1.9D power delivery?

[m1tch1987]

Hi all,

I am still getting used to my V40 1.9D, I have never had a car with a VNT turbo before, so im not sure what to expect, my previous car and my RX7 has a standard turbo with a wastegate etc etc, so the power delivery meaning the car runs off boost, then when I want boost it will spool under load etc giving that 'kick in the back' feeling. With my V40 I don't get that, does the VNT turbo spread the boost out due to its variable geometry so that there is no sudden boost but just a gradual increase in power?

I am just checking as the car seems a lot different from my other cars, my previous car (pug 306 Dturbo) had 90bhp when it was new vs my V40 which is 115bhp when new but is heavier, so the power/weight should be about the same, but the V40 doesn't really feel like it has much power.

Any suggestions on this? Should I check the EGR isn't clogged?

[baldmosher]

I'm no expert but coming from a 55kW 1.9TD Golf (not the TDi) which I guess is similar power to your 306, although was a lot more clapped-out...

The V40 does weigh 1.7tonnes unladen, it's a big beastie, and the gearing will be vastly different, so I'm not sure your power/weight ratio calculation is totally indicative. More comparable to try out a Laguna estate with the same 1.9D engine...?

I get pathetic power below about 1500rpm I guess mainly because of the weight of the car, but then approaching 1800 it'll quickly ramp up as the turbo takes over, and above 2000 is pretty much whoomph. The real power I find is in the 2500-4000 band, especially in third gear. Don't be afraid to drop a gear - Volvos are geared for easy overtaking! - but I've found it's got more acceleration in 5th gear than most other similar cars, common rail or otherwise.

Ford's TDCi is the benchmark for motorways if you ask me - massive mpg and plenty of power across the range. This Renault one's pretty good for its age, but it's no T4 that's for sure.

The biggest benefit compared to a standard throttle/turbo I've found is that the ECU controls acceleration so flooring it at low revs doesn't use more fuel. In fact there's studies to show the most efficient way to drive is to let the ECU do the work and change up at 1800rpm before the turbo kicks in. If you're a boring old fart anyway.

There's a few threads about remapping, costs about £400 and easy to fit, and ramps the F9Q engine up to 145bhp with a big improvement in torque, so that might be an idea, but probably not worth it unless you've money to burn.

[m1tch1987]

Thanks for your input, I guess I never really though about gearing, what would be the best speed for MPG? I have found there is about a 5mpg drop between cruising at 60-65 vs 55-60, also the car seems to scrub off speed quite quickly vs my other cars, I thought with a heavier car shouldn't it coast for longer?

Also a kingquick box (fitted to Graham's V40) is running at about 170bhp, box costs about £200 and isn't just a resistor lol

http://kingquick.co.uk/store/home.php?cat=1379

[Jabe]

Originally Posted by baldmosher

There's a few threads about remapping, costs about £400 and easy to fit, and ramps the F9Q engine up to 145bhp with a big improvement in torque, so that might be an idea, but probably not worth it unless you've money to burn.

Remapping is different to chip tuning, just to clear that up A remap shouldn't cost no more then £250 for a car of this age, the engines been around for 10 years and has been tested thoroughly throughout so it shouldn't take no more then 10-15 minutes to tune and give you your new figures on the rollers.

[baldmosher]

Originally Posted by m1tch1987

what would be the best speed for MPG? I have found there is about a 5mpg drop between cruising at 60-65 vs 55-60, also the car seems to scrub off speed quite quickly vs my other cars, I thought with a heavier car shouldn't it coast for longer?

If you're going downhill, yes. Uphill, no. ;-)

I don't have a trip computer in mine, so I just fill up every time and calculate based on mileage out vs fuel in. I always fill up at around 500miles. Reserve light is probably at about 5l (40 miles or more). The most I've got out of the tank was 560mi and there was about 2l left in the tank. Cutting it very fine. Unless the tank's bigger than I thought....?

I got 41mpg average from my first few tanks, I didn't really push it around too often for the first couple of weeks, then I tested "economical driving" by keeping it under 2500 for a full tank. Made virtually no difference at all, I got 46mpg as a reward for driving like an old man, so that was the end of that.

I can't help motorway cruising at a steady 85 (allegedly, that's why I wanted a bigger car) but that's only 3000rpm which is pretty low. (Six gears or dropping to 60mph @ 2000rpm would probably give another 5-10mpg.) As long as I do a couple of hundred miles on the motorway, I nearly always get about 43-46mpg from every tank. I do tend to take it easier on my commute as it's 3 miles of stop-start down urban side streets. I rarely invoke the turbo. Avoiding the motorways pushes mpg down a fair bit. This is not a car designed for nipping around town! It is very forgiving of driving style though.

Slowing down a bit always helps mpg, of course, although below 60mph the benefit drops off, as wind resistance matters less. Cruise control behind an HGV and you'll inch up above 50mpg without any trouble. But you'll soon be bored out of your mind.

If it helps to put all this in perspective, I do about 12k miles a year. If I was averaging 55mpg instead of 45mpg, that would only save me £100 in fuel each year..... You just have to ask yourself whether you'd prefer to get there quickly and have fun doing it, or take your time and save a couple of quid. It usually depends on my mood :-)

[m1tch1987]

I have done some testing on a long 400 miles run, details for my 1.9D after cleaning the EGR:

Town: about 42mpg
Cruising at 50mph - 65mpg
Cruising at 60mph - 55mpg
Cruising at 70mph - 45-50mpg

Pre EGR clean, cruising at 50mph - 58mpg
Post EGR clean, cruising at 50mph - 65mpg
Cost to me to clean the EGR - £0

Check my MPG thingy in my sig