Clutch switch bypass

fielderz · Post by **fielderz** » Sat Jul 27, 2013 11:47 am

Hey chaps, I have a 2001 zze122 fielder, manual C60 with a 2zz-ge.

What bugs me is that to start the engine, the clutch must be depressed, I find this mildly annoying and I don't really like the idea of having the engine under axial load when starting form cold with no/low oil pressure. As above, I was considering bypassing the switch but I'm not sure if it serves other purposes to - eg allowing the ecu to retard timing for gear changes or what have you.

Basicly I would like to know if this a retarded idea or not.

Cheers, Phil.

Grrrrrrr! · Post by **Grrrrrrr!** » Sat Jul 27, 2013 12:06 pm

I doubt it is used for more than the starter disable, but if you are worried use a relay driven off the keyswitch signal to bypass it.

captain crescent · Post by **captain crescent** » Sat Jul 27, 2013 12:22 pm

I have done this in the race car (2zzge runx) as climbing in and out all through the roll cage is a PITA, so i put a missile type switch (for wank factor) in and just tee'd into each wire.

The car starts just the same and I would doubt there would be any link to the ecu and if there was it will still see that the switch is being engaged so it would do the same thing.

fielderz · Post by **fielderz** » Sat Jul 27, 2013 1:00 pm

Cheers guys, I was a little worried I would be driving around with the timing retarded or some such thing if I bypassed the switch.
After my mid morning coffee and the ensuing corrected brain operation I remembered about that google website haha and I found this 2zz-ge pinout diagram:

http://www.google.co.nz/url?sa=t&rct=j& ... 4469,d.dGI

The clutch switch does not appear to have any connection to the ecu as suggested above, so seems like it should be fine to bypass it. Will do a little more searching just incase before I bypass it though.

Bling · Post by **Bling** » Sat Jul 27, 2013 1:23 pm

Why is it such a bad thing? Odd that manufacturers are intent in putting it into newer cars if it's bad. Hell, even my van has it, and that's been stress tested to the max in every way for reliability.

iOnic · Post by **iOnic** » Sat Jul 27, 2013 1:48 pm

Has been linked to thrust washer wear/crank walk but I personally think the difference it makes is hardly earth shattering. Especially if the car had been running around for tens/hundreds of thousands of kms before you even set eyes on it :lol:

My Evo had one and the RX8 has one. More of an annoyance than anything for me, you don't necessarily want to be inside the car every time you start it.

Manufacturers use it to stop you starting in gear/from outside the car. Its a safety thing. Dunno why they don't just have a neutral switch.

Scottie · Post by **Scottie** » Sat Jul 27, 2013 2:56 pm

Another 'pro' point could be that the gear box is disconnected, less work for the starter motor to do.

fielderz · Post by **fielderz** » Sat Jul 27, 2013 3:23 pm

BZG|Bling wrote:Why is it such a bad thing? Odd that manufacturers are intent in putting it into newer cars if it's bad. Hell, even my van has it, and that's been stress tested to the max in every way for reliability.

I don't think its a seriously major issue, although I'm pretty sure that manufacturers will tend to err on the side of safety issues/reducing the potential idiot factor over long term reliability, and will continue to so more and more. Its just the occasional annoyance to me and the potential thrust washer wear that motivate me, especially considering its like 5 minute job to do a tidy job bypassing the switch.

iOnic wrote:Has been linked to thrust washer wear/crank walk but I personally think the difference it makes is hardly earth shattering. Especially if the car had been running around for tens/hundreds of thousands of kms before you even set eyes on it My Evo had one and the RX8 has one. More of an annoyance than anything for me, you don't necessarily want to be inside the car every time you start it.

Manufacturers use it to stop you starting in gear/from outside the car. Its a safety thing. Dunno why they don't just have a neutral switch.

I agree, although my wagon is pretty low mileage ( <100k km) and I plan on keeping it for a while (seriously stoked with it!) and as above, super easy job, providing it doesn't confuse the ecu into some sort retarded igniton map or something, so why not.
And yeah, neutral switch, I was thinking exactly that to.

fielderz · Post by **fielderz** » Sat Jul 27, 2013 3:28 pm

Scottie wrote:Another 'pro' point could be that the gear box is disconnected, less work for the starter motor to do.

Hmm, true, although I doubt it would be significant in comparison to the work required to turn the relative hi-comp 2zz-ge. I've actually just done the bypass and it starts with no trouble whatsoever.

matt dunn · Post by **matt dunn** » Sat Jul 27, 2013 7:32 pm

Scottie wrote:Another 'pro' point could be that the gear box is disconnected, less work for the starter motor to do.

