Usually it would be low if it wasn't bled fully actually. If it's high, it may not be the hydraulic mechanism. What pedals are you using?
Usually it would be low if it wasn't bled fully actually. If it's high, it may not be the hydraulic mechanism. What pedals are you using?
Its an OBP pedal box, obp clutch cylinder mated to a pagid slave.
Was the clutch you put in new ? Where did you source it ?
A high bite point often indicates the clutch plates are reaching end of life.
Only oher thing is...Have you had a problem where you dumped the clutch or been clutch kicking it ? Did the problem only appear after your mate was drifting it ?
If so, it could be that the clutch release pivot has snapped. They fatigue below the ball then snap when stressed. They can sit in position even though broken or move slightly so you only get a half-clutch that bites at the top.
If its that, the good news is that the part only costs about 7 quid. Bad news is you'll need to take the box off. On a 13 that can be done without removing the engine. In your case, I don't know.
See if you can move the release arm by hand in any plane other than back and forth. If you can, that's almost certainly your problem.
Last edited by Jonny Wilkinson; 29-09-2014 at 12:12.
The new exhaust looks cool, the time lapse video is sweet as well,as are the other vids tbh
and I over looked the diff ratio question as one forgot your on 13s with low profile rubber and it's crazy light
, Id guess its less than half of what a s13 weights? (about 1220/1240 kgs)
I think there are enough clutch suggestions above my post to try,
only thing I can think of is possibly the clutch master cylinder and the slave your using are not ideally matched?
as in bore sizes are causing the high bite point,but thats a pure guess mate tbh
as I assume the clutch pedal lever ratio has been worked out to that master and slave combo (possibly?)
Hi Jonny thanks for the reply as usual :-)
The clutch came with the old engine and whilst used was barely worn in. The plates were still fresh and not bedded in.
The pivot isn't broke, I checked before I fitted the box.
The clutch has always been like this since installing, I think the issue is probably down to cylinder to slave ratio but I don't know how to work out what I have in that regard?
I thought about loosing half an inch off the length of the slave rod, which in theory should move the biting point?
I don't have a s13 clutch master to hand,but I have a s14a one and its marked as 5/8th or 15.875mm
and a 14a slave cylinder is marked 3/4 19.049mm I'm taking a guess that is the bore sizes of the stock parts
and not sure atm till can check in daylight if the 13 has same bore sizes
and I have no idea how to work out its ratio,but if your cylinders are marked somewhere it may help
has the clutch pedal got just one pivot hole? as I'm not familiar with the pedal box set up your using
Hi Andy,
Just checked the details - the MC is 3/4 and the slave is also 3/4.
Okie dokie we may be onto something, just had a look at my 13 and the master is marked 15 (15mm bore size I'm guessing)
its a different cylinder design but same bore size as the 14a master
and the slave is 3/4 same as the 14a slave so you may need a smaller clutch master cylinder
to be the same as the stock nissan cylinder sizes
I do recall you were cable clutch on the zetec set up and I had a look at the obp pedal boxes and the pictures were too
small to really ID the parts but I did notice there are cable box's and hydraulic pedal box's
possibly the difference is the clutch master mounting holes on one and a small hole for the cable version?
maybe drop them a call or email to confirm if the clutch pedal is same ratio of leverage on both types?
as they only mention the brake pedal ratio at 5:1 couldn't see any info about the clutch pedal
hopefully you just need a smaller 15mm bore master cylinder and it may lower the biting point
and some pedal push rod adjustments will get it spot on
Thanks for trying to help Andy,
If I understand correctly because my MC and slave are the same size atm that means for every mm my clutch moves the slave rod move the same, therefore I have a 1:1 ratio instead of a 5:1 ratio?
If that is the case can I not just shorten the slave rod?
I think if you do that you'll still have the 1:1 ratio, it'll just be lower down, might make it tricky slipping the clutch etc???Originally Posted by DaveB666
That's what I was thinking. Unless you change the ratio, the bite is going to be all in one short degree of movement. Changing the pin length is only going to move the range not increase it. The ratio will be what is making it like an on-off switch.
The obp website only mentioned the brake pedal as 5:1 ratio ,I'm guessing that's the leverage and pivot point of the brake pedal
They don't mention the clutch pedal only the brake pedal,sorry if that was confusing things a bit
I think you will need the smaller bore 5/8 or 15mm clutch master cylinder to get it close to the OE nissan pedal feel
and possibly lower the biting point etc
I have a neighbour who builds race cars like cossie turbo's into space framed chassis's and cool stuff,I run it by him later on
if the mcyl and slave are the same then the movement ratios are 1:1 but the pedal ratio then comes into play. a 1:1 mcyl to slave with a 5:1 pedal ratio means the clutch pedal has to move 125mm for 25mm at the slave. From memory you need about 40-50mm at the slave.
try to keep the clutch at a reasonable travel, so its easy to modulate and slip especially if you have a paddle clutch or the bloody thing will kangaroo down the road every time you try to creep forward in traffic lol
the pedal ratio essentially alters the effort levels and distance to modulate the clutch biting point. A lot of bike engine cars come unstuck as a bike clutch has little travel, and is light in operation (generally one finger on the clutch lever) so ones size 11 boot can be a bit excessive!
I've no real issue with the harshness of the biting point, its not as snatchy as previous paddle clutches that I've driven, its just annoying that the bite is so high to the top - that's why I was wondering about shortening the push rod which in theory will lower the biting point,I think.
God its hard to get your head around this stuff lol
Alternatively, you could slot the slave bolt holes so you could move the slave back and to on the bell housing. Not certain that's a good idea. Just a thought is all.
just cut a bit of threaded bar/old bolt etc.. a bit shorter than the current push rod and see what it feels like when its fitted. just get someone to operate the pedal whilst its still up in the air so you can check its in-gauging/ dis-in-gauging.
the release bearing/bearing carriers are different between pre facelift/facelift s13's and s14's are different too. some aftermarket clutches come with their own specified release bearings aswell. so you could have a bit of a mish mash causing you grief.
Told my mechanic mate about it today and he seems to think its not been bleed properly. He's gonna take a look on it on Saturday for me.
Best let the experts look before I start modifying bits.
Been out in again tonight, absolutely epic. Gets no traction until third LOL
Since the post above the clutch is better but still not great.
The gizzmo has been fitted and setup to about 1bar of boost but last night I think I've done a coil in....fix one problem and find another :-(
http://youtu.be/ixzePXCGcZ4
Can't see the vid at work but if it is misfiring/hesitating when coming on boost, check the plug gaps and set to 0.8-0.9 and not 1.1 as it says in the manual. 1.1. is OK for small boost but the spark gets blown out on higher boost.
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