Hi All,
I know I probably belong in another forum as my car is only veedub when it come to the chassis, suspension and gearbox but I need a little advice.
Background: I have Purvis Eureka with a 12A turbo motor. The motor seems to be bog stock but it does have a Haltec E8 ECU hanging off it. Last month the right side axle sheered the splines on the disc hub and did some damage in the transaxle as well. The front transaxle mount was sheered as well. All of this has been pulled out and now sits on the garage floor in shame
Project: Since I live just 20mins from Willowbank I would like to put back in a really good transaxle setup that will handle a bit of a beating, ei go down the 1/4 mile. I intend to stick with the 12at for Qld rego legal reasons but happy to do as much as possible to the setup to see what can be done.
Experience: I'm one of those fat old farts with 4 kids who wants to try something different. I can swing a spanner but just need some guidance.
Rear end: Swing arm
Brakes: 4 disc
Hubs: 5 stud ea pattern

I'm in contact with Rancho in the states but I would like to check out other options/ideas.

Thanks all.
Dean

gearbox rebuilds - dave butler - "dangerous"

yeah welcome......

Don't worry, it's the right place for Eurekas too.

yes Dave will be able to build you a gearbox to handle anything you can throw at it.........and he is just down the road from you.

http://forums.aussieveedubbers.com/viewprofile.php?memberid=3145 

after you have 5 posts you will be able to send him a personal message.

have a look around for posts by Aaron AKA "quickcamper" in the drag race forum, 700hp rotary powered kombi nutbag

Thanks heaps guys, just what I needed!

One of the first questions I'll have is:

What would be the maximum power I would see from a streetable 12at?

I can download 2 seperate maps into the Haltec. One for the strip and one for the street.

Need this info to sort out what the drivline needs to handle before I go annoying Dave.

Any guesses?

I should add that there are limitations to this project and basically they are that it needs to be streetable (The Eureka isn't the best drive anyway) and I'm stuck with the 12a turbo due to Queensland rego laws (getting approval for a different motor is not part of the plans).

If I'm going to put bits in I don't want them to break. I want the weak link in the chain to be were the wheels meet the road. Then I can work on et's.

both Aaron and Dave would be the most down to earth approachable people you could hope to meet, so don't think you will be a "bother"

ask Aaron about the rotary, for sure he will know of a mazda forum where you will find any info you're after.

this would be Aaron actually "20bkombi" now........

http://forums.aussieveedubbers.com/search.php?srchuname=20bkombi&searchsu...

Thanks Scotty.
Doing it right is the plan.
The previous owner did well with paint and interior but the mechnicals left a lot to be desired.
Which has opened an opportunity to replace broken things for this project, and have a little fun on the way thru.
I'm not after "the best", as there is always someone better out there. Just getting behind the wheel on a 1/4 mile is my goal.
Thanks again everyone, I'll go chasing.
Will update along the way.
Dean

I just needed to stick up one more post so I can start PM'ing.

This was the last photo before it was retired to the shed for the current gearbox repair. Thanks to the towy, great bloke.

Say g'day if you see me around.

Still love these cars.... Looks cool dude

Looks nice and slippery for the quarter (ie. aerodynamic compared to a beetle!)......I can vouch for Dave being the go-to man for boxes (as I'm sure reub and damo [hellbugged]) can attest to as well.

Good luck with the motor/box rebuild!
Al

You could also consider a naturally aspirated rotary. You can get good power out of them for the money, a 12A or 13B bridgeport or extend port would move it along nicely. With injection they're a little friendlier to drive than carb fed ones too, especially the more they're modified. The only real problem would be exhaust noise and fabrication, with bridgeports if you shut them up they just don't go very well, and being rear engined there isn't much room for a decent rotor suited exhaust. Sticking with the turbo eliminates a lot of exhaust noise.
A Renesis 13B (RX8) could work too, it would give you pretty good power while having low emissions and noise, better economy and reliability too.
Just a couple more options anyway.
If it were me, I'd go for a 51mm Weber fed 13B bridgeport, it'd be loud and cranky but so much fun and I like old school stuff

Hi All,

Dropped off the box, axles and hubs to Dave today to do his thing. I learnt lots and will keep you all posted as we go. Sorry to hold you up for so long Dave.

First step is to order a set of heavy duty axles off Rancho and get a Quaife centre. I'd like to go to solid rear end but I need it streetable.

Dave also suggested the Rhino case which sounds like an excellent option.

I'll also need to chase up the hub centres (I run EA Ford pattern rear disc's) with John Sherman but that'll be a couple of weeks before he gets back. The old hubs weren't tigthened to the axles, things got sloppy and has sheared off the LHS splines. I think they call that free-wheeling.

I'll look around for a gearbox strap kit, poly mounts and the intermediate (extra rear mount for the box). Again, I could go solid mounts but I have enough squeaks and rattles in the Eureka without adding any more.

Dave had some good suggestions about beefing up the Y fork area holding the gearbox (not sure what you call it). That area will have some braces added between the Y to the shocky struts to give it some torsional strength. There is a kit available that can be welded in. I suck at engine and gearbox rebuilds but I can weld a little.

Let the searching start.

Dean

P.S. Thanks for the heads up guys.

