Joel's LS1 FC parts list/swap thread (remixed)

[largeorangefont]

@frijolee Saw I missed your call last night bud. I'll give you a buzz today!

[frijolee]

Okay, in addition to the Magnum F plans (still looking more McLeod RXT feedback if you have it), there's a couple more issues to solve and I could use a sanity check from folks who have gone before.

The Wahlbro 400 fuel pump is rated at 13-18A.  My multimeter reads 0.7 ohm at the pump connector which implies 20A at 14V.  Either way it's a bit too much for the stock 16 gauge wiring (might be 18, I'm eyeballing).  I burned up a relay at autocross.  It happened to me once before so I had a spare.  Installed that, got one run in, then it failed too.  These were all just stock Mazda relays I'd wired in (free was too appealing).  Contacts on the power side seem to have a bit too much resistance so they heat up and corrode, which creates more heat and eventually it spirals.  The connector failed before the fuse popped, but either way it's marginal.

No bueno.


The cut wires and duct tape isolation?  Yeah, that was me striping wires with a knife and hard wiring the halves together... in the rain between runs.      I missed one run but the dudes at my autocross are chill bruthas, so they let me take a bonus run at the end rather than giving me a DNF.  Didn't matter because my car is a HANDFUL in the rain so I wasn't fast, but hey, still cool of them and it's good to practice that kind of car control.  It at least got me home, but I was thankful for the breaker at my battery (controversial subject for some but I still like it).  At the moment if the battery is connected the pump is running so dead battery potential is high.  Obviously not gonna leave it this way and have until Nov 22 to square it away before the next event.

The piece that has me scratching my head a bit is what to do at the ends.  This guy--https://www.youtube.com/watch?v=fix3a2sKkQw--does a good job laying out the system and talking about a few versions of rewiring.  Downside, he's only ever tapping into the fuel pump connector's stock wiring, so he does nothing to address in tank wiring.  I've never had a problem at the tank's bulkhead connector, but if the stock mazda relays contacts had issues I'm not especially inclined to trust the stock stuff back there, particularly if the failure mode is an excess generation of heat.

Fuel pump hanger doesn't have a lot of space to work with if I bought an ATL two wire bulkhead fitting (https://www.summitracing.com/parts/abt-cfd-504?).  Here's mine pulled out as of last night.



It seems like the only place left for me to put a larger bulkhead fitting would be to drill out the entire existing bulkhead and find a 4 wire bulkhead.  That sucks and the wire sizes are so specific for the tank level sender and warning light I'm not sure it can be done.  Anyone else do this with success? 

The alternative I'm thinking about would be to run a single wire bulkhead for the power lead to the pump, then upsize the ground to the hanger hat (you can see it in the pic above).  It's just a ground so if run a bigger wire to the hat internally then I can add extra grounding to the hat externally as well.  Any downsides to this thinking?  Anyone know for sure if the FC fuel tank is already grounded?  I would assume yes, but I don't know for sure.  Running an extra wire externally seems like cheap insurance.

If that theory all works, I already have a stack of single wire bulkhead connectors that might work from the MillenWorks' closing haul.  The most likely would be this guy.  https://www.tme.eu/en/details/hummel-1609070060/glands/hummel/1-609-0700-60/  While it's just a generic cable gland, in looking through the cut sheet I don't see any obviously incompatible materials.  Ref: https://www.tme.eu/Document/501ff04cd9c399afb24d993205565977/HSK-M_EN.pdf 

It's nickel plated brass, polyamide/pvdf internals (related to nylon and these guys give it an A+ vs. gasoline: https://www.ipexna.com/media/1485/pvdf-chemical-resistance-guide.pdf), while seals are buna-N which is also good to go.  If I'm missing something please chime in but it looks okay as far as I can tell.

So if that all works, that just means I have to be sure I can find wiring that good for in tank use.  I got tired of searching as there's a ton of diverging views (teflon coated wires etc).  I also probably need to standardize on a style of electrical fittings that I know can carry the current.  Figuring that out was on the to do list for the FJ40 anyways, but if folks have thoughts I'd appreciated it. 

