Club G40 Forum
Technical => Superchargers / G-Lader => Topic started by: GAF2 on August 03, 2011, 08:15:14 pm
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Hi guys,
i managed to get my hands on a 58mm toothed pulley a while back and today my nose finally got the better off me and i fitted it. Now i know that in a perfect world i would need a new chip/map to run the smaller and i am goin to contact PPP for a custom chip but before i get that will it be dangerous to run it as is?
The chip i have is set up for my 65mm pulley and it has always ran rich which i read is common with off the shelf chips so with the smaller pulley = more air is it possible it could be ok or is that wishful thinking and not as easy as that?
I havent driven the car just idle and it seem to run fine and when you rev it... ha ha what a noise.
cheers Grant
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only issue is that at 7,000 engine rpm, the charger bearings are at their max safe rpm with a 65mm pulley, so watch yr rpm!!!
I know one person who revved a freshly serviced charger with a 60mm pulley 3x to 7.5k and then the top charger bearings seized and it grenaded!!!
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Sounds fun! any chance you could count the teeth on the pulley for me? I'm toying with going to the next size down my my current pulley and would like to know some drive ratio's.
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cheers for the warning pete, is there uprated bearings available do you know?
Am shite at maths any idea what the max rpm would be now? suppose just need to be sensible see how it goes. What do we think service intervals would drop to with a 58mm pulley, every 5000 miles?
Dont think am gonna run it all the time will prob just put it on every now and then or get my spare charger ported and rebuilt and put it on that. Its sounds sweet tho my 65mm pulley never made any noise at all me being a big kid i love the whine.ha ha.
Justin an not gonna be near it today but will count them for you tommorow or saturday. You thinking about making a 60mm or something?
cheers Grant.
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cheers for the warning pete, is there uprated bearings available do you know?
Am shite at maths any idea what the max rpm would be now? suppose just need to be sensible see how it goes. What do we think service intervals would drop to with a 58mm pulley, every 5000 miles?
Dont think am gonna run it all the time will prob just put it on every now and then or get my spare charger ported and rebuilt and put it on that. Its sounds sweet tho my 65mm pulley never made any noise at all me being a big kid i love the whine.ha ha.
Justin an not gonna be near it today but will count them for you tommorow or saturday. You thinking about making a 60mm or something?
cheers Grant.
Well I have some custom made steel ones that i machined myself so know the drive ratios, also know the ratios of the PSD ones ( they are a different amount of teeth but the same drive ratio) so at the moment I'm on a 2x crank speed pulley (1.6x is standard) next one up is 2.18x just wanted to know what PSD would call a 58mm drive pulley - so i can see what 2.18x would be comparatively.
Hopefully it would be around 60/62mm so its not massively brutal on the charger like a 58 could be, chances are its probe the same as your 58 though.
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Straight over my head mate. ;D. Will get them counted tomorrow.
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you can get top bearings which are higher speed, but the seals on them arent as good (they are shields) so shit can get in and grease come out!
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you can get top bearings which are higher speed, but the seals on them arent as good (they are shields) so shit can get in and grease come out!
How long will they last? Can you get some? they are ZZ code are they not? quite tempted to try it out but would have to make a stand alone oil supply so i don't feel guilty for the G-Lader
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they are zz's and are same price as normal shielded ones... these are the only bearing in the lader that is not oil fed, just grease lubed. Not sure how long they'd last tbh...
these at bartek are supposedly higher rev range - http://www.bar-tek-tuning.com/lshop,showdetail,28272,en,1312484027-28327,g-lader.1132925576,1100007,9,Tshowrub--g-lader.1132925576,.htm
probably means the seals are viton so absorb heat better. (thats all difference between rubber shielded and metal ones will be i think)
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i used them and never had problems. Just pack em with a little grease between the two side shaft bearings, obviously dont fill the gap with grease though.
Oh, i wasn't using a 58mm (deep pockets pulley) nor would i have even though the bearing supposedly could take it.
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cheers for that pete, just getting a stand alone oil supply sorted out. Might see about getting my other charger rebuilt with these bearings and see how it lasts with the 58mm pulley.
cheers
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not sure what would be better, the bar-tek ones or some ZZ's if the ZZ's shit grease everywhere they might not last long.
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i'd sooner use the barteks in my opinion, be interested to know their code to see if can be sourced in uk
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i'd sooner use the barteks in my opinion, be interested to know their code to see if can be sourced in uk
http://ahrinternational.com/SKF_nomenclature.shtml
according to this the SKF code for bearings with a viton seal is '2rs2' so i suppose the bearing you are looking for is a SKF 6003.2RS2
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now you need to find specs of bearing for differences in rpm, if there is one!
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now you need to find specs of bearing for differences in rpm, if there is one!
After googling(< holy shit that doesn't set off spell check) for hours I can't seem to find anything, maybe i'll have to buy the Bar-Tek ones to see. I'll probe contact them as 2.18*6500 is 14170rpm in the charger which is a huge amount so if its substantially above that I'd be quite tempted to rebuild the charger, make a stand alone supply and run the smaller pulley.
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i'll ask my bearing supplier if they can supply.. Expect they'll be quite a bit dearer as they arent as comon
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Got loads in the shed.
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Got loads in the shed.
of the Bar-Tek bearings?
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Got loads in the shed.
of the Bar-Tek bearings?
he means the zz bearings - they are the same price as rubber sheilded and dead easy to get.. We meant the viton rubber shielded bearings.
pete
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Ok, I contacted Bar-Tek and they say those Viton high RPM bearings are rated to 18,000 rpm. Pete do you know the next RPM limited bearing after this top one? I presume the Viton seals you sell are better at dealing with the heat from the friction on the main shaft than the black ones I got from jabba last time I rebuilt it?