That is the reason for it.

You will find that most six speeds will have a clutch switch do to the weight of the gears in the gearbox.

Doesn't make a difference that you will notice,
but will over 100,000km/3 years which is what the warranty would have been from new.
Have you seen how small the armature is in the starters on them?

touge rolla · Post by **touge rolla** » Sun Jul 28, 2013 1:02 am

price of replacement starter < price of repairing crank walk
This may be affected by how many starters you go through before having made a difference (if any?) on the crankshaft.
Personally I'd go with a bypass though, you can always push start it

gt4dude · Post by **gt4dude** » Sun Jul 28, 2013 1:32 am

i'm not sure i see where the crank is going to walk off to? prehaps go on smoko break?

i think the manuf. knew we would race their cars, so they put the clutch switch in to make it easier for the owner to install launch control.

iOnic · Post by **iOnic** » Sun Jul 28, 2013 8:35 am

I hope you're joking. Lol.

Boosted_162 · Post by **Boosted_162** » Sun Jul 28, 2013 9:21 am

My new Legacy has the clutch switch (6 speed) and i know it wasn't put there for launch control :lol:

Grrrrrrr! · Post by **Grrrrrrr!** » Sun Jul 28, 2013 12:45 pm

matt dunn wrote:
Scottie wrote:Another 'pro' point could be that the gear box is disconnected, less work for the starter motor to do.

That is the reason for it.

Pretty sure its to stop people from starting cars in gear, they've been doing it since the early 90s (at least) on USDM cars, but not on the equivalent JDM cars, at least until recently when things became more nanny state/idiot tolerant.

matt dunn · Post by **matt dunn** » Sun Jul 28, 2013 7:17 pm

Grrrrrrr! wrote:

Pretty sure its to stop people from starting cars in gear, they've been doing it since the early 90s (at least) on USDM cars, but not on the equivalent JDM cars, at least until recently when things became more nanny state/idiot tolerant.

That because US spec people are dumb.

Japs usually only do it to the 6 speeds due to the gear weight.
Pretty sure that 6 speed fielders do and 5 speeds dont,
even though they are the same year and model.

phoenix · Post by **phoenix** » Sun Jul 28, 2013 8:52 pm

My BP5 Legacy GTB (5 speed) had one too, I got annoyed and bypassed it.

Figured if my car stalled on a level crossing and wouldn't restart I could now starter motor it off..... :lol:

wde_bdy · Post by **wde_bdy** » Sun Jul 28, 2013 8:56 pm

matt dunn wrote:That because US spec people are dumb.

Japs usually only do it to the 6 speeds due to the gear weight.
Pretty sure that 6 speed fielders do and 5 speeds dont,
even though they are the same year and model.

Have two of the same model Mazda Demios, both 5 speed B5 engines and 5 speed boxes, 98 model has no switch but 2001 does. Seems more an age thing for Jap vehicles.

Callum

fielderz · Post by **fielderz** » Sun Jul 28, 2013 9:16 pm

touge rolla wrote:price of replacement starter < price of repairing crank walk
This may be affected by how many starters you go through before having made a difference (if any?) on the crankshaft.
Personally I'd go with a bypass though, you can always push start it

Yah, that what I was thinking to. Also, I don't actually drive it that often, so more worried about a dry thrust washer than burning the starter motor out.

Grrrrrrr wrote: Pretty sure its to stop people from starting cars in gear, they've been doing it since the early 90s (at least) on USDM cars, but not on the equivalent JDM cars, at least until recently when things became more nanny state/idiot tolerant.

Haha yeah, that was what I was thinking to.

As a side note, there was not any voltage to either of the two wires to the clutch switch when the key was in the acc or on positions, but I forgot to test when in start position. The former indicates to me that it is used only to inhibit starting with the clutch engaged.

Luke - BZG · Post by **Luke - BZG** » Wed Jul 31, 2013 6:20 pm

JDM supras don't have clutch switches, the US ones do, (because if you're stupid you can sue people.)

If any new members join one of the first questions they are asked is if the clutch switch has been disabled yet.... and if not.. they are told to disable it immediately.

I don't think it would do any damage to a motor while it's still within the manufacturers warranty, but after 15+ years of cold starts it seems to take it's toll. There are several pictures of ground up thrust washers in oil pans and it seems to happen mainly to the cars that still have the clutch switch active, (a heavy single plate clutch doesn't help either.)