[largeorangefont]

If you want to spend $500 there is the Built2Apex Fuel pump hanger. It is the easy button.. but not cheap.

If it were me I'd run a new bulkhead fitting with the larger power wires needed and call it good.

I'm not running the 400 pump at the moment, but I just ran a new fuel power circuit and new pump relay in the back of the car. I run the stock connector that came off the fuel pump hangar, but it is 12 gauge wire from the battery, to the relay and from the relay to the OE tank connector. If I upgrade the pump, I will be changing that OE connector and run that 12 gauge wire all the way to the pump through a bulkhead like you are thinking.


https://www.built2apex.com/product-page/fc-dual-pump-hangar-kit

[attachimg=1]

Stu Kelley has one that is more economical, but again, I think you can get what you need modifying what you have.

https://www.stukellymotorsports.com/product-page/86-91-rx7-fc-fuel-tank-cover-sending-unit-an

[frijolee]

So no issue with the strategy of running a bigger power wire all the way in via a single wire cable gland and then relying on an upsized ground channeled through the hat plus existing ground wiring?

All my fuel lines are specific lengths and angles so I'd like to avoid redoing those and everything else on my hat is working well.  That has me trending away from fancy hangers, but good to know there are options.

[largeorangefont]

So no issue with the strategy of running a bigger power wire all the way in via a single wire cable gland and then relying on an upsized ground channeled through the hat plus existing ground wiring?

All my fuel lines are specific lengths and angles so I'd like to avoid redoing those and everything else on my hat is working well.  That has be trending away from fancy hangers, but good to know there are options.

Yea you should not have any issue with that wiring/grounding strategy.

[cholmes]

Joel, I agree with largeorange, you're on the right track. Use the Mazda wiring to activate a Bosch relay at the back of the car, 12 gauge power wire from relay to the pump, and from battery to relay is a good idea. Adding a 12 gauge ground wire to the outside of the pump plate is good insurance, too. A Bosch relay with a built in 30 amp fuse is handy and works well for this.

FYI, the multimeter check of the pump resistance doesn't tell the whole story, the inductance of the pump windings also affects the current draw, so the 13 - 18 amp rating is probably correct.

[largeorangefont]

Joel, I agree with largeorange, you're on the right track. Use the Mazda wiring to activate a Bosch relay at the back of the car, 12 gauge power wire from relay to the pump, and from battery to relay is a good idea. Adding a 12 gauge ground wire to the outside of the pump plate is good insurance, too. A Bosch relay with a built in 30 amp fuse is handy and works well for this.

FYI, the multimeter check of the pump resistance doesn't tell the whole story, the inductance of the pump windings also affects the current draw, so the 13 - 18 amp rating is probably correct.

Yea, I did use the relay with integrated fuse as well.

I too recycled the original fuel pump power wire as the coil trigger for the fuel pump relay to the ECU.

Just shot a couple pictures:
You can see the entire power circuit here from battery to relay
[attachimg=1]
Close up of relay to pump, OE connector I reused on the shock tower.
[attachimg=2]

[frijolee]

Thanks for the chatter gents.  The fuel pump rewiring is looking mostly straightforward on the chassis side.  The biggest wildcard at this point is the in tank wire bits and pass through.  PTFE (teflon) insulated wire seems to be the hot ticket.  I need to find a source where I can get only a touch though...  $434 for 100' of 12 AWG?  Damn... https://www.digikey.com/en/products/detail/alpha-wire/AT121925-RD005/3717842? 

EDIT.  Getting a little closer but still ~4' a foot.  https://www.amazon.com/BROWN-10AWG-Stranded-600V-Insulated/dp/B008NC3GV2/ and it looks like Mcmaster has it for $3 a foot, minimum 10' lengths...  https://www.mcmaster.com/catalog/121/826...  That's not great but it's liveable.

