vacuum, and closes under boost, so the tank and canister stay vented under the right conditions. If you use a vented cap, your garage will start smelling pretty nasty and wifey probably won't like it very much.

I know nothing about Autronic programming, but I doubt if there's any way for it or any other ECU to "know" whether the 2nd pump is working or not, short of sensing its fuel flow or its current consumption.

What it may be capable of, however, is sensing a too lean condition under boost, and then popping the wastegates open, or taking some other executive action like cutting ignition, etc.

BTW, I'm not a big fan of Walbro's, and they ARE known to fail unexpectedly, so you might want to consider returning to the Denso(s) or go to Bosch's. Frankly, unless you're shooting for triple digit HP, I think a single Supra Denso pump and a Kenne Bell BAP should be all you need. I've had that combination tested at RC Engineering and it's proven to flow 800 HP of fuel. And I'm sure the Autronic, like the AEM, probably has some PWM outputs, where you can control the "average" voltage the pump sees, so you could send it 8.5 or 9 volts at idle, then go up to 12v for normal acceleration, and 16 or 18v for high boost.

 

[XR8tt]

Imo one of these with controler ..
http://aeromotiveinc.com/products-page/fuel-pumps/11101-a1000-fuel-pump/

If it fails the engine stops...

 

[SC400TT]

Imo one of these with controler ..
http://aeromotiveinc.com/products-page/fuel-pumps/11101-a1000-fuel-pump/

If it fails the engine stops...

That is my plan if I decide to change out the Walbros.
Ryan

 

[spf_lexus]

I grabbed a Marshall 100psi liquid silicone fuel pressure gauge and a adaptor bolt and mine threads into the stock "fuel-in" line by deleting the small fuel filter that mounts at the rail. $50 total for the gauge and the through-bolt. I threw the old rubber fuel line + banjo for aeromotive banjo + ss line but the stock fuel banjo works fine. Hope this helps:





Sorry for the large pics but this setup for me was the easiest/cost effective way to add a the fuel pres. gauge

 

[stevechumo]

John's recommendation on the Supra TT Denso fuel pump for is good. That's a quiet and high capacity fuel pump.

 

[SC400TT]

I do not have the stock pump in my car anymore. I have a custom made Billet, double fuel pump holder made for the SC and for Walbro's. It has cups sized to fit the Walbros perfectly, and I had to modify it so that I could plumb through the outer cap with AN fittings so there would be no leaks. I have already built part of the fuel system around it. I am not changing now, even though I do appreciate all the suggestions. I don't have chinese knock-off Walbros, because I got them from a reputable dealer that I know makes sure they only buy OEM products.

I have gotten to the point that I am not changing anything further at this point, as I will never get the car done if I continue. Again, I do appreciate the suggestions, and I take no offense guys, so keep sending and writing your honest opinions. I do have a gauge for my Aeromotive FPR, and I have a DEFI FPR as well, so I can watch my fuel pressure at all times.

Ryan

 

[SC400TT]

My return is similar to yours, Except that I do not have the stock rails, so I do not have to deal with the banjo fitting like you did. Here is my basic fuel system:

• Dual in-tank Walbro 255's, each connected to -6 SS lines which connect to a billet Y Block with (2) -6 connections merging into a -10 single outlet.
• I run the -10 uner the car next to the stock hard lines, with (2) Summit Billet fuel filters, one is a pre-filter.
• The -10 connects to another Y Block that converts from a -10 to (2) -6 Fittings.
• from the Y split, I run a single -6 into the back of each custom billet rail, which has 8 900 cc Delphi injectors in place.
• I run a -6 out of the front of each of the rails into the FPR.
• Then I run a _6 out of the FPR and connect it to a flared hard end AN fitting onto the stock Hard line return.

That is pretty much it, in s nutshell.

Ryan

I grabbed a Marshall 100psi liquid silicone fuel pressure gauge and a adaptor bolt and mine threads into the stock "fuel-in" line by deleting the small fuel filter that mounts at the rail. $50 total for the gauge and the through-bolt. I threw the old rubber fuel line + banjo for aeromotive banjo + ss line but the stock fuel banjo works fine. Hope this helps:





Sorry for the large pics but this setup for me was the easiest/cost effective way to add a the fuel pres. gauge

 

[Zuffen]

My new set up is very simillar to yours.

The only real difference is I feed into the front of the rails and out the back of the rails.

My tuner had me swap mine from rear in front out as he said it would affect the way the fuel flowed into the engine.

Can't see it myself but he's built and tuned a lot more performance engines than me so who am I to argue. It was simple change so I did it.

