sub £3k TDi remapped with 70 mpg cruise?

[Griff]

I have two interests, namely tuned high reliable torque and very good cruise economy

I am open to suggestions as to how to optomise these goals by targetting right base vehicle and mods - would consider inexpensive mods to airbox / cleaner, rear box and increased diameter tyres for lower rpm

Where can i find details of the featured 406 TDi mods? - Torque sounds interesting and i have heard they are very economical (presently using v old 405 GT non turbo diesel for runabout and it is exceptionally comfortable but thirsty - 36 mpg overall..)

[waynne]

The 406 TDi would be the one belonging to HDI-fun.

I really rate the VW Golf GTTDI unit. A friend of mine has his remapped to around 190bhp and gets over 60mpg around town with a few runs thrown in.

Increased diameter will effectively make the gear ratios longer, this will slow up the acceleration are you sure this is the price you want to pay?

[HDi fun]

I see about 40mpg from my 2.2 HDi in mixed driving. But when you consider 320+ lbft and aound 190bhp that's not bad.

To drive - it's lively, to say the least

[waynne]

Ha beat you by 4 minutes! You're slowing up HDi

[pgarner]

ok this is what waynne meant by reading them in the wrong order

[HDi fun]

It's my age.!!

[waynne]

Have you made a decision yet Griff?

[turbo]

I`m going to get my Saab 9-3 2.2 diesel remapped tomorrow. It has 125 bhp and 280 Nm of torque as standard. I`m not sure whether to go for a stage 1 (155 bhp) or stage 2 (168 bhp). There`s a difference of £80 but the car`s done 102000 miles and although we all know diesels go for ever, nearly, I may go for the lesser one as it may be a safer option. I think the torque figures are fairly similar between the two. I knew someone who had a BMW diesel remapped once and it blew all the leakoff pipes off the injectors one night when he was pushing on. Obviously something can`t have been set-up right but I always wonder what could go wrong if you try for too much out of them.

[HDi fun]

Go for the bigger one. My cars at 120,000 miles now and it's on a 192bhp map since 55,000 miles. Just be sure to use the correct oil (preferably fully synthetic), get it changed on time and let that poor turbo cool off for 2-3 minutes after driving.

Also, make sure if you do need to top up engine oil (even tiny amounts, mine uses about a wine glass volume every couple of thousand miles) you use exactly the same stuff. Not the same spec, the exact same brand and product. Synthetics should NOT BE MIXED.

[turbo]

Thanks for that information. Is £475 about right then for a remap? I run the car on 0/30 fully synthetic oil. I have been changing it every 10,000 miles but I`ll do it every 5000 from now. I`m looking forward to getting the remap done. Do you think I`ll notice a big difference in perfomance? ....oh and the fuel consumption`ll be better if I can stop myself from showing everyone that gets in the car how fast it goes. Cheers

[HDi fun]

You WILL notice the increase, without any shadow of doubt. Where are you going to have it done. I'm a Celtic Tuning enthusiast.

I wouldn't worry too much about 5000 mile changes, better to get a good synthetic that really will remain in grade. Current favourite for me is AMSOIL DEO 5w/40. Once you increase the torque output (and, as a result, bhp) you need to be a little more sympathetic when the engine's:

1. Cold - don't over use the power right after starting

2. Hot (after a swift drive) - let is cool for 2-3 minutes.

Beyond that, go and enjoy the extra (and quite significant extra) muscle power. I think you'll get better MPG as well. I do and that's over nearly 70,000 miles of use.

Remapping, if done well, is clever. The first phase is to iron out all the high spots in the torque curve, thus giving a much smoother power delivery. Only when this is done is the overall output increased.

Often the fuel rail pressure is increased earlier in the rev range to allow for shorter injector dwell times. The rail pressure should never exceed that standard maximum, even if it's at max at lower revs. That will lead to injector failure, and, as you said, the return lines bearing excess fuel pressure.

[turbo]

Well I took the Saab in today for a remap but received a phone call some time later and was told that that particular car cannot be remapped due to the type of ecu on it. I`m gutted. Even tuning boxes won`t go on it so I`m stuck with 125bhp and 280 Nm. The technician tried three different remapping centres and all came back negative.

[pgarner]

unlucky mate.
is it possible to get a kiddy back ecu to work with it ? more expensive

[pgarner]

also who did you use ? im trying to find local ones and with carlise only being 15mins away it beats newcastle or glasgow

[turbo]

Hi pgarner. Abbottracing do a plug in, 30 bhp, and a fair bit of torque and you can switch it on and off inside the car. I think it`ll fit mine but its £500. I have read reports of black smoke and suit though when pushing on. May give them a ring and see what they say.
I went to Wigton, Brookside Garage to have the work done. They are really good there even though they were unable to remap mine. That was to do with the files and the fact that they could not be sent to the car because of the type of ecu. I have the chance of a 2.3 9-3 Viggen convertible, (cheap) with low miles but they`re only 4 seaters and quite often there are 5 of us in the car! They are fast (230 bhp) and can be remapped to 270 but even in standard form they are a bit of a handful. Maybe I should spend my money on suspension and the aero alloys could do with being refurbished.

[HDi fun]

Don't even consider plugin boxes. These are the finest way to completely bugger up an engine. You'll chew up diesel and spit out black soot.

AVOID is my advice.

[Griff]

Originally Posted by waynne

The 406 TDi would be the one belonging to HDI-fun.

I really rate the VW Golf GTTDI unit. A friend of mine has his remapped to around 190bhp and gets over 60mpg around town with a few runs thrown in.

