Rewiring entire engine bay...
 

I'll preface this by saying that I'm extremely particular about how all the work I do on my car looks. All the wiring under my dash that I did is neatly tucked into plastic sleeving and secured with zip ties even though its probably not necessary in some parts. Every bracket on the engine has been painted so it doesn't look like shit. I even took a wire brush to the inside of my transmission housing to clean a little bit of crap off. I have no intention of bringing the car to shows, but I don't want people to think I'm some backyard retard whenever I pop my hood. I've seen too many cars in my area come out of performance "shops" that look like shit under the hood.

That said, I want to redo my stock engine wiring harness. Has anyone on here made a new wiring harness for their car and if so what gauge wire do you recommend using and are there any tips/suggestions that you have looking back on it? I already have another harness, so I have a full set of connectors to use. If I screw up, I'll just throw the stock harness back on.

Re: Rewiring entire engine bay... (d@ve.G)
 

i relocated all my wiring to under the dash behind the firewall....i think i used 18 or 22 gauge , i forget off the top of my head...I plan to do it on my other car again this winter...this time im just gonnna pick up a few spare harnesses to keep the wire colors consistent...

Re: Rewiring entire engine bay... (Mpir3)
 

Sweet. Got any pictures of it?

Now if I could just get rid of all the damn vacuum lines with a turbo setup...

Re: Rewiring entire engine bay... (d@ve.G)
 

i read somewhere on honda-tech that a fellow rewired his engine bay entirely with 16 gauge wire. Super super clean looking. Even better was the HP advantage. He had a b18c, and gained 13 hp on the dyno, 5 days work later. He said it took him quite a while in front of the tv to get is all wired up, but he said it was well worth it.

Re: Rewiring entire engine bay... (snoochtodanooch)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by snoochtodanooch &raquo;</TD></TR><TR><TD CLASS="quote">i read somewhere on honda-tech that a fellow rewired his engine bay entirely with 16 gauge wire. Super super clean looking. Even better was the HP advantage. He had a b18c, and gained 13 hp on the dyno, 5 days work later. He said it took him quite a while in front of the tv to get is all wired up, but he said it was well worth it. </TD></TR></TABLE>

Thats what I remember seeing somewhere too. I want to say it was LegendBoy or someone like that. Bump for more info. https://honda-tech.com/forums/images/smilies/emthup.gif

Re: Rewiring entire engine bay... (d@ve.G)
 

What do you want to know specifically? Im running 20 gauge Tefzel wire with Raychem Heatshrink/Transitions. Its expensive but to me its worth it. Im also running AMP CPC Connectors for the firewall connection. Ill have to get some pics of my current progress. Ive been lazy lately with the car and havent done much.

Re: Rewiring entire engine bay... (TurboLSVtecTeg)
 

http://www.imagestation.com/picture/...e/f801b52e.jpg
http://www.imagestation.com/picture/...d/f801b527.jpg
http://www.imagestation.com/picture/...f/f801b509.jpg

Re: Rewiring entire engine bay... (Mpir3)
 

I have since moved the injector wires.
http://www.falcongsr.com/pictures/al...end1.sized.jpg

Re: Rewiring entire engine bay... (snoochtodanooch)
 

This sounds just like the stereo speaker wiring mentality. By this logic, if 0gauge wires are installed, that'll be worth, what, 100hp?

As a electrical engineer I have yet to hear or see facts on this. Far more likely is that it's something else. When you know how this stuff works, and the current levels involved, it just won't matter. Now in the case of alternator wiring, specifically the high-current wires, okay, fair enough, there may be some wire heating when the alternator is under a high load, but it's going to amount to only a few watts of heat. 13whp?! Yeah, if the car is tuned like sh*t before, has crappy wiring (as in loose), and add in dyno variance, then I can see coming up with that number. Otherwise it's marketing pseudo-science.

Re: Rewiring entire engine bay...
 

i would have to stress what kb58 says as well... imo u should do some research before u jump into something like this... u switch some wires by accident there goes ur ecu for example...
as far as wire guaging... u really need to know how many amps are being pulled through the wire... if ur redoing an entire engine bay... headlights and all... u should be needing a couple 18awg wires, some 20awg and a whole bunch of 22awg and 24awg if u want to use it

then it comes down to what connectors u want to use... if u want to chenge them at all, do u want to heatshrink it? use transitions? bulhead on the firewall? mil-spec/autosport? use stock connectors, deutsch connectors or the little sutosport connectors... it really comes down to how much money u want to put into the harness as far as parts. dont forget depending on what connectors u use also dictates the crimping tools u need... which can get real expensive, real fast

i have some pics of stuff iv done but the server's thats hosting it is down down right now

