Boost problem - from too little to too much!

[boltoa]

As I discussed in an older thread, my boost pattern was 10-5-6, which was solved by swapping two solenoid connectors over. Great! Full boost back again.

Except doh - now it is spiking betweent the turbos - as bad as 10-14-10 in some gears. This is causing clutch slip at 4500 rpm! This is probably a symptom of the clutch on it\'s way out, which I\'ll probably look to replace anyway, but can\'t be good generally.

I have got fairly extensive breathing mods on the car - twin filter intake, huge intercooler, backbox (but not cat replacements as far as I know) - could this freer breathing be causing this much spiking, or is there something wrong with the controllers for the transition between turbos? Anyone any ideas?

If it\'s something that just can\'t be avoided, does anyone have any experience with boost controllers - would a good one sort this spike out? I seem to recall reading that the Blitz one (for instance) can "learn" the boost pattern and smooth out spiking. Anyone recommend one?

Thanks for any assistance

Andrew

[maximtaylor]

Which ECU are you running Andrew?

Regards

Max

[Glenn Butcher]

Hi Andrew,

Before you pop your engine, I would look at installing a more restrictive exhaust.

Even if you have an aftermarket ECU etc. (like an Apexi) it still won\'t stop the spiking.

[boltoa]

As far as I know just the bog standard one. It came like this from Japan. I\'ve done very little to it myself (apart from adding a boost gauge!).

Why?

Andrew

[boltoa]

Sorry - my last out of sync - we replied at the same time.

It can\'t be impossible to cure this - all it needs is some finer control over the wastegate so it opens up some more than normal at 4000rpm or so. There must be something that can manage this, surely?

Andrew

[maximtaylor]

mmmmm....

As Glenn says - restriction will improve matters, but to be fair mine runs fine unrestricted without a bolt on boost controller!!

You really need to look at ecu mate - the apexi does seem to be smoother than stock ecu boost wise. The stock ecu was never intended to control boost on a car that is very free flowing through mods.

Regards

Max

[clive]

Cheap way / Glenn\'s idea.

Expensive way/ Max\'s way

But l would consider putting a more restrictive back box on
( stock one) before you start boost cutting and kill yer engine anyway while you decide the above.

Sorry your clutch is dead, classic FD me clutch is worn out symptom.

Hope this helps,

All the best Clive
clive@mazdarotaryclub.com
//www.mazdarotaryclub.com

[boltoa]

Yeah - thought so about the clutch . Anyone got any recommendations for an aftermarket clutch then? And suppliers? How many hours does a garage usually take to replace (so I can work out how much I\'ll be shelling out ).

I\'ll probably swap the solenoids back over in the meantime, until I work out how to control the boost...

Andrew