Bobby Singh A4 3.0 TDI build thread

H
bobby singh said:
2/12/15 - 3" Exhaust fitted

Well I fitted the 3" exhaust during the weekend and to be honest it looks great and sounds great. But I'm not sure I can live with it. I'm basically doing a lot of miles and I always wanted a stealth but fast car.

Here is a audio (need headphones really)

http://vidmg.photobucket.com/albums/0903/cossie_power/Audi A4/Exhaust- driveby_zpsm4boyvpj.mp4

It does look good:



As for performance well its the best I've seen with zero back pressure at 4.6k rpm and only 45mbar in the midrange.
Im sure its old age but I want my car to be silent. So I'll be fitting the standard system back which was giving me 130mbar still not so bad as the 2260 has to deal with at least 500 to 600mbar with the dpf.

In the future if I find the back pressure is too high then maybe I'll fit a active exhaust valve.

I've also now found the limit of the CP4.2 pump - I can get 97mg in the mid range with 81mg @ 4k before rail pressure becomes a issue.
Still smoke free which is great - time for another dyno i think.

Cheers
Bobby
Click to expand...

bobby singh said:
April 2016 - Exhaust tips

I had the exhaust tips made so the bore goes over the stock back box pipe around 50mm. The tips are around 100mm so they fill the hole nicely.

End result:





April - Santa Pod 12.4 @ 111mph





Took Class J :)



Here are some video's:

Note this run was done with a 2.8k take off and this results in 4.5secs to 60 with a 3k take off I have seen 4.1 secs so I feel this time can be improved upon.
Also, the run was done with full weight, half tank of fuel so around 1.8 tons I would say.



Incar



Cheers
Bobby
Click to expand...


Hi Bobby
Congrats on achieving those power numbers, superb results!
I also have the 3.0 Tdi Quattro but in an A5
Reading through your thread, except for the dpf delete down-pipe, are you still running the standard exhaust?? Including back boxes??

From what I've read elsewhere, the backboxes are extremely restrictive.... Is there no scope to increase flow??
 
bobby singh said:
Not from what I've seen 300 odd mbar back pressure isn't much to worry about @ 900nm.
Click to expand...

Hang on, I just need confirmation as I just can't believe this @bobby singh ! :D You are doing 440 bhp with the standard exhaust (minus DPF?)

If so, that's just incredible.
 
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The standard exhaust has a fairly large bore if you've ever looked underneath your car. Looks close to 3" to me, so once all the restrictions are removed....

Sent from my SM-A310F using Tapatalk
 
Standard exhaust diameter of the downpipe is around 63mm. About 40% smaller in CSA than 75mm pipe.
It's not so much the exhaust that's making the power it's the much bigger hybrid turbo along with higher flowing high pressure pump and 2200 bar rail pressure.
Theres no doubt going to a 3 inch system all the way through will give you a few more bhp but when it gets that big there is the law of diminishing returns. I have seen 3.0 TDI cars with 90mm exhausts to try and extract the last bhp or two but it's not really worth it.
As Bobby says above he is seeing about 300 mBar back pressure which is about 4.5psi back pressure.
I have made checks on my car measuring the back pressure with a gauge in the Lambda sensor port and I am seeing about 3.5-4 PSI.
A bigger exhaust may drop that to 2 psi maybe less. If you connect an Exhaust Manifold Pressure gauge to a standard remapped turbo running about 1.8 bar you will see EMP's of 40 PSI plus . The restriction in the exhaust system is not the exhaust itself but the turbine and VNT mechanism. The turbine in Bobbys turbo is a lot bigger than even the hybrid I have in mine so the effect of the back pressure on his car is lessened.
This explains some of the effect of reducing exhaust back pressure and a reduction of say 2 PSI on the exhaust gives you more than 2PSI overall because of the turbine pressure ratio but the overiding big blockage in the system is the small turbine / VNT .
http://www.tercelreference.com/tercel_info/turbo_exhaust_theory/turbo_exhaust_theory.html
 
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Every car is different however I would only change parts if there is a requirement.
Test and only replace if needed.
All dpf cars have a delpaP sensor so after a small change in the map you can use this sensor to measure exhaust back pressure.

Unless you gather test data you can't say for sure what works and what doesn't - who would think for example the small stock TIP can flow 320hp worth of air.

I still have a full 3" exhaust system if anyone wants it my ears couldn't take it haha

Maybe time for more rail pressure and see what it does with some smoke.

Other than that haven't done much to the car apart from new front pads & disc's (replaced the rear pads as well)

PNVOBYz.jpg


I've been running the pads and disc's that came with the S4 kit so I've managed to get some good use out of them.

Cheers
 
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Good to meet you today Bobby, Great performance from your car, don't know if you cracked the 12 second barrier but the 12.1 run I saw was very impressive, Very little smoke compared to most diesels running there.
The six second wait at the start probably had most people thinking you had stalled it, or you were giving the other guy a chance.

 
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July 2016

Decided to turn up the rail pressure, not as clean as the before but still acceptable. Estimated power is 465hp / 930nm.
Went to GTI International on the weekend and managed 12.1 @ 113.8 mph.
High 11's would have been nice however my air charge temp was at 52 deg by the second run. Sitting in the queue wasn't helping so settled 12.1 and enjoyed the show.

sBeR1qb.jpg


Here is a video:



Logs suggest:

0 - 60 4.2s
0 - 100 9.3s
0 - 120 13.9
 
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desertstorm said:
Good to meet you today Bobby, Great performance from your car, don't know if you cracked the 12 second barrier but the 12.1 run I saw was very impressive, Very little smoke compared to most diesels running there.
The six second wait at the start probably had most people thinking you had stalled it, or you were giving the other guy a chance.

Click to expand...

