Hi all,

I have got a new (March 2013) Vrs with the new CTHE engine.

It is now fully run in (2000 miles) and i had a question about the power delivery.

If i floor it in any gear to redline i get a nice steady pull (as i would expect) to about 5k rpm then get a definate extra boost in the power delivery to about 6-6.5k rpm.

Im just wondering if anybody else has noticed this? Is it normal?

Thanks,

Mark

not driven a CTHE in anger... I will soon though , and report back seems pretty linear in the CAVE engine...

Vtec kicked in yooooooo

Seems pretty smooth in my CTHE at 5000 miles

Rachel

My CAVE does seem to wake up a bit more around the 4.5k-5k mark; there was an ECU update (to CAVE in 2011 sometime) that would only apply full throttle from about 4750, irrespective of pedal position (only 75% open below 4750rpm). Had it applied on my 2010 Scirocco and it felt a little odd..

Not tried a CTHE though. Mine is a June-ish 2012 build, so not long before the change to CTHE.

Edited 10 May, 201313 yr by philhoward

Can anyone shed any light if this is the case on the CTHE engine? only 75% to a certain RPM??

Thanks,

Mark

IIRC vRSy said it was kind of the other way round: 100% power from as early as 75% of the gas pedal trip. Certainly mine doesn't feel as something's happening after 5K. Actually at 6K it feels like it doesn't have much more to give...

I'm guessing only a dyno graph of the CTHE engine could prove the OP's claims.

If im flat out without using the kickdown function from say 2k rpm, it pulls great then gives extra from 5-6.5k rpm.

Im not talking about depression of the go pedal, that is well and truly planted....

Edited 10 May, 201313 yr by Silicon

What gear are you in at 5000 rpm, and at what speed, over 70mph say over 100 mph then a surge.

So in 'D' & 6th or 7th, or in 'S' and 6th or 5th.?

What age is the car , how many miles on the engine.?

Has it had a ECU Update?

**EDIT, Sorry missed the 2013/2000 mile bit, need glasses on.)

?? Do you understand how the Supercharger then Turbo & Supercharger, then just Turbo works,

& @ what RPM the max torque is achieved at.?

THIS IS THE IMPORTANT BIT, (max torque)

*'CAVE engine' Max Performance, 180PS/6,200 rpm

"Max Torque Nm/rpm 250, 200-4500 rpm"

george

4000rpm can be over 100mph, and it matters if you dropped 2 gears and bring it up to from 4500-6200rpm or more.

above 3500rpm is where you are on Turbo & not Twincharging.

George, thanks for the reply.

Yep, understand the twin charger setup.

2000 miles

No ecu update

It happens in manual say in 3rd or 4th. I accelerate from 2k ish say and at 5k in the same gear I get extra oomph.

Not sure what you are trying to get at with hp and torque?

The max torque is slightly irrelevant as it depends on what gear, rpm and your gearing ratio to determine max power.

I.e. you wouldn't change up into a higher gear at the max torque (4500rpm) in order to achieve the best performance results.

Does your vrs show any additional oomph at 5k?

Thanks,

Mark

If i am at 5000rpm the oomph is the last thing i am thinking about, i am on it at that point.

Watching for lifting off again.

I do not do manual upshifts ever.

I use 'S' to decelerate, or manual to change down, all upshifts done in 'D'.

Not all Twinchargers behave the same,

similar obviously, but there is also obviously differences from one to another,

and how many miles on the engine can be obvious sometimes when driving them.

You engine will get even more oomph after a few more thousand miles on it.

george

My guess is it's the turbo kicking in. I can plant the foot at 80kph, get up to 100kph and just when I think everything is petering out, there's an extra, surprising surge of momentum. I couldn't tell you the rpm where this is happening, but it's definitely high up in the turbo end of the range.

Because the acceleration is so linear, the response so instant, it's easy to forget this is a -charged car at times. Every now and then a touch of lag, or a sudden boost, reminds you.

Edited 10 May, 201313 yr by OzFabia

Silicon,

If you put your car in 1st Manual and boot it, does it go through the gear Automatically at the Red Line if you do not shift the gears?

