Scooby2.5

We may not have tested the difference with a good pos battery feed with each module.

We didn't figure out until way later to go is direct to the pump and neg off the module with larger wire.

It was zorro that did it first and Shawn found it in that NASIOC thread.

I was initially going to feed the module more voltage direct (since the original feed was such tiny wire and a 2 volt drop) and then from the module to the pump on the pos lead as well

This is where you saw more of a difference in the modules depending on what you fed it.

I think the better way is pos from battery and relay straight to pump and neg from module.

That way you don't have voltage drop across module on pos lead but you still have PWM "ground"

Found one more FPCM A/B comparison...

Or this one, finding 11.6v stock...

 

So Shawn picked up .2V to .3V but again that was with stock wiring like Scooby2.5's results. I'll see what the differences are for both modules on the upgraded wiring when I get mine.

 

I swear there was one more set of measurements somewhere else - someone was getting 14v, but maybe that was the alternator reading - I just can't find it

I think it was coldscooby (sp). He had an alternator with higher output.

Shawn changed his alternator as well at some point and it put out 14.2

Another factor is using a meter. A PWMS needs to be looked at with a scope

With the meter, test it by checking it from pos on pump and then to chassis ground. See what voltage is actually at the pump.

Then check it from pos on the pump and on neg (PWM) coming from the module.

This reading will be an AVERAGE reading unless you look at it with an O scope

Find the thread on NASIOC, we posted a link to it in the other thread. It actually showed some scope readings and what the neg lead waveform looked like.

It seems that with good voltage going to the module we saw about .5 to .7 more out of the STI module than the the legacy module. It was way more expensive as well in the 04-07 years

Just remember though depending how good your meter is etc it's averaging the reading to "ground" because of the PWM signal it sees on the neg lead from the module.

Its sort of a floating ground

I'm going to get my O scope out one if these days and take a look at it myself

Forester blogger's Alternator Diode fix - nicely done.

 

Much more involved, and one of the reasons that the HBK PTC MK3 Diode/Fuse costs what it does.

Yea I followed this thread to make my first one but just wanted something more clean. When I found out the MK3 was a resettable fuse I decide it was worth it. Very fine piece.

If we could get some vendor on here to stock these and get a handful of them we might be able to cut the cost. Some of the expense is the crazy certified shipping from Australia

This was my concern as well, otherwise the FPCM is "neutered".

 

Believe that B+ is where the relay power (from the stock FP Relay) comes in so it looks, as least on paper, that the FPCM still has +12V from that source. Am I missing anything? Will attempt a re-perusal of the wiring diagrams posted earlier in the other thread to see if I can identify the specific FPCM pin-outs. If someone has the time to do this, it may be a while before I can get to it.

Check the initial thread I think all this data is in there with factory wiring diagrams and everything.

Fuel Pump plug only. I didn't look into the FPCM pins, since they need to be spliced/tee'd anyway. Correct me if I'm wrong, but you still want +batt power to the FPCM for proper PWM manipulation of the ground wire.

Yes this is correct. It would be nice to have the pins for this though.

You could crimp your splice right to the pin.

I think I did that I'd I remember correctly. I was cannibalizing pins from a spare STI pigtail like the one in the picture above with the keys

I'm cool if we want to call out 12ga in the diagram. It's what most will use, especially if they are going straight to the pins.

 

 

 

I've got a couple posts up front to work with, I'd like to convert one to a "Variations" post. Help me with the list fellas. Comments in italics.

 

 

1. FPCM upgrade - I still think this could be considered optional, I saw a massive improvement even with the stock module.

a.

22750AA010 Module

- Performs better than stock LGT module (

22648AA081

)

- Have we quantified this yet? I can when I get mine...

b.

22648AA140 Module

- Performs better than stock LGT module (

22648AA081

)

- Have we quantified this yet?

2. Wire directly to connector pins

a.

New pins from Sumitomo

- for fuel pump housing plug

b.

81803FG010 12ga Pigtail

- for FPCM plug

c. Salvage OEM pins from existing connectors

3. Alternator sense wire diode mod

a.

HKB MK3 diode fuse

or (

DIY alternate

)

b.

Diode spliced into alt sense wire

 

Others?

Calvin Dotson (Cobb Plano Tuner) and I quantified the difference between the two modules. I think I reposted it earlier in this thread. I'm running around for work today so I can't look but if someone has time and can look in this thread or the original thread and repost that would be great.

I think in the other thread it's in the first few pages.

Ooops MK3 from HKB, the diode fuse.

By the way it is expensive but if you factor in all they did to get it made and where it has to ship from its not too bad.

Plus its a resetable un-blowable fuse. It will last forever.

updated wiring diagram with changes incorporated. Thanks everyone for the input on this. Lmk if we need to fix anything else. Can create alternative solutions as well, just let me know what you want/need.

impressive!!!! Love it!

Yes, it's not like the stock wiring is burning up as it is, but if the idea is to eliminate as much voltage sag as possible bigger is always better.

