Progress being made with the A4

[Oranoco]

Not been about much partly due to work being very busy, trying to sell my old flat and buying a TT to play with.

Anyway, bits are starting to gather for my B5.

Steel rods


New coil packs, loom and ECS spacer.



Ordered a host of bearings, gaskets and ready to find a few more bits that need attention when it comes apart.

Just need some time to pull the lump now.

 

[aragorn]

are the rods drilled?

 

[Oranoco]

Yes the rods are drilled. After much faffing over the eBay rods I ordered them from the UK. Still a Chinese rod but they do additional quality control. Figured it was worth the extra few quid.

 

[aragorn]

good stuff, and yeh i did similar with mine, cept mine came from the USA. Wasnt any other rifle drilled options available then though.

 

[Oranoco]

Need to be careful or my budget build could spiral. Looking forward to the next track outing though

 

[VAG-Slag]

What turbo you going for out of interest? . . And how much did them rods set you back?

 

[Oranoco]

The turbo is a K03/K04-023 hybrid and the rods were £360 (I think, ordered a few bits at the same time) from TSR.

 

[Oranoco]

At 12psi the MAF logs indicated almost 250bhp, mapped for 20psi so hoping this will make some tidy numbers.

 

[VAG-Slag]

Nice, who's the hybrid built by?...

It's mad, that's about the same price I paid for my IE rods in America... I was looking at Quaife diffs not long ago and they're roughly a third cheaper in the US. Which is utter ridiculousness seeing as they're made in the UK!?

 

[aragorn]

hmm, if your not changing the turbo, whats the point of all the upgrades? Unless its blown up or something?

 

[Oranoco]

I've kicked it's head in for over 180k miles so it's probably in need of a freshen up and has a couple of leaks that need attending to. If I'm going to do new bearings I may as well do a set of rods for peace of mind. The current turbo seems to work well so at this stage there seems little point in swapping it. As a boost junky should I decide to tweak the turbo the ground work is there.

 

[aragorn]

yeh fair enough.

I guess i'm of the view that if i thrash on a standard engine and it breaks, its a few hundred quid for a standard drop-in replacement.

If i thrash on a built up shiney engine and it breaks, i'm losing a load of cash. And sure, the built engine should be more reliable, but given the failures Marks had with his builds, you can see thats not always the case, due to bad luck mechanical failures, or something like lean running where you'll ruin even the best shiniest of parts.

I guess there comes a point where you NEED to build the engine for it to remain reliable, but if i were building a motor with the same turbo as yours, i would probably lean towards it being fine as standard, and tuning a little conservatively. That said, i guess if its apart for a freshen up, adding rods is a small cost comparatively, and means the engine should be able to take good power.

Given the mileage, you definitely want to put a new oil pump into it, if you havent already. They're usually well worn by that sort of distance.

Also hone the bores and fit new rings rather than reusing whats there.

 

[Oranoco]

Ahead of you there, oil pump will be added to the parts stack, rings etc will be obtained once it's apart. Not going mental as done it once before and it just makes me nervous if it goes pop when I give it man foot. A standard or fairly standard engine going pop won't make me cry.

 

[mikeya4]

What is confusing me is how they can do this to a standard engine and not bend rods?:

http://www.atpturbo.com/root/releases/release050304.htm

What is the benefit with those coils? are they more powerful?

 

[aragorn]

Age, fatigue and luck.

The rod wont pop at exactly 301lbft. But once a certain amount of torque is exceeded, the rods move from something that will essentially last forever, into a time limited item. The stresses weaken the metal and eventually it fails.

So yes, you can bolt a GT28RS onto a standard engine and if your lucky it'll work just fine for a while. The older the engine is, the less likely its going to last.

 

[mikeya4]

Fair enough, I guess its the rpm the torque comes in too? bigger the turbo the later the torque comes in would help?

 

[aragorn]

A bit yeh, and also how its driven too, and how good the mapping is etc etc. Many factors.

 

[VAG-Slag]

Arguably, a big turbo might put less stress on the rods due to it's slower/more gradual spool up... Where as a hybrid is capable of proper quick spoolage, which if not controlled/mapped properly can create dangerous boost spikes.

I believe some cars in a particular race series back in the day used to run 500hp on standard rods... (Apologies for the vagueness of that statement )