If you are in 3rd manual, or 4th in Manual and really doing for it and too sow in shifting up, will it shift into a higher gear automatically?

I will tell you shortly what it feels like in 4th at 5000 rpm in my car.

george

Yep, it goes though the gears automatically just before redline when in manual. To be honest it does feel like extra boost pressure kicking in if I were to have to guess at it.

Tried it earlier - didn't feel any difference in the acceleration (the change in the Scirocco was very definite - the throttle was limited to 75% opening until the 4750-ish mark) although the engine note does change about 5k? Test done in 3rd gear to stay below NSL..

Well i just tried it and surprised if anyone feels a surge or oomph at 5000 rpm in 3rd or 4th.

Unless the Engine is still tight or a different Map on the Engine or DSG.

3rd manual is up to the red line that fast, and the gearbox shifts up to 4th Automatically and Redlines,

that over 100 mph at that point.

Torque steer on the 205's and acceleration almost too much to be pressing the button for the pictures.

(on a disused runway. Not a smooth surface and its raining.)

My car and any other Twincharger i have driven is much faster if in 'D' and up shifting to 4th, 5th and 6th automatically,

even in 'S' and Redlineing it in Each Gear is Faster than doing Manual Shifts. IME.

&

your oil Temp does not rise like it did there with mine when sprinting in 'D' with TC Off.

george

Hmmm, thanks for going out and trying yours.

I just went out and had another go. I findi only get the extra pull at 5k if I'm flat out. I can be doing the same run at 3/4 throttle and then I don't get any extra through 5k?

Weird really. It's as if I have to be right on the max to experience it. Wish I had a dyne close by to see the power and torque curves!

Just thinking,

Do they come from the factory on different maps? I wold have thought they were standard no?

Yes, there is a little "power-surge" from 5k and onwards.

The "v-tech kicked in, you" is actually right!

Variable camshaft-timing is something these cars have and I've noticed it on the 3 vRS that I've driven.

Re the Max Torque and 2000rpm-4500rpm.

Just where you want it when overtaking.

The CAVE engine came with a MAP in 2010, that required updating.

Your car has come with the MAP that they think will suit the CTHE engine,

and is possibly what VAG wanted to reduce the problems suffered by the CAVE engine.

No idea yet if your MAP on a new vRS CTHE is the same as on a 2013 Cupra CTHE,

but it does not feel like it to me.

Hard to tell because the Cupra sounds very different, and handles differently.

I would go Road Test someone elses or a Demonstrator vRS and see if it feels like yours.

george

PS

You say fully run in.

Well the tyres and Brakes might be, And Modern engines do not need running in as such in some peoples opinion..

I think you will notice a difference in your engine after 4-5 thousand miles,

They do actually Run In with more miles on them, become quite nice IME.

I have the new CTHE engine and can confirm that there is a very slight surge at 5000rpm that soon dies out heading the wrong side of 6K.

Its not crazy noticeable but it felt similar to the turbo surge in my DS3 but obviously a lot higher up the range and only for a fraction of a second.

Its almost like boost surges for 1000 rpm... only slightly.

It may be a bit of placebo effect but its definitely noticeable to some extent

Hope this helps! I'm on 3600 miles by the way, still a little tight in the engine bay.

Are you people driving it in Manual and just driving along normally and changing up 3rd to 4th,

or holding it in 3rd and booting it and noticing 5000 rpm.

How is it not just Redlining in 3rd or 4th if under acceleration ?

george

It is redlining in 3rd, but as I'm booting it through the 3rd gear rev range at from bottom to top at 5k I get the extra kick which dies at about 6.5k then I'm pry much ready to be changing up to 4th...

Mine does this when overtaking first smooth then booom headrest job it is like supercharger first then a powerburst when turbo kicks in

Silicon, i would go and do the same bit of road at the same speed in 'D' and see when the DSG does its changes and the RPM.

Also in 'S', but that feels much like holding on for too long in 'Manual' IME.,

I am surprised that when booting it in 3rd that its not already at the Redline and the box is changing for you.

I suspect your engine will loosen up quite a bit in the next couple of thousand miles.

Are you using 98/99 ron petrol.

george