2004 A4 B6 convertible 2.5 BDG engine tuning options

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Princy

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Hi all

I'll be looking to get the car mapped in the near future but am wanting to get some other supporting mods done before hand to make the most of the potential the engine has. I've been browsing a here and a few other sites trying to turn up as much information as I can but there seems to be so much conflicting information out there, all my research has succeeded in is confusing me even further.

Mechanically, the car is pretty much as it was the day it left the factory except for a plate blocking the EGR as it enters the intake pipe.

My plans are :-

Gut the cats
Modify the back boxes, cutting them open, removing the baffling and piping them straight through to the tailpipes
Change the injector nozzles
Upgrade the turbo

I'm not looking for ridiculous power but would like to release what the engine is capable of without overstretching it at the cost of reliability, what I'm looking for is some solid advice on whether I'm heading the right way with the above or is there anything else I should be doing and advice as to which nozzles and turbo I should be going for and where these can be sourced.

Sorry if some of these questions are a bit tedious and thanks in advance for any help

Carl
 
Hi Carl, give Me a ring when YOU have time, I can give you what you crave ! Meanwhile do a search on a6 turbochip and read the thread as it's been an unpaved road with a lot of trial and errors !
 
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Thanks for the quick reply Chris, I was kind of hoping you'd spot this thread and chime in. That is one of the threads I've browsed through but will give it a good read through now you've pointed me in that direction. I want to keep the car fairly sensible with minimal smoke, any idea of rough performance figures and could you pm me a price and where in the country you're based?.

And thanks for the number, I'll be in touch very shortly

Carl
 
Up to 300 Bhp is available which are plenty in today's money !
 
That's a bit more than I was expecting, what kind of torque figure does that come with mate?
 
Well that was one hell of a read, its certainly opened my eyes to the amount of variables to deal with.

I'm thinking anything over 250bhp is going to transform the car, huge power is going to be a total waste of time with only 2wd but the extra power won't go to waste at anything above 50 which is right where the car feels limp and sluggish considering the torque available. I suppose it's all going to boil down to cost, I'm thinking you've got working on the 2.5 down to a fine art and know exactly what's needed to get the end goal I'm looking for?.

Any chance of a ball park figure and time scale you'd need to make this happen mate?
 
I can supply a turbo package for about a grand and with injectors for £1500. Best would be to pop in and I will take you for a spin in my Allroad so you can see how it puts the power on the road-it's heavy but the 4 wheel drive system helps with all that torque. Up to 800Nm is possible however the flywheel is not playing ball so I keep it at 500-600 Nm to give it a decent life !
 
Are those prices for plug and play and ready to go stuff (obviously after a decent map), after reading that thread you pointed me at it's confused me even more than I was before, it seems a proper minefield for someone as uneducated in diesel tuning as myself. Would there be anything else needing doing other than obviously the mapping like pop pressure setting, injector balancing etc... and is that for complete injectors or would you need my injectors or are they not even useable being a BDG motor?.

I would have thought the fact its only 2 wheel drive will take a bit of pressure off the clutch and flywheel with the tyres losing traction if things get a bit much. And hopefully the engine should be solid enough with having just shy of 77k on it with service history or is there anything else I should be looking into replacing, I'm thinking of camshafts for one thing having seen what can happen to the hollow ones and assuming mine are hollow?.

Power wise, what would you say the hardware you've quoted above should achieve with the right map mate?.

I'd best get putting some cash aside
 
Yep, plug and play turbo kit: either hybrid which looks stock or gtb2260vk converted to vacuum. The nozzles are just supply only there is a choice of 3 types- depending on power goal- they would have to be fitted to your injectors and pop tested for even fiting. I do not offer an exchange service as the later needle lift sensor built into the 3rd injector is prone to fail and cost big money to buy on toys own ! You will also need early style intercoolers if you want to retain the twin setup or you can go for FMIC. I can supply pretty much everything but costs are easily spiraling ! However to get over 100 Bhp power hike for a smidge over £1500 in parts is very, very good value for money ! In tuning world the first 50 Bhp cost you a few hundred pounds and the next 50 Bhp cost you a few grand !
The power increase is unreal, my 2 tonnes Allroad is just as nimble as my b6 s4 v8 and picks up speed quicker just does not handle or stops as quickly ! Give me a ring on 07789912128 when you have cash ready, I keep turbo kits in stock and they are very reliable especially as I test each kit on my car for similar results...
 
If I'm honest, I'd be relying on your advice with regards to turbo choice. I haven't a clue what would be involved in converting to vacuum would entail but if it was the better choice with regards reliable performance then I'm pretty much up for any amount of work with a bit of guidance.

The 3rd injector needle lift sensor does sound a bit off-putting, is there any way to minimise the risk in damaging that or is it just an inherent risk in the nozzle replacement process?. I'm wondering whether it would an idea to set aside enough money to factor in a replacement if needed. Power goal wise, it would be nice to future proof any upgrades as much as possible by allowing a bit of headroom for further fettling if I felt the need in the future so with a 250bhp goal in mind with the potential to go further would be nice.

FMIC was probably on the cards anyway as again, any information I've found seems sketchy at best, some say they're good for 300bhp, others not but my logic was it wouldn't hurt to increase flow anyway as I'm imagining the twin cooler setup being more restrictive. Size calculation being next thing to look into.

