N75 valve from ECS Tuning

[moreboost]

Interested to know what the general concensus is regarding the fitment of ECS Tuning's race version N75 valve. They claim that it is the " absolute quickest & most inexpensive way of getting more HP out of your turbocharged VAG product".
Was wondering if anyone had fitted one of these and whether a modified tune would be needed to support the mod. Usually any increase in boost needs more fuel but are Mk4 GTIs sufficiently rich to cover the 1 to 3 psi boost spikes?


Volkswagen Golf IV 1.8T > Engine > Electrical > N75 Valves > ES#122 Race N75 Frequency Valve - RACEN75VALVEKT-A

[noone]

Results differ greatly, I ran a J on my Polo GTI, didn't do much, boost seemed to come on slower, maybe peak higher.

Lots of opinions on Vortex.

[McDub]

Was wondering if anyone had fitted one of these and whether a modified tune would be needed to support the mod. Usually any increase in boost needs more fuel but are Mk4 GTIs sufficiently rich to cover the 1 to 3 psi boost spikes?

if it manages to increase boost, your MAF will read an increased mas air flow, and hence the computer will increase fuel. So I wouldn't worry about running lean, the computer should controll all that.

But for the record, i've tested both the factory and the J valve (not H) on a dyno. Changing them didn't make a difference to the results (boost or power curve).

However when driving home with the old valve, i noticed i was only boosting at around 17 psi. So as soon as i put the J back it, it went back up to around 20psi. (not the factory tune)

And as to your question about would this mod require a modified tune, it makes more sense to ask the other way around, "does a factory tune require an updated N75" It is probably a good idea

[Chi3f]

Hi All im new to this forum.

just wondering if its worth going the n75j valve or not

specs of my car
Polo Gti 1.8t dec05
forge FMIC
BMC OTA
turbo back exhaust
upgraded brakes
lower with bilenstiens
APR stage 2 (only getting 12psi (which is quote by the guys from APR) but alot of people mention alot higher numbers. just wondering if this is normal. i have changed the dv still feels the same.

i maybe go to do a leak test.

Any ideas
thanks Carlo

[Blitzen]

Hi All im new to this forum.just wondering if its worth going the n75j valve or notspecs of my carPolo Gti 1.8t dec05forge FMICBMC OTAturbo back exhaustupgraded brakeslower with bilenstiensAPR stage 2 (only getting 12psi (which is quote by the guys from APR) but alot of people mention alot higher numbers. just wondering if this is normal. i have changed the dv still feels the same.i maybe go to do a leak test.Any ideasthanks Carlo

May want to move this to the Polo section...

Anyway, you are way down on boost... I have a APR stage 1 V2 tune, and I am seeing 20PSI, and I only have the standard N75 Valve...

[h100vw]

[QUOTE=Chi3f;683163]APR stage 2 (only getting 12psi (which is quote by the guys from APR) but alot of people mention alot higher numbers. just wondering if this is normal. i have changed the dv still feels the same.
/QUOTE]

Welcome to the forum mate.

How are you measuring the 12PSI? The best way would be with a VCDS lead and read the ECU directly.
You can't take the peak boost in 1st or 2nd gear, 3rd or 4th would be more realistic and likely to give a truer reading.

Gavin

[Chi3f]

thanks Gavin.

i went to see john From DNA tuning and we did a few runs with the vag com plugged in. he mention the requested boost was only 14psi and i was getting mid to high 12 psi then dropping down to 9psi then back up to 12psi. he also mention the timing was a bit all over the place

i recently changed my dv to an n one. i had a forge 007 before the change.(might just need to service it) but there were a couple loose pipes my mate tighted from the cooler to the turbo and i also had the major service with timing belt done etc. but in saying that the car doesnt feel any different.

hope that helps.

ill be putting the n75j valve on this weekend and be doing some more runs and get john to do some more logs and hopefully we can fine tune