Tuning / performance update

[Sharkie]

How good was that 155kw guess of mine ....

4-5kw of that figure is due to the intake. Average for the 2.0TSIs with remap only, around 150-151kw .....

Stock 125, you'd find 95-100kw .....

[Pullstarter]

Yeah that's with APR stage 1 and home made intake. The dude at the dyno place said they dynoed a stock one and it was 98kw at the wheels so a huge improvement

[Glennb]

Great result there!
0-100km/hr times anyone??

[clip]

I'm a bit surprised at that loss through a manual transmission. Although, I wouldn't regard the actual figure as accurate in any case.

But I'm confused - because this seems to be indicating that the 200kW Tig has basically the same percentage loss as the stock 125 (125 down to 98 rear wheel kW). Increasing an engine's power (as we have done) doesn't involve changing the drive line. So while there is an approx 22% percent loss from the remapped 125 (now putting out 200 with the remap and CAI), this should not equate to a 22% loss with a stock 125. And yet the 125 is producing 98 rear wheel kW, which is virtually same percentage loss as the 200 producing 155 rear wheel kW. This doesn't seem to make sense as the drive line hasn't changed.

I've got a headache now, so I'm going to sleep on it some more!

[Sharkie]

Its actually spot on clip, drive train loss stays at the same percentage all the way through as it is only a percentage. It is a constant.

Even if you're making 300kw the loss factor will still be around 22%.

Having studied the dyno graph I also have the following observations .....

1.. See how wide that torque curve is? In excess of 2000rmin of max torque across the rev range. Brilliant
2. See how well that kw figure is delivered? In excess of 150kw atw (190 on the engine) for over a 1000 rmins ....
3. Significant power is available up to 6800rmins at least. You don't have to change at 5500rmins ......
4. The intake contributed about 5kw atw (8kw on the engine) which makes it a really good addition. A Carbonio would make another 1-2kw atw, but for the extra $$$ do you really need it? (Considering what you paid for it, Simon, a full price Apollo may make the Carbonio a viable alternative)

[Pullstarter]

Very true Johan, I got the Apollo at bargain basement price but at the full purchase price plus odds and end would have been around $350 so I guess most would probably go for the Carbonio.

For all you dyno masters out there does the AFR look ok? Dyno dude reckons it was spot on but I don't know much about AFR readings?

[jimbomort]

Its actually spot on clip, drive train loss stays at the same percentage all the way through as it is only a percentage. It is a constant.
Even if you're making 300kw the loss factor will still be around 22%.

Sharkie I'm with clip - my head hurts, above if I read it right, you say a percentage and then a constant? Oh sorry, you probably mean the % is a constant?

But can anyone explain why drivetrain losses are a % no matter what?

I understand that power and torque at the wheel is the real deal (well actually the performance is but guess thats the reason for?), but of interest how does 22% for the manual Tig compare with other cars?

[Guy_H]

OK,

The Tig 125kw 6 speed manual gearbox code is LMV.

Good news!

Same as the 147kw version (in countries where it is sold) - this also explains the same size clutch in the two variants.

The only diff ratio they give me is this number:

67/14/19/17 so I'm not sure how to interpret that.

Only other reference I have is a Tig with a 1.4 Twincharger has the numbers:

66/15/20/18 - so certainly something different for the small motor.

My New GTI has the numbers:

71/18/23

See if anyone can work that out ???????

[clip]

Its actually spot on clip, drive train loss stays at the same percentage all the way through as it is only a percentage. It is a constant.

yep, I agree Sharkie, it is a constant, but I don't think it can be expressed as a percentage. I think it's pretty much a fixed loss throughout the kw range. If the stock Tig (125) loses around 25kw from flywheel to wheels and then that same car with a mod makes 200kw at the flywheel, the power loss will surely still be around the 25kw through the drive train. Shouldn't it?

In this case, I was thinking that the Tig would have been putting out closer to the mid 170's at the wheel (if it was actually now developing 200Kw as Simon's should be). I knew that the 125 put out around the high 90's at the wheel and that loss equates to around 26Kw (which just happens to be around 22% - which we are using as the base line figure of a stock Tig). So a 200Kw Tig should be putting out around 175Kw: 200 - 26 = 174Kw, which is not a 22% loss. And yet it seems it did (22% of 200 = 156). Simon didn't change gearboxes, diffs, tyres, CV's or wheels. So why would the drive train now eat up 45Kw just because he increased the power output of the engine?

The only logical conclusion therefore is that the baseline stock engine figure is not correct - i.e. the stock Tig puts out less Kw at the wheel than 98 quoted because the exact same engine and drive train with 200Kw loses 45 Kw from flywheel to wheels, therefore the 125 Tig looks like this: 125Kw - 45Kw = 80Kw at the wheels.

Of course the other conclusion is that the Tig with the mods in this example is not actually putting out 200Kw at the flywheel, but closer to 180Kw (155Kw measured + the 26Kw that the stock Tig loses through the drive train).

[team_v]

AWD drivetrain loss is a constant percentage.
As sharkie pointed out, it will be fixed percentage loss of power from the fly to the wheels no matter what figures you use.

That is the way the system works, it doesn't just determine a 30kw loss through the system no matter what power you are putting through.