Prawn and BigAls A3 Track Car

Rifle drilled FTW.

Sounds good mate, you going to have the boost tweaked when the motor is built or leaving as is for a while? Though i suspect it is already pretty rapid as it is haha.

It's amazing how far the car has come since the beginning of the thread, it's what inspired me to do my little project:icon_thumright:
 
Cheers mate.

Map will indeed be altered once the new engine is in, it's currently on a very safe map with little timing or boost to keep the figures low. Torque is only around 250-260lbft, and power is capped at under 300, but to get it this low Niki still had to taper boost off at the top end actually dropping onto actuator pressure at 6500rpm to stop it from making too much power.

I don't particularly want more power, I just want a better delivery with peak boost made around 4000rpm, then held as flat as possible all the way to the top end.

I'd rather 17psi of boost right to the limiter than 22 peak dropping to 18 at the top end for example, I want it to be really linear, which can be done.

During mapping it made 312bhp and ~280lbft at about 16psi, and 329bhp / 300lbft at 19psi, so somewhere around 320 would be nice I think, and should give it a chance of being reliable!
 
If you fit a pro alloy sump remove the rubber baffle doors as they come off and block the oil pick up
 
If you fit a pro alloy sump remove the rubber baffle doors as they come off and block the oil pick up

If that the case then thats a flaw with the product... the Seat Sport sumps (on which the design is copied from) and the Backdraft versions of these have the rubber flaps and I know Bill has used one for years on his Ibiza race car...

The flaps do go a little hard over time as we saw in Bills sump when it was off the last time...

<tuffty/>
 
different flaps tuffty

BMW Sport ones used in the seat sport copies.. AKS make them now.. (alex, formerly of backdraft)
these are fine..

I have seen the pro alloy ones... two little pips hold them, and they have been known to fall off and block the pickup pipe.. Happened to someone who bought my old mk4 gti after fitting one.
 
different flaps tuffty

BMW Sport ones used in the seat sport copies.. AKS make them now.. (alex, formerly of backdraft)
these are fine..

I have seen the pro alloy ones... two little pips hold them, and they have been known to fall off and block the pickup pipe.. Happened to someone who bought my old mk4 gti after fitting one.

Ah yeah... now you come to mention it I vaguely remember you telling me about this :D

Damn my old man memory lol...

<tuffty/>
 
Been looking more info baffled sumps, and found a cheaper option that uses the seat sport style baffles and stainless trap doors. Cost is considerably less than the seat sport type also.

Engine is almost out now, only had a few hours here and there to work on it, and as usual, I'm taking my time and not rushing.

Will either pull it out this evening or tomorrow morning
 
So, things are moving forward again. a bit quicker than i first expected, but I just can't stand having it off the road any length of time at all, so why wait?

A few hours work over the weekend, and my engine bay is now scarily empty!

One lovely engine bay on friday:

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definitely no bent crash bars here.....

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It did it's job though, the intercooler core hasn't got a single mark on it!

Front end all stripped down and ready to lift:

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And it's gone!

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216 000 miles of faithful service, mapped for over 100k of those miles, making 290lbft of torque from 25psi of ko3S fury for over 60 000 miles, and most recently, pushing out exactly DOUBLE the factory 150bhp, and it took it all in it's stride, never had the head off, original rings, the lot. what an engine!

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And a close up of the evil hole that caused me to do all this work:

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Stripping down of the new AGU lump starts this week, and I'm off to Badger 5 this weekend to have the short engine built up, then I'll assemble the rest at home and get it back in as soon as possible :)

In other news, my baffled sump is mid way through being made, off to the welder this evening before winging it's way to me!

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really looking forward to getting the new lump in :) It'll be nice to not have to worry about it the entire time. i've been worried about the rods for a long time, and just the mileage in general, but the old girl did very well indeed I think.

Will get the new lump in and run in on actuator pressure (that'll only take me a few hours), then when it goes to have the map tweaked I'll be very interested to see if the new engine makes noticably more power than the old one.

airflow logs suggested that the old lump was already beyond 300bhp, but the delivery was very smooth indeed. i'd quite like it a little more aggressive this time around :)

Then when the hybrid eventually gives up i'll have to man up and fit a GT unit instead. muhahahahahahaha
 
I find the rebuild motor in my saloon feels a lot more perky than the ~130k motor in the avant. Its not that it feels faster, it just feels more responsive, especially round town and the like when off boost at low throttle angles.
 