Re: Rewiring entire engine bay... (ek9t)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek9t &raquo;</TD></TR><TR><TD CLASS="quote">then it comes down to what connectors u want to use... if u want to chenge them at all, do u want to heatshrink it? use transitions? bulhead on the firewall? mil-spec/autosport? use stock connectors, deutsch connectors or the little sutosport connectors... it really comes down to how much money u want to put into the harness as far as parts. dont forget depending on what connectors u use also dictates the crimping tools u need... which can get real expensive, real fast
</TD></TR></TABLE>

You brought up an interesting point that sort deals with something I've wondered about. I've had to wire in a dimmer switch plug (because the car didn't have the switch and the lights didn't light up without it, so the guy cut and spliced the wires so the guages would light up for the drive home but he cut them to short to splice so I had to remove the old wire from the metal pins and put the wire from the car in them) and then I just recently had to do the same to my VTEC Oil Pressure Sensor because one of the wires snapped. My question to you is, can you buy those metal pins inside the plastic plugs for when you have to do somethng like this or when your making a complete harness? Or do you have to reuse the old pins by removing the old wire ends, which is a total PITA.

And when you were talking about the different connectors, do you mean different style plastic plugs?

Re: Rewiring entire engine bay... (TouringAccord)
 

u can buy the honda pins... its nearly impossible and not worth reusing the old ones...

yea... u can use differant types of connectors... like in arts picture... u can see by the coil and by the drivers side mount there are those little grey connectors... those are dtm's... they are plastic plugs using mil-spec pins though... u can also use weatherpacks which are a cheap alternative... if u want to get really nice with the harness u can use autosport's which are pretty much really small aluminum (or ti if u want to pay for it) connectors... they run for the cheapest ones about $30 a side though

Re: Rewiring entire engine bay... (ek9t)
 

RyanAutry did it to his teg.. contact him, he showed me a lot of links.

edit - http://www.hondaswap.com/forum...80&hl

Re: Rewiring entire engine bay... (kb58)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">This sounds just like the stereo speaker wiring mentality. By this logic, if 0gauge wires are installed, that'll be worth, what, 100hp?

As a electrical engineer I have yet to hear or see facts on this. Far more likely is that it's something else. When you know how this stuff works, and the current levels involved, it just won't matter. Now in the case of alternator wiring, specifically the high-current wires, okay, fair enough, there may be some wire heating when the alternator is under a high load, but it's going to amount to only a few watts of heat. 13whp?! Yeah, if the car is tuned like sh*t before, has crappy wiring (as in loose), and add in dyno variance, then I can see coming up with that number. Otherwise it's marketing pseudo-science.</TD></TR></TABLE>

by no means am i saying, on the one hand, use the biggest gauge wire you can find to gain loads of power. i am, on the other hand, saying that wiring on an older car, example being a 93 civic, is definently not at its top capability, nor was it at top capability when it came from the factory really; everything can be done better, hence aftermarket performance parts.
Apexi is a company i think that all of us trust to a good degree. http://www.apexi-usa.com/news.asp?ID=62. That is just a grounding system. 8.5 whp gain. Rewiring the engine harness has gains from the fact that if you do it properly, it will conduct better than the used and beat to death stock harness and do so for much longer. I am sure you could do the harness just as well with 18 or 20 gauge wire, i was simply relaying what i had read previously. The gauge is not as important as the craftsmanship in this situation, and i think that the craftsmanship is what gives you the power not the gauge of the wire.


Modified by snoochtodanooch at 1:46 PM 11/3/2004

Re: Rewiring entire engine bay... (ek9t)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ek9t &raquo;</TD></TR><TR><TD CLASS="quote">u can buy the honda pins... its nearly impossible and not worth reusing the old ones...

yea... u can use differant types of connectors... like in arts picture... u can see by the coil and by the drivers side mount there are those little grey connectors... those are dtm's... they are plastic plugs using mil-spec pins though... u can also use weatherpacks which are a cheap alternative... if u want to get really nice with the harness u can use autosport's which are pretty much really small aluminum (or ti if u want to pay for it) connectors... they run for the cheapest ones about $30 a side though</TD></TR></TABLE>

I can just go to the Honda dealer and buy the pins? I didn't know that, Thanks.

Do you have any links of where to buy other connectors and matching pins?

Just run the fuse box into the cabin and the left over wires on the shock towers into the fenders. extend if you have to.

