3mm vs 2mm
I wish I was driving!
Joined: Dec 2001
Posts: 5,241
Likes: 84
From: BC, Canada
quickly:
On a turbo car, where running lean and detonating is a problem, a single detonation can crack a 2mm apex seal.
Supposedly, a 3mm can take a couple more knocks before it'll crack.
I personally do not think it will make any difference. Its better just to be careful and tune the engine with a wideband.
There are rumours that a 3mm seal will cause more friction and thus less housing life. The claims are that the bigger SA causes this. This isn't true. The only extra friction would come from a larger mass of the apex seals (larger centrifugal force = higher normal force), or if they were of a different material, and I think 2mm and 3mm seals weigh the same.
Got a big turbo car and you're just tuning and you got money to blow? go for it. I'd stick 2mm.
Sean Cathcart
On a turbo car, where running lean and detonating is a problem, a single detonation can crack a 2mm apex seal.
Supposedly, a 3mm can take a couple more knocks before it'll crack.
I personally do not think it will make any difference. Its better just to be careful and tune the engine with a wideband.
There are rumours that a 3mm seal will cause more friction and thus less housing life. The claims are that the bigger SA causes this. This isn't true. The only extra friction would come from a larger mass of the apex seals (larger centrifugal force = higher normal force), or if they were of a different material, and I think 2mm and 3mm seals weigh the same.
Got a big turbo car and you're just tuning and you got money to blow? go for it. I'd stick 2mm.
Sean Cathcart
Eats, Sleeps, Dreams Rotary
iTrader: (1)
Joined: Jul 2001
Posts: 3,383
Likes: 3
From: Stinson Beach, Ca
Originally posted by JoeD
thats the first usefull post i have seen by you.
good job.
thats the first usefull post i have seen by you.
good job.
Get a life.
Stick with the 2mm apex seals. Many racers out there use 2mm seals. If your running lean enough to pop a 2mm, theres a good chance youll blow the 3. I dont believe in hogging out rotors to put a 3mm "band-aid" solution for not having proper fuel management.





