Shinobi'sZ

There has been a lot of cam discussion over which is better (straight pattern, split pattern, reverse split pattern). It seems that some went reverse then back to straight up. My personal opinion is that the cam should be matched more towards the size of the Turbo and kit characteristics. I would like to see if anybody has a different opinion or has tried something different since the last time we visited this subject. What cam would you use with a pair of GT30s or like Turbos?
Thanks

JZ 97 SS 1500

iTrader: (2)

I try to match the cams like you said to the turbo, but more importantly the header or manifold design. With log manifolds I like to run a reverse split since backpressure will become an issue I try to minimize reversion on the exhaust. With a real header design and assuming the turbo is adequate, I like to run a dual pattern cam. Of course I like to keep overlap to minimum. Typically no more then 6-7 degs. Kevin seems like we are always talking turbo tech eh?...lol

Jose

Shinobi'sZ

Yes I am very focused on Turbo LSx R&D. I am convinced that reverse split pattern cams are a band aid fix to a poor manifold design or two small a turbo for the motor....or even both. The arguement is that a reverse split pattern will help scavenge and prevent reversion. My arguement to that is that if the Turbos are correctly matched, the manifold flows well, and the rest of the kit components are efficient (downpipes etc..) that there should not be reversion back into the cylinders at all. I think it would be a good idea to get information on existing kits on other hi po cars (Supras, GNs, GTP Formula 1, etc..) and see what cams those cars are using with their Turbo kits..they are usually the most efficient (external waste gates, manifold/header with collector, properly sized plumbing, etc..). Supras and GNs make amazing power off of a V6 platform.

JZ 97 SS 1500

iTrader: (2)

Well on my supra I run dual pattern cams. They are HKS 264's, which is 264 dur @ .06. On the Supra's we tend to always run dual pattern 264's or 272's. The inline 6 motor is very efficient. Now on the GN's, I run dual patteren with headers, with stock manifolds I tend to stick to a reverse split.

Jose

Shinobi'sZ

So for example a 224/224 .581 114lsa would be ok for a Turbo system utilizing a header/merge collector?

JZ 97 SS 1500

iTrader: (2)

Yeah that would work very well, and looks like it has a -4 deg of overlap which is nice and tight. Should definitely make good power with an efficient combo.

Jose

Shinobi'sZ

Very cool!

V8_DSM_V8again

On DSM's its HKS 264/272 that is popular as well as a 272/272 for those with less restrictive turbine housings and/or manifolds... HKS has there own metric advertised duration so 272's come in at 213 at .050.

Comp has some similar grinds and two new ones for strokers (~2.4). These are around 220 at .050.

Centerlines are around 108 installed straight up... On twin cam engines you just get different intake and exhaust cams and can also fine tune your LSA with pulleys due to seperate cams.

Just like anything else the bore, stroke, heads etc..etc come into play too..
You can rev the heck out of 4g63 with just a forged bottom end, ti retainers and upgraded springs... 8k is nothing on a 2.0.. It takes a modified trans to shift anyhigher than that.. The trans limits it more than anything..