i have urges to buy an S4. how much do they drink?

[Matt82]

i take it that newer maps achieve more power? i had a mk2 golf years back that had been remapped by amd after some headwork. amd then gave the guy two updates a couple years later

having read a fair bit about remaps, it seems mrc remaps produce more power. has this actually been verified at all or is it just a dyno lottery? (some places dynos are optimisic compare to others)

if i bought a non-remapped car i wouldnt get it changed unless i had a chance to see dyno plots of car mapped by the various places

 

[Nez]

Hi Nez

I didn't mean the S4 should be on a par with the E36 M3 but hoped it would not leave me standing in no time at all, it feels a totally different car. I would hope that the S4 would at least keep the M3 in it's sights for a little while at least, I know how quick an M3 is but not sure if my S4 should feel quicker than it does?

Hi oh I thought you were talking about the E46 E36 M3 is different even a standard S4 should keep up with it for somethings as the 0-60 E36 M3 is 5.3 sec and S4 is 5.6 sec

And you S4 is not running right for sure once you sort it out then you feel the power of the S4 before the MRC remap and health check my S4 was only doing 249 BHP and it wasn't feeling as fast as it should have but now is different case car is flying

 

[Nez]

i take it that newer maps achieve more power? i had a mk2 golf years back that had been remapped by amd after some headwork. amd then gave the guy two updates a couple years later

having read a fair bit about remaps, it seems mrc remaps produce more power. has this actually been verified at all or is it just a dyno lottery? (some places dynos are optimisic compare to others)

if i bought a non-remapped car i wouldnt get it changed unless i had a chance to see dyno plots of car mapped by the various places

I have just done the MRC remap and believe me the car is just flying and before I done the remap I ask the MRC for a test driver with their mapping and on test driver I just feeled the power right out

 

[Dan Gliballs]

i take it that newer maps achieve more power? i had a mk2 golf years back that had been remapped by amd after some headwork. amd then gave the guy two updates a couple years later

having read a fair bit about remaps, it seems mrc remaps produce more power. has this actually been verified at all or is it just a dyno lottery? (some places dynos are optimisic compare to others)

if i bought a non-remapped car i wouldnt get it changed unless i had a chance to see dyno plots of car mapped by the various places

The modern maps don't necessarily give more PEAK power as a rule, but they tend to give a less spikey curve and a smoother more usable power delivery.

They don't just whack the boost up these days, but fiddle more with optimising the timing,.............kinder to turbos.

Going by my foot dynometer I'd say mine would be more than the 301 I got if I were to go out on a COLD day,.............not 'much' more, but slightly more.

Obviously the torque figure is a crucial number to look at too

Yeah, different rolling roads vary slightly, as do the conditions on the day.

 

[Matt82]

ive had a lot of friends with 20vt lumps and from what i can tell so far, the remaps on those produce similar looking torque plots to these 2.7s (like you said, its the torque that matters)

unfortunately it seems the remaps result in a big torque spike which then tails of quickly after 4k rpm, hence my "diesel-like" comments

one thing im sceptical about getting an s4 is that the power delivery will bore me to tears

 

[Matt82]

all downhill from 3.5krpm

 

[aragorn]

So? Powers still climbing nicely.

Even on the stock car with the nearly flat curve, it pulls much harder at 5k than it does at 3k. It has less torque, but that doesnt matter as its making 75hp more.

Torque dropping isnt as big a deal as you seem to think it is, as long as the RPM's are climbing faster then the torque is dropping then the total work done (ie the accelleration) will continue increasing.

 

[Dan Gliballs]

Similar idea to the torque curve on mine.

Over 300 lb ft all the way from 2500-5000rpm isn't what I'd call a spike

The bhp doesn't tail off after 3500 like a diesel though.

Maybe a revvy M3 would be better for you, but that screaming 'hard-work' delivery would bore ME to tears

 

[Matt82]

So? Powers still climbing nicely.

Even on the stock car with the nearly flat curve, it pulls much harder at 5k than it does at 3k. It has less torque, but that doesnt matter as its making 75hp more.

Torque dropping isnt as big a deal as you seem to think it is, as long as the RPM's are climbing faster then the torque is dropping then the total work done (ie the accelleration) will continue increasing.

bhp is nothing more than maths. its the torque thats pushing you down the road and the torque on that plot is tailing off from 3.5krpm onwards

at 5.5-6krpm its still over 250lbft so its not that bad but a bit sad considering it peaks at almost 400lbft.

power deliveries like that, i find, are really disappointing. to improve it though youd need a decent sized turbo

 

[Matt82]

Over 300 lb ft all the way from 2500-5000rpm isn't what I'd call a spike

good point well made, but since when is it fun keeping the revs down, thats what taxi drivers do.

id love an e36 m3 evo, i love the revvy nature, but im not keen on the in-yer-face/chavvy image