Increased diameter will effectively make the gear ratios longer, this will slow up the acceleration are you sure this is the price you want to pay?

I have presently narrowed list to X Type, 406 HD1 and Golf.

I will only go for the Golf if the surprising economy can be verified - several people have suggested routine high 60s mpg which doesnt really stack up against other similar power to weight vehicles or the new crop of green super economy / hybrid vehicle getting same consumption..

Would you kindly ask your friend to contact me (via here is fine) with specific economy stats and exact details of his Tdi Golf variant

My budget is very restrictive and c. £2k privately / auction would be the goal, which unfortunately puts the Jag out at this stage (not sure about suitable Golf - folk are suggesting the 130) - Pug appears to be available in the £2k sector and if 300 + genuine lb ft is available then 40 mpg may have to do! - What is stock HDi 2.2 Pug torque?

So unless there are better suggestions it will have to be a re-mapped Golf or Pug followed by X Type, then 2.7TD S Type (if no gbox issues, torque with re-map should be entertaining)

[HDi fun]

Stock is 235lbft. at 2000rpm.

I've read 328lbft on a dyno under ideal conditions. ie. cold day large fans flinging cold air into the front grille.

It's reliably over 300lbft in all conditions.

And it is genuinely quick. You don't need to apply the suffix 'for a diesel'.

I'm well acquainted with 'proper' performance cars so it's not a case of this being the quickest car I've driven. It isn't.

190bhp is not all that special, I agree, and the 406 is heavy at over 1500kG but the midrange shove is simply magnificent with all that torque on tap.

I, too, question some of the 60mpg claims made of the PD engines. I also dislike the VW TDi 4 cylinder units because they're quite rough and noisy.

[turbo]

But HDi fun, what else can I do? Should I leave it standard and treat myself to a £500 koni lowering kit (30-35mm lowering springs and adjustable shockers) or go for what should be a tried and tested tuning box, (which actually I found can`t be turned off once its fitted.) I`ve contacted Abbottracing and they say I`ll get 30bhp more and torque`ll be about 60 Nm more than standard making it 340. They`ve fitted loads of them too. What can go wrong?

[HDi fun]

The 2.2 diesels and V6 petrols have stiffer springs and dampers anyway. 35mm lower and you'll be removing bit's of front bumper over speed humps.

340 Nm is not that much really. If you convert the 320lbft mine's delivering you get over 430Nm.

This is a fragility of tuning boxes - they work basically by interfering with sense and control data. This is a very crude way of controlling fuelling and boost. By remapping the ECU you still let it see the engine sensors directly (there's a lot of 'em). What the remap does is actually alter the output data WITHIN the ECU directly. This is much more accurate than the plug in method which only intercepts the signals. Which means they can push the boost and fuelling 'harder' as it's much more finely controlled. A lot of boxes just work by stretching the injector dwell time. The HDi engines use up to three injection operations per cycle so clearly this is a bit of a bodge. Resulting in unburnt fuel, in turn resulting in heavy exhaust smoke.

With a remap there are other parameters that can be changed. For example the fuel rail pressure can be increased earlier in the rev range (but never be allow higher than the original 1300 Bar). The pilot injection happens as normal with the main injection being achieved in a shorter time frame due to increased rail pressure.

I think tuning boxes are expensive as well. I paid £300 for the ECU remap, and it's very impressive. Consider that it's been in this tune since Easter 2006 with no subsequent issues as a result.

It's up to you, but I'd completely dismiss tuning boxes. It's as crude as trying to remove a minor paint scratch using a hammer and chisel whilst blindfolded.

[turbo]

But it can`t be remapped. Its not possible to alter it on this car although turbochips in Carlisle say they can do it, but it somehow doesn`t work off the ecu. Its a seperate unit on the fuel pump on this car. Could I adjust the turbo actuator possibly? Abbottracing, Saab tuning specialists say it cannot be done. The only way of improving the car is through their performance box.

[HDi fun]

What model year is your tid? The earlier ones, although directly injected didn't run the stupid fuel pressures of the CDTi derived engines. These might well be mechanically actuated with an electronic 'control' of fuelling simply to regulate exhaust emissions.

If so then a box might be the only way, but let's have a look. Please tell me the year of your car.

Cheers,

Paul.

[turbo]

Its a 2001 Y reg. the 115 bhp models can be remapped but not the 125 bhp cars. A bigger intercooler might make a 10% improvement but at a high cost. I think the only way is with a box. Abbottracing have done alot of work on their unit and it links into quite a few different places on the system.

[HDi fun]

That may be the only way in that case. Shame though because it's much cruder than changing the ECU code.

[edk]

Sorry to jump into this convo late...

What ECU do you have?

If it did come down to using a tuning box I rate the DPT (Diesel Power Tuning) box. It's a digital box that plugs into the fuel rail sensor and since I've had it, smoke is near gone even under hard acceleration (which is a shame cause sometimes that's a bit of fun ), and drive is smoother and certainly stronger. My MPG went up 5-7 even giving it a bit of stick, and I can cruise for happily in higher gears. It's amazing considering it's only controlling fuel. Tuning boxes are a very densly packed minefield. I wouldnt choose any other and I'm glad I went for this.

Having said that though a box cannot substitue a good remap. I've done the box for now (a year or so) as a stop-gap until I get a turbo upgrade which'll bring on a remap.

Another option over an intercooler is water injection. Just as effective if not better for cooling air by injecting water vapour into the intake manifold. Adding up to 30% meth to the mix will again increase power, and there's the bonus of having the engine interals kept clean too!