I have been addicted to this thread for months now! only pop in here every now and then but things change so fast!! amazing progress and real dedication, gives me so much enthusiasm.

I am currently building an agu/Ko4 Setup for my Mk2 Golf.
 
I have been addicted to this thread for months now!

I am currently building an agu/Ko4 Setup for my Mk2 Golf.

Thanks man, it gives me something to do!

A ko4'd AGU in a mk2 golf will be utterly mental. A chap I know runs one, and he says he gets wheelspin in 4th gear in the dry on R888's! You're looking at an easy 300bhp/ton in a mk2 - mental!

Started stripping the new engine down yesterday, reading for assembly on Sunday at Badger5 :)

Pistons before:

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Pistons after:

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Head before:

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Head after:

466DA820-F56A-438B-A85A-3CBE6F755D71-7616-000007FA71FF5BBD.jpg


Sump should arrive today too :)
 
Excellent job on the clean up, all looking good.
What did you use for the head cleaning out of interest?

I am going to use a relentless manifold on the MK2, with plenty of heat shielding.
Only restriction will be the 2.5" downlipe/exhaust.

The 4 door is going to be a test platform/proof of concept running on the AGU ECU, with i'm thinking Saab red tops and a vr6 MAF housing.

Then i will be prepping a propper 2 door chassis and hopefully running Emerald or DTA with a MAP setup.

Recently my brother achieved a reliable 232Bhp from a Ko3s setup with Emerald/MAP/Wideband so im pushing for more :sob:
 
A ko4'd AGU in a mk2 golf will be utterly mental. A chap I know runs one, and he says he gets wheelspin in 4th gear in the dry on R888's! You're looking at an easy 300bhp/ton in a mk2 - mental!

That doesn't bode well for me then haha. I'll have to invest in a diff sooner than I thought.

Nice work Prawn.
I snapped my dipstick tube aswell :(. They're so brittle it's crazy
 
A diff is essential is you're running near 300bhp or above. it'd be useless without!

New sump arrive today :)

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Pics of the gates, as requested by Stacey:

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Also cleaned up the gearbox ready to go off to Jardos Dad to have the Diff swapped over:

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Question for those in the know:

Both boxes, old and new are ENJ code. This means they will have the same ratios, and same crownwheel/pinion. Can I drop the Quaife diff and crownwheel as one unit into the new box to save time? They're the same final drives, same teeth, but obviously not an original pair.

What's the better of two evils, swap the diff with existing crownwheel into the new box? Or drill the rivets on the new diff and swap it all over?

One option means undoing and retorquing the ARP crownwheel bolts again, and one options gives a non original, although technically identical crownwheel.

Which is best?
 
You going to remove the aircon pump this time? I've just taken the one out of my TT and couldn't believe how much weight the system weighs, it has to be done on your A3.. Plus the aux belts only £15. Can't have a race car with aircon!
 
Yup, all that crap is coming out Dan! going to remove all the pipes back to the bulkhead connection.

Do you have the part number for the non aircon aux belt? Most motor factors seem to get confused when I try to get one!
 
06A 145 933 D

Steve at GSF got it for me.
You can tell if it's the right one as it only has grooves on one side as it doesn't need to reverse over the air con pump
 
aaaaaaaaaaaaaaaaaaah. I should have known. Steve who can get anything. Cracking bloke, he always remembers me and asked about the A3.

Will call him Monday :) Cheers Dan
 
Hahaha. 2 driveshafts get me into enough trouble as it is. I don't know where I'd be if I had 4 of the *******s!
 
Haha so true.

Prawn what bolts did you use btw, where did you get them?

Had to cut one of mine out after some monkey rounded it!
 
Cheers for the pics mate I was just a bit worried that if the gates are lockwired incorrectly and don't open easy enough it would be a very quick way to destroy an engine ;)
 
What a long, but fantastic day!

An absolutely Massive thanks has to go to Bill and Tuffty, to put up with me for an entire day takes some extreme patience!

I can think of very few tuners who would be happy to give up a Sunday to help a Prawn build up a new engine, but Bill let me come up today, with the original intention of me doing all of the work under the watchfull eye of Bill and Tuffty.

What actually happened in reality is that with me in a strange place, not knowing where tools were, and a little lacking in confidence on my first 20vt build, Tuffty ended up doing the majority of the difficult work, with me doing the leg work and cleaning things and prepping stuff.

I can't thank Paul enough for all his work today, and to Bill for watching over, it's great knowing that you've got so much experience making sure it goes together properly :)

So, some pictures!

