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+25bhp Performance Chip

97 posts & 41 voices | Started 11 months ago by bland | Latest reply from bland

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speed12 - Member

Go on then, name another diesel race car.

I can think of one, off the top of my head.....

Peugeot 908 (also in LeMans)
Ricardo-Judd engined LMP from a few years ago
Seat Leon (one of the most successful touring cars of modern times)
JCB Dieselmax (not a race car, but has the land speed record for a wheel driven vehicle)

I think there are a few more but those are the main ones!

May I congratulate you on a job well done then, because if the stats are close to the real world they are excellent.

Are certain manufacturers further from the stats than others then?

I'm not going to lie and say they are exactly the same as you have to make compromises to hit the CO2 target in the NEDC test zone - but they are as close as you are probably going to get. Volvo made a big deal about getting real world fuel economy good as in the home market they would get shredded if people replaced their current Volvos and didnt get at least the same or better fuel economy.

The NEDC test is defined around a set of coastdown terms which are notoriously simple to fudge. Some manufacturers fudge them a lot more than others. Unfortunately that is one area we don't have control over when we calibrate an engine and so have to go with what we are given. The Volvo ones were certainly realistic though - they are easily the most honest company I have worked with.

Posted 11 months ago #
molgrips - Member

Your two-stroke sounds like a ship engine, Molgrips

Hmm, interesting, not familiar with those. I forsee that the issue with this design would be a suitable compressor.

One day I'll buy old cars and bodge these crazy ideas into them, see how I get on

Some manufacturers fudge them a lot more than others.

I don't suppose you can tell us which ones? Anecdotally, BMW are bad for this - but that could be because BMW drivers like to boot their cars about - and also Fiat are getting slammed for the real world economy of their Twin Air 500.

Posted 11 months ago #
speed12 - Member

I don't suppose you can tell us which ones?

I could, but then I'd have to kill you......

In all serious, it's probably best not to just in case.... Some we have 'evidence' for and others you can just tell that something is a bit dodgy when you look at all the numbers. I'm sure a slightly less unscrupulous engineer has put them somewhere up on the big wide web!

Posted 11 months ago #
molgrips - Member

Well I should let you all know that I can get the govt figures from both the Prius and the Passat in summertime, whilst sticking to the speed limit

Posted 11 months ago #
gwj72 - Member

Diesels.......Take as mentioned as a good modern example - the jag 3.0 diesel. Only 271bhp from 3 litres with 2 turbo's. Peak power at 4k. That's good? My 1996 petrol car mullers it for power with lower displacement, half as many blowers and another 3k before I hit my redline.

That's not progress chaps. It does 48mpg while I average 24. Definitely an advantage on that front I guess.

Posted 11 months ago #
bland - Member

Some good points and discussion there chaps.

In summary my plan is to run this 20p resistor for the next tank of fuel, (i put in 50 litres at 136.9 totalling £68.45) thats just so i remember when i tap the figures into fuel economy calculator.com.

Im running it with miller diesel plus stuff in as apparently it reduces the unburnt fuel and black smoke emmisions you can get.

Im not after power, however if it will return 75mpg then your talking, especially at todays prices.

I will get back to you when the fuel light comes on and let you know the results (on mpg, when i want a faster car ill buy one)

Posted 11 months ago #
speed12 - Member

The jag diesel also has around 500Nm of torque - which is more than an F1 car produces. That is what 3 litres an two turbos gives you (as well as the good mpg).

Torque is generally what you want in a road car, not outright power (only available at full throttle and very high rpms), so in that case the jag engine is a pretty good bit of kit.

Posted 11 months ago #
gwj72 - Member

The jag diesel also has around 500Nm of torque - which is more than an F1 car produces. That is what 3 litres an two turbos gives you (as well as the good mpg).

F1 cars spin to 20k revs, they don't need a high torque figure. My car has way more torque than a f1 car too. Hot hatches do these days. Meaningless stat that.

Posted 11 months ago #
cbike - Member

Martin does vans - http://www.vantuner.com

and does not over estimate your power increase.