 

[Dan Gliballs]

bhp is nothing more than maths. its the torque thats pushing you down the road and the torque on that plot is tailing off from 3.5krpm onwards

at 5.5-6krpm its still over 250lbft so its not that bad but a bit sad considering it peaks at almost 400lbft.

power deliveries like that, i find, are really disappointing. to improve it though youd need a decent sized turbo

Well no passenger has ever accused my power/torque curve of being 'sad' or disappointing lol

No, a B5 Audi petrol turbo DEFINITELY isn't for you then

Just to mention the E46 M3 as an example again - Only 269 lb ft peak torque, but all that revvy bhp at the top gives it serious power and speed. Torque isn't ALWAYS everything.

 

[Dan Gliballs]

good point well made, but since when is it fun keeping the revs down, thats what taxi drivers do

Keeping the revs down? Not 'screaming' them is probably a more fitting term.

Some people just like more effortless power. That's why I like M5 V8's and Monaros etc,.......and V-engined turbos. A 535D is a hoot in my book too.

We're all different I guess.

The M3 appeals to me too, but not as an every day car, and I sure as hell couldn't get my drums in one lol

 

[s4marsh]

Similar idea to the torque curve on mine.

Over 300 lb ft all the way from 2500-5000rpm isn't what I'd call a spike

The bhp doesn't tail off after 3500 like a diesel though.

Maybe a revvy M3 would be better for you, but that screaming 'hard-work' delivery would bore ME to tears

you got a hell of a lot of torque going on there for only 301bhp as like you say torque is the most important thing or is to me,with my remap you dont notice the power dropping of till around 5500rpm but by that time the bhp is doing its business at peak output so it win win really, certainly aint like no diesel,i upped my boost yesterday to hold 17psi but dropped my wastegate down to 5psi to stop it spiking at 18 and holding 15ish and its made quite a difference 2psi

 

[Dan Gliballs]

certainly aint like no diesel

Indeed, nothing like one.

Smells better too

 

[aragorn]

both our 1.8T and craigs S4 accellerate in accordence with the power graph not the torque graph.

You plant the boot at 2k, and you can feel the accelleration building continually until you hit peak power around 5800-6000ish then it starts to feel like its not pulling hard any more.

The physics that goes into an accellerating car is actually quite complex. Its not simply the case where you can say "theres a torque spike its going to be rubbish" I diesel feels rubbish because it doesnt rev. You get on boost at 2k and by 4k your out of puff and on the governor. An S4 comes on boost at 2k, and continues pulling to 6k.

The fact the torque drops isnt an issue as long as the power is still building. I personally find the S4 motor much nicer in terms of power delivery than an E36 M3 Evo, even though the M3 has 40hp more. Becuase when you open the S4 up at any point in the revs it goes.

MOST engines naturally have a torque plateau around 2-4k and peak power around 6. If you wanted to have your torque peak at 6k all that means is absolutely nothing would happen at 2-4k and the car would be ****** horrible to drive.

I think you need to have a drive in an S4, and feel the power for yourself, before condemning it due to the sketchy understanding of a graph.

 

[Matt82]

The fact the torque drops isnt an issue as long as the power is still building.

BHP = (torque X rpm) / 5252
power is just a mathematical forumla.

a group of us bought some gtech timing gear a couple summers back. whilst showing 0-whatever times it can also plot accelerative G force and by knowing the engine revs and weight being accelerated, can calculate the force being applied to accelerate the vehicle at that level (torque followed by bhp, using the rpm signal)

provided there is no wheelspin and youre not doing silly mph (aerodynamic issues), the g plot mirrors the torque plot. the torque being applied at the wheels is what accelerates the car

sure an S4 has shovel loads of torque at the bottom (and response to go with it) but it doesnt maintain that torque, hence it doesnt make huge bhp like youd expect for a motor that can make 400lbft.

diesel plots. the reason i said the s4 delivery was diesel like is the way the torque tails off after the spike.

ive not condemned the s4, im stll looking for the right one to buy. in fact, im buying it because i want something more civilised so the "easy access" torque delivery will suit the car just fine as well as my needs

ive driven two s4s, both remapped. the response is obvious, the tail off in power isnt that obvious but i wasnt pushing the car particularly hard (not my car!)

20vt lumps suffer exactly the same problem though, its due to the turbo being so small. a couple proper size turbos on there would make that engine a total monster (i keep telling myself i dont want to go down that route though... this is meant to be a sensible car!)

