Checking to see if car has been remapped

[rowly_747]

Hi, was at the Hull cruise on Saturday. When coming home I had a head to head with a WRX. Was surprised to find my Octy vRS pulled on him straight away and over took no problem. He kept trying to get away from 50 up over but couldn't.

How can I find out if my car has been mapped? I mean it pulls like a bitch!

I am going to fit an electronic boost gauge to see if the boost is higher than stock which I believe is 0.7 bar isn't it?

Any help would be appreciated.

[vRSLen]

Welcome

Sounds to me like he was having a play with you

[Wardy]

It's the classic; how do you know he was trying? But let's not get into another debate, please...

Best to get it on a Rolling Road and get some power runs and graphs done

Steve

[Bodge]

Well if it was a standard '00 to '03 Impreza WRX then you're probably right.

They had 215bhp and weighed 1410kg (152.5bhp/tonne). Remapped vRS is say 210bhp and 1375kg, so 152.7bhp/tonne.

Standing start and cornering are a different matter, but in the situation you described, it sounds feasable. So i'd say your car is mapped.

Or maybe his car was nakkered, or maybe he was a crap driver! Who knows.......

What the hell is a cruise anyway? Isn't that where a bunch of old pensioners go somewhere boring on a ferry!

[ap0gee1978]

Of course, if you have reason to believe the car's been mapped then your insurance company need to be informed otherwise they'll void your cover...

[Wardy]

Today is hereby named Insurance Tuesday!

[chicken_eyebrow]

What the hell is a cruise anyway? Isn't that where a bunch of old pensioners go somewhere boring on a ferry!

LOL Bodge I just choked on my sandwich!

[rowly_747]

After fitting a boost gauge I found out the Max boost i achieve is 0.8 sometimes 0.9 depends. So probably not mapped then.

[Bodge]

After fitting a boost gauge I found out the Max boost i achieve is 0.8 sometimes 0.9 depends. So probably not mapped then.

Standard spec is between 0.6 - 0.7bar.

A typical generic stage 1 remap (APR for example) should see 1.2bar.

So you either have a very low boost map, or maybe someone has adjusted the wastegate actuator pre-load (not sure on that as I'm pretty sure doing that would kick up an error code).

What pressure does it settle at if you point the car up a long hill and keep your foot planted? If it only spikes to 0.9bar for a moment, then settles back to 0.7bar, then maybe you have a lazy N75. Can you see if the N75 has been changed at any point in the cars life? I think the N75J and ECS 'race' N75 both have this slow response characteristic, and give a momentary over boost.

[ap0gee1978]

If you know somewhere safe to try it, you could always do the ((unladen weight)/(0-60 time))×0.9) power estimate - it's surprisingly accurate as long as you remember 60 is really about 63-64 on the speedo... Using my G-meter to measure 0-60, I get within 1.3bhp of its dyno result...

[Wardy]

Now where did I put my runway...

[chicken_eyebrow]

Checked mine on the way home tonight, was running 0.72 bar so as Bodge said 0.8-0.9 suggests it's had something done to it.

[The Ors]

It's also possible that the 'WRX' was not in fact a 'WRX' but a tarted up.

...especially possible when driving away from a 'cruise'.

Edited 28 October, 2009 by The Ors
OCD

[stig1]

scoobys am a pile of crap anyway had 2 including a 555 ltd edition sti still think the octy is a better car i know a chap thats got a 1997 sti 276 bhp standard and his car has had work done , i can keep up with that so i cant see why a standard vrs cant keep with a wrx GO ON SAY WHAT YOU LIKE its all down to your car and you at the end of the day:thumbup:

[rowly_747]

Hi, did wot you said and it peaked at 0.9 again and settled at 0.7 will check N75 valve when i get the chance. Should i replace it or ?

[Bodge]

Hi, did wot you said and it peaked at 0.9 again and settled at 0.7 will check N75 valve when i get the chance. Should i replace it or ?

Ahhar! Sounds like it has a N75J or ECS N75 fitted then.

The N75 is the little valve just mounted on the top of the turbo intake hose (2 small diameter hoses and wiring running to it), so only takes a sec to check. If the hoses are held on with Jubilee clips or zip ties then it's been changed, if it's got the original one use clips and looks untouched, then I'm wrong and I don't know what it is!

No need to replace it if your engine is running fine and not showing any error codes.

Read more about the ECS one here: Volkswagen Golf IV 1.8T > Engine > Electrical > N75 Valves > ES#122 Race N75 Frequency Valve - RACEN75VALVEKT-A

Matches your symptoms perfectly. Maybe you got a free mod!

[the cat]

I pulled away allbeit very slowly from a wrx on a number of occasions. He rubbed his hands with glee when we were next to each other at a set of lights.....i might as well have not bothered!

[rowly_747]

Just thought I'd have a quick look while at work. Seems OEM to me clips are the original ones and the colour of the valve is greyish not brown like in that pic. So i'm goosed but at the end of the day no problems with car so all is good.

[Bodge]

Just thought I'd have a quick look while at work. Seems OEM to me clips are the original ones and the colour of the valve is greyish not brown like in that pic. So i'm goosed but at the end of the day no problems with car so all is good.

Meh! God knows then! Like you say, no problem with it so forget about it.

If you ever get a related error code though, you know the likely culprit. I'd guess that when the N75's get tired, their responsiveness reduces and they allow an initial overboost. Just a guess though.

[Awol]

I think in a straight line in good conditions where grip not an issue anything 4x4 will lose some power because of all the transmission parts??

so 180bhp/215bhp might be comparable?

[mannyo]

The 4x4 losses of the scooby are actually quiet big, especially as its an always on system. A scooby would certainly need more power than an octy to have the same performance. However the octy is FWD and would struggle off the line, wheras the 4x4 would leave it behind from a standing start.

[chicken_eyebrow]

Even Suzes 4x4T Octavia seems quicker out of corners than my vRS, thats with 30bhp and 25ft/lb less

[mannyo]

Even Suzes 4x4T Octavia seems quicker out of corners than my vRS, thats with 30bhp and 25ft/lb less

The octy 4x4 is still only FWD though until you start to lose grip at the frontend, then the haldex kicks in and transfers some power to the rear. Until that happens the car is the same as any other octavia.

[rowly_747]

Well Bodge and the others who tried to help thank you. Might purchase the N75 race valve anyway as you said there prone to going anyway so may as well replace it before it actually does. Cheers Guys

[Bodge]

Well Bodge and the others who tried to help thank you. Might purchase the N75 race valve anyway as you said there prone to going anyway so may as well replace it before it actually does. Cheers Guys

No probs bud, glad to be of use.

You found out the hard way how obsessed people get by vRS vs. scooby etc. comments! I found it quite amusing how a few of us were discussing boost pressures, then a totally random comment about subaru's would pop up between!