Author Topic: Yoof's Turbo  (Read 99794 times)

Offline RyanC

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Re: Yoof's Turbo
« Reply #315 on: February 18, 2014, 09:48:00 pm »
you can't swap the bell housings over, that's why he's using an adapter plate
Nice work Pete interesting stuff!!

Offline Yoof

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Re: Yoof's Turbo
« Reply #316 on: February 28, 2014, 06:08:48 pm »
History

085 Transmissions have a reputation of being weak especially in higher powered boosted applications. Not surprising given the 084 is was based on had to handle 895cc of power and a lightweight Mk1. Add a little weight, and lots more power (about 4 or 5 times the amount of the Mk1) and it’s not surprising a 230bhp G40 will strip gears for fun.

So far my 085 failures have been:
•   Inner CV Joint
•   2nd Gear
•   3rd Gear
•   5th Gear
•   Diff/Final Drive Bolts
Time for a change...

Gearbox Options

Various options are available depending on budget, time and ability. My own headline figures to work to are:
•   200kW (268bhp) Crank Power
•   300Nm (221lbft) Crank Torque
•   750kg + 2 Passengers (150kg)

Other consideration needs to be given for:
•   Gear ratio options
•   LSD options
•   Clutch/Flywheel Combination
•   Chassis Modifications Required
•   Quantity of non-OEM parts
•   Cost

That leaves some obvious choices:

085 Gearset
 http://www.klaus-bernert.de/rennsport.shtm

Not a huge amount of information about these, especially at the power/torque levels required. To benefit from the sequential requires an EMS change, or additional control for torque reduction (ignition/fuel reduction) during shift. Cost is high (6500EUR+)

Getrag R65 5C39


From a Mini Cooper S, 6 speed with triple shafts, so is shorter than most conventional FWD boxes (ala 02M). Custom clutch and flywheel required, along with mounting, shifter mechanism, and must be hydraulic clutch. Good spread of ratios with a 540mm tyre diameter (175/60R13 or 20/54-13 slick) gives 150mph in 6th at 7000rpm. One to think about...

Sequential Sadev/Gemini/Ricardo etc

£10k+ not being considered!

02a/02J


Validated to 250Nm for production in larger (note heavier) applications, so should be capable of handling more torque in a lighter Polo chassis. A good range of gear ratios, gear sets available, wide range of LSDs readily available. Gearbox can be had from £50 upwards, and have been in production recently. A mix of VW parts means cable change for the clutch, and flywheel/clutch combinations should be achievable without too many custom parts.

Worth noting 02M is a 6 speed, but is heavier and larger than the 02J, it has a torque capacity of 350Nm, and obviously has a bolt on transfer box for the 4wd applications (S3 etc) little overkill though.

Gear Ratios
I run various wheel/tyre combinations on the Polo, for gear ratio calculations the diameter/circumference of the tyre is important, here’s mine:
175/60 R13 (Stock G40) – 540.2mm
20/54-13 (Slick) – 540mm
18/53-13 (Wet Slick) – 530mm
20.8-14 (Drag Slick) – 508mm

For the comparison I’ve used a 540mm diameter tyre. I rev the Polo to 7,000rpm on track and have used half max rpm to calculate a cruising speed at 3500rpm.

Stock G40 gives:



150bhp 20v 02J gives:



Not really ideal, similar to a GT box in terms of ratio spread.

180bhp 20v 02J gives:



Ratio spread with ATV on a 540mm tyre:



Next instalment will cover adapter plate design and machining to couple the 02J to the PY block, all for now!
Pete

Offline z3i

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Re: Yoof's Turbo
« Reply #317 on: February 28, 2014, 06:51:23 pm »
Pete you dam legend! Thanks for that! Can't wait to see what's next!!! :D

Offline z3i

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Re: Yoof's Turbo
« Reply #318 on: March 01, 2014, 05:03:45 pm »
Saw it on Facebook and rich has posted it, roettele racing have got an 02a gearbox that fits polo

Offline Yoof

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Re: Yoof's Turbo
« Reply #319 on: March 01, 2014, 08:45:11 pm »
They have- similar principal to how Sorg used to do it, although it wouldn't be my first choice because:

- 2 gearbox casings required
- Tolerance hard to achieve with welded in components (centre of clutch spline to dowels <0.1mm)
- You have an expensive gearbox casing!

It does save you the width of an adapter plate (10-15mm) though.

Plus I guess it's a similar price to Sorg, so fairly expensive. 