Posted 11 months ago #
The Flying Ox - Member

Anyway, big downside is insurance - I declared it and my premium doubled and most insurers will no longer touch a modified car - so it gets harder and harder each year to find anyone who will quote (other than specialists who charge a small fortune).

You aren't looking hard enough. Difference between my old standard car (~225bhp) and after I'd tuned it (~290bhp) ended up being a big fat £0. And it wasn't a small fortune either. Maybe £500 fully comp.

What's the point? The last time I drove in the UK all the much, much, more powerful vehicles than the one I was driving seemed to achieve was a zap of gratuitous acceleration before braking as the gap to the vehicle in fornt diminished. A sort of "I'm a frustrated prisoner of this metal box and this trafic saturated road" statement.

Or, there's the thrill of booting a car from standstill up to 60 in 4.8 seconds. It's fun. I'm a frustrated prisoner in a metal box when I'm in the missus' Ka.

Posted 11 months ago #
Edukator - Member

Colin McRae Rally 2005 objecively gets my pulse higher than any real car I've even driven in a straight line and produces micrograms of CO2 (the computer is solar powered). Your 4.8 seconds of tyre-smoking, look-at-me-I'm-macho, anti-social "thrill" belongs to a more superficial age when Yanks had 400bhp big blocks and a 55mph speed limit.

If you really want thrills then having found an appropriate place something like a basic Seven on skinny tyres won't do your 4.8 seconds but will provide hours of entertainment. Choosing from the cars I've driven this one rewarded skills with thrills.

www.youtube.com/watch?v=-ahKPnq4emU

Posted 11 months ago #
The Flying Ox - Member

Colin McRae Rally 2005 objecively gets my pulse higher than any real car I've even driven in a straight line

I get the skill/thrill ratio thing. I've had an immense amount of fun ragging an old Sierra round Knockhill. But there's a lot to be said for sheer brute force acceleration.

EDIT: and what's antisocial about it, anyway? Antisocial is pissing through someone's letterbox, not giving it beans off the lights.

Posted 11 months ago #
simons_nicolai-uk - Member

Antisocial is driving too fast (which may well be within the speed limit), or "giving it beans off the lights", in a built up area increasing the danger to pedestrians, cyclists and other road users, and damaging people's quality of life with increased noise and pollution.

If you want to be a racing driver, please go to a race track.

Posted 11 months ago #
molgrips - Member

271bhp from 3 litres with 2 turbo's. Peak power at 4k. That's good?

Yes. You already said it's twice as efficient! And who cares about the redline? I honestly don't care what the max rpm of the engine is. If it bothers you that much why not cross out the numbers 1-5 on your dial and replace them with 1-8 instead? Cos that's all the difference it makes.

Likewise specific power. Utterly pointless to compare two different engine technologies. Utterly. What matters is driveability, torque distribution, and power. And efficieny, too. A big V8 petrol might be lovely to drive, and have slightly better characteristics than that V6 diesel, but in the real world where we have to drive to the supermarket and pay for our own fuel, that diesel would win hands down for me.

Progress? Absolutely.

Im running it with miller diesel plus stuff in as apparently it reduces the unburnt fuel and black smoke emmisions you can get.

That stuff should increase mpg on its own, so if you are going to contrast and compare make sure the fuel is the same each time.

Re antisocial driving - a lot of people really don't like it when other drivers f*ck about on the roads that we all have to share. that's why it's antisocial.

Imagine me riding my bike around Tescos at full pelt. That would be antisocial for the same reasons.

Posted 11 months ago #
The Flying Ox - Member

Well that's me told.

Posted 11 months ago #
thisisnotaspoon - Member

F1 cars spin to 20k revs, they don't need a high torque figure. My car has way more torque than a f1 car too. Hot hatches do these days. Meaningless stat that.

For comparison, the average cyclist.......

~1000N @ 0.175m = 175Nm

The downside is you wont do that much past 85rpm, or for very long.

Posted 11 months ago #
bland - Member

Righty ho, the results are in.

604 miles from 50litre tank so its a load of shite and its out.

