Hi

It is a simple enough thing to determine which is quicker for a given output. Say we have a modified PD130 and a LCR engine both producing 225bhp. The diesel will produce its torque curve as a fairly steep sided thing, with peak torque arriving at around 2500rpm and falling off from there maybe 30% to peak power near 4000rpm. The petrol turbo will be producing a relatively shallow sided torque peak near the top of the rev range. To suss out just how fast each car will be, we need to produce a graph consisting of the torque delivered to the driven wheels in each used segment of the engines speed range. This will look like a set of stepped bumps reducing from 1st to top gears. The engine / gearbox producing the greatest area under this line will be the faster vehicle given similar weight and drag.

On this basis, the diesel will produce more torque per gear at the driven wheels where the gear spacing is large (in the lower gears) so in thoery should be a little quicker. Higher up the rev range, there would be much less in it as each higher and closer spaced gear will see less of the torque peak at upchange on the diesel, robbing it of its marginal advantage.

So a specced up Fabia vRS should on paper perform similarly to the standard LCR. All the debate about rev ranges is largley irrelevant as power is the mathematical combination of engine speed and torque, so if the headline power figures are the same, the perfomance will be very similar.

Whatever you buy, you will have to suffer someone being faster, it is just the way life is. Big power will always win because there are two factors at play. Power to weight and power to air resistance. A small FWD hatch will be nippy if tuned to say 275bhp, but as the speed goes up, particularly noticable past 3rd gear, a big properly powerful car will absolutely storm away as it is able to punch a hole in the air so much more effectively. If you want a proper accelleration hit, try a Supra twin turbo, which in standard form will eat a 275bhp hatch for breakfast with the added advantage of being able to deploy the power as it is RWD. For a more subtle take on the theme, try an XJR Jag (the V8 one). These have quite remarkable accelleration.

Chris

It is good to know the Fabia vRS has a proper brick shape to help with it's aerodynamics then

Grab a Caterham-type car. Very low weight, fairly low power, but it don't half shift

Used Monaro - similar money to a new LCR and much, much faster. There's no substitute to CCs and your little 2.0 engines will seem puny in comparison.

Budget for an LPG conversion though

Used Monaro - similar money to a new LCR and much, much faster. There's no substitute to CCs and your little 2.0 engines will seem puny in comparison.

I overtook a Monaro the other day - he was making lots of noise but not getting anywhere so his car was either screwed or he was having more trouble than me making traction in the wet :rofl:

Chris

he was having more trouble than me making traction in the wet :rofl:

Chris

Now nobody mentioned wet weather!!

The answer is a factory 4WD 200+ BHP diesel leightweight that would do me niceley but there arent any!

Actually, the real answer is to keep the Furby and buy yourself a decent sports motorcycle !

That way you smoke the M5 and just about anything else for that matter !

If you want "really quick" then get a bike !

Edited to add: For those that are not into bikes, put the bike engine in a SMART CAR and then go looking for M5's ! :D

He he he....something can't have been right there. A V8 Monaro losing to a diesel Mondeo, albeit a modded one.

No offence intended but he either couldn't drive or his traction control was screwed.

Those engines are pretty old school though. A pushrod Chevy single valve V8, albeit a massive one shoehorned under the bonnet of a Vauxhall.

Immense torque but crap top end. It'd sound like a diesel if it weren't for the fact it'll only do about 15mpg if driven gently.

He he he....something can't have been right there. A V8 Monaro losing to a diesel Mondeo, albeit a modded one.

No offence intended but he either couldn't drive or his traction control was screwed.

None taken! I was expecting to be left for dust, especially with all the noise it was making Chap must live reasonably locally to me though as I heard and then saw him this morning driving it properly - so it sounds like any issues have been resolved

Chris

I've just been reading....the same engines powered Corvettes to victory over Ferraris recently! You can't beat masses and masses of torque..... Oooh it's making me wet just thinking about it.

