Like the subject says, what's the theory behind using reverse split cams on turbo motors?

 

some gn guys use them...do a search on http://www.ls1tech.com/
...some guys are using them too...i'm not sure what the deal is either

 

Theory is you open the intake duration up further to CRAM more air the have a smallerexhaust, so the exhause pulse has greater velocity. this greater velocity will spool/push the turbo better then if they were equal.

 

thanks for the info.

 

You really have to look at Exhaust Valve Opening (EVO) and Exhaust Valve Closing (EVC) separately.

EVO: Turbo and Supercharged motors retain more pressure in the cylinder further down the power stroke than Natural Aspiration. Therefore, opening the exhaust valve early would only bleed off pressure that could otherwise be used to push the piston and make power. So, you open the exhaust valve later and depend on a good valve and port to get the exhaust out.

EVC: Overlap can be especially detrimental to the performance of a turbocharged motor since there is more pressure in the exhaust manifold than intake. So, during the overlap period, exhaust can not only get back into the cylinder, but into the intake port as well. Therefore, you close the exhaust valve early to avoid overlap.

Late EVO + Early EVC = short exhaust cam duration

Mike