Average worked out at 54mpg however it was saying that each journey was averaging over 70mpg so it clearly kids something.

However on a more serious note when removing the said resistor(which the clip broke on and was a t$%t to remove) i noticed a bung sat in the engine bay...............then saw gear box teeth!! uh oh

put some oil in and it came straight out the bottom.

Now the last time i noticed a change was about 18 months ago when i thought the clutch may have been getting rough so it could have happened then, there is no oil anywhere on the engine bay and its been running fine with no drones or whines etc.

So in short the 20p resistor has saved me breaking down somewhere random, how long i have had a dry gear box for i havent a clue but fair play to VW.

Next question, how much for a new gearbox, or recon one, any ideas

Posted 11 months ago #
hora - Member

I was lucky to get 300 miles from a tank on the Puma, I estimated approx 25-30/gallon

Count-zero I thought it was just me. 270 and its running on the limit of the tank. Mind you that engine seems to go up the rev range waaaay too easily

Posted 10 months ago #
benjamins11 - Member

I recently bought a vw box from a breakers for 450. recon was looking over 1000. the box came with warranty and had done only 40k, have a look on ebay. another tip is if you find out what the box code is it will likely be fitted to lots of other vag group cars so i found its cheaper to buy the same box from a skoda or seat than it is for an audi, even though the box is utterly identical.

Posted 10 months ago #
molgrips - Member

However on a more serious note when removing the said resistor(which the clip broke on and was a t$%t to remove) i noticed a bung sat in the engine bay...............then saw gear box teeth!! uh oh

Missed this earlier - good spot though!

Used gearbox.. £2-300 I suppose if it's an old car.

Posted 10 months ago #
spooky_b329 - Member

You don't need a new gearbox...not yet anyway! Replace bung, give it a few oil changes with cheap oil over the next couple of weeks to flush out any metal particles, refill with decent oil and cross fingers would be my approach!

Posted 10 months ago #
spooky_b329 - Member

I was just looking at the vantuner link and this sentence caught my attention...have I miss-understood it or has someone done a cheeky edit (due to the repeated use of 'or' at the end?!)

The Eco tune map is a mild tune that focuses on torque and attempts to maximise mpg, so is ideal for towing, motor homes or very high mileage vehicles or Jews.

Posted 10 months ago #
MrOvershoot - Member

bland - Member
i noticed a bung sat in the engine bay...............then saw gear box teeth!! uh oh

put some oil in and it came straight out the bottom.

Now the last time i noticed a change was about 18 months ago when i thought the clutch may have been getting rough so it could have happened then, there is no oil anywhere on the engine bay and its been running fine with no drones or whines etc.

So in short the 20p resistor has saved me breaking down somewhere random, how long i have had a dry gear box for i havent a clue but fair play to VW.

Next question, how much for a new gearbox, or recon one, any ideas

Hang on "bung" "gearbox teeth" are you saying you could see gearbox teeth through the hole where the bung fitted?
And when you poured oil in it came straight out the bottom?
If so are you sure thats not the ring gear on the outside of the flywheel, as I don't know many gearboxes that just have a "bung" breather plug maybe but most flywheel/clutch housings have an inspection bung?

Posted 10 months ago #
spooky_b329 - Member

If it is the ring gear I wonder where he poured the oil in?!

Posted 10 months ago #
torsoinalake - Member

Careful. In my VW the plastic bung covered a hole used for timing (so you can see the timing marks on the flywheel). Pouring oil in there is not a good idea.

Posted 10 months ago #
molgrips - Member

D'oh! Yes.. tis the timing inspection hole - little plastic thing with a tab on the end? You see one large 'cog' about 1/2" thick? That's the flywheel, and the teeth are for the starter motor.

Gearbox gears are a few inches across, and a few inches thick afaik, and have diagonally cut teeth...

Posted 10 months ago #
bland - Member

I took it to be checked out and i was told that its casing was cracked and a gasket had gone so who knows. Its gone now anyway which it needed to anyway as it was starting to feel a bit of a dog to drive and was going to start costing too much to keep going

Posted 10 months ago #