The missus wants one for some insane reason. Would be a bit of a step up from a Peugeot 306 HDi 90.....

Back to the original topic, a mate of mine used to have a TT 225. Isn't that the same engine as the LCR? That car wasn't bad. Not hugely fast but ok. Scoobies still ate him alive though, as did a Porsche Boxter S too one time.

He sold it to buy an E46 M3.

The turbo lag was always noticable though and it was really wheezy at high RPM. There was no point going past 5k as it ran out of puff. Wierd considering the 20v head.

Yeh, the TT's have the same engines, as do the S3's i have a N/A 20v engine and didnt find the top end that good, however i had it rolling roaded and it did peak at 6000rpm

Having had a go against a standard LCR 210 in my remapped Fabia vRS I can confirm that the Fabia will not match the LCR. On a long straight off a roundabout on my private track I lost about 2 lengths to 90 mph and I got a better run off the said roundabout, once the LCR reached 90 he almost seemed to press the "GO FASTER" button and pulled maybe 10 lengths to 130 where we had to slow. An LCR 225 would be even further ahead, and a remapped LCR would simply drive away IMO.

P.S. I did this run x2 once one way, once the way back and both results were the same.

I suppose I could summize that 2 lengths up to 90 isn't bad from say 30 mph off the roundabout, however in reality I could easily tell the difference in power, and yes I was giving it some...

I weight 16 stone, same as my friend, on both cars the reserve light had just come on, and neither of us had passengers or anything in the boot etc, so it was a fairly even comparison.

Just my 2p worth.

Yeh, the TT's have the same engines, as do the S3's i have a N/A 20v engine and didnt find the top end that good, however i had it rolling roaded and it did peak at 6000rpm

Where did peak torque appear? Just out of curiosity....

Having had a go against a standard LCR 210 in my remapped Fabia vRS I can confirm that the Fabia will not match the LCR.

Probably why the LCR is ins group 16 (I think) and the Fabia is a 9.

On a long straight road, the extra power from the LCR will show.

The Fabia will prove to be an easier motorway drive though, with easy shove from the high amounts of torque and narrow rev band. At 70mph in 6th, floor them both and my bet is that for a time the Fabia will pull away. But, get to higher speeds where the LCR comes 'on cam' and away it'll go.

Can I ask though, why are we even comparing a nippy diesel hatch to a high output turbocharged petrol? Surely it's clear that even mapped, the little Fabia doesn't have the punch or the rev range to be a match for the LCR.

People go on about gear ratios combined with torque making up for the diesels lack of revs, but you still have to be in third to hit 60 mph, and changing gear takes time.

The more gearchanges you do, the more you'll lag behind. This means that by say 100mph you'll have done 4 or more likely 5 changes, and the LCR will have done 3 or perhaps 4.

Not only this but peak power comes higher in the rev range in the LCR. This means that as the speed and revs build, the LCR will accelerate harder, whereas the Fabia will whack out all it's power earlier on requring even earlier gear changes.

The broader spread of torque from the LCR will mean much more even thrust throughout the revs and a more consistent acceleration.

I'm not buying a Fabia to race M5's.....you need an RS4 for that. I'm not buying one to race LCR's either (although I'm sure you could give one a short intense scare before they drop it a cog or 2 and leave you). I'm buying one to sit on the motorway in 6th with bags of torque under my right foot for rapid and effortless progress and to bullet up hills.

All this being said, how much does a LCR weigh? With an all alloy engine surely it's lighter than the chubby Fabia?

^^

good points, with a remap however with the standard clutch you can't exactly floor it in 6th from say 50-60 mph, that way you'll have no clutch left. just a pointer, if your considering remapping, don't drive it like this unless you have upgraded the clutch. as standard however it's fine.

Yes, but the initial argument if the fabia had a hybrid turbo, we know a remapped fabia hasnt a hope against a LCR. There is a difference of 55 to 60 bhp between a hybrid turbo car and a remapp.

