after 2 years and 2 month and grand later my 40 is running revs too over 8 grand awsome alls next is mot and thas it on the road :)
Over 8 grand!! :o What's the point in revving it that high? The charger won't like it, especially if it's got a smaller pulley and it's way past peak power anyway.
Take it easy mate. Good luck with the MOT.
iv rebuilt it all proply and worked out the calculations
which bearings did you use on the pulley countershaft?
i got the rebuild kit from bartek
charger bearings with metal seals? It's the future.
metal seals/rubber seals - all have same rpm raneg -
even the bartek ones, which i presime are justbearing with better grease and viton seals most probably have same rev range.
are you using solid lifters?
so what is the point in people making and selling ecu chips that go over 8000 rpm for g40s if its just gonna blow the charger ???
Quote from: PeteG40 on April 14, 2010, 10:38:39 PM
metal seals/rubber seals - all have same rpm raneg -
even the bartek ones, which i presime are justbearing with better grease and viton seals most probably have same rev range.
are you using solid lifters?
Not according to my catalogue they dont. Bearings I use offer a 6k rpm increase over standard rubber seals.
And what is that higher RPM limit Rich? What size pulley are you using bushy? If my quick sums are right, with a 65mm pulley at 8k engine speed the charger will be knocking on the door of 15k rpm.
65mm pulley i think its something like 15600 have too find the paper and well if it goes bang it goes bang witch i know it wont at least i tried something different and didnt stick to the norm that every one dose
normal countershaft bearings have a safe limit to 12,600 rpm if i remember correctly.
True Richg40 - the metal ones do have a higher limit, which i was unaware of - however, generally they have gap seals. not lip seals - so i believe most lader rebuilders dont use them as they dont seal as welland are more likely to spunk their grease out and let shit in as far as i'm aware. And as they are inside a lader you can't see them if they have!
charger aside - the 8krpm, will need solid camlifters to avoid float and it'll need a new map sensor and remapping to work effectively - as anything overabout 1.2 bar andthe stock map sensor goes spazzy
Been there, done that, built the engine, destroyed any charger that was on it, even on a stock pulley and vee belts! couldn't handle the RPM and how quick it would rev to get there, including heel n toe downshifting. Hence a turbo conversion was on the cards.
Do you realy gain all that much from revving your engine that high? Can't be good for reliabilty or longevity of the engine I'm thinking but I don't know half as much as these guys do.
Quote from: liam on April 14, 2010, 10:47:35 PM
so what is the point in people making and selling ecu chips that go over 8000 rpm for g40s if its just gonna blow the charger ???
the original reason was simply to move the rev limit up out of the way so you wouldn't hit it. Hitting the hard-cut rev limit causes a sudden decrease in rpm which isn't good for the charger at all, so PSD set rev limit to 8k rpm so it was well out of the way and then it was up to the driver to keep a better eye on revs.
Then on top of that, big numbers sell parts....
Sure you can build an engine to withstand 8k and tune it to make power up there but I'd not want to do it with a g-lader and you should also convert to solid lifters too or there is a risk of valve float at much past 7k rpm.
Quote from: dub-disaster on April 15, 2010, 09:16:45 AM
Do you realy gain all that much from revving your engine that high? Can't be good for reliabilty or longevity of the engine I'm thinking but I don't know half as much as these guys do.
You seen berg cup cars then? 10Krpm!!! ;D
Well they aint gonna last 100kmiles if you know what i mean. mine was rebuilt after 10K, although I clocked that up on road miles for which the car was not originally built for. Build a solid engine though, it'll last and be reliable, rebuild will conissit of pistons rings and freshen up generally, as yoof before has said ignition becomes a problem.
As for any gain up there, you need to find the right cam to make the best of it, I tried a newman 264deg, crap, peaked power at 6600rpm, a 1000rpm under what i wanted and couldn't really play with the vernier. Never got to try anything else.
Although i do agree that a lower rpm and a bigger turbo say will give you as much benefit.
in my opinion anybody who sells chips for g40s that rev over the safe limits of the charger should at least supply some information regarding this, i didnt know about the safe limits of the charger and have had to buy another one because of this and it could of easily been avoided if this information was supplied with the chip.
Quote from: liam on April 23, 2010, 10:46:03 PM
in my opinion anybody who sells chips for g40s that rev over the safe limits of the charger should at least supply some information regarding this, i didnt know about the safe limits of the charger and have had to buy another one because of this and it could of easily been avoided if this information was supplied with the chip.
Liam,
When you buy speed rated tyres- it doesn't mean you can drive at 149mph all the time...
The same is with the raised rev limit, it's there to stop you hitting it and causing damage to the charger seals, it's not there so you can rev to 8,000rpm with no prior thought.
Fortunately Andy will (and does) spec chips with a custom rev limit, should the customer wish- therefore the choice is all in your hands, rev high and take the risk or retain a stock rev limit and hope you don't hit it.
Pete
i had a little feeling you would reply to this Pete, i`m not trying to blame anyone i know it was my fault but i just didnt know,
i just think it would be beneficial for everybody if it was mentioned in the instructions.
because of me not knowing this it has just cost me another 800 pounds for a new charger and i had to split the block and have it checked for damage as there were shards of metal all through my boost pipes.
It's unfortunate you've had to learn the hard (and expensive) way... good effort on splitting everything apart, hopefully the pieces of charger havn't got too far.
For future info the higher rev limit is employed to stop the engine hitting the rev limiter and causing a pulsation in the oil system pressure, which in turn caused charger oil seals to be spat out. Ideally a soft cut limiter (usually done with fuel trimming rather than ignition cut) would be put in, unfortunately digifant doesn't have provision for this.
Unless any PY engine has been specifically built with RPM in mind, I've never seen one make peak power past 6500rpm with a g-lader on. Save the revving to those who don't have boost ;) ;D
Am i right in saying that maybe a shift light might come in handy? ???
Maybe set it at 6000rpm to give you 500rpm delay and reaction!!!