EDIT#2, well crap.  Ran across some stories where fuel wicked up the inside of the wire insulation and tried to cause at fire at an adjacent relay.  The only good news was a gent who fully melted his plugs under the hat without setting stuff on fire. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/word-about-re-wiring-your-fuel-pump-%5Bpics%5D-921896/

If you want to wire all the way it appears the insulated stud approach is the best call.  What a PITA.  Can't find a good stud either.  This is as close as I'd found thus far, but still a bit too big... https://www.racetronix.biz/p/bulkhead-stud-6mm-delron-viton-ss/bhs-6mss?  I can pay out the nose for Radium but they only come in 6 packs.  http://www.radiumauto.com/Electrical-Bulkhead-Stud-Kit-6-Pack-P1049.aspx.  I might end up doing some DIY.

EDIT #3.  Forums to the rescue, in this case the chatter by the 3000GT guys is the best I've found.  https://www.3si.org/threads/fuel-resistant-wires-for-aftermarket-fuel-pump-hangers.816583/

EDIT #4...  After wasting just about my entire morning on the internet looking at this shit, I'm going to say the most commonly available wire that looks appropriate for mere mortals is probably cross linked polyethelene (XLPE).  It's sold per SAE J1128 and available in three insulation thicknesses: TXL, GXL, and SXL (thin to thick respectively).  Add to that PTFE (teflon) heat shrink and I should be ok.  These are fairly common automotive wires.  This comes with buyer beware warning though.  If I look at the guys who make serious harnesses, they're running teflon coated... IE:  https://www.racetronix.biz/p/universal-bulkhead-wiring-system-4-way/bcws-001

For a slightly more exotic material, one possibility would be FEP (Tetrafluoroethylene-hexafluoropropylene / Fluorinated ethylene propylene).  One of the more knowledgeable sounding gents on the 3SI forum above has a pretty good break down here:  https://www.3si.org/threads/fuel-resistant-wires-for-aftermarket-fuel-pump-hangers.816583/#post-1056287295 and thankfully his amazon link is still live.  Debating trying this stuff: https://www.amazon.com/Electrical-Primary-Voltage-Automotive-temperature/dp/B0749H6CBD but it does have a few disadvantages, thinner insolation and low strand count (very stiff).  Bah, at least I'm circling the drain here.

If the wicking is real (which seems to be a widespread claim), how the heck are there so many of these?  https://www.summitracing.com/parts/fue-74101?

[Cobranut]

Thanks for the chatter gents.  The fuel pump rewiring is looking mostly straightforward on the chassis side.  The biggest wildcard at this point is the in tank wire bits and pass through.  PTFE (teflon) insulated wire seems to be the hot ticket.  I need to find a source where I can get only a touch though...  $434 for 100' of 12 AWG?  Damn... https://www.digikey.com/en/products/detail/alpha-wire/AT121925-RD005/3717842? 

EDIT.  Getting a little closer but still ~4' a foot.  https://www.amazon.com/BROWN-10AWG-Stranded-600V-Insulated/dp/B008NC3GV2/ and it looks like Mcmaster has it for $3 a foot, minimum 10' lengths...  https://www.mcmaster.com/catalog/121/826...  That's not great but it's liveable.

EDIT#2, well crap.  Ran across some stories where fuel wicked up the inside of the wire insulation and tried to cause at fire at an adjacent relay.  The only good news was a gent who fully melted his plugs under the hat without setting stuff on fire. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/word-about-re-wiring-your-fuel-pump-%5Bpics%5D-921896/

If you want to wire all the way it appears the insulated stud approach is the best call.  What a PITA.  Can't find a good stud either.  This is as close as I'd found thus far, but still a bit too big... https://www.racetronix.biz/p/bulkhead-stud-6mm-delron-viton-ss/bhs-6mss?  I can pay out the nose for Radium but they only come in 6 packs.  http://www.radiumauto.com/Electrical-Bulkhead-Stud-Kit-6-Pack-P1049.aspx.  I might end up doing some DIY.