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from previous posts and searching..
normal top bearings have a limit of 12,600rpm
the charger spins 1.6x crank speed on a 76mm normal pulley.
therefore at 6500rpm= charger spins at 10,400 rpm
76/65 = 17% smaller (ish)
therefore a 65mm pulley is 12,160rpm
a 60mm pulley is 13,173 rpm
a 58mm puley is 13,628 rpm
so the bartek ones be fine.
I've asked my supplier, who's gettin back to me with prices.
And yeah - viton seals i supply deal with heat better (and actually cost 10x price to have supplied rather than nitrile - black - ones)
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Well my bottom pulley has 48 teeth and my charger pulley has 24 teeth, so thats 2:1 drive, so at 6500 rpm its 13,000 rpm already - PSD's toothed systems where also 2:1 so should put out 13,000 rpm too - unless there is another measurement I haven't calculated about pulley sizes?
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I don't see how how any of this makes any difference, everyone knows that 58mm pulleys destroy chargers so why bother? The bearing arent all you need to worry about, what about shitty apex seals sitting in waffer thin aluminium guides and tiny little teeth on tiny little belts? Yeah it be great fun for a while, and then a pretty big paper weight not long after that.
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They seem to get away with it in portugal though, 58mm seems to be a standard upgrade there. I've almost done 40k with the charger spinning up to 13k rpm, with different bearings and other oil supply modifications why not another 1k rpm? I understand what you are saying - but sometimes its good to do something different.
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you very rarely go up to the full speed anyway, 6500 probably past peak torque
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(http://www.roettele-racing.de/shop/images/dbimages/artikel_0000093_362_b.jpg)
Maybe I should make some of these too....
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Is that the 20mm internals Justin? If so you need a bit of milling to fit them.
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i'd not bother.. seeing as i've never seen one fail (wider ones anyway) without top bearings failing.
Plus the fact that the bracket is also weak, the last 8 i've seen have hairline cracks in them at the top bolt hole where the oil feed P clip is. Routing it out to take these will only weaken it more i would've thought.
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IIRC Bar-tek took material out of the casing; don't know how much would be available, but pretty dicey I'd imagine.
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they take it out of mounting bracket and off the charger pulley too.
You cant take it out of the charger casing itself as the top one has a bearing in the way and behind that is a counterbalance weight and the bottom one has an oil seal and then a bearing!
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yeah its about 11mm i think, not a huge issue - is there any load on the cover that you need to mill out though?
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dunno, you'd have to find out... though milling the cover, charger pulley and getting hold of the belts for me is a ballache for no gain - i mean if you're going to this trouble - why not fit a wider toothed pulley belt or timing belt as they are just as likely to snap! if not more so!
The top pulley will only be held on the shaft by the same amount of shaft as the original pulley anyway.
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Sorry it took me so long Justin, my 58mm pulley has 23 teeth on it.
If you can get the uprated bearings from your supplier pete i would interested in a complete rebuild kit including them and a 1000 length belt too.
Cheers Grant
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am waiting for supplier to get back to me... but have rest of rebuild stuff to hand... club g40 doesnt supply 1000 belts though!
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So you don't think having the wider pullies or belts is worth it then? Sure they'd be quite easy to source here.
Wow. 23 teeth? If you have the rest of the pitstop set that's a 2.26x drive! Amazing.
Here are the 1000 length belts btw.
http://www.amazon.co.uk/gp/aw/d/B002T8V2CG/ref=redir_mdp_mobile/275-6099685-4312206
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Yeah i have a the Psd crank and altenator pulleys. So what rpm is the charger doing when the engine is at 6500rpm,
6500x
2.26
=14690rpm?
So that uprated (Bartek) bearings are within spec to handle it. Cheers for the belt link.
I havent tackled a charger rebuild my self so not sure but how many bearings are we talking about? all of them or just the 2 main shaft bearings?
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yeah 14690 is about right, anything over 14,000 is extremely high but with my calculations I've been up to 13,000 for almost 40k now - though i know there is a fine line between a high charger rpm and a dead charger.
If you are planning to run this pulley I would replace every bearing & seal, using the high RPM bearings as well - just to be safe. its a huge amount of force to be putting on the top bearings & the scroll.
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Can we get all the bearings required in the higher spec or is it just the two main ones and get the rest of the charger serviced as normal because my charger was serviced just over 1000miles ago at jabba so everything should be ok still.
I have since put my 65mm back on and its just not the same now, i want to be able to run the 58mm all the time and when you factor in the new bearings, the amount of miles i do as its not my daily, now have a standalone oil supply and as pete says 6500 is proberly past peak torque i think it will be worth trying -no?
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If its only had 1k on it only change the top 2 bearings then, how much more thrust did it feel like it had with the 58mm on?
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yeah thats what am gonna do then. It was mint with it on, my boost readings nearly doubled and it pulled harder faster if that makes sense. Reckon it will need a chip tho, i think (not totally sure coz i only did bout 10miles) there was a slight flat spot in the the rev range possibly to do with fueling?
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all the other bearings are over that spec anyway as they are oil fed...
however if you get in the chagrer and it has black seals, they are nitrile, so i'd change them for viton, which can handle higher temps.
AS for wider toothed belt - i'd not bother, but i'd put a new one on when the charger is off , and check clearance against the mounting plate... some do catch!