audi c4 a6 01a swap to... ?

[vantsen]

Hello, new guy here.
Lately have bought my first project. Audi A6 C4, orignaly it was V6 automatic. Now it swapped to 1.8t 20v AEB, manual. Power goal is around 450-500hp. All parts to achive i have but.... the gearbox is the questions here !

Gearbox is "01a". For that power to handle, friends have recommended to go for "01e". Because 01a is that weak i will lose 3rd gear, when i go 4 puck clutch etc "sachs sport clutch". Or is there more some kind of alternitive ways ?

Ive read here that some run very successfully with 01a. Some not.

So what should I do here... what parts exactly do I need to change that gearbox out, is it a direct fit ? or rear diff is needed also ?



Kind regards

[K Simmonds]

You want the gearbox, it's mountings, also prop, rear dff & mounts, linkage and gear lever as well as various interior trim parts etc.

A 30V C4 quattro has right sort of ratios for a 20VT engine as they refline at 7K RPM...

I have most of those parts having just broken a 30V quattro, however really you want a complete donner car as it surprising just how many componants are differnt.

An 01A will just about cope with that sort of power, it's the torque that goes with it they're not keen on.

Any more questiow feel free to ask.

Oh yeah...

[K Simmonds]

The 01E six speed is considerably stronger, they're much more expensive however, also the the change from first to second is notchy even on a low milage box.

My RS2 has only done 100K miles with a full Audi service history and the first to second change is a little irrritating, however one does get use to it and I'm going to be fitting a new clutch as the current one is broken, I hope that improves things a little.

A URS4/6 box would fit without too much bother but it still a big job, one could also use a B5 six speed or an S2/RS2 box.

There was a member on here with a highly tunned 1.8T in C5 S4 Avant. Think his user name is 'Slepper Avant' but I've nt seen him post for years...

[vantsen]

Thank you. Yes what i found out pretty irritating to swap it out. Maybe i should test it out with little bit on 01a with RS4 clutch kit.
Saw yesterday also a gearbox pop out in market, with a code 0468299EKM. c5 2.5 132kw. Its from diesel and it must be direct fit on my C4, or not ?

If somebody can source out parts what i need. Rear dif, 4.11 ratio, complete gearbox + mount.

Also some have done/sold gearbox adatper for BMW e39 getrag compatibility. Hows that work out ?

[K Simmonds]

Audi gearbox's are highly interchangable between B3/4 and B5 cars, however you may have to make custom mounts and obvioulsly the final drive needs to be 4.11.

I have a spare 4.11 rear diff and propshaft.

[K Simmonds]

A Diesel box will fit okay and be stong however the ratios will be wrong for a 1.8T, it would work but you'd probably find you only use 2'nd-4'th gear.

[vantsen]

Audi gearbox's are highly interchangable between B3/4 and B5 cars, however you may have to make custom mounts and obvioulsly the final drive needs to be 4.11.

I have a spare 4.11 rear diff and propshaft.

Are you able to tell me what are the OEM codes ? exact gearbox code, propshaft and diff. I try to source it out in Estonia. PM me

[K Simmonds]

Yes I can find you that info, I'll just need to dig out the service book from my old 30V C4 quattro. That would be for an 01A five speed transmision that would suit a 1.8T engine very well, top speed would be roughly 155mph in top gear.

The other advantage to using a five speed is weight saving, the six speed box is very heavy.

I'll the find out gearbox and diff codes for you this eveneing and drop you a PM.

[K Simmonds]

Just had to pop up to the house and find a set of clocks for my B3 80 quattro which were in the same cupboard as my C4 30V quattro's service book...

Here is the build sticker, ACK is the Engine, CKF the Diff and DJT is the Gearbox. Not sure what code relates to the prop but I will clean it and find you a part number.

An S2 3B box would also work fine in place of the DJT, in fact it would be even better as is designed for an I5 20V Turbocharged engine. The 03A boxes are okay for quite big power as long as you don't intend on drag racing. I was running 380+bhp with over 500NM and use to thrash the pants off my old S2. Never has any gearbox issues, though did have to fit an SRE clutch.

I have all the parts you need, right down to the instruments for the 30V set up appart from the box as that has been sold.

However it would have cost a fortune to send all the heavy stuff. But if you need any smaller parts feel free to drop me a PM.

[vantsen]

Nice what a lucky timing then, hehe, thank you so much. 03A is direct fit like 01e/01a ?

[K Simmonds]

To the engine yes, you may need to move the location dowls about but it bolts up just fine.

If you use a B3 S2 or 7A gearbox then you'll need to swap drive shaft flanges over and fabricate gearbox to subframe mounts, but this isn't hard.

Personally I'd see if I could find a crashed, rusty or blown up ACK C4 quattro cheap... Audi sold quite a lot over in Europe and it'll give you all the parts required to do an 01A quatttro swap, hell even the instuments should work perfectly well... Saloon or Avant, doesn't matter they're the same underneath...

Then if that gearbox breaks it wouldn't be too hard to addapt things for a six speed in future, but I expect the 01A will handle a pretty powerful 1.8T. It's 400cc less than an S2 motor so doesn't have the same bottom end grunt that'll kill a five speed.

Which of the V6 engines are taking out of your C4?

[vantsen]

original setup was AAH 128kw auto.1995

[K Simmonds]

Sorry, I got gearbox codes a bit mixed up in my head as I'm playing with various differnt code engines and boxes today here at home... When I said 03A I meant 01A, think I got the 03A part No from the engine code of my B3 Audi 80 quattro which is an 03A engine with another five speed 01A gearbox.

Sorry to confuse you.

[vantsen]

Oh haha no worries.
I will start with 01a anyways, got Audi 80 single mass flywheel for free, and put rs4 clutch kit on it.3000 951 848 is the code, you can check it out. It will handle easily 450hp for starts, but i want 01e in near future, just for upgrade and ofc its stronger.

[vantsen]

Also found a website where i can enter the gearbox code, its show what the end ratios are. https://en.kolhosniki.ru/gearbox&code .
What is the perfect gear length, some are pretty lazy for 1.8t