 

Taking a look at the admittedly academic example below, anyone wanting to do this mod can determine their own point of diminishing returns and pick a gauge to go with.

Yea I understand the math BUT, 10ga massive wire into the connector pins, through the fuel pump rubber plug etc etc is not worth .2 volts. I am not sure you would even see that much drop on an actual meter.

If you want to pick up a few more tenths of a volt do the diode mod.

13.8 is low for a alternator anyway hence the reason the toyota guys came up with the HBK fuse.

If you have a Braille battery like I do, 13.8 isn't even enough to charge it well according to the Braille specs.

I used 12ga throughout my whole modification.

has anyone used the DW kit yet? or recommend it?

I did and with the pigtails on the socket it was long enough. you can see my pictures earlier in this thread I believe.

^ I am about to place an order with Waytek for the relay/socket/fuse/wiring. I think DW's kit is overpriced and who knows what quality relay they are including. I will add part #s.

 

Btw, I think pins/crimping is definitely the way to go. I have been always under impression that soldering wires is not recommended for car environment.

Relay seems to be top notch from what I saw. I installed the DW kit.

I am an EE major and work for a one of the 4 main Xray companies Toshiba.

I deal with this stuff all the time and the stuff from DW and Aeromotive seemed to be great stuff.

I personally would crimp and solder the pins but thats just me. I did that as well as heat shrink wrap the connections.

To each his own though.....

Give credit to Zorro, for doing this and figuring it out first. When it comes to wiring direct to the pump on the pos side and then leaving the neg PWMS alone.

IMHO 10GA:eek: wire is complete overkill for a 13.7 15-20a circuit. 12ga is more than adequate and fits in the pins much better.

Any lockout cable with a STS, like from Cobb etc will need to be tie wrapped.

The cable is made for the length of the shifter down through the hole to the transmission.

If you shorten any part of that the cable is long.

I had the STS from STI for a spec b and installed it with my tranny swap.

It was fine until I installed the Cobb STS.

Just go to Cobb website and look up spec b 6 speed STS. One you find it there is a link for the instructions PDF

That's what I placed the link to. Not sure why it's not working

By the way franz where did you source the pins. Id like to get some. I cannibalized some other connectors to get mine but would love to have some.

I think it was you that found them?

The factory fuel pump relay is in the passenger kick panel. Might be trickier to run the wire from there to the FP, but maybe not. You still have the problem of the voltage drop through the FPCM harness.

 

Has anyone experimented with running the PWM voltage+ signal from the FPCM straight to the new relay sense input? Most relays have a 25ms delay so with a high frequency PWM signal, the relay should stay latched and not care. I am considering trying this out first. I ran the 12AWG wire from the battery to the fuel pump area. I'm going to perform this experiment this week with extra long wire in case it doesn't work out. Also, a small shunt capacitor could be added to level out the PWM voltage if the relay doesn't stay latched closed.

First the positive leg is not PWM, only the negative lead out of the module is.

See original thread.

Second someone did that in the other thread and sometimes the new relay would not turn on.

Its in the last few pages.

Why everyone is trying to come up with a different way to do this all the time is baffling me.

Even the pump manufactures are providing drawings on how to do this for their pumps. The only thing different we are doing is leaving the FPCM in the circuit.

Why we have two threads to keep track of now on the same exact subject is irritating.

We could have just put the write up that was done at the beginning or end of the other thread

Did anyone consider running a thicker wire from the factory fuel pump relay to the FCM (and then from FCM to the pump)? Essentially replacing the wiring only and avoiding the extra relay? One less thing to malfunction (and the generic relays are often of dubious quality).

If you add the relay for wiring direct to the pump it really is not changing it much from stock.

Stock has a keyed on relay. So power to the coil on the relay and direct feed from that relay to the FPCM.

With that said as small as the wire is feeding the stock relay I would guess that the rating on that relay is pretty small and wouldn't handle the voltage and current draw of the larger pumps.

The way it's being wired now we are just using the old one as a key on signal for turning on the new relay so it should be fine.

Purchase one of the premade kits from DW or aeromotive. Both seem to have good wire and the relays seem robust

Last night I installed a Spec.B reverse lockout cable on the 2010 STi transmission in my '09 LGT so it would work with my Cobb Spec.B adjustable STS. I can confirm that the Spec.B cable is definitely a couple of inches longer than the STi cable.

 

I drove for about 5 miles & heard some rubbing noise from the cable on the driveshaft... the cable needs to be longer, but the STS positions the cable lower than on the stock shifter, so there's a lot of slack. The damage surprised me... a clean ring around the driveshaft where the paint scraped off, and a chunk of plastic gone from the cable housing. No good, but no need to replace anything. I hung it up with two zip ties & will try it out today.

From the Cobb instructions......