EDIT #3.  Forums to the rescue, in this case the chatter by the 3000GT guys is the best I've found.  https://www.3si.org/threads/fuel-resistant-wires-for-aftermarket-fuel-pump-hangers.816583/

EDIT #4...  After wasting just about my entire morning on the internet looking at this shit, I'm going to say the most commonly available wire that looks appropriate for mere mortals is probably cross linked polyethelene (XLPE).  It's sold per SAE J1128 and available in three insulation thicknesses: TXL, GXL, and SXL (thin to thick respectively).  Add to that PTFE (teflon) heat shrink and I should be ok.  These are fairly common automotive wires.  This comes with buyer beware warning though.  If I look at the guys who make serious harnesses, they're running teflon coated... IE:  https://www.racetronix.biz/p/universal-bulkhead-wiring-system-4-way/bcws-001

For a slightly more exotic material, one possibility would be FEP (Tetrafluoroethylene-hexafluoropropylene / Fluorinated ethylene propylene).  One of the more knowledgeable sounding gents on the 3SI forum above has a pretty good break down here:  https://www.3si.org/threads/fuel-resistant-wires-for-aftermarket-fuel-pump-hangers.816583/#post-1056287295 and thankfully his amazon link is still live.  Debating trying this stuff: https://www.amazon.com/Electrical-Primary-Voltage-Automotive-temperature/dp/B0749H6CBD but it does have a few disadvantages, thinner insolation and low strand count (very stiff).  Bah, at least I'm circling the drain here.

If the wicking is real (which seems to be a widespread claim), how the heck are there so many of these?  https://www.summitracing.com/parts/fue-74101?

I've made insulated studs from delrin and stainless socket head screws, though not in a fuel tank bulkhead.
Just turn a step on the face of one bushing and bolt it through the bulkhead.
I think delrin is compatible with gasoline and ethanol, so I see no reason it wouldn't work.
Use a bit of anaerobic gasket maker on the bolts and between the delrin and the bulkhead.

[shainiac]

I've made insulated studs from delrin and stainless socket head screws, though not in a fuel tank bulkhead.
Just turn a step on the face of one bushing and bolt it through the bulkhead.
I think delrin is compatible with gasoline and ethanol, so I see no reason it wouldn't work.
Use a bit of anaerobic gasket maker on the bolts and between the delrin and the bulkhead.

Ive done similar with a nylon bolt from the hardware store as a passthrough. I bought a 3/8" nylon bolt and drilled it through the middle for a #10-32 tap. I used a stainless #10 screw through the bottom of the bolt, through the bottom of the fuel pump hat. The top of the fuel pump hat had a nylon nut to keep the passthrough in place, and a #10 nut for 12awg wire and eyelet from the pump relay.
I sandwiched viton o-rings on top and bottom of the hat to seal the 3/8" nylon bolt  and double-nutted it to keep it from falling into the tank. Worked for several years before I switched to a surge tank setup.

[frijolee]

Well, I ordered my pump wiring stuff.  Turns out Ebay is by far the most cost effective source for teflon (PTFE) insulated wire.  Seems quite a few folks are selling military surplus in 10' lengths.  Also grabbed some telfon heat shrink.  I did verify I have enough hardware to make my own pass bulkhead through.  I am going to to upsize grounds for the hat on the negative.  On the power side, I'm planning on a m6 stud in consideration that 304 SS has about 2-3% of the conductivity of copper.  I think the bolt is actually 18-8 but 304 is damn similar electrically.  Radium claims it's manufactured studs are tested to 30 Amp and that's a #10 screw size, but having some headroom makes sense to me (plus I already have the hardware which is nice)

[Cobranut]

Well, I ordered my pump wiring stuff.  Turns out Ebay is by far the most cost effective source for teflon coated wire.  Seems quite a few folks are selling military surplus in 10' lengths.  Also grabbed some telfon heat shrink.  I did verify I have enough hardware to make my own pass bulkhead through.  I am going to to upsize grounds for the hat on the negative.  On the power side, I'm planning on a m6 stud in consideration that 304 SS has about 2-3% of the conductivity of copper.  I think the bolt is actually 18-8 but 304 is damn similar electrically.  Radium claims it's manufactured studs are tested to 30 Amp and that's a #10 screw size, but having some headroom makes sense to me (plus I already have the hardware which is nice)

Mine are 1/4" SS as well.
I use them for charge ports through the trunk floor of my Cobra. Conductivity shouldn't be an issue for such a short distance and large cross-section.