No need to re-wire from scratch. You can get it very clean without re-inventing the harness..

Re: Rewiring entire engine bay... (snoochtodanooch)
 

"...wiring on an older car, example being a 93 civic, is definently not at its top capability, nor was it at top capability when it came from the factory really;"

What does "top capacity" mean? Wires don't wear out other then physically breaking. That's a separate issue, replacing the bad wire with the same size fixes the problem, irrespective of guage


"Rewiring the engine harness has gains [because] it will conduct better than the used and beat to death stock harness and do so for much longer."

"Better" is a relative term. Okay, so the thin wire gives you 11.95V and with the thick ones you get 11.98V. So it's a higher voltage, but what does that improve?

"The gauge is not as important as the craftsmanship in this situation, and i think that the craftsmanship is what gives you the power not the gauge of the wire."

Ugg, no, the guage is extremely important. The nicest craftmanship doesn't matter if there's too much IR drop.

I have yet to hear where this mystery horsepower comes from. You're telling me that a properly tuned car with, say, a 13.0AFR, has it's wires changed and now will have 8whp more with no change to the AFR? So where did the power come from? Better fuel delivery? No, it was fine before, and what would "better" mean here? How could the AFR be better? Richer, leaner? That's all covered by tuning, not changing wires. I'm not buying it.

Re: Rewiring entire engine bay... (kb58)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">"...wiring on an older car, example being a 93 civic, is definently not at its top capability, nor was it at top capability when it came from the factory really;"

What does "top capacity" mean? Wires don't wear out other then physically breaking. That's a separate issue, replacing the bad wire with the same size fixes the problem, irrespective of guage


"Rewiring the engine harness has gains [because] it will conduct better than the used and beat to death stock harness and do so for much longer."

"Better" is a relative term. Okay, so the thin wire gives you 11.95V and with the thick ones you get 11.98V. So it's a higher voltage, but what does that improve?

"The gauge is not as important as the craftsmanship in this situation, and i think that the craftsmanship is what gives you the power not the gauge of the wire."

Ugg, no, the guage is extremely important. The nicest craftmanship doesn't matter if there's too much IR drop.

I have yet to hear where this mystery horsepower comes from. You're telling me that a properly tuned car with, say, a 13.0AFR, has it's wires changed and now will have 8whp more with no change to the AFR? So where did the power come from? Better fuel delivery? No, it was fine before, and what would "better" mean here? How could the AFR be better? Richer, leaner? That's all covered by tuning, not changing wires. I'm not buying it.</TD></TR></TABLE>

I'm just as skeptical as you are about the mystery horsepower from the new wiring. All I said was I remember seeing it. I'm not looking to gain power from this; its strictly so that things look cleaner and if I need to ever pull the engine, I can pop a couple connectors.

By the way, your project car is simply amazing. That's the level of attention to detail that I'm talking about. https://honda-tech.com/forums/images/smilies/emthup.gif

Re: Rewiring entire engine bay... (d@ve.G)
 

Hate to jack your thread but the info I'm looking for may be useful for you also.

I'm completely rewiring my car, everything. All electronics are being moved to behind the seats (fues block, relays, ecm,etc.) I've been looking for some nice bulkhead connectors to go through the firewall that will contain all the wires connected to the engine to make engine removal a bit easier by just unscrewing the connector at the firewall and unbolting the engine. All I've been able to come up with is some on digi-key but they dont have pics (just drawings) so its hard to tell if its what I need plus almost all of them are for 22gauge wire with a max current of 2-3amps per contact which just wont cut it for some items.
It looks like I'll be running 25-30 wires just to the engine with most being in the 18-20 gauge range. The largest current draw obviously would be the injectors and coil pack( not counting starter)

Can someone point me to a place to find these bulkhead connectors?


Hopefully to be of some assistance here are a few places where I've been getting my wire, terminals, etc.

https://www.delcity.net/tstore...=Home
Sells SXL (thickest insulation) wire in 100ft minimum spools. Decent price on shrink tube though its not DR-25 which seems to be preffered. Also they have the best price on bussman fuse blocks I've found on the web.

http://www.kayjayco.com/index.htm
Quite expensive but sells all SXL, GXL, TXL insulation thickness wire in very short runs in case you only need a small quantity of a particular gauge.

http://www.waytekwire.com/waytech.htm
Best selection of color, gauge, insulation thickness I've found. Only sells in 250ft spools which doesn't last as long as you would think. Also reasonably priced terminals, splices, etc.


http://www.digikey.com/
Some reasonable prices on raychem heatshrink, though they dont carry dr-25.


