N75 Valve

[ADAMWIGGY]

Hi im new to this forum and have recently brought a leon cupra, its standard apart from a forge 007 recirc valve and a boost guage, but i have a couple of problems with it.

Every now and again the car just stops boosting to its standard boost about 8ish and drops down to 4psi
ive done a search and people seem to be pointing towards the N75 valve.

So ive done a search on the N75 valves and now ive got one big headache????

Ive come to the conclusion that standard it runs a F on my car and J is better and H is for chipped cars but can encourage limp mode.

Am I understanding this right or am I just thick?

Im quite handy with a spanner and could fit the part if i could find out what it is F,J,H,C= HELP

Also I have plans for the car power wise and ill prob go down the forge fmic and remap as i live in gloucester so its handy for me.(once ive sorted CAI and Zorst system)

So if Im going to end up bying uprated parts in the long run then I would rather spend the extra hard earned and get them now.

One last question(sorry for going on) Intermittantly the car sometimes idles funny whats all that about?

It will be sat there happily at around 800rpm and then woahh all the way down to very near stalling then back up for a second or two then back down and so on.

please help as i feel i may have entered the Seat world with my eyes closed and brought a bag of

Sorry for such a long post they wont be this long in the future (promise)

 

[h17och]

welcome my boy!!

rite n75, to find out which one it is look ast the part number and the last letter will determine which one you have!

and the rough idle sounds like the trottle body needs re-alining (excuse the spelling) no big deal!

hope that helps

HoocH

 

[ADAMWIGGY]

Thanks hooch ill check tommorow and see when its light which one i have, as for the throttle body alignment i remember forge mentioning that to me when i brought the 007 valve but i totally forgot.
thanks for reminding me.
Adam

 

[LNeves]

Not sure if the Cupra has the F or C as standard. Check the part number like h17och said.
H is a "race" valve, more radical one, which gives you limp mode often because of overboost.
J is good with standard maps and some still use it after the remaps but some fallback to standard N75 (C or F), again because of limp modes and power surging.
K is a mix between H and J, gives a nice boost peaks without danger of limp mode (?)

This is the info I gathered myself. Correct me if it's wrong.

 

[cordobabrendy]

for leons, standard ecus the j valve gives a little more power and smoothness
for a remapped ecu standard F valve every time, the programs are written for the standard valve, if you doubt this, have a search for the dyno graphs ive got to prove it.
the c and f are very similar and the biggest difference is between the j and the c, approx 5 bhp and 5 lb/f on a revo stage 2 motor, not totally conclusive but definately suggests sticking with the standard valve once remapped/chipped.

 

[Pabs]

Yep see brendys post: F Valve is std and the one to run

As for your idle problem - I have had the same since day 1 of buying the car - its "normal" on leons according to my dealer but dont believe it.
Had the dealer clean the throttle body and change the MAF and this certainly helped for a while, but then back to shoddy idling again. I also run OPTIMAX and find this does improve the idling and general running of the car too - feels more responsive.

If car is still in warranty, get dealer to look at the idle issue - tbh not much I can suggest as i still suffer from it. Doesnt stall completely tho, and only really seems to do it after driving for a while and then coming to a stop - either at lights or when i get to my destination. I always let the turbo cool down for 30secs-1min after a journey and always see the idle problem.

Hey ho... if you solve it please let me know!