Best DERV in terms of modding potential?

[B5QUAT]

Hi,

Just a quick query. I believe there to be several options in terms of the B5 diesel engines. A 90, 100 110 and 115bhp. Is this true?

Out of interest which would be the best one from a modding perspective? The aim would be a B5 car with a diesel engine with around 180-200bhp and a huge dollop of torque but still returning half decent mpg.

Obviously the 115 is the best start point as it has a 25bhp advantage over the 90 before you start but if the engine isn't as reliable etc etc it may make other options better? Just after some advice or pointers as to the best start point and what mods would be worth doing.


Thanks.

 

[aragorn]

there are two different technologies for a start.

90 and 110 are rotary pump engines
100 and 115 are PD engines

PD is technically better for tuning, as the ECU has much finer control over the fuelling than the rotary pumps, but the 115hp engines fitted to the B5 arent a great basis as they're a bit weak and are built with small limiting parts.

Personally if i wanted a big power derv i'd want to be using a PD130 engine from a B6, as they have much stronger blocks with lots of uprated parts, much bigger injectors as standard, better cooling etc. Your power goal is likely achievable on a PD130 without modifying the engine at all, just a good exhaust/downpipe and decat etc and upgraded intercooler.

Without changing the engine a 110 is probably your best bet, but they arent as easily tunable or as refined as the PD engines. You'll get upto around 170hp on the stock pump if you really push things with an upgraded turbo and larger injector nozzles, but after that your looking at a pump rebuild, or finding/fitting a larger pump head.

Having said all of that, most TDI's are FWD, and FWD sucks, especially with a tuned derv that has a big wodge of torque. Quattros do exist but the 1.9tdi's are all pre-facelift as facelift TDI-Q's are all V6's.

 

[adamss24]

Well said by Aragorn. As pointed, the pd115 is not strong enough as it uses the same rods and pistons as the VE engines. The pd 130 is a great base but it wont work well on the b5 platform as many modules speak trough the CAN BUS network wich the b5 lacks. You will have all sorts of warning lights due to missing signals from ABS controller,etc. From a reliability point of view the 110Bhp AFN engine cannot be beaten, it can safely double the factory power output and there's tons of mods for them: big heads, big nozzles, rods, pistons,etc. I have modified a FWD AHH 90 Bhp engined audi a4 (same engine as the AFN but has 11mm pump, VNT 17 turbo and tiny nozzles for emission purpose). I then took the engine out as it's meant to go into a quattro a4 (i had a 1.9 tdi quattro sport but i sold it so it will go now into my v6 tdi quattro avant) as it's not fun in FWD guise. With the gt1749 VA hybrid and race nozzles it would slip the clutch and wheels in any gear. When i had examined the clutch and flywheel all the springs were broken in the clutch disc due to high torque and the flywheel started to cut into the bolts holding it to the crank ! I would advise a 1.9 Tdi Quattro sport with a 11mm pump head, BV43 turbno, Bosio race 520 nozzles, decat, front intercooler, strong clutch and a custom remap for 200Bhp. Any more than that and you would lift the head (you can use ARL pd 150 bolts cut to size) and forged rods are needed. The beauty with the VE is easy to tune with bolt on mods, revs higher than a PD and pulls harder whilst still returning 50Mpg when taken easy !

 

[adamss24]

Also wanted to add that the first 50 Bhp will cost you 500 quid and the next 50 will cost you thousands ! Set your goal right from the begining as power is addictive and you getting used to it quick. The way i wanna do mine is by ditching the v6 tdi engine (the v6 is great at 250Bhp) and installing the 1.9 Tdi lump. This way i get a strong 01E gearbox and provision for larger 240mm clutch. I dont know what clutch to use though, either single mass or uprated Sachs SRE clutch ?

 

[aragorn]

The 240mm clutch fits just fine with the standard 012/01A 5 speed boxes!

adam: i'd look at one of the 1.8T upgrade kits that takes an S4 clutch, and then use an RS4 clutch coverplate with it. It will bolt straight onto your TDi.

At least then your using standard clutch parts rather than expensive preformance aftermarket bits. You'll retain the comfortable factory pedal feel and whatnot, and the RS4 clutches are proven to over 450hp and similar torque in a heavy RS4.

 

[adamss24]

Having said all of that, most TDI's are FWD, and FWD sucks, especially with a tuned derv that has a big wodge of torque. Quattros do exist but the 1.9tdi's are all pre-facelift as facelift TDI-Q's are all V6's.

There are 1.9 tdi quattro sports facelifted models but they are all imported. I have just missed on a tidy facelifted one this morning...It's a beauty but hey, too long of a trip to get there...

 

[aragorn]

Yeh the UK model range was very constrained. They did the same with the 1.8T quattro, only releasing it as a special edition after the facelift, whereas most of the rest of the world got quattro 1.8T's from the start.

 

[B5QUAT]

Thanks for that guys. Some really valuable info there. Just what I needed.