 

[JustenGT8]

For what it's worth, i run the stock in tank EFI pump as a lift pump to a surge tank. The surge tank supplies x2 044 pumps in parallel which feed a -8 line to the fuel rail. -6 lines join the rail front and rear and a SARD reg (off one of the stock dampner ports) handles return line duties via a 8mm hard line.

I've run this setup for 5 plus years on the street and track with no issues. Pumps a re a tad noisy but i have no insulation or much in the way of rubber mounts so you could make them a lot quieter if needed.

ECU just controls a bunch of relays that feed each pump individually.

Return line runs to the surge tank with an overflow from the surge tank back to the main tank. I have no issues with heated fuel etc etc.

This was a bit overkill for my hp goals and even 400rwkw was easily handled. About to switch to E85 which will test it a bit more i think.

Anyways, just some info if it helps.

For the record, i don't like walbro's. They are the small dia pumps and have to work much harder than the larger diameter style pumps like the 019s, 044s etc. Yes they work, but so do carbies

 

[Mandrel]

^^ So you have one pump per rail? Then they meet at a fpr after?

 

[SC400TT]

My new set up is very simillar to yours.

The only real difference is I feed into the front of the rails and out the back of the rails.

My tuner had me swap mine from rear in front out as he said it would affect the way the fuel flowed into the engine.

Can't see it myself but he's built and tuned a lot more performance engines than me so who am I to argue. It was simple change so I did it.

I have not had anyone mention that to me Rod, and so far, it does not seem to be an issue. If it becomes one, it would be easy to switch around.

For what it's worth, i run the stock in tank EFI pump as a lift pump to a surge tank. The surge tank supplies x2 044 pumps in parallel which feed a -8 line to the fuel rail. -6 lines join the rail front and rear and a SARD reg (off one of the stock dampner ports) handles return line duties via a 8mm hard line.

I've run this setup for 5 plus years on the street and track with no issues. Pumps a re a tad noisy but i have no insulation or much in the way of rubber mounts so you could make them a lot quieter if needed.

ECU just controls a bunch of relays that feed each pump individually.

Return line runs to the surge tank with an overflow from the surge tank back to the main tank. I have no issues with heated fuel etc etc.

This was a bit overkill for my hp goals and even 400rwkw was easily handled. About to switch to E85 which will test it a bit more i think.

Anyways, just some info if it helps.

For the record, i don't like walbro's. They are the small dia pumps and have to work much harder than the larger diameter style pumps like the 019s, 044s etc. Yes they work, but so do carbies

Justen, when have you ever not overcompensated???

^^ So you have one pump per rail? Then they meet at a fpr after?

Well, I have two pumps and two rails. But they are run in parallel with each other, and flow into a single hose, and split back into separate hoses to feed each rail...So kinda, sorta...

Ryan

 

[SC400TT]

A question for you guys:
Should the IAC be connected to the charge tube, or opened to atmosphere with a filter attached to it?

Thanks,

Ryan

 

[stevechumo]

A question for you guys:
Should the IAC be connected to the charge tube, or opened to atmosphere with a filter attached to it?

Thanks,

Ryan

I connected mine to the TB before the bufferfly plate.

 

[SC400TT]

I connected mine to the TB before the bufferfly plate.

Thanks Steve. Close up pic please?

Ryan

 

[SC400TT]

The AquaMist Water/Meth System is installed, tested, and working. A huge thanks to Dan Osypian!! Great job, my friend.

We had a few snags with the wiring, but all is well, and I am finished with wiring, except for the Autronic Reluctor that converts the analog speed sensor signal to a Hall signal so that the Autronic Traction Control can function.

The reluctor is on its way to me, and I am almost ready for the tuner.

I did not drive the car last weekend, but I do plan to drive it this weekend. I will keep you all posted!!

Ryan

 

[cribbj]

A question for you guys:
Should the IAC be connected to the charge tube, or opened to atmosphere with a filter attached to it?

Thanks,

Ryan

Ryan, I tried to reply the other day, but kept losing the Internet connection.

In my 2JZ Supra, I had the stock IAC going to atmo with the little K&N filter. I didn't like it, and thought it really detracted from the appearance of the motor.

I'd either plumb it to the intake, or consider going with a Ford or Chev TB that has an integrated IAC. Very clean solution.

 

[stevechumo]

Sorry for the delay Ryan. I circled the IAC and its line.

 

[SC400TT]

Thanks Steve. I see how you did it. Are you still running your MAF?

I have posted a pic of my IAC and how it is plumbed into the Charge Air Tube. I don't see that this would present a problem.



Ryan