Offline Karlos the jackyl

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Re: Yoof's Turbo
« Reply #320 on: March 02, 2014, 07:08:32 am »
They have- similar principal to how Sorg used to do it, although it wouldn't be my first choice because:

- 2 gearbox casings required
- Tolerance hard to achieve with welded in components (centre of clutch spline to dowels <0.1mm)
- You have an expensive gearbox casing!

It does save you the width of an adapter plate (10-15mm) though.

Plus I guess it's a similar price to Sorg, so fairly expensive. 

The rottele method would also save you additional costs of fly and clutch setup.

Offline Yoof

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Re: Yoof's Turbo
« Reply #321 on: March 02, 2014, 07:56:32 am »
They have- similar principal to how Sorg used to do it, although it wouldn't be my first choice because:

- 2 gearbox casings required
- Tolerance hard to achieve with welded in components (centre of clutch spline to dowels <0.1mm)
- You have an expensive gearbox casing!

It does save you the width of an adapter plate (10-15mm) though.

Plus I guess it's a similar price to Sorg, so fairly expensive. 

The rottele method would also save you additional costs of fly and clutch setup.


Flywheel yes as you can use a polo item, clutch friction plate needs a golf spline, and 200mm, so custom required... Like the one you're selling.

Also clutch release bearing needs adapting for golf arm to Polo clutch fingers.

Offline Karlos the jackyl

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Re: Yoof's Turbo
« Reply #322 on: March 02, 2014, 09:05:58 am »
They have- similar principal to how Sorg used to do it, although it wouldn't be my first choice because:

- 2 gearbox casings required
- Tolerance hard to achieve with welded in components (centre of clutch spline to dowels <0.1mm)
- You have an expensive gearbox casing!

It does save you the width of an adapter plate (10-15mm) though.

Plus I guess it's a similar price to Sorg, so fairly expensive. 

The rottele method would also save you additional costs of fly and clutch setup.


Flywheel yes as you can use a polo item, clutch friction plate needs a golf spline, and 200mm, so custom required... Like the one you're selling.

Also clutch release bearing needs adapting for golf arm to Polo clutch fingers.


True , helix or any other good clutch manufacture can make a G40 cover plate to suit an 02a bearing if needed ,  it could be more cost effective in the long run as you'd save on a custom flywheel and 10mm + on the chassis side. Both methods have their benefits .  Some people may not want to cut into the chassis leg due to potential issues with MOT for picky testers. Not too much of an issue on a track car though





Offline z3i

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Re: Yoof's Turbo
« Reply #323 on: March 02, 2014, 10:59:50 am »
Don't really fancy cutting my chassis legs, they are weak enough as it is lol. Is it more than likely I will need to cut the chassis leg where 5 gear is on the box if an adapter plate is fitted
 
The starter would be on the front of the box for a golf box :) would be soo much easier for access

Offline Yoof

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Re: Yoof's Turbo
« Reply #324 on: March 02, 2014, 11:52:58 am »
You need to cut it for both methods, and potentially the bulkhead.

Helix want £300+ for the clutch, as do Sachs but they won't alter a pressure plate to take a Golf bearing.

IMO better off with a Golf flywheel, Golf clutch (organic) and Golf release bearing. Can make the assembly weigh similar to stock G40 although the inertia is slightly larger due to a bigger diameter.

Golf starter motor also lighter than a Polo one by over a kilo ;)

MOT not an issue, nor are MSA regs

Offline robt

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Re: Yoof's Turbo
« Reply #325 on: March 03, 2014, 09:26:00 pm »
Sounds like a damn good idea to me Pete  ;D

Hello by the way. First post on this here forum  ;D

Offline z3i

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Re: Yoof's Turbo
« Reply #326 on: March 04, 2014, 05:38:34 am »
Cutting chassis leg on my genuine g40 eeek!, if that's the only possible way, I'm having second thoughts :(

Offline Yoof

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Re: Yoof's Turbo
« Reply #327 on: March 04, 2014, 12:26:59 pm »
Cutting chassis leg on my genuine g40 eeek!, if that's the only possible way, I'm having second thoughts :(

No way it will fit without.

Offline z3i

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Re: Yoof's Turbo
« Reply #328 on: March 04, 2014, 01:52:24 pm »
Dammit!! That's pissed on my fire. If I can't fit a gold box I can't go g60 :/

Offline z3i

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Re: Yoof's Turbo
« Reply #329 on: March 04, 2014, 05:47:09 pm »
Not doing it, roettele racing posted pics of thier progress cutting the chassis leg, looks horrific, not for me thanks. Not on a genuine G anyway