Non standard exhaust causing problems with boost!?!??

[Kier]

I've got a peco exhaust system and I now have a problem with my turbo boost, which I'm told is connected.

The Lotus specialist where I got my Elan tuned say that my problem is because I have a non-standard exhaust, however I know loads of you have the same exhaust system I don't believe for one minute that you all have the same problem!

The problem I have is that when I accelerate hard and the boost kicks in, it doesn't switch itself off before it gets too high. Instead the engine management kicks in and shuts things down. On a couple of occasions now I've accelerated past someone up a hill, only for this to happen. Once the management system kicks in I can't accelerate for about 10 seconds so (as has happened on each occasions) whatever I've just overtaken goes back past me as I slow down waiting for the light to go off.

Any ideas?

Cheers.

[paza1]

Sounds like overboost caused by the PECO and is a known issue. It has been discussed at length. The ECU is doing what it should and protecting your engine by cutting the fuel. One solution is to widen the wastegate. I am sure if you do a search of the site and the WIKI it will all become clear. Someone with more knowledge than me will be along soon.
Cheers
Mark

[GeoffSmith]

It's boost creep. Quite a few (including me) have suffered and the only guaranteed way to resolve it is to port the wastegate - see the Wiki for more information.

[Kier]

Thanks gents.

[SteveB]

Not fited a Peco as yet but Im wondering if it will be OK to port my waste gate with the standard exhaust ? will there be any effect before I get a Peco ?
Regards SteveB

[Candles]

Shouldn't cause a problem.

[Enright]

Not fited a Peco as yet but Im wondering if it will be OK to port my waste gate with the standard exhaust ? will there be any effect before I get a Peco ?
Regards SteveB

If I were you I'd wait til after.
There's no benefit in doing it before, and not all Elans suffer from the problem.
Also, the 3 pre-cat to downpipe nuts are the most heavily rusted in place on the car. They often require oxy-acetylene to get the old ones off, so it makes sense to let whoever fits your exhaust for you tackle this problem, then if they have to be undone again, they'll already have been either loosened or replaced.

[Foo]

Also check your wastegate flapper valve isn't sticking, and that the actuator is operating smoothly. There's a bit more in the wiki about it here:
http://wikilec.9600.org/index.php/Relea ... _wastegate

That would seem worth checking before going through the process of porting the wastegate.

[Kier]

Also check your wastegate flapper valve isn't sticking, and that the actuator is operating smoothly. There's a bit more in the wiki about it here:
http://wikilec.9600.org/index.php/Relea ... _wastegate

That would seem worth checking before going through the process of porting the wastegate.

Had the car in at another Lotus specialist during the week to get some bits done. when I picked it up we were talking about the exhaust and I said about the problem I'm now having with the boost. I said that i'd been advised that it could be overboost and he said it's far more likely to be the wastegate sticking!!!! So I shall be following your advice and checking this out first Foo, cheers for that!

[nitroman]

Did the problem only start after you installed the Peco? cause/effect
Time-wise, are the events related?
That's how I'd look at it.