Fuel Cut, Rev limit 6800 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

2K3_Boxster_S · 09-06-2009, 09:28 PM

recently installed Headers w/Cats, bypass midpips and high flow muffler. I noticed the car no longer cuts fuel or hits rev limit at 6800 like before.

I have been carefull not to go anywhere near past 7000 rpm. I am getting a CEL for the rear O2''s reading the same as the front's P0420, but cant see how it would be relevant.

I don't want to take it any higher to find out if it indeed may still be working at a higher RPM as I am on the stock IMS. Any ideas of whats going on? Thanks.

blinkwatt · 09-06-2009, 09:38 PM

If your IMS is gonna go,it's gonna go. Pushing it towards 7k isn't gonna make a difference.

People cruise,idle and push their cars and IMS failures have occurred at each.

2K3_Boxster_S · 09-06-2009, 09:51 PM

Quote:

Originally Posted by blinkwatt

If your IMS is gonna go,it's gonna go. Pushing it towards 7k isn't gonna make a difference.

People cruise,idle and push their cars and IMS failures have occurred at each.

Yes, I understand watch your saying. and I am sure Porsche meant to put a very "safe" rev limit in the car. But I don't know what isn't safe, is why I try not to take past 7000. Also, I believe from my dyno sheet, if am i reading it correctly the car is making max HP at 6500 rpm. But to stay on topic, what happen to the fuel cut or rev limit? what would make it go away? any ideas. thanks for the input.

blue2000s · 09-07-2009, 05:06 AM

The redline on a 3.2 L engine is 7200 RPM. The fuel cutoff is just a tad higher.

Brucelee · 09-07-2009, 05:10 AM

Suggest you PM Jake Raby. He might know what your issue is.

Good luck.

Cloudsurfer · 09-07-2009, 05:32 AM

Car should have never been hitting fuel at 6800. It's somewhere past 7200, but I've never found it.

As to higher revs, the IMS isn't what you need to worry about. It's things like connecting rods and and the valvetrain...

2K3_Boxster_S · 09-07-2009, 04:36 PM

Quote:

Originally Posted by bmwm750

Car should have never been hitting fuel at 6800. It's somewhere past 7200, but I've never found it.

As to higher revs, the IMS isn't what you need to worry about. It's things like connecting rods and and the valvetrain...

The car was cutting before 7000 rpm. I remember the needle never made it into the 7's. I did change the plugs as well. Maybe something else was triggering it. I dont know. But it's not doing it anymore and as you stated I havn't found where it is now yet and probably wont' . thanks for the input.