Agreed on the price per bhp increase, having been down the tuning road before allbeit only with petrol engines before, some fairly serious money can be spent chasing fairly minimal increases, especially getting to the higher levels of an engines output.

It all looks to be exactly what I'm after, sorry if I'm going over ground that's been covered a million times in the past but as I say, all my previous experience has been with my weekend toys which being petrol are completely different animals so diesel tuning is like learning another language :blush:
 
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Ok mate, give Me a ring when YOU're ready !
 
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Will do mate, I may well have the parts off you in stages as the money becomes available, and I'll definitely be in touch if I'm ever heading down your neck of the woods.

Out of curiosity in the meantime, do you have any recommendations with regards FMIC core size and inlet/outlet sizing?
 
Sure, when you're ready... I used a 80cm x 40cm cm x10 cm...intercooler
 
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Brilliant mate, I'll be in touch as I can, thanks for your help
 

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Cheers for that mate, was that one a custom jobby?, I'm having a hell of a job finding one 10cm deep.
 
I might have the intercooler sorted mate, I've got a brand new similar sized one that I bought for another project, it's not as deep as yours by 2cm but I'll check on the flow rates, whip the bumper off and have a look if it's going to physically fit and I'll get back to you.

I think this might be the first job I'll get out of the way.
 
On an unrelated note, I've set the dynamic pump timing as it was slightly retarded and having done a bit of research there seems to be a fairly common train of thought that a little advanced timing is a good thing. Knowing how catastrophic advanced timing can be to petrol engines I thought I'd best check with the man in the know before I made advances, any recommendations or should I just leave it at factory spec bang on the green line?
 
With stock nozzles I would advance it towards the top line however by doing that the engine becomes a touch coarse. You might feel slight improvement In fuel consumption and a touch more torque however most times the changes are minute !
 
My pleasure ! As i said, best bang per buck is a turbo upgrade, this will make use of The extra fueling and give The CAr a new lease of life...
 
Without doubt I'll be in touch as soon as poss about the turbo mate, I'm not expecting any gains from the timing setting, it was just to check while I'm doing it that it's set to the best it can be for now. I've set the timing to -0.4 and to be fair, it seems to pull slightly better lower in the rev range and cold start seems better so I'll leave it where it is for the time being, thanks for the pointer.

With regards the turbo, I'm assuming there's little gained by fitting it without a map or some form of tuning box?. I'm just getting things planned out in my head as to whether I get all the parts together from you before I start working on the car and just have the one mapping session once it's all done or fit them as I get them.
 
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You can fit a turbo without much lag but without nozzles you won't get much gain. The bits I use in my turbos are latest technology so they spool better than the smaller gr2052v turbos so you won't notice much lag compared with stock. It will feel stronger in midrange and will have better top end due to extra flow from the larger turbine and compressor...
 
That looks to be the plan then, I'll be looking at a bespoke map once all the bits are on so it's good to know things can be fitted with no ill effect, I'll look to get the exhaust as free flowing as possible and get the money together for the turbo then sort the nozzles with you just before I'm ready for the mapping session.

Thanks again bud ;)
 
YOU best to have the map made by me, I have tried every possibility with them v6 diesels !
 
Suits me mate, I can't think of anyone I'd rather have do it, my main concern was having mapping sessions done after every upgrade making things get expensive really quickly, hence me thinking of fitting everything in one go and having a one mapping session.

Are you able to make a map based on the parts upgraded to the car that I'd be able to upload somehow or will it mean having a run down to you?.
 
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Whilst i am able to make a map and tune with logs and based on your feel, I don't really advice on going down that path... I can get a satisfactory map based on the mods I use to make power however I need accurate boost and fueling logs in Order to make a smooth tune...I thread carefully when tuning on the fly as everyone's desire/requests are quite different ! I only charge for the base map once, after that every tweaks I make I don't charge as it's not that much work involved from my side !
 
I also had a few a4 and a6 from 2004/5 which dropped comms and bricked the ecu whilst flashing however with a few select tools you can recover it in boot mode...bottom line is better if you come down to me but it's not imperative...
 
No worries mate, I'll leave the mapping in your capable hands, I'll make my first priority improving exhaust flow and fitting an FMIC then probably get the turbo and nozzles in one hit and run it down to you for mapping.

That's on the assumption it will run normally although not at peak performance with the uprated nozzles?.
 
It will smoke like Mad with large nozzles, The turbo will clean some smoke when it boosts but YOU will have high egt and might get The VNT clogged if YOU drive it for too long...
 
I'll knock that idea on the head then, it's a 200+ mile trip down to you from North Wales so it'll have to be a transporter or trailer job.
 
Won't the bigger nozzles have to be fitted with pop pressure set and balanced before mapping though?
 
To be honest, most quality nozzles are decent and have even flow and in many cases I have used new Bosio nozzles and slapped into a good set of injector bodies and had absolutely no problem whatsoever yet every set k sent away to diesel specialists were pop tested and idled like sh*te and made the engine Gallop on idle ! Most modern injectors are two stages and every specialist can only set the pilot pop pressure only and they cannot set the main injection event !
 
Would you be able to fit the nozzles prior to mapping then?
 
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