Posted: Tue May 20, 2008 4:58 pm
definatly is worth the money , hope it stays ok , ill see wat its like 2nite!Jeff GTi wrote:it definately provides a difference when working correctly eh
UK-POLOS.NET - THE VW Polo Forum
Probably the Worlds greatest Polo resource
https://uk-polos.net/
N75J let down!! Or is it!!!
Page 2 of 2
Posted: Tue May 20, 2008 7:15 pm
stopped working again, today its like it goes into limp??? is a light not meant to come on if it does?? then as you drive it kicks in working again, emailed the guy cos i jst want my money bak! tried everything!!! 
Posted: Tue May 20, 2008 8:42 pm
just send it back, get your money sorted and get a brand new one from vag parts, youll not regret it
Posted: Tue May 20, 2008 8:50 pm
i know cos i clutching at straws with this sh1te one, 
cant race anyone incase it packs in then i fooked!! lol
cant race anyone incase it packs in then i fooked!! lolPosted: Tue May 20, 2008 10:19 pm
do you have an mbc? if not will running high boost with the n75j not put it in to limp mode when it overboosts?
Posted: Tue May 20, 2008 11:03 pm
Read in other forums that the J valve throws a some cars into limpmode due to over boost. Thats the reason am not sure bout gettin one
Posted: Tue May 20, 2008 11:07 pm
kenny the general rule is the h valve is too aggressive and throws it in to limp mode, im not running approx 16 psi of boost, which is more than the standard map, and even with the j valve fitted iv never had a problem with it or limp mode
Posted: Wed May 21, 2008 8:40 am
A should just get one to try it out, if it doesnt like it a can just sell it?
Posted: Wed May 21, 2008 6:27 pm
Whitepolo - you need to get Vag-com - to see what is happening.
You can get limp when you get the initial overboost or you can get limp if the valve keeps boost too high further up the rev range.
The Map is designed to work with the F valve - boost is aggressive and then tails off towards the red line for safe running.
You can get soft limp at anytime the ecu decides that the actual boost deviates too far (less or more) from the requested boost. (and you dont get a management light on just get wastegate pressure boost)
It may not always happen, say you drive the car all evening and everythings warmed up it might go ok - jump in the car in the morning when everythings cold - it can go into limp.
Trust me the ecu does some funny things
Now Jeff has not had a problem with the J valve, this could be the way the MAP works (some software has overboost protection removed) or that he has full MILLTEK from turbo back, the better exhaust helps to reduce overboost limp.
The full exhaust from turbo back is really worth doing, especially the downpipe and cat.
Now I have K04-001 it really shows that the downpipe and maybe exhaust is neeed. It just cannot run more than 1.1 bar reliably because there is just too much back pressure - so much that it forces the wastegate open from the other side so you get boost on/off/on/off etc.
So I need to get exhaust sorted before I can do the custom MAP. Using VAG-COM to work out the power using torque and MAF readings getting approx 215bhp at 5200rpm with 14.5psi (1bar) boost.
With downpipe etc it will be able to run 1.3-1.4 bar 18-20PSI to the red line What power will that make ??? Cant wait to find out hehehe.
J
You can get limp when you get the initial overboost or you can get limp if the valve keeps boost too high further up the rev range.
The Map is designed to work with the F valve - boost is aggressive and then tails off towards the red line for safe running.
You can get soft limp at anytime the ecu decides that the actual boost deviates too far (less or more) from the requested boost. (and you dont get a management light on just get wastegate pressure boost)
It may not always happen, say you drive the car all evening and everythings warmed up it might go ok - jump in the car in the morning when everythings cold - it can go into limp.
Trust me the ecu does some funny things
Now Jeff has not had a problem with the J valve, this could be the way the MAP works (some software has overboost protection removed) or that he has full MILLTEK from turbo back, the better exhaust helps to reduce overboost limp.
The full exhaust from turbo back is really worth doing, especially the downpipe and cat.
Now I have K04-001 it really shows that the downpipe and maybe exhaust is neeed. It just cannot run more than 1.1 bar reliably because there is just too much back pressure - so much that it forces the wastegate open from the other side so you get boost on/off/on/off etc.
So I need to get exhaust sorted before I can do the custom MAP. Using VAG-COM to work out the power using torque and MAF readings getting approx 215bhp at 5200rpm with 14.5psi (1bar) boost.
With downpipe etc it will be able to run 1.3-1.4 bar 18-20PSI to the red line
What power will that make ??? Cant wait to find out hehehe.J
Posted: Wed May 21, 2008 7:46 pm
gunna leave it as it is now withthe orginal valve cos it just keeps shutting down boost with the j then back on!!! so it sounds like the valve is ok just the car doesnt like it, ill keep the valve and wait till i get a full exhaust system!! 