Help with Camshaft Choice

[Deano 1]

Help with Camshaft Choice

Hi Guys n Girls

Ive got a new engine in the build, and my machine shop wants a set of camshafts so they can mock the engine together in the workshop to ensure all the clearances are correct before they hand it all back over. So the decision for a cam, spring, retainer package has become abit important. 

Anyway the setup is as follows, 

Spool 2.8 stoker, 

86.5mm pistons factory comp

1mm oversized tomei Valves 

plan to run a EFR 9180 - 1,0 rear

and all the other bits like ross trigger setup, 6boob twin scroll, twin 3inch exhaust, HKS 100 cooler, E85 blah blah blah. 

The main things are the items listed.

As the car is a street car, and will be driven on the street, i dont really want 280-290 Dur cams with 12mm of lift that makes the car a complete pig, i understand the 9180 is not going to be a v8 when putting around town so we dont need to go there. 

Ive spoke to Camtech and Kelford and they both guide me down the mega cam path, i think to myself surely i can go somthing alil bit lighter on, specially with the 1 mm over sized valves. 

 

Ive looked into the JUN high lift low Dur cam packages, but dont want to use crappy jap springs..

272 dur 11.35mm lift  

The JUN cams call for a 1.5mm offset retainer. 

And also have a 29mm base circle, which im guessing will call for thicker buckets as the factory base circle is 32mm.

 

Anyway, im sure someone out there has gone though the same situation so id like to hear your thoughts and suggestions. 

 

 

[GTSBoy]

I would not go past ~270°, preferably 260.  And fit as much lift into that duration as possible.  So from Camtech, that would be something like their CTRB26 413B.

Unigroup have a 260° cam with 10.8ish mm lift.

 

You're going to need the very best Ferrea or Supertech springs with the Unigroup cams, because they have a fairly aggressive ramp rate.  Probably still need them with the Camtech cam I listed also.

[jet_r31]

Its only a tiny 67mm  turbo..you dont need 272 cams on any rb unless you put a something in the 74mm + size  turbo wise. I still woudnt use them then

unless it was for drag racing..

Something in the 260 to  mid 260;s is going to be nicest choice. Id use 260s, but thats just me..

Rb street cars work best with...small cams..decent size turbo with really good turbine flow. let the turbo make the power..

 

small  Cams will bring it on earlier..high flowing turbine/exhaust housing  will make power hold on up top due to less backpressure..not camshafts

cheers

darren

Edited September 24, 2016 by jet_r31

[Deano 1]

Hmm, I'll give Unigroup a call and see what they got to offer.