3 litre diesel engine
- Thread starter Caesium
- Start date
Why would you want that ? There is no gearbox in the VAG's parts bin strong enough to cope with the amount of torque that engine will do with 2 turbos ! Even strong race gearboxes will have trouble coping with 800-1000Nm of torque on a daily bassis...Remember that these cars need to last for a good 10 Years ! They will need to use auto gearboxes with conventional torque converters wich will rob power and return poor fuel ecconomy. Manual boxes are out of the questions as well !
That engine will not make anywhere near 800-1000Nm of torque, the V10 TDI only develops 735Nm.
The BMW 535d (twin turbo) uses the same box as the 530d and that copes alright, are the Audi gearboxes weak then?
The BMW 535d (twin turbo) uses the same box as the 530d and that copes alright, are the Audi gearboxes weak then?
You shure about that mate ? 2.5 Tdi do over 600Nm when tunned with an x5/merc AMG CDI VNT 2560 turbocharger on stock boxes ! Also the v10 tdi is seriously undertunned just to help the gearbox cope... With a twin turbo engine you nearly double the stock torque and the power to weight ratio increases massivelly. I am not teaching grannies how to suck eggs but BMW still use ZF auto gearboxes (audi used them too for a long time on high power quattro's) wich have a torque converter...
Also do a google search on ABT 3.0 tdi tuning package...310Bhp and over 600Nm of torque. Their demo a5 tdi was 1 second quicker than a s5 on Nurburgring circuit... Thats on 1 turbo only ! 
bar shaker
Registered User
The reason for using two turbos is that they can be smaller so spool up quicker. Two turbos doesn't automatically equal twice the torque.
I do know that, what i said is the engine has the potential to double the torque in standard trim. New diesel engines blocks are made from Graphite Compacted Iron and can wistand massive cylinders pressures while being relativ light. Throw a Massive VNT turbocharger and you get the best of best worlds: decent spool at low rpm and high boost at high speeds. The CR injection system has more than enough pressure to fuel the needs of that engine...The limitation are the engines internals: rods, pistons and wrist pins. Crank is forged so wont snap that easy. If you take a v6 diesel apart, you will see that its over-engineered and it has girdles, massive crank bearings and strong conrods. The 2.5 tdi bottom end can take easily 500 Bhp without touching the internals. They restrict the torque as the Bhp are meaningless on a diesel and only come into play when doing speeds of over 150Mph. Having soo much torque from tick-over is too much and unless they use ceramic clutches and strong auto gearboxes, there is no way that car will take the abuse of 500Nm on a daily bassis without compromising the warranty. BMW is using wastegated turbos wich are easy to control but they bound to go wrong as the car ages. A4 2.7 BiTurbo also had 2 Borg Wagner(KKK) wastegated turbochargers as they generate high exhaust temperatures wich will dammage a VNT turbo. They fit VNT turbochargers on diesel engines as their exhaust runs cooler than the petrol ones and they prove to be reliable...
Who needs all that work? Check my signature. Effectively bolt on extras. If you got the same proportional increase on a 261hp/406ftlb 3.0TDI you'd end up with 390hp and 676ftlb. Your clutch will be struggling before the gearbox gets it if my experience is anything to go by.
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Yeah, i have seen your RR printout-impressive ! Just wanted to give the OP some food for thought. As a matter of fact, ABT released a tunning package for the 3.0Tdi wich took it to 310Bhp and 620Nm all on stock running gear(they might have massaged the turbocharger and re-programmed the gearbox though!) some 2 years ago ! It was 1 sec faster than the s5 on Nurburgring ...
wow... what clutch do you need to get a 2.5TDI to handle that much torque?!?
is that on a regular gearbox or have the higher gears been "stretched" to give it a higher top-speed?
what sort of performance stats will that get compared to a stock 9-ish sec 180bhp?
