G40s = Value for money... Bang for buck.... FACT!

[confusionhunter]

Afternoon folks,
I thought it was about time that I showed some of the g-tech readings I have taken over the last few years to compare some cars I've had the honour of owning/having a shot in etc.
Ive read some posts of late that seem to show G40s in a bit of a crappy light showing better value for money elsewhere etc.

I thought I might show what they are truley capable of. No pub talk, no opinions. All fact.


I have a G tech competition performance meter and I find this thing really interesting as it confirms what your bum feels! Combined with VAGcom it can give you a really good idea of the effects of mods and the pros and cons of some modding.

You can also have a virtual race in your mind! For me it allows me to remember just how fast or slow cars actually were rather than just remembering they were rapid when they actually weren't....  

I do realise there are serious flaws in using G performance meters, the main one is any power figures are at the wheel AND are less air resistance which is almost impossible to calculate. To do it properly you need air speed, direction, speed (which isn't constant anyway!) etc so I've just come up with estimates considering size and rolling resistance estimates....and not forgetting transmission loss. However for before and after comparisions its ideal.

So, pressing on, competitors for this compare are:

Main run: (Black line) The control car. This is the car I built for my Brother its an S4 saloon, KO3s, 2.25 dual exhaust, MRC remap, RS4 ICs, APR Bipipe, 18inch wheels, H&R coilies. Approx 350bhp.

Run 1 (Red line) My recent project S4 Avant ( now sold), approx 500 bhp did a standing quarter in 12.4 with a sy-pathetic start. Dropping the clutch can take of some serious time but I didnt have teh balls for that (or the mind to replace gearbox and clutch parts). At this run it was running a safe map and a manual boost controller.

Run 2: (green line) A6 4.2 V8 Quattro Auto, Custom exhaust otherwise std. Approx 300bhp

Run 3: (Blue line) My old VW Polo G40, PSD Full blend Charger, dewedged Throttle body, derestricted airbox, Boost return valve bypass. Std IC, std exhaust, 65mm Pulley, 1272cc 8v, 4 cyl, Rolling Roaded at 156bhp at some point...860kg! This run was done some time ago!


On both the S4 runs I didn't do a 'proper' launch through having mechanical sympathy which is why the ¼ mile times might look low and the Avant run was done in the wet too. Not to mention the rubbish shifting times in the Red Avant.

So the first Graph is power estimates....ignore the first half of the red line...

So you can see clearly the Avant is ahead of the game, as I would hope!
Max power according to this is 341.5bhp. So lets do a little sum:
341.5 plus 25bhp for Air resistance gives 366.5 times 1.25 for Quattro transmission losses gives 458bhp... nice! And probably about right at that point in time ( was still tuning).

The Black S4 says 239.2bhp, using the same rule plus 25 times 1.25 give 330bhp! Sounds about right but probably a little low considering the mods, but a head wind could easily account for that.

The V8 says 189 bhp which sounds pitiful but lets work the maths.... 189 plus 35 bhp for the fat lardy A6 shape times 1.35 for the quatto, wide body tyres AND the fact its an auto brings it to just over 302.... actually thats pretty spot on...

Next G40: 125 plus 15bhp as its a tiny car and times only 1.15 as its FWD gives 161bhp.... not bad, not bad at all..... Clearly showing this as the underdog.

So it 'kind of' makes sense....
Because these power runs are part of a ¼ mile run you don't get the torque delivery but I might have files that shows those somewhere.... .

More on power this time mapped over time, however this is about  power to the floor so gusts of wind and traction loss show up too.....


Well as you would expect the avant takes off but you can see the effect of the wheelspin as the acceleration Gs drop to almost nothing forcing an early change to second which seems to take a while to get going again. S4 saloon line isn't as bad a change but isn't ideal. As you would expect the V8 Auto has almost no drop in acceleration G force compared to the manuals.

The Blue G40 line is low and all over the place in 2nd as there simply is bugger all traction in the light 2wd FWD vehicle. So in real terms all the Quattro audi's have probably pulled a few car lengths already.

Whats also interesting is that the Avant gets MORE power to the ground as it gets faster rather than less like all the others.... clearly showing the big power advantages as speeds get higher. Really obvious in 4th.

Considering the vast differences in power output you wouldn't think you could even compare the some of them! However..... lets look further...

This is estimated speed over time:


As you would expect the Avant buggers off without too much bother, with the S4 Saloon following a similar pattern behind. The Saloon spends over 2 seconds longer in 3rd gear than the avant. You can see I'm shifting slightly earlier in the Ko3d car in 1st and second, as the power tends to die off at the higher revs.  That is made even more obvious by the curve in the black third gear line and looking at the area between the black and red. 80mph plus the Avant just starts to bugger off...

Some interesting lines in the V8/G40 race too.....The V8 auto has no dips in Gs as there's little shifting time. Despite the traction issues the G40 has a significant weight advantage so in actual fact the 1st gear acceleration is pretty much identical until the first change. Then the V8 gets ahead, g40 comes back till the change to third gear. Then the little g40 gets rid of its traction issues and shows its strength in mid range acceleration and starts pulling back on the big V8. In fact , looking at the angle of the lines its now accelerating harder than the S4 saloon! You've got to admit you'd be pretty surprised to be out accelerated from 50mph by a standard looking early 90s polo if you were driving a modded S4 or V8! Love those G40s!


Lets have a look at the actual G readings, theres no arguing with these....


Well you can see my 'sympathetic starts' in the S4s signified by the double humps as I bring up the clutch until fully engaged before I bury the throttle, hardly dropping the clutch at 4500revs...

You can also see the effect of the wheelspin has on the Avant and it takes several seconds to get back up to power in second as the change drops the revs to below the turbo spool sweet spot. That really highlights the difference in spool up time between the KO3s and KO4s. Clearly I need more practise in changing in the Avant as Im capable of better changes like in the saloon. Both had Tanoga shifters and the Avant has the ESP Gearbox brace.

Again the V8 plants it down with little interruption from the tiptronic and the G40 lines are up and down like a yo yo for 1st and 2nd.
Ah ha!!!!!.. suspicions confirmed. The G40 does pull harder in third gear than both the V8 and the S4 saloon. Amazing machines, thats why I love em!

So lets get this straight.... standard looking standard exhaust in 3rd gear out accelerating a 4.2 V8 and a modified 350bhp 2.7 v6 Bi turbo...... Now thats bang for buck, espcially considering the S4 had a few Ks worth of mods.

Lets not5 talk about the advantages of 4wd of course.... But Ive still top try my carbon turbo polo with LSD on this thing....!

Ok nothing was going to argue with the red avant but you could have bought 10x G40s for the money that needed to go that quick.... oh and what was that....15mpg? 22 from the black one?? what does the G return? 32 was that? 

Value for money through and through if you can put up with ethe lack of leccy windows and creature comforts. After all thats what makes these cars go! no weight!

Hope you enjoyed the blurb....
Cheers.
Mark

[Jezza-7]

Thats really interesting. Good read. Would like to see what my car would be like just to see what the 1341 bottom end makes.

[DMWG40]

very nice read mate

[scotsjohn]

Nice one Mark! I reckon in real world motoring what happens between 50 and 100mph is what really counts and where the G really shines. Good to see it on paper

[ereeiz]

I LOVE the way mine goes in 3rd and 4th. 4th is my fave I reckon. Pulls like a train 
Regularly do expensive cars, Jags, Beemers, Audis, etc.