 

[s4marsh]

dont forget tho a custom map is exactly what it says...you can have the power delivery exactly how you want it within certain parameters,you could have savage power delivery if you wanted but thats not very driveable in the corners where being able to gently feather the throttle to adjust the turn in and balance. my throttle maps were smoothed right out making it feel no where near as quick as it is and will keep up with a 343bhp m3 all day long without revving the nuts off it

 

[Rallyman]

Yendall, what LPG system are you running?
I have a liquid hybrid (ICOM JTG) system on my 1.8 QTS Avant, I had it on the rollers at Emerald and got another 10bhp on LPG!
If you are worried about $$$$£$££$$$£$£$ think about getting a LPG system on it, the only downside is that you will loose your boot space with a spare - as the tank sits where the spare is....
I get about 35mpg is on a sensible run on petrol and about 27 on Lpg but the maths for £ per mile is much better!
Michael

 

[aragorn]

A pair of monster turbos will just move the torque up the rev range, and make the car horrible to drive tbh.

You still get a spike, its inevitable in a turbocharged engine, it just happens at 4-5k where you dont really need it.

Power is the rate at which work is done.
Torque is the force applied to do the work.

An example: 200lbft at 2000 rpm, or 100lbft at 6000rpm, which produces the most accelleration?

The second one while making half the force, is making that force three times as often, so the total work done is higher. Higher value of work done means more energy has been used and that energy is being put into accellerating the car...

 

[Dan Gliballs]

The 430 bhp/450 lb ft K04'd S4 I drove (and dithered around and missed out on) definitely made more power slightly further up the rev range.

The power wasn't as easy to get, but it was truly ballistic between 4000rpm and 6500rpm.

 

[Matt82]

dont forget tho a custom map is exactly what it says...you can have the power delivery exactly how you want it within certain parameters,you could have savage power delivery if you wanted but thats not very driveable in the corners where being able to gently feather the throttle to adjust the turn in and balance. my throttle maps were smoothed right out making it feel no where near as quick as it is and will keep up with a 343bhp m3 all day long without revving the nuts off it

a guy i know has a 20vt in a vw corrado, its a ko3S (slight upgrade from ko3) turbo and makes c.230bhp. it has a typical 20vt remap (big torque spike, then it tails off) which caused comedy wheel spin.

he is having the DTA mapped sometime soon to make it a lot smoother to give the front tyres a chance, but remaps like those are popular becuase they make a car feel "nippy" due to the enormous lump of torque at the bottom end.

from what i felt on the testdrives ive had in the S4s its nowhere near a pronounced as in a 20vt, and explains how it absolutely dashed from 80-100 in 6th.

cant wait to get my hands on one though!

 

[Dan Gliballs]

makes c.230bhp. it has a typical 20vt remap (big torque spike, then it tails off) which caused comedy wheel spin.

My sub 1000KG Astra GTE was pure wheelspin comedy gold in frost/wet/mildly damp conditions. It 'dug in' and gripped like **** in the dry though (with a Quaife ATB).

 

[Matt82]

looks like the plots from my old mr2 turbo from back then. that must have been savage at under a ton

 

[Dan Gliballs]

Yeah, this was the sumptuous interior......

 

[Blue_Thunder]

Commuting in stop/start traffic I think I used to get around 250 miles to a tank. Now that i'm running 400+bhp I get 230 miles to a tank.

However, on long motorway journeys I have seen over 300 miles. Managed this a few weeks ago, and I was not hanging about!

ps. If you can afford a K04'd S4, the torque curve looks a lot nicer!

 

[Matt82]

ah... so it drinks badly, but if you tune it a fair bit higher, the fuel consumption really isnt effected that much, so you may as well go for big beans

 

[Blue_Thunder]

Drinks badly??

I'd say for a 260bhp standard car the S4 has fairly modest fuel consumption. If you compare the real world MPG figures of cars of similar power (Imprezas, Evos, E36 M3's), you won't find many which give you more than 20mpg.

 

[aragorn]

My mates E36 M3 was actually quite impressive on fuel economy. High 20's to low 30s on day to day driving.

In theory a turbocharged motor should return better economy than a similar powered naturally aspirated motor, as when your cruising, its generally a smaller engine, and so uses less fuel, but that doesnt seem to ring true with the S4 for some reason.

If you notice that huge swathes of the audi range are now fitted with turbocharged engines, even the base model 120hp 1.8 A4 has a turbo, simply because it gives the fuel economy benefits of a smaller engine, but reasonable performance.

 

[Matt82]

and with a bazilion torque at no rpm you wont have to go above 2krpm that much... im hoping to be suprised with the economy tbh. i will be putting a fair few miles on the car. i put 70k on my golf in the last 3 years

 

[marsie]

My virtually standard S4 averages out at around 26mpg but if i drive like miss daisy i can get 30ish.However this week i have been doing lots of short runs and giving it some boot and its around the 17mpg mark

Get the S4,you wont regret it.I am a new convert to them but now would only swap it for a RS4 or RS6
Paul:icon_thumright:

 

[Matt82]

i can live with that, just looking for the right one. wont be long