Just gone from tdi to vrs...few questions

[yesiamtom]

I bought my tdi what must have been 5-6 years ago now and have always wanted a VRS. Luckily one came up cheap near to me, already modified and I bought it! I know a fair amount about the diesels but not the VRS so got some questions.

 

Firstly, my tdi has very grabby brakes, always has despite 3 sets of pads/2 rotors and 2 brake bleeds in the time I've owned it. I assumed this was normal for these cars but the new VRS has less grabby brakes, I'm sure it can produce a lot of force in a hard stop, is this normal though? I don't think it's running fast street pads.

 

Secondly, a previous owner fitted a "carbon intake". From what I can tell it's just a cold air feed from the MAF/TIP down to the front bumper with a cone filter placed down there. Did the owner completely waste their money? Should I remove it? It's fairly large bore and looks to be made specifically for the octavia.

 

Also, the car is running 1.5 bar boost at spike and then settles back to 1.2 if I remember correctly. Is this a safe level on what I assume to be a ko3s turbo?

[KenONeill]

Well, firstly my TDi (Elegance 110) doesn't have grabby brakes in either the jump-in or the pull sideways sense.

 

As for the CAI, unless the car's running a custom map (and I think a non-standard turbo) then it was a waste of money, but so would spending out on putting a stock airbox back be unless you have one so it's only time and you can put the CAI on Fleabay.

[Saints92]

A CAI makes a louder "Whoooosh" noise. Well worth the money.

[yesiamtom]

I must admit I like the noises it makes, as long as it's not losing too many horses I'm happy to keep it.

 

When I say grabby I don't mean like the car pulls sideways, just the initial push of the pedal produces quite a lot of force compared to most other cars I've driven. 

 

Car is running a custom map according to previous owner, he reckons it's putting down close to 230bhp. Frankly I am dubious, it has what I believe to be a 3" piper exhaust (might be 2.5"), has the CAI and that's it from what I can tell engine wise. TIP is standard, DV is standard and has many miles on it presumably. I expect it's more like 210bhp . More than fast enough to scare me silly at the moment!

Edited 18 October, 2016 by yesiamtom

[KenONeill]

A CAI makes a louder "Whoooosh" noise. Well worth the money.

That's what I mean; the stock airbox isn't restrictive below about 260bhp is the filter is clean so you're spending out on making the intake noisier and higher insurance for no extra power.

[KenONeill]

I must admit I like the noises it makes, as long as it's not losing too many horses I'm happy to keep it.

 

When I say grabby I don't mean like the car pulls sideways, just the initial push of the pedal produces quite a lot of force compared to most other cars I've driven. 

 

Car is running a custom map according to previous owner, he reckons it's putting down close to 230bhp. Frankly I am dubious, it has what I believe to be a 3" piper exhaust (might be 2.5"), has the CAI and that's it from what I can tell engine wise. TIP is standard, DV is standard and has many miles on it presumably. I expect it's more like 210bhp . More than fast enough to scare me silly at the moment!

I'm saying I think it was a waste of money fitting the CAI, but unless you already have a spare stock airbox it's a waste to revert too.

 

That's what I mean by jump in; you get a faster initial buildup of braking force, which I'd expect because you've got 312mm discs and stiffer callipers compared with the 280mm and FSIII on the TDi.

 

210bhp is about what I'd expect from a generic map plus a stock intake and exhaust. A CAI and 3" cat back might add another 10 between them. If someone told me 230 my response would be "dyno graphs or it didn't happen".

[yesiamtom]

Thanks Ken, I did not buy the car on the basis it was making 230bhp, so don't worry about me getting conned on that front! 

 

Sorry if I wasn't clear, I was saying the TDI has grabbier brakes than the VRS, at least initially. Could larger pistons on the VRS mean more force is required from the foot? 

[KenONeill]

This means dissembling the braking system a bit.

 

Travel is basically governed by the ratio of master cylinder to wheel cylinders (all round) bores.

Force is governed a by a mixture of travel, servo vacuum level and servo size. So answering your question quantitatively requires a fair amount of detailed technical data that I don't even know where to look for.

"Jump in" could be described as "the rate of initial build-up of force at the brake pad faces". If you increase the wheel cylinder bores for a given servo and master cylinder, you need to push more fluid into the wheel cylinders to achieve a given pad force, so jump in reduces and pedal travel increases.

[petrolbloke]

I had the discs and pads (all round) and rear calipers replaced on my car not long ago - brakes now have much more bite and it feels like there is plenty of stopping power in reserve. Previously the brakes felt a bit wooden but did pass an MOT not long before they were replaced. I put it down to rubbish front pads (old ones were Apec, new ones Pagid) and/or the old rear calipers sticking a bit.

[yesiamtom]

Funny you should say they felt a bit wooden, that instantly reminded of the VRS pad feel. I'll have to take them out and see if they have any kind of manufacturer mark. Could be crap pads.

[kentphil1]

The main question I would ask yourself is do the roads flood quite deep where you are at this time of year and the coming months. If the answer is yes, then you may want to consider either a standard airbox or different intake. If you are quite happy with the risk, keep the intake, as they do seem to work quite well.

 

Does it have a front mount intercooler or standard side mount?, as 230 is a little optimistic on just a map,exhaust and intake unless it is an r-tech map or similar.

 

My Vrs was very dead on the pedal on OEM pads, but I now run pagid which are a little fierce when warm, but have so much more feel now. I really noticed the fierce brakes on the Octavia when I first had it coming from a Jap Primera GT, I have driven a few now and they are all the same, I think the initial fierceness at low speed is more a characteristic than a fault that you just get used to and edit it out of your driving.

[yesiamtom]

It's the standard side mount, DV and TIP. So I am inclined to agree with you on power. Previous owner did mention something about it originally having a revo map, then changing it for a custom one. God knows what though.

[sharkrider]

I bought my tdi what must have been 5-6 years ago now and have always wanted a VRS. Luckily one came up cheap near to me, already modified and I bought it! I know a fair amount about the diesels but not the VRS so got some questions.

 

Firstly, my tdi has very grabby brakes, always has despite 3 sets of pads/2 rotors and 2 brake bleeds in the time I've owned it. I assumed this was normal for these cars but the new VRS has less grabby brakes, I'm sure it can produce a lot of force in a hard stop, is this normal though? I don't think it's running fast street pads.

 

Secondly, a previous owner fitted a "carbon intake". From what I can tell it's just a cold air feed from the MAF/TIP down to the front bumper with a cone filter placed down there. Did the owner completely waste their money? Should I remove it? It's fairly large bore and looks to be made specifically for the octavia.

 

Also, the car is running 1.5 bar boost at spike and then settles back to 1.2 if I remember correctly. Is this a safe level on what I assume to be a ko3s turbo?

Mine is running those boost levels on the K03s, and its fine , hasn't blown up yet!

[yesiamtom]

Great, thanks sharkrider.

[sharkrider]

Great, thanks sharkrider.

and its fast as fook I am also de-cat, 3" downpipe and system , oversize tip, air filter ect ect ... I estimate maybe 220 bhp ?

[yesiamtom]

Yep, mine is pretty fast, enough to scare me very easily. I'm sure in due time I'll get used to it and want more, but for now I'm trying to sort out improving reliability, things like oil catch can, new silicone hoses and DV.