When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am a new owner of a used evo x sst. It has a bolt on hybrid turbo, cosworth cams and stiffer valve springs. The car has 60k kms (the last 20k of them with the bigger turbo and the cams)
A couple of days ago, out of the blue, the exhaust MIVEC sprocket broke. I attach some photos.
Any ideas about what can be the cause of the failure and what needs to be done, in order to not have such a failure in the future? I fear simply replacing the sprocket, is just waiting for it to break again..
Thanks a lot for the input guys!
Between deleting the exhaust mivec and installing a reinforced sprocket, the latter is a much better solution I think..
I will try to find one somewhere in Europe. If you can suggest a european eshop, where I can buy one, please do so.
Basilis
Thanks a lot for the input guys!
Between deleting the exhaust mivec and installing a reinforced sprocket, the latter is a much better solution I think..
Basilis
There are reinforced cam gears for 4G63T but I cannot recall if I ever saw one for Evo X in Europe
I would go with MIVEC delete for sure. It will only benefit your engine.
The catastrophic failures tied to MIVEC when upgrading the cams and valves springs has been a known issue for many years. Shortly after the issue arose we had come up with a solution. Higher engine acceleration rates cause the PID of the camshaft control to be unable to operate within its limits. Adding larger turbo’s that spool up above 4500 RPM negate advantages of having MIVEC control. Deleting the MIVEC altogether gave us consistent camshaft control. Locking the cam gears in place results in smoother power delivery as the ECU is not constantly trying to readjust for camshaft error. Consistent high rpm tuning and camshaft adjustability result in being able to dial in your power band more effectively.
You delete the exhaust mivec, not the intake. There is zero effect on reliability. And you want to leave the intake mivec in because even with large turbos it definitely helps with spool up.
