Was wondering if by changing the N75 valve It would help cure my "slight" surging problem. The car is 3 months old, done 3000 miles and has just been Revo'd. I am experiencing a very very slight surging at around 2500 - 3500 rpm under slight acceleration, nothing major, you have to really feel for it. I have heard that by changing the N75 valve you can eliminate this. Have heard that the N25 J is the one to have??? BTW car is fine in stock mode.

Thanks

Adam

Hold fire on the N75.

Did you get 3 or 4 bar Revo?

N75J increases boost over the standard N75 so could potentially make the problem worse. On the other hand if it feels like the wastegate is opening and closing unnecessarily a stronger N75 'may' help.

Hold fire on the N75.

Did you get 3 or 4 bar Revo?

3 Bar, just been doing a few runs and it seem to hesitate on light throtle (1/4) from around 2500 rpm upto around 3500rpm , but it is ever so slight. Also if you boot it in 5th at at about 2000 rpm then ease off gently at 3200rpm it kind of snatches a little, if you do the same but just take your foot off at the throttle at 3200rpm it is smooth and you can hear the dump valve, is this just a characteristic of a car running higher than standard boost. :confused:

N75J increases boost over the standard N75 so could potentially make the problem worse. On the other hand if it feels like the wastegate is opening and closing unnecessarily a stronger N75 'may' help.

How do I tell if this is happening, it is only a slight flutter in the power delivery, would the wastegate give a more pronounced effect?

If it's only light throttle I can't see it being the N75.

What DV have you got?

If it's only light throttle I can't see it being the N75.

What DV have you got?

Bailey DV30......

I'm not familiar with that particular DV, however I assume it's a piston type. If it is when was it last serviced as it may be sticking.

Yep, its a piston type from Jabba, was fitted brand new the day before it was Revo'd, which was last Thursday. As I have only done abot 200miles since it was Revo'd will it get better with time as the ecu adapts :confused:

Don't think it's the DV then! These things are really hard to diagnose over a forum, it could just be normal and you're over sensitive to it as it's new. Give it a bit longer and see how it goes. BTW are you running 95 or 98 prog and what fuel?

I get a bit of this, I would be interested to here whether you use 96 or 98ron, I have a feeling it could be down to 'lesser' fuel - I generally use 95 though am planning to switch to Optimax as soon as the tank is empty. I've tried boost settings LB8, LB9 and HB0 and timing 3 and 5 without noticing any improvement btw. Interestingly I've never heard this 'problem' being mentioned by people with the 4bar program.

I'm on 4 bar and always use optimax and haven't noticed any of the things you mention.

I'm on 4 bar and always use optimax and haven't noticed any of the things you mention.

4bar here we come! James won't be too busy on Sunday will he, its not like he'll have anything to do?!

I'm running the 98ron program with Optimax, did switch to 95ron, still with optimax and it felt the same. So what is envolved in getting the 4 bar program, will it work with my SPS2?

I'm running the 98ron program with Optimax, did switch to 95ron, still with optimax and it felt the same. So what is envolved in getting the 4 bar program, will it work with my SPS2?

Your SPS2 will work fine, just as it does now in fact. Getting the 4bar program involves replacing the standard 3bar fuel pressure regulator with a 4bar item (VAG part, Cupra R, TT etc) then reflashing the ECU with the 4bar program (for free usually!!). Job done. I believe the 4bar FPR is about

Your SPS2 will work fine, just as it does now in fact. Getting the 4bar program involves replacing the standard 3bar fuel pressure regulator with a 4bar item (VAG part, Cupra R, TT etc) then reflashing the ECU with the 4bar program (for free usually!!). Job done. I believe the 4bar FPR is about

Sounds like overboost to me...slight surge stepping off accelerator around 3k mark and a slight dip when accelerating through 3k. Your REVO dealer should be able to tune this down for you.

N75J will give around 0.1 bar more boost and allow boost to build quicker. Upshot car will be a bit more responsive and will hit boost limiter quickly.

The odd thing is even though it does sound like overboost this isn't something I've really experienced since having Revo. It was quite vicious with my Super****e and from what I hear depending on what you ask Jabba for it can happen with their maps. Odd one.

I did originally wonder about the timing settings but after chatting with Eddy it appears SPS2 uses a stock 98 ron setting. Even more odd.

I suggest, as others have said, that you stick some Optimax in it and leave the SPS2 set to 98 RON. I know that if I fiddle with my settings it takes a few runs to settle down.

I know that if I fiddle[/color'] with my settings it takes a few runs to settle down.

I fiddle? Come on now, admit it, you were to tight to buy an SPS.

The odd thing is even though it does sound like overboost this isn't something I've really experienced since having Revo. It was quite vicious with my Super****e and from what I hear depending on what you ask Jabba for it can happen with their maps. Odd one.

I did originally wonder about the timing settings but after chatting with Eddy it appears SPS2 uses a stock 98 ron setting. Even more odd.

I suggest' date=' as others have said, that you stick some Optimax in it and leave the SPS2 set to 98 RON. I know that if I fiddle with my settings it takes a few runs to settle down.[/quote']

OK, will leave it on 98ron with optimax and let it settle, if it's no better will talk to REVO to see if they can sort it, although if it is a generic map how can they alter the overboost :confused:

I fiddle?[/color'] Come on now, admit it, you were to tight to buy an SPS.

OK. What I meant by 'I fiddle' was that I get you over from Rotherham, get my mum to make you and your dear lady a nice cup of tea and then make smalltalk until you've forgotten that you paid

generic map

Hmm. What are you doing on Sunday?

OK. What I meant by 'I fiddle' was that I get you over from Rotherham, get my mum to make you and your dear lady a nice cup of tea and then make smalltalk until you've forgotten that you paid

Hmm. What are you doing on Sunday?

Why :confused: :confused:

Why :confused: :confused:

A little Briskoda get together at JBS's RR day for the mkIV forum.