"People go on about gear ratios combined with torque making up for the diesels lack of revs, but you still have to be in third to hit 60 mph, and changing gear takes time.

The more gearchanges you do, the more you'll lag behind. This means that by say 100mph you'll have done 4 or more likely 5 changes, and the LCR will have done 3 or perhaps 4."

Take a look at the 2 videos, both cars change from third at 80mph as the gearing is very similiar, same amount of gearchanges to 100. Also the TDI changed gear at 50 into third but vcould have went to 60 but didnt need to, was still 2 secs faster.

The TDI... Could not hit 60 in second gear unless the rev limiter has been removed or raised. I know this for a fact, 52/55mph at the most and the rev limiter cuts in. And 55 mph is about 50 mph on GPS, don't just go by the clocks. Whereas the Cupra can go just above 60 on the clocks in second.

Octy MK1 vRS with its 5 speed box, hits 76MPH in 2nd gear and well past 100MPH in 3rd, but thats outside the toque curve. You tend to lose time once outside this as your accelleration slows. Best to change up and stay in torque curve.

Comparing the Octavia vRS the Leon Cupra 180hp uses the same engine.

Have a quick read of my thread over on SeatCupra.net .. Leon Cupra VS Leon Cupra R - SEAT Cupra.net

If your quick with the gear changes like i am its not a problem. Just looked at the video again and timed both from 30-60, the LCR does it in 4.2 sec in one gear, the TDI with 2 gears (second then into third at 50mph) 3.6 secs and that includes a slight loss of traction for a second so the extra gear to 60 didnt do it any harm.

Octy MK1 vRS with its 5 speed box, hits 76MPH in 2nd gear and well past 100MPH in 3rd, but thats outside the toque curve. You tend to lose time once outside this as your accelleration slows. Best to change up and stay in torque curve.

76mph in 2nd gear :eek: I've never pushed mine faster than 70mph in 2nd and 110mph in 3rd (on a private road naturally )

As you say this is certainly outside the torque curve, change up at around 6000rpm or so for the best effect

If your quick with the gear changes like i am its not a problem. Just looked at the video again and timed both from 30-60, the LCR does it in 4.2 sec in one gear, the TDI with 2 gears (second then into third at 50mph) 3.6 secs and that includes a slight loss of traction for a second so the extra gear to 60 didnt do it any harm.

Wrong. The LCR was in first gear at 30mph and changed at 40mph into second. Is this a windup?

Sounds like a windup to me

At 30mph the LCR would certainly have been in 1st in that video (30mph = approx 3000rpm in 2nd)

76mph in 2nd gear :eek: I've never pushed mine faster than 70mph in 2nd and 110mph in 3rd (on a private road naturally )

As you say this is certainly outside the torque curve, change up at around 6000rpm or so for the best effect

Yes, and using all the rev range once you have done it is very adictive. You need to try it once. Just hold your foot flat on the throttle untill you hit the rev limiter at just over 7K RPM, then look at the speedo, then the rapidly decreasing fuel supply.

Never really had the balls to hit the rev limiter :eek:

I'm quite happy to hit 6200-6500rpm but I dont really take it above that. I tend to find that by 6000 or so the torque is dropping and by 6500 is has dropped significantly.

At high rpm on wide open throttle you can almost see the fuel gauge moving towards empty

Wrong. The LCR was in first gear at 30mph and changed at 40mph into second. Is this a windup?

My bad that i didnt notice 2 gear changes on the LCR, so both had 2 gear changes and the diesel had traction control cut in but was still quicker. 0-60s have very little in it at that bhp anyway and wont be much in it but by the time the TDI gets to 100 the LCR will be in the rear view mirror anyone with intelligence could work that out when looking at the vids.

The TDI had only 220bhp at the time the video was taken, it now has 230bhp and noticably quicker with a few more tweaks, must do a fresh recording tomorrow.