Quote:

Originally posted by 77dual You could also consider a naturally aspirated rotary. You can get good power out of them for the money, a 12A or 13B bridgeport or extend port would move it along nicely. With injection they're a little friendlier to drive than carb fed ones too, especially the more they're modified. The only real problem would be exhaust noise and fabrication, with bridgeports if you shut them up they just don't go very well, and being rear engined there isn't much room for a decent rotor suited exhaust. Sticking with the turbo eliminates a lot of exhaust noise. A Renesis 13B (RX8) could work too, it would give you pretty good power while having low emissions and noise, better economy and reliability too. Just a couple more options anyway. If it were me, I'd go for a 51mm Weber fed 13B bridgeport, it'd be loud and cranky but so much fun and I like old school stuff

As Daimo says, the Y frame, is called the fram horns....

In reference to the rhino case, PM mick058, and ask if he has one for sale... I think he may have.

In regards to Rotors, You would be right in saying that you cannt run a 13b Turbo.... at least thats what iv always been told about beetles.
If you haven't contacted Aaron yet, do it. he is a super nice guy and knows alot about rotors... he built that 715hp engine himself. He may even be able to do a rebuild on your 12a

if you have an ecu, don't bother going carby. even though a 51 would be sweet... :P

if this was me i would keep the car rego'ed and put a 13bt motor in it once your motor dies
no one would spot it let alone know what motor is legal in the car. if you know what i mean.

as for the gearbox get whatever can handle the most power you should be getting 250hp up
stick with the rotas you get a lot of bang for your buck.

Aleks
Fellow VW/ Rotary addict

Ps check out this site ausrotary.com
Should help you out for all your rotary needs

It sounds to me like the car is already engineered for a 12at setup. I can tell u now police or road side inspector will bother checking the details of your blue plate on a car like this. Unless u are doing somthing stupid and they really want to through the book at you.

Hello again guys.

Yep, the Skateboard is rego'd for the 12at so it'll probably stay that way unless the 13bt becomes a prefferred option Blown motor or really good buy on a race/worked 13bt.

Quaife Verses Rancho GT Diff's?
I just had an email back from Rancho saying: "GT Diff same as Quaife but better $1xxx".
I'm a little confused. I thought the Quaife was just about the best you can get without going to a locked centre?? Anyone got input?
I'd ask quaife and rancho themselves but I don't want the sales speak just yet. I'd rather the facts

This is the GT(Guard Transmissions) Limited Slip Diff.
It has clutch packs instead of the torque bias design of the Quaife.
Although I believe that GT 'DO' make a torque bias diff too.

Some interesting reading for you Dean:

http://www.shoptalkforums.com/viewtopic.php?f=50&t=128682 

http://ultimateaircooled.com/simplemachinesforum/index.php?topic=2595.0 

Har har. Thanks Dave!
Don't you ever sleep?

But which one to use, Quaife or GT, TBD or LSD??

I have just started reading the first thread (shoptalk) and I found this comment very interesting. You had mentioned something about it the other day.

"Rear-engined Porsches and VWs have always performed better with true LSDs than with TBDs, because LSDs have decel lock-up and TBDs don't. TBDs are more suited to front or mid-engined cars."

Are they more suited to a drag application also? As you back off the power at the far end the diff dis-engages? Or am I totally confused?

I think the 'Torque bias' version is best for drag racing,
but perhaps the GT 'torque bias' is better designed than the Quaife?

The GT 'clutch type' limited diff would be excellent for any form of circuit racing.

The quaife is a very nice unit though.

Any of these diffs will be stronger than a normal diff, superdiff, or factory ZF limited slip.
To give a stregth comparison, I think the crownwheel and pinion would fail long before any of the above mentioned diffs.

Always up at 5am.

Thanks Dave,
Now it's all becoming a little clearer.
More reading...............less questions.

Edit: I have just done the sums and the difference between the Quaife and the GT is about $460.67AUD with the Quaife being cheaper (not including freight). If the TBD diff isn't going to be the "weak link" in the chain I think the Quaife gets my vote atm.

Edit 2: Unless the GT will have a better design that helps prevent the problem of one wheel gripping a fraction earlier than the other wheel at burnout (not sure of the terminology of that action). Which will help avoid gear shock/shudder.

hey just thinging about your car
i think the next biggest problem you will have is the axles. then the gearbox itself
i have never got around to finishing my car but i was on the hunt for a cheap porche or aftermarket transaxle to put in.
i remeber my brother telling me that the guy with the 20b kombi had his axle replacment skills down pat. and that he used to carry around spares and tools in the back.

aleks

Thanks Aleks,

Dave asked me to order a set of heavy duty axles. I'll get them out of Rancho this week (unless somebody has a set they want to sell?). Their weak point is at the ends were their a little skinny.

EDIT: I ordered the axles from CIP because they sell the EPMI units. Rancho sell the Swayaway units which have their issues in the current batch.

I read somewhere about Aarons axles and CV's been under a bit of stress with his setup and he changes them regularly. I'm sure he has that proceedure down pat. lol

Dean

Quaife test:

http://www.youtube.com/watch?v=YyKbywmc9Y4 

I'll leave my testing to race day.
Totally "Cop fodder" but none the less, impressive!