9. Go under the car and release the reverse lockout cam so that it can operate. Check the reverse lockout operation in the cabin at this time to ensure proper function. If you will be setting the height of the shift lever short, you will have to use zip ties to keep the reverse lock- out cable from contacting the drive shaft as it did on the test car in the below picture. Setting the height in the higher ranges may not make this a requirement. Due to the geometry changes and how they may affect this cable, COBB Tuning is not responsible for any damages to the cable or driveshaft if you do not check the clearance and secure the cable if necessary.

There is even a picture:

http://www.cobbtuning.com/Double-Adjustable-Short-Throw-Shifter-LGT-Spec-B-p/224316.htm

Click on the link for the instructions the picture is in there

This may be a stretch, but thought I'd also post here:

 

P0171 code 3 times in 3 days.

 

Only @ 27-2900rpm cruising freeway speeds and very light throttle. Afr gauge will pop up to 15 from the cruising 14's.

 

Who wants a guess why I don't have fuel at light throttle??

 

ID 1000 complete top feed conversion, w their fuel line kit, oe fpr and dw 300 pump in Modded basket and has been run this way since last February. It doesn't run lean @ wot, just very light throttle.

 

Additional info: temps just dropped dramatically from 90's daytime to 60's max (but tune was done in the 60's anyways) and at idle my volts gauge drops to 12's or even 11's when in gear, at idle at a stoplight and HID's and factory radio are on....

 

Other than testing for vac/air leaks, looking for where to look next.

Wow with your setup If I I would get the wiring kit from DW and follow this thread and rewire your fuel pump direct from the battery. Then rewire from the neg on the FPCM to the pump.

Aftermarket pumps are flow rated at about 13.5-13.7 volts

Also if you measure less than 13 volts at the battery with the car running you have a really weak alternator.

I'd do the diode trick and if you don't want to do that replace the alternator. Maybe even do both.

I'm not sure why you are having partial throttle problems but it can't hurt to fix the voltage to the pump. Especially running 1000's

Is this still only needed for E85 and over 350hp?

 

Not needed for DW65c and DW740's with a VF52 on 93?

 

I just bought the DW wiring and the STi FPCM then read the 36 page post...

 

Great job on the walkthrough though!

I would do it as all aftermarket pumps are rated at about 13.5 volts

So, by doing this it gives the fuel pump a constant 100% power, or it still does the 33,66,100% power?

It depends on whether you keep the stock or STI FPCM in the circuit or just rewire direct to the pump

Read the last half of the thread and you will know your answer

Did any of the vehicles have the ground mod upgrade? Or has anyone tested the voltage at the pump with a ground mod on their LGT?

I'm amazed that the first quote you use from this whole thread is an early one during the verification stage of this problem

Are you talking about the grounding kits people use under the hood?

How would this affect the neg PWM signal coming from the FPCM to the fuel pump?

The voltage drop is because of the voltage feed wire to the module being too small, and the wires from the PWM module both neg and pos being too small.

It's funny, I have followed this thread back when Hammer Down and NSFW had separate threads, before I even had an account here, and always wondered why it was so difficult to find the SpecB axles, besides the limited production of the car. Now it makes more sense.

 

Does anyone know the differences between the SpecB and STi versions of the Cobb STS? Trying to determine if one or the other is necessary with my 05STi 6MT that is going in this coming weekend. Same with stainless steel clutch lines, does anyone know if I need a SpecB specific part? I have tried to search these forums and spent a good amount of time cross-referencing on opposedforces.com, but I haven't been able to find anything conclusive for either question. Any help is greatly appreciated. And if I have missed something in my searching, feel free to let me know that I should have looked harder.

I had all the Cobb shifter stuff in my 5 speed as well, loved it.

 

I actually just removed my Kartboy (Cobb) front and rear shifter bushings from the 6 speed. The noise in the first few gears into the cabin is pretty bad in a 6 speed.

If I didnt drive my car every day and about 25k a year I probably would have left them. My car is already loud with the Cobb exhaust.

 

I just purchased and installed stock STI shifter bushings from a brand new STI that someone removed on NASIOC.

 

I then installed a Cobb double adjustable STS. I love how short you can get the throw and still adjust the stick height.

 

This combo is perfect IMHO. The Cobb Shifter stiffens everything up (no rubber in the stick) and the STI shifter bushings keep thing somewhat stiff yet quiet.

 

If you decide to get the Cobb Shifter for the 6 speed, you order the Double adjustable for the SPEC B.

 

The only difference in the STI vs Spec B Cobb shifters is how the boot attaches.

 

The way the legacy and Spec B shifter boot is you need the Spec B Cobb shifter

 

Here is a portion of Ian armstrongs email to me:

 

"Greg,

 

The only difference between the 215315 STI shifter and the 224316 Spec B shifter is the top rod. On the STI, the shift boot holder screws in from underneath, so our happy shaft has provisions for this. The Spec B shift boot holder screws in from the side. Therefore, the shaft has a thicker portion where this screws attach to. Therefore, you'll just need to determine how your shift boot holder attaches, and order the appropriate one. If you have any other questions, please let me know. "

 

Here is a video of what a newer STI transmission sounds like with the Cobb/Kartboy bushings