Hi all.

I'm considering a vRS Octy for my next car.. so just having a nose around at the mo

I just have a few questions which I haven't been able to find the answers to.

I know that the 1.8T is able to be remapped to get power, however I cant figure out quite yet some other points.

What boost does the 1.8T run as std, and is it modulated?

Does the remap change the boost (ie, is the boost set by a manual BCV or BMV, or is it controlled by an electronic boost controller in the ecu)?

If it's the later of the above, is it possible to manually up the boost with the use of a BCV, and simply let the ecu alter the fueling to suit?

I've also heard about a possible ecu with 2 maps... a std one and tuned one. Basically, flick a switch on the dash and choose whether you want performance or economy. Is this true?

What is the safe boost to run on the engine, or rather what's the maximum boost that has been previously run on std internals?

I assume the turbo on the vRS is smaller than the one on the Leon CR? Does running higher boost create any inlet temp problems, or is 225bhp within the limits of the turbo? I believe it's a kkk03? No idea what's on a LCR, so at what stage do people upgrade, and to what? I know there's a Garret GT28RS kit out there.

I'm just trying to figure out why a remap seems to be prefered to upping the boost and fitting a nice big FMIC.

Is a decat do-able? Or is there one of those sensors after which need to be messed with?

What sort of 1/4 mile times do vRSs run before and after remaps?

Oh, and what sort of fuel economy is normal on std and remapped octys? Is 30mpg possible combined? The official figure is 35mpg combined IIRC?

Sorry for the large amount of questions but I have about 6 months before I'm planning to change cars and I want to get the right one...

TIA

Alex

To answer some of my own questions I found the answers to...

The decat is do-able, however a light will appear on the dash as there is a sensor in the std centre pipe, which if unplugged throws up an error on the ecu. Just a case of removing the bulb then...

The ecu controls the boost.. I think from what I read it does it through the dump valve? Wierd.... Why do they have to make things complicated, wtf is wrong with normal wastegates, actuators and map sensors?

Although it seems it is possible to fit a BCV, however it's frowned upon? Not sure why yet, more boost is more boost. Something like a GBE will maintain steady boost with no spikes, and only costs

MPG on my stock car is around 40 on a run M/Way, 32-36 urban. My wife does a short run to work and doesn't get up to full temp and that is really poor for MPG.

I get the same MPG with the remap as before, exept when I boot it (of course).

MPG depends on how heavy 'ya' right boot is!

I see your in the Southen area, talk to Mike at Impossible Performance, he's in the Rochester, Kent area.

I haven't heard of a BCV. Do you mean BOV (blow off valve)? I recommend that you read elitedub's troubleshooting guide for the 1.8T here to get a feel for the various components associated with the 1.8T engine. There is a good explanation of the N75 valve (described as a dump valve on the parts box, as an electrochangeover valve on the official parts list, and better known as a wastegate regulator valve) in that guide.

The boost map for my Jabbasport custom-remapped 4X4 has recently been changed to 1.25 bar max, then 1.15 bar sustained falling to 1.1 at 4000rpm and 1.05 at 5000rpm.

I believe that Jabbasport will be offering switchable maps (using VAG-COM) for the 1.8T in the foreseeable future.

Cheers for the info, I'll have a read.

BCV is Boost Control Valve. Basically it's a manually adjustable valve which goes in the line for the wastegate actuator, meaning the wastegate will remain closed until boost reaches a pre-set pressure, the valve opens and the wastegate opens.

These are used on a lot of cars, allowing maximum boost to be reached low in the rev range. I know on rovers these are used instead of the std Boost Modulating Valve as it allows the boost to come in suddenly, giving more of a kick, and increasing the midrange torque significantly.

However, it seems that the boost on the VAG 1.8T is controlled by the ecu, and most people seem to get it changed that way. Cant help wondering what would happen if you stuck in a BCV and watched the turbo spool up to 1.25bar at low revs and hold it through the rev range.

I'd have thought the MAF would see the increase in flow and sort the fuelling?

Any idea why the remap drops the boost off? What's the benifit of dropping to 1.05bar at higher revs?

Alex

The problem with BCV or bleed valves is the boost doesnt usually remain constant, spikes are common which can damage the turbo/engine.

Boost is regulated by the ECU by means of a MAP sensor mounted in the intercooler. The ECU operates the N75 valve on a duty cycle which opens a regular wastegate in the turbo. The problem with fitting a BCV is as the ECU control the pressure via a closed loop system (i.e monitor-record-adjust) all it would do is open the wastegate earlier as the pressure set in the ECU is reached.

The LCR runs the same K04 turbo and twin intercooler set up as the Audi TT/S3.

Hi Sheaf - you probably remember me from Rovertech As you know, I made the jump from Rover to Skoda having had two modified 620ti's.