I arrived at Badger 5 around half 10 this morning, and after a tea, we unloaded my donor engine from the my French Deisel Coupe, and bolted it up to an engine stand. I whipped the sump off, cracked the caps off the big ends, and we pushed the pistons out and onto the bench

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Paul removed the circlips, and pushed the wrist pins out of the old standard rods. When they were all seperated, we removed the old rings, and I got to work with the parts washer cleaning the pistons up:

8E366B5E-D58F-40F1-BAE7-7AB97E55C0D5-2706-000002CDB15238DD.jpg


I also cleaned up the oil pick up pipe, which came up like brand new:

09328CE6-21AE-4494-8E16-EA90748B18CA-2706-000002CDBA3B07AC.jpg


With the pistons cleaned up, and the ring grooves clear of carbon deposits, the master PT began installing the pistons on my DM forged rifle drilled rods:

020C63EC-35C4-4CF0-805F-ED6E297FADD7-2706-000002CDC195F3C7.jpg


4 AGU pistons, now with forged rods :)

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Next, I got to work cleaning up my head a bit more using Bills parts washer. it came up brilliantly and looks almost like new!

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Whilst I was cleaning the head, Paul used the flex hone to freshen up the bores in my 108k block:

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He also gave the deck of the block a bit of a clean up too:

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With that done, the rings were gapped. This took a while as most of them needed a tiny bit taking off. This seems like a good sign though, as it would suggest bore wear is minimal. With that done (again by the expert PT) the rings were fitted to the pistons:

2B498FDB-4F87-4BCE-94AB-648C01FC7D3F-2706-000002CDEBB5BCE6.jpg


Then the shells were fitted, ensuring everything is clinically clean before hand:

82F12303-5908-4377-A8E1-9DB252BE39F6-2706-000002CDF07C1500.jpg


With the rings aligned at 120 degree intervals, the pistons were slotted into the bores, and the big end caps torqued up.

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Interestingly, something I'd not read before, the big ends were torqued up to 55lbft, and released again 3 times to ensure everything was seated correctly. Another point that I'm sure many have missed not having the benefit of experience.

The oil pump was fitted, followed by the windage tray, and then finally my new baffled sump, and the whole lot was torqued up, and the engine turned the right way up ready to recieve the head:

902D8728-C8FB-4237-822F-DB7A35D758AF-2706-000002CDFA9D4231.jpg


Yes - the head gasket is up the wrong way round. I just dropped it on for a picture without paying much attention, and quickly got told I'm a muppet
laugh.gif


The head was dropped on, and the 10 bolts torqued up. what a HORRIBLE experience that was! 60Nm, then 2 lots of 90 degrees on the stretch bolts - most odd, but the correct way to do it!

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With that done, I fitted the new waterpump and tensioner damper, and we fitted timed up the engine and fitted the gates timing belt:

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And that's it done! I'm not able to work on it for a week or so now sadly, but I'll crack on with it next weekend and start bolting up the ancillaries.

Had a really good day, even if I was most use in Danes roll as Tea Boy :) Thanks guys!

And for those that didn't know previously, Tuffty is spelt with 2 Fs! I think I've been spelling it wrong for about 2 years! Ohps!
 
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Wow, nice to see some engine build pics.

I need a parts washer I think, always cleaning heads by hand!!

The week between working on it must be a killer..
 
Well done guys, at this rate, shouldn't be too long till its back out.

Keeping a close eye on this, as its the same way I want to go with my a3
 
Ahhh have been watching one very simular for £50+postage but was a bit unsure but now I know people have been running these for a while makes me feel more confident in using one.....that'll save me £50 ;)

Cheers
 
oil pickup pipes however.... and long life servicing.. has killed 2 local customer TT's in the last 2 weeks.....

Dreadfull idea from Audi.. Its killing the engines now.. sludged/blocked oil pickups..

if in doubt, drop the sump and replace the pickup pipe.. £15 ish for pickup pipe plus some sealant and some time... well worth the investment to preserve your engine from no oil pressure and carnage it can cause.
 
I got a GSF equivalent too. There's not much to go wrong on a oil pump luckily.

They do wear out once over 100k

I've seen a few A4's including my old one, where the pickup was perfectly clear, yet it'd struggle to hold oil pressure.

My old A4 would drop to 8psi at idle once fully hot. Raise the revs to 1100 and it would come up to about 20psi. 3k would give you about 45psi rather than the expected 75.

It ran fine like that for yonks, though if you sat idling for more than a minute or so all the lifters would start clattering.
 

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