Club G40 Forum
Technical => Engine and Transmission => Topic started by: SteilheckG40 on November 25, 2012, 04:02:00 pm
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So, here's the story.
Since I bought a Polo MKII, and we don't really know what to do with it, so we decided to prepare a new PY engine for the car witch is a little bit different to what we are used to.
(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-snc7/384301_272603909526834_1007411516_n.jpg)
For Worthersée 2013 we are trying to get the max out of a G40 PY engine.
Tough the setup is almost completely worked out on paper we still have some questions I hope you guys can answer.
First problem would be the clutch, what clutches would you recommend? I've seen the Sachs ''racing'' clutches that are claimed to survive a maximum of 300nm torque but my buddy is saying it is probably not enough. Suggestions?
Second unsolved problem is the gearbox, does anybody know howmuch torque/hp the average g40 gearbox can handle without breaking?
Ive heard story's about gearboxes collapsing in Polo's with about 165-180 hp.
Also i am aware of the modification needed on the fifth gear (oil supply), thats something that has to be done for sure.
So,
- What clutch will do the job for us
- On what torque/hp does an average gearbox decide to give up
- What 085 gearbox is the toughest (so we can already start stacking up a huge pile of those fuckers ;D )
Hope somebody could provide us some answers :)
Cheers!
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I don't know how on earth you're going to get more then 300lb/ft from a g40 engine but forget about using the 085 gearbox with that, I dare say it'll just smash itself to pieces every time you put your foot down.
You can kill the box in a standard g40 with some spirited driving, with about 200bhp, 200lb/ft the gearbox needs to be considered pretty much a consumable item much like tyres or oil filters. I currently have 4 of them in my garage, some OK, some awaiting rebuild. The differential needs fairly regular rebuilds too. It's a gearbox that was originally designed to handle something like 50-60 lb/ft, I doubt when they designed it in the 1970s they ever even thought VW would attach it to an engine with 113bhp, 110lb/ft.
Anyway, I'm interested to see what you have planned that'll produce >300lb/ft that doesn't involve putting a 20VT engine into it :)
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just to add, with mine, which is 194bhp, ~180lb/ft, I use a Helix Paddle clutch and it handles the power very well and has lasted a decent amount of time (even though most miles are on track).
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Adding oil to 5th gear, whats this modification ive missed this one? :-(
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I don't know how on earth you're going to get more then 300lb/ft from a g40 engine but forget about using the 085 gearbox with that, I dare say it'll just smash itself to pieces every time you put your foot down.
You can kill the box in a standard g40 with some spirited driving, with about 200bhp, 200lb/ft the gearbox needs to be considered pretty much a consumable item much like tyres or oil filters. I currently have 4 of them in my garage, some OK, some awaiting rebuild. The differential needs fairly regular rebuilds too. It's a gearbox that was originally designed to handle something like 50-60 lb/ft, I doubt when they designed it in the 1970s they ever even thought VW would attach it to an engine with 113bhp, 110lb/ft.
Anyway, I'm interested to see what you have planned that'll produce >300lb/ft that doesn't involve putting a 20VT engine into it :)
he was talking about NM, you are talking about lb/ft, if im right thats a difference of 106nm(thats a lot)
And polomon the 5th gear on the g40 gearbox dosn't get enough oil sometimes and thats why you can destroy a g40 gearbox by driving fast in 5th gear for a long time. And as a mod some people drill the oil hole bigger so it gets more oil and then it should handle high speed driving a bit longer.(thats what i heard)
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just to add, with mine, which is 194bhp, ~180lb/ft, I use a Helix Paddle clutch and it handles the power very well and has lasted a decent amount of time (even though most miles are on track).
i think 180lb/ft is abount 265nm, so i think the 300nm should be easy to go over with the crazy thing we got in mind. Our starting goal was 200hp just to see if the setup would work at all and then go on from there.
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180lb/ft = 244.0472306994 NM
Our goal, 300 NM = 221.26864478340818 lb/ft ;)
By the way, I drive always like an idiot, tough i've never had any problems with the gearbox on my old G40.
Well... did manage once to ruin a gearbox in a +- 50hp Polo ::)
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I've put 285Nm through a Helix Paddle Clutch and it's been fine so far.
There's no easy/cheap solution for the gearbox.
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d;oh I should have read the post more closely. Yes I was thinking 300lb/ft which is over 400Nm.
Anyway, if you've never knackered a gearbox on a g40 before, you'll definitely have that to look forward to sooner or later :)
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Anyway, if you've never knackered a gearbox on a g40 before, you'll definitely have that to look forward to sooner or later :)
thats 1 thing we can be sure of. And i think more then only the gearbox wil go. I think those driveshafts wil not take it to long either, and the body needs to be modified a bit for that power, else it will rip itself apart i think.
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Has anybody actually carried out the oil feed modification for the 5th gear??
josh
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Yup done it on a few boxes now :)
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Could someone do a quick write up or a few pointers on what needs doing to this oil way please. I'm on with rebuilding a knackered CEG box as a temp atm so I wouldn't mind getting my head around it with this box then doing it on which ever new box I get for long term:-)
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Could someone do a quick write up or a few pointers on what needs doing to this oil way please. I'm on with rebuilding a knackered CEG box as a temp atm so I wouldn't mind getting my head around it with this box then doing it on which ever new box I get for long term:-)
X2.
Think with what ive got I need all the cooling I can get