I had a GBE fitted to the later 620ti and was very pleased with it. I have (so far) avoided tuning the vRS, for a number of reasons but mainly that I did not want to risk losing the warranty and just wanted nothing to go wrong (once bitten and all that - note that my problems were not linked to the fitment of a GBE).

I have had the vRS for just over a year now. My average MPG is between 31 and 32 but I do mostly short journeys around town so that's not ideal. On a run back to Cornwall I can get around 38 to 39 MPG at a steady "slightly higher than 70mph".

I have loved my vRS since having it. I know it's new but in 13 months and over 12,000 miles the only notable problem I've had was an intermittent fault on the headlight switch and that was fixed under warranty.

Having been on this forum a while I would only consider getting the vRS remapped using a tuning company like Jabbasport. The whole turbo setup is a lot more complex and advanced than on the T16. A manual BCV may or may not work well but personally I would not go that way.

on the topic of 1/4 mile runs standard cars come in around the 15.5 area where as remapped cars 15.2-14.9 not a massive diffrence because the traction problems at the start... your right the octy is a heavy car and most of the power arrives in huge lumps in 3rd and 4th sadly the 1/4 is over at the top of 3rd doing approx 90-95 mph

EDIT after reading your sig: Comming from that rover with the mods done i dont think you will be happy with the vrs unless you remap it and chnage the suspension... add approx £1500 on top the forsale price and you on to a winner mate...

Joel

Hi Wayne, yeah I remember you from RT - BRG ti with the SW kit right?

I remember seeing pics.. looked a lovely car!

How's the Octy compare performance wise to the rover?

It does seem slightly odd on here with all the remaps and tuning companies compared to RT where people whack on a GBE, GTi-R intercooler, 2.5 exahaust and uprated dif bearings and have a stupidly quick car for much less cost.

Joel, I suspect that a vRS will be a decent jump in straight line speed compared to my present car (about 120bhp and 1100kg), however I must admit I'm slightly dubious about the handling as I'm used to a very fun go-kart ride. However the main reason I'm thinking of changing cars is I'm beggining to want a bit of comfort and refinement, which unfotunately my car doesn't do so well on. Oh, and more power.

Still got other options mind... considering civic 1.8VTi, BMW 323ci, Integra-R (not so comfy!), Accord TypeR etc.

Does no harm to investigate though

Joel' date=' I suspect that a vRS will be a decent jump in straight line speed compared to my present car (about 120bhp and 1100kg), however I must admit I'm slightly dubious about the handling as I'm used to a very fun go-kart ride. However the main reason I'm thinking of changing cars is I'm beggining to want a bit of comfort and refinement, which unfotunately my car doesn't do so well on. Oh, and more power.

[/quote']

sorry missunderstood your car to be the 2.0 turbo...

in that case i with draw what i said you should be quite happy...with a standard set up

Joel

Hi Wayne' date=' yeah I remember you from RT - BRG ti with the SW kit right?

I remember seeing pics.. looked a lovely car!

How's the Octy compare performance wise to the rover?

It does seem slightly odd on here with all the remaps and tuning companies compared to RT where people whack on a GBE, GTi-R intercooler, 2.5 exahaust and uprated dif bearings and have a stupidly quick car for much less cost.

[/quote']

Yep, that's the one. It was a lovely car and I do miss it but tbh I do not miss the regular grief it seemed to cause and I was starting to spend lots of money to keep it well maintained. Even with the uprated bearings, the gearboxes are still the weak link - and don't even get me started on the exhaust manifold mounting problems and electric windows...

Performance wise, the Octavia is not quite as quick as the 620ti was in a straight line. Although, you have to remember that I was running 209bhp at the last count in the ti and the Octy runs 180bhp standard. But, the power delivery is sooo smooth in the Octy, it's lovely.

Also, I would say that the standard vRS handles very well and is just as good as my Rover was even with the lowered suspension and wider tyres. Also, the standard brakes on the vRS are better than the upgraded setup I had on the ti.

When you then factor in that the car is so well built, so reliable and rather refined it is altogether a better package. The clincher for me was that I could always remap the Octy and it would then be faster than the Rover was in a straight line and given the experiences on here there don't tend to be many problems with modded vRS's (not compared with T16's anyway).

In terms of tuning, I think there are not as many DIYers on this forum probably mainly due to the fact that the cars are newer and higher value (?) Also, the engines are more complex than the T16 unit on the Rover so that's another factor.

Cheers

Wayne

sorry missunderstood your car to be the 2.0 turbo...

in that case i with draw what i said you should be quite happy...with a standard set up

Joel

I wouldn't withdraw the bit about the suspension... a 216 handles better than a 220

Well the Octavia definatley sounds like a nice car, and after a remap I expect it goes well too

I must admit I'm slightly disappointed about the lack of DIY mods, as I do like to do mods myself.. it adds satisfaction to it. Plus some of the mods seem to be uber expensive compared to what I'm used to paying. I'm tempted to keep the rover for a while longer now and keep saving... I appreciate it's small impact on my wallet now, lol.

Alex