Hi, i sow few conversion plates,and i decided to go with the aluminium one, with thickness something about 5-6sm, the seller says that it doesent change the original gearknob place, but i am wondering about the gears shaft,is it enough long to use with 6sm plate between the engine and the gearbox?
Hey there. I have the 6mm plate for this conversion fitted by Polo on this forum. by gear shaft do you mean the shaft that runs into the clutch from the box?? If so Then this is not a problem. There is already a 2mm gasket/spacer between the block and gearbox as standard so you are only moving the box 4mm further back. Also the shaft at the front of the RB box is longer than the SR. Even with the box being further back, the shaft locates better than original. As for the shifter, I run a modified standard r33 shifter to allow the interior trim to be refitted. I have pictures in the below thread.
Check out this thread for more information.
yes the same shaft that goes into the clutch, how longer is than the sr20 shaft? 1-2-3-4-5-6sm?need to know how much can move the box back, i can put spacers between the box and the engine, but need to know how longer is the rb25 shaft, as you can see on the picture, the aluminium plate is much more wider than the polo's plate:
that looks about 60mm thick, bit of overkill.
Why do people not just cut and weld bell housings??? so simple and everything bolts on as easily as a std box...!!!
Ive done loads
i would guess one reason would be the cost for people who cannot weld and possibly another would be that if the box breaks you cant just bolt another on you would have to change internals??
im not sure about how much longer it is. As for saying that 60mm plate looks over kill, with a 6mm plate my shifter is about 60mm forward, sorted with a cranked shifter
yes, but the manufacturers of the 60mm plate says that when you put their plate the shift knob stays on its place, and there is nothing to do just plug-and-play ... but what is strange for me, if i use 6mm plate, its ok, when i use 60mm plate, again ok ... how long is that shaft and where it go with the 6mm plate, maybe 60mm deeper?
u must of got that from a picture i postedOriginally Posted by lidlleecher
yes the same shaft that goes into the clutch, how longer is than the sr20 shaft? 1-2-3-4-5-6sm?need to know how much can move the box back, i can put spacers between the box and the engine, but need to know how longer is the rb25 shaft, as you can see on the picture, the aluminium plate is much more wider than the polo's plate:
i can give u more info on it
the reason why its so thick is so the gearstick can still go threw the standard hole in ur car (it only sits a little off)
it uses a spacer which sit between the flywheel and the crank shaft so the input shaft still goes threw ur fly wheel
here is a picture of wat i mean
thats exactly what i want to know, and what about the starter? after the distance between flywheel and crank is increased with that spacer, can it still work with the original starter?
Starter motor mounts on the plate and that aligns with the flywheel, but the startermotor holes needs it's threads to be drilled out.
From my measurements the R33 input shaft is SHORTER than the SR20's so once you space out the gearbox 6mm, you're loosing even more "location" in the spigot.
Cut/shut/weld jobs are hit and miss - some are ok and some are shit - misalign it by a mm and you'll forever have issues. Some cut/shut/weld jobs break and if that happens you don't just kill the gearbox, say bye bye to your clutch and motor.
6mm only works with the s14 flywheel, which is a good thing.
60mm only works with the s15 flywheel... when spaced out. What do you think will happen when you space out a heavy s15 flywheel (which is always significantly heavier than s14) on a crank turning at 4/5/6/7000rpm+, supported by bearings on one end and nothing on the other?
HINT: think of what happens to your wheel bearings when you use fat 20/30/40mm spacers
thanx to everybody, i am planning to use 35mm aluminium plate without spacing the flywheel, the spacing of the flywheel is scaring me enough, but are you sure about the r33 input shaft length? because in the threads of r33 box conversions i always read that the shaft is longer and you will have more location in the spigot. making 6mm plate is the easiest job on the earth, but i want at least 30mm spacing from the engine, and just to bent the gearstick not to cut/weld
Why is the s15 flywheel heavier?
Polo's conversion with a modified gearstick shaft to get it centre'd back into original position sounds the best to me.
Cheers Aj
Thats the one i will be going for.
Check out the design of the s15 flywheel VS the regular s14/s13. The s15 from factory is "dual mass" and hence has more material in it. Most (if not all) aftermarket flywheel options convert the s15 flywheel into "single (regular) mass". Does this mean aftermarket "single mass" s15 flywheel's weight will equal the aftermarket "single mass" s14 flywheel? No.
This is because manufacturers need to keep the same s15 dimensions in order to place the spigot, ring gear, clutch face, etc in the same place as standard, so the overgrown "dual mass" s15 flywheel will forever stay overgrown, and hence will always be heavier than it's s14 counterpart.
The biggest issue with the 6mm plate idea is exactly that - 6mm's. You're hanging 50kg of metal off 6 studs supported by 6mm of metal. Try to picture the whole set up the way it is...
- A long and heavy chunk of metal, supported only on the far ends with their respective mounts... now where will the most stress be on? The centre.
- Now change that long and heavy chunk of metal to two pieces (motor and gearbox), still supported only on the far ends with their respective mounts. The stress will still be in the same position, centre, but this time it is concentrated on the weakest point... which is where the gearbox bolts onto the motor.
- Finally, change that weak connecting point with a few studs welded into a 6mm plate.
Add in hundreds of miles of bumpy roads and pot holes and the way I see this gearbox and motor set up is exactly like an accordion.
You're planning on a 35mm spacer plate? Why 35mm? I measured up the R33 gearbox and even if my measurements are off by a few mm's, I am 1000% sure that my measurement is not 35mm off, or anywhere near that.
I don't know what gearbox so and so measured, but I measured a Skyline R33 GTS-25T gearbox and the input shaft is SHORTER than anything from a silvia. Also... my factory OEM "sandwich plate" thing is LESS than 2mm.
I'll be under my car tomorrow so I'll measure the powertune spacer plate and let you know. You'll need to use a slightly thicker spacer plate as the powertune one still sits the shifter and shifter housing too forward, anything thinner will mean you will have to start cutting away at your chassis shifter hole. I'll say approximately 5-10mm thicker off the top of my head would be best, but then you have to seriously consider if you want to go down the path of the s15 flywheel and flywheel spacer.
oh mate, now i dont know what to do ... if its for s15 only, and they are so different, i dont know what to do, pls measure your plate and refer back to me, i have very strong bolts, so dont worry, i always use black steel 10,9 strength bolts for my car, but i will decide what to do when you measure your plate
WTF are you talking about? The 6mm plates have been proven, they work just fine and hold the box perfectly well. I even got the beggest lever bar i have 1.5m, and leverd the box from the engine, it does not flex or move in the slightest, i even went to the extent of using a DTI! if its not flexing and moving it will not fetige or stress. I have 20 of my plates in cercilation and not one of them has broken or had even the4 slightest of problems.
The thick plate looks dangerous to me!! fly wheel spacer = insane and dangerous!!!
Aswell, it looks to me like there is now spigot location for the input shaft on the box = Insane and you will lunch box after box!!!
Last edited by Polo2; 27-08-2009 at 08:08.
I didn't know what to do either, I've had a few different conversions through my car and only (stupidly) AFTER buying, installing and running them and then AFTER spending all the time, effort and money did I realise the issues, so now I'm sharing my findings.
I can't wait to get my next gearbox in, there's not going to be any compromises this time
I measured the plate for you, it's ~45mm, but what are you going to do about the spigot?????
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