Thanks Karl - it was good meeting you finally :)
Would you know if any diesels ran any quicker after I left? I went home after 3pm.

Cheers
 
Hi Bobby, I doubt there were any diesels there that would come any where near your time. I left a bit before you to get home and watch the Grand Prix. You were a lot faster than most of the petrols :) .
If your looking to get into the 11's spotted some nice lightweight wheels at a bargain price on Tyreleader.co.uk. Sparco wheels are made by OZ so great quality.
These are pretty much the same as the Team Dynamics Pro Race 1.2 but at the moment only work out at £420 for a set of 4 . Bargain price.

https://www.tyreleader.co.uk/alloy-wheels/sparco/tarmac-864/8x18-et35-5x112-75-77540
 
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Ok great. I did try fb for final results but I couldn't find much.
If possible i'll aim for high 11's again maybe during a non event day like rwyb day. Hopefully queues will be a lot less and less heat soak.

I think another 20hp could do it.

Cheers
Bobby
 
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A bit less tyre pressure might help the launch but 1.78s is pretty good with standard road tyres.
 
That's a great 1/4 ET Bobby
 
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Nice results Bobby...catch up soon!!
 
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Awesome build this! Proper sleep.
 
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Great build thread Bobby, inspires me to start working on my 3.0 TDI CAPA which has been stock for 3 years already.
Some questions (I'm familiar with ECU tuning, but I have only worked on petrol cars before):
1. What software do you use to view/record data logs? I tried VCDS, but the sample rate is very low, it's impossible to add more than 2-3 PIDs. I used to get 200 samples per second on my previous car (Mazda).
2. What EMP or EMP/MAP ratio is considered safe on the 3.0 TDI? I never measured EMP before or considered it important.

Thanks!
 
I use VCDS to log measurements on my CAPA and it works OK. If you select Group UDS and hit the turbo button you can get a reasonable update rate. Nothing like 200 samples per second, not sure why you want that many readings anyway.
 
fireboy said:
Great build thread Bobby, inspires me to start working on my 3.0 TDI CAPA which has been stock for 3 years already.
Some questions (I'm familiar with ECU tuning, but I have only worked on petrol cars before):
1. What software do you use to view/record data logs? I tried VCDS, but the sample rate is very low, it's impossible to add more than 2-3 PIDs. I used to get 200 samples per second on my previous car (Mazda).
2. What EMP or EMP/MAP ratio is considered safe on the 3.0 TDI? I never measured EMP before or considered it important.

Thanks!
Click to expand...

Thanks - generally UDS ecu have good support in VCDS and sample rate is decent upto 8 channels. However, i did notice VCDS in their latest update now allow 12 channels but I haven't had a chance to test it yet - just got back from my break.

More than double emp over boost is what I consider max. Also, I use it to tune the stop screw as you don't want to choke the engine during spool.
 
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August 2016

So after messing about with a number of different aerials for my retrofit DAB radio install I decided to go down the oem route.

Purchased the kit from

https://www.kufatec.de/shop/de/fist...ennenmodule/fistune-antennenmodul-a4-8k-avant

Audi very kindly cut of the dab signal from the rear 1/4 glass so it's just case of connecting the 3 wires and running the supplied cable to the dab unit.

My signal is now perfect - finally :)

VxlFCGF.jpg


WZrOIeX.jpg


ZJZI1ly.jpg
 
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This finally turned up yesterday:

gVBp8U5.jpg


Makes me want to attend more events :)
 
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bobby singh said:
Thanks everyone - they sure took their time but at least they sent it
Click to expand...
At least they did not give you a sponge and bucket ! I have a few friends and that's what they get at few events as the organisers could not afford anything else ! Well done mate !
 
Cheers Chris - mine always needs a wash doing 450mile a week so it's a proper daily car.
It won't win any show and shine events :)
 
Hello Bobby, have you carried out a transmission oil change as im looking to do mine at 90k?
 
No still haven't looked at gearbox oil change - its on my TDL :)
I have contacted a few suppliers but they don't sell the right kits (with the correct oil).

Cheers
Bobby
 
Gaz - its zf lifeguard 8 fluid.
The pan/filter appears to be pain to get. Most sell plastic whereas Audi's 6hp 28 uses a steel item.

Cheers
 
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I've just read through this entire thread, absolutely amazing!

I was wondering if you could help me with a few things, I've got a 3.0 TDI dark side downpipe and a full 76mm exhaust with a revo air filter and remap; I'm going to be getting a bigger fmic soon and I'm still running the stock turbo. every thread I read suggests a additional fuel pump, can you tell me the part number or where I might be able to find such a pump? Also are you using this pump in addition or in replacement?

If your feeling nice is there Any other things you can recommend to get the most out of the stock turbo?

Hybrid turbo isn't quite on the horizon. Yet!
 
I would fit the stock air filter back for a start.
What hpfp or engine code do you?
If you have a cp4 then to get the best out of a stock 2260 you need to fit a cp3. Fitting a stronger feed pump is a waste of time.
I would also fit a 4 bar map sensor.
 
Bobby how much boost would you say is safe to run. I.e on my turbo dynamics hybrid? We maxed the map sensor out at 2 bar a few weeks ago..

Sent from my SM-A310F using Tapatalk
 
bobby singh said:
I would fit the stock air filter back for a start.
What hpfp or engine code do you?
If you have a cp4 then to get the best out of a stock 2260 you need to fit a cp3. Fitting a stronger feed pump is a waste of time.
I would also fit a 4 bar map sensor.
Click to expand...

Engine code CAPA I believe, 2008 3.0 TDI
Anywhere links as to where I might be able to find a cp3? I've found a 4bar map sensor on dark side developments, I'm assuming both the cp3 and map sensor will need mapping in?
 
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