Modified by KP at 10:00 PM 11/3/2004

Re: Rewiring entire engine bay...
 

It's more like recovering lost power from fixing bad wiring, but never "gain" power if all the stock wiring on the car is in good working condition.

The only way I see an improvement is only when the stock wiring is under-sized for its application. If you managed to find any wires that are causing unneccessary resistance to things such as engine fan, fuel pump, any other higher amperage devices, there would be benefits by putting a better quality/thicker gauge wire and and in turn put less load on the alternator --&gt; more power to the engine.

Honda in particular though, never had a problem with under-sized wires or overheating wires from the factory. It is a misconception that you gain power from new wiring, but rather recover lost power especially on older cars.

I completely rewired everything in the engine bay on my '94 Toyota Camry... The car was basically winter driven for the past 10 years, and a lot of the wiring was beaten up and corroded. You'd be suprise how much damn wiring is in a OBD-II mid-sized sedan, especially when it is a Toyota.

It took about 1 month (approx 50 hours) to rewire all the wires... Such as stepping up to the next thickness gauge (replacing 24 gauge with 22, etc...), replacing the grounding cables (and adding more at certain places), extending or shortening wires to tuck them out of sight (cleaner look), and also shielding them with heat insulators from heat sources by the way my turbo and exhaust pipes disect through the engine bay. The car does indeed start better, less dimming lights during high amp draw, etc... I didn't notice any power gains, but I am sure there was some better driveability involved.

http://www3.sympatico.ca/h.leung/Camry/Cameng6a.JPG
http://www3.sympatico.ca/h.leung/Camry/Cameng6b.JPG
http://www3.sympatico.ca/h.leung/Camry/Cameng6c.JPG

And most of the cars we have here on Honda-tech are all done up anyway, and with the very least, a set of gauges, accessories, etc.... Along the way, it is much cleaner to start a new set of relays and fuses grouped together then to have wires fraying here and there.



Modified by Tony the Tiger at 11:58 PM 6/6/2005

Re: Rewiring entire engine bay... (Tony the Tiger)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tony the Tiger &raquo;</TD></TR><TR><TD CLASS="quote">It's more like recovering lost power from fixing bad wiring, but never "gain" power if all the stock wiring on the car is in good working condition.

The only way I see an improvement is only when the stock wiring is under-sized for its application. If you managed to find any wires that are causing unneccessary resistance to things such as engine fan, fuel pump, any other higher amperage devices, there would be benefits by putting a better quality/thicker gauge wire and and in turn put less load on the alternator --&gt; more power to the engine.
</TD></TR></TABLE> thats what i was struggling to get out

Re: Rewiring entire engine bay... (Tony the Tiger)
 

is that a camry????

and why is the vin tag removed from the tranny in that ryan autry guy's ride?

Re: Rewiring entire engine bay... (paul vang)
 

yea thats tony the tigers turbo camry.

Re: Rewiring entire engine bay... (paul vang)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paul vang &raquo;</TD></TR><TR><TD CLASS="quote">
and why is the vin tag removed from the tranny in that ryan autry guy's ride? </TD></TR></TABLE>

https://honda-tech.com/forums/images...es/emdgust.gif

Re: Rewiring entire engine bay... (KP)
 

For the Firewall Bulkhead Connectors. For the best cost while still keeping something that isnt cheaply made. I decided on some AMP CPC(Circular Plastic Connectors). They work great.

Here are the connector. They also didnt sell at 63 pins when I ordered them. Which would have came in handy. But for the price you cant beat them. Way better then the price for a Mil-Spec bulkhead connector.

I went with the Series 1 Connectors. If you plan on running some power wires to like your Alternator or Starter and want to run a bulkhead. They have Connectors that will take bigger gauge wire like 10-12 GA if you wanted.

http://www.alliedelec.com/cata...m=106

Here is the contacts for these connectors. Choose them depending on your wire size that you will be running.

http://www.alliedelec.com/cata...m=109


I would also suggest getting the Extraction Tool. Trust me you wont get them out any other way. For insertion you can just push them in until they click. You might also want to check out the Right-Angle Cable Clamps and Straight Cable Clamps on this page too.

http://www.alliedelec.com/cata...m=110

All in all for the price im very happy with these bulkhead connectors. They work great and are very durable and the price cant be beat. The best thing about Allied Electronics is that you dont have a minium buy order like Digi-Key.

If you want any other info on these connectors or anything feel free to PM me with questions.

Sal