1.8T Map Tune Kmaps Boost Pressure

[Lovel]

I have been driving my 1.8T for around a year and am really impressed with the performance in 160 form. However I finally gave in and purchased the 200ps tune from Kmaps which makes it even more of a road rocket. The car gets hard use on a daily basis using the full potential and just seems to thrive on revs. However on the very odd occasion I seem to get overboost for a brief moment and once it passes I get that wonderful performance again and on average even with spirited driving of 33+ mpg brim to brim.

The usual suspects have all been changed out, all original parts including the hoses at the solenoid, so today I temporarily fitted up a garret boost guage. The results were interesting with 12-13psi at full load/throttle. I changed back to my original ECU which has the 160ps tune just to compare. The gauge read 8psi boost at full load/throttle which is to spec, however I get absolutely no overboost jerking at all. Just a steady 8psi max.

My question is with the 200ps tune should the boost solenoid be changed for a higher rating to allow for the higher boost pressure as the ECU seems to kick in on the odd occasion. Or perhaps the Kmap takes care of the overboost ?

[VVC-Geeza]

Originally Posted by Lovel

My question is with the 200ps tune should the boost solenoid be changed for a higher rating to allow for the higher boost pressure as the ECU seems to kick in on the odd occasion. Or perhaps the Kmap takes care of the overboost ?

It's not necessary to change the OE solenoid as long as it is in good robust condition.Mark points out that they can become 'sloppy' over time and extra boost will certainly cause issues.Perhaps worth replacing it as they aren't too expensive

An alternative is available http://www.the75andztclub.co.uk/foru...id#post1130852

[P3AHE]

If you contact Mark at K-Maps he will give you a link for a Subaru / Evo boost solenoid to suit. Cured same problem on mine. Cost approx. £30.00 . Sorry can't give details myself but have lost details.

Andrew & Cherie

[rich17865]

The original boost control solenoid is rubbish, my car is on its fourth now at 41,000 miles!

I just replace it with a new one when boost cutting occurs, it appears to be the culprit every time.

[Lovel]

Originally Posted by VVC-Geeza

It's not necessary to change the OE solenoid as long as it is in good robust condition.Mark points out that they can become 'sloppy' over time and extra boost will certainly cause issues.Perhaps worth replacing it as they aren't too expensive

An alternative is available http://www.the75andztclub.co.uk/foru...id#post1130852

I replaced the solenoid just before the new map with genuine. Tried old solenoid and a number of others and basically the same result.

[doopydug]

I had this exact same problem and just reduced the gap on the spark plugs - sorted

[Lovel]

Originally Posted by doopydug

I had this exact same problem and just reduced the gap on the spark plugs - sorted

I
Have eliminated all the usual suspects. It is now down to managing the boost levels now that I have discovered that the 200 map runs boost at 12psi or compared to 8psi on the 160 tune.

[VVC-Geeza]

I note in the OP you say the car gets hard use on a daily basis and driven to it's full potential.I remember Mark saying he doesn't recommend this,more on a as and when basis.If you are thrashing it everywhere it's quite likely the boost cut will operate priodically.

[Lovel]

Originally Posted by VVC-Geeza

It's not necessary to change the OE solenoid as long as it is in good robust condition.Mark points out that they can become 'sloppy' over time and extra boost will certainly cause issues.Perhaps worth replacing it as they aren't too expensive

An alternative is available http://www.the75andztclub.co.uk/foru...id#post1130852

Just some feedback on the use of this solenoid.
http://www.ebay.co.uk/itm/2221343661...%3AMEBIDX%3AIT

I fitted it some time ago, with the 200ps tune ECM fitted and found that the boost pressure between 2 and 3 thousand revs to be lower (approx. 4psi) than the standard factory fit boost solenoid, ie less torque available, however no stuttering was ever encountered when on full throttle at high load/revs 12-14psi was noted on the gauge. There is also some chattering noise on initial throttle opening from the exhaust port of the solenoid, which I tried to disguise with a length of hose. I could have perhaps plumbed it into the inlet manifold as per standard and the noise may have gone away. However I fitted it discreetly so it looked as though the standard solenoid was still in place hence I did not use the inlet tapping.

Have now refitted the standard factory fit solenoid and have a better response at lower revs (6-7psi). In fact I have gone back to the 160ps tune ECM and am going to settle on that for the moment. Car revs freely (steady 8-9psi) and there is no form of hesitation.

What's the moral to this little story? Hang on to your money as the quest for more BHP is not always the best route to go down. I have the standard factory fit hoses and solenoid now and it still runs great with no hesitation.

[Sheraton]

Are you sure it was definitely ecu cut-out from Overboost ?

when i experienced ecu cut-out caused by overboost - it wasn't what i'd describe as a brief moment which passed - more of a violent loss of power which throws you forward in you seat (under full throttle)

i've also had misfire issues under full throttle - which were brief stutter/loss of power and could be powered through - these were ignition related

pretty sure an upgraded solenoid wouldn't stop the ecu from cutting power if there was overboost resulting from the remap - and i'd have thought the remap would adjust for the increase in boost - so as not to trip the cut-out


Paul......