Hi All,

So I'm now 2 weeks into ownership of Quenten's old Silver MK1 Octavia with the Vf34 conversion.

Seems to run sweet, idle is a bit lumpy at times but overall it goes well! I have a couple of questions I wanted to ask someone who has owned a car like this.

• I'm seeing 1-1.5 Bar of boost depending on how I accelerate. Fast up through the gears tends to peak at 1 Bar but steady part throttle acceleration sees 1.5 Bar. Does that sound about right? Sounds like a lot of boost to me?
  
• I'm getting a lot of popping from the exhaust when changing down a gear and the exhaust is hot, I'm assuming its extra fuel being burned in the exhaust?
  

I'm going to pop it over to MB motorsport this week for a once over, I know some folk have been on about changing the rods but Mike at MB assures me that for 300bhp the bottom end is fine even with 109K!

For what the car is worth, I dont think there is much value is rebuilding an engine that runs fine, will just keep the oil changes frequent.

Cheers

Ron

boost sounds odd

when you floor it you should hit a peak of x and then it should drop and hold Y

with that setup i would think 1.5 peak hold 1.3 to red line?????

Agree with Clive regarding the boosting.... Has it got the normal N75 valve (F) rather than the 'J' version which is prone to causing problems.....???

I don't think it should be popping excessively on the overun either, their might be an issue regarding the fueling with the current map-this could also explain the lumpy idle at times....

Just a thought anyway.

Steve

Edited 20 June, 201016 yr by Steevie Wonder

If Jabba built it perhaps they are the best ones to give it the once over? Could be the mapping needs updating as the conversion was done a while ago.

1.5 bar (21psi) is about right, when I had that setup on mine I was getting around 335 bhp though.....not 290-300.

I know this car was mapped again getting rid of the original Jabba map that was on it... Might be worth finding out who did it and get their opinion.

Regards,

Steve

There is another factor here. Basically the car had a cracked turbo (exhaust housing) and now it has a new turbo. It has been suggested that Jabba built it, it ran fine....then the turbo cracked and started leaking boost and it ran badly, it was then re-mapped (next owner) by RS in leeds believing that it was the jabba map at fault. The turbo was replaced last month and the last owner said it pulls a lot harder than it did before it was changed. It pulls very very hard, I had a stage 2 MK2 Octavia before making about 250bhp and this seems SOOOOO much quicker.

I wonder if the map was done for a cracked turbo and now that is fixed it isnt quite right.......will see what MB say later on in the week, If Jabba have the map on file then I could roll back to that map?

Also, the 1 to 1.5 is with the MBC turned down to the bottom setting.

I wonder if the guy who fitted the new turbo set the wastgate up properly? if it is adjustable on the Vf34?

Cheers

1.5 bar (21psi) is about right, when I had that setup on mine I was getting around 335 bhp though.....not 290-300.

I know this car was mapped again getting rid of the original Jabba map that was on it... Might be worth finding out who did it and get their opinion.

Regards,

Steve

if it is adjustable on the Vf34?

Cheers

As far as I know, the wastegate is not adjustable.

Did you get it sorted?

Steve

Hi Steve, thanks for that info. I can discount that as a problem at least.

I ran vagcom on it a couple of days back and I get:

17608 (P0343) - Boost pressure control valve (N249): Mechanical Malfunction

So I suspect I cant realy on the boost behavior being down to the mapping at the moment. Gona get her booked into MB motorsport next week as i also have to change the front springs which are badly corroded.

I'll get her back in shape!

As far as I know, the wastegate is not adjustable.

Did you get it sorted?

Steve

Hi Steve, thanks for that info. I can discount that as a problem at least.

I ran vagcom on it a couple of days back and I get:

17608 (P0343) - Boost pressure control valve (N249): Mechanical Malfunction

So I suspect I cant realy on the boost behavior being down to the mapping at the moment. Gona get her booked into MB motorsport next week as i also have to change the front springs which are badly corroded.

I'll get her back in shape!

Best advice would be to get rid of the N249 valve, it's a pain in the ar$e, especially with high powered 1.8t's.

Steve

Hi Steve, been looking that mod up online, seems to be several ways to go about it? Any recomended online write ups you can think of?

Best advice would be to get rid of the N249 valve, it's a pain in the ar$e, especially with high powered 1.8t's.

Steve