[frijolee]

Fuel pump rewire almost done... 

Spot picked out for the bulkhead pass through (see scribe mark).




3/8" hole with nylon bushings (carved a step into topside to index it) 18-8 stainless hardware.  Teflon insulated wire and heat shrink (as already noted).




I'm grounding via both an upsized -12 wire to the hat and the OEM wire.  The original power line was de-pinned at the under hat connector.




Up front I decided to take the long way around so my relay can live with all the normal ones.  I'm going to fuse at the main power block.  Downside.  I had a contact for my fans come loose here and smoke the position I planned to use.  Oops, that was probably 4-5 years ago so I'd forgotten.  Thankfully @largeorangefont was willing to part with his spare fuse box. 




Kinda crazy I did the original swap in 2005.  Apparently the past 5 years managed to melt my corregated tubing into the harness where it passes the header closest.




Yeah, we'll be strapping that down to be sure it's all the way back against the frame rail when I put that back.  Unwrapping and re-wrapping old harnesses in situ is finger killer when it's baked on there.




Amazing how stupid little jobs can take this much time.  Still, it's one of the only shortcuts I ever made on the wiring front so it feels good to get it squared.  Overall run: Battery -> starter -> behind front bumper to the main fuse block (using 30A fuse) -> 30A relay -> all along the full length of the interior to the new bulkhead connector -> pump.   It's longer this way but it makes for a clean run and I didn't want to bury my relay and fuse under carpet.

-Joel

[Cobranut]

Joel,

In addition to voltage drop, another issue with a long run can be noise.
Electric motors can generate a lot of noise, and the wiring can couple it into other circuits.

Just something to keep in mind if you have any noise problems.

[wickedrx7]

So I'm gonna hang with the cool kids like @largeorangefont and pick up a Magnum F.  I like this damn car a lot and I'd love to drive it more so it's time to give it some love.  From my looking the Magnum F is supposed to be quite a bit nicer shifting.  I'm also eyeballing a McLeod RXT.  I thought I was there and was planning RXT over RST for some added abuse potential (well that and I just don't trust organic discs with the clutch dust issues on slaves).  But then I find reviews like this  https://ls1tech.com/forums/manual-transmission/1692102-mcleod-rxt-my-experience.html where it's nothing but dudes bitching about terrible chatter, terrible wear, and I don't know what to think.  Maybe I should just keep my monster and assume my problems are with dowels and hydraulics. 

Thoughts appreciated.

I was in the same boat as you, RST vs. RXT about a year ago.  I settled on the RST because I don't have plans for more than 500 RWHP and really don't drag race the car (Although I do have a brand new set of drag slicks to try to get in the 10's).  I do track the car and definitively put it through it paces but based on GNX7's advice, I went with the RST. 

So far I have been happy with my decision.  The feel is as good as my previous LS7 clutch and it has handled everything I have thrown at it.  I have yet to push it beyond its limits or notice it slipping.  My only complaint with the entire setup is that there is a vibration/shutter/Harmonic at 1700/1800 rpms.  Multiple guys on here that have the exact same problem, all of them with FD's and a variety of clutches.  After much research and discussion, the only conclusion I can draw is that it is a result of the RST clutch not using sprung clutch discs.  This is the only common element I can find between a few of us having this issue and some other discussions on other forums.  If I wanted to spend a bunch of money, I would probably go with a Mantic clutch next time.  I have no plans to do this anytime soon.

As for the Magnum F, you won't be disappointing.  It is by far the best 6 speed I have ever driven.