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Discussion Starter · #1 ·
I am looking at the Tomei procam for the Inlet 260/10.25 and Exch 252/9.15. Along with a set of lifters and some type B springs and ported head.

I also plan on getting a pair of -5 Turbos, bigger inejctors and a mappable ECU.

I know I wont be able to maximise the potential until I get the bottom end rebuilt, oil pump changes, new rods, pistons etc etc..

Does that profile seem suitable for what I have in mind? looking for around 600-630 bhp.
 

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it will be fine and run well still with those durations, I run apexi 260d 10.3mm lift intake and exhaust and it cruises good and makes over 700 hp.
 

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This is just IMO, but I would go at least 10mm on the exhaust side if you are working the head. I don't have anything factual to show you the comparison and difference, but I do know the exhaust side flows worse than the intake side and it is easier to blow through a larger opening than a smaller one. I have some at 264/10mm IN+EX, and the difference compared to stock is pretty large.

There are a couple cams available at 252, 260, and 264 @ around 10mm lift. Some have stock base circles, which would allow you to run stock lifters, while others are 1mm or so smaller base circle. :wavey:
 

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Discussion Starter · #6 ·
I looked up the Mines spec stage 2 setup they seem to run same on inlet 260 and 10.2 except they have an exhaust cam at 9.5 252 cam, and I cannot find one of the same. Does an exhaust need a higher lift cam? I can understand the need in inlet but on a turbo setup?
 

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Stock cams with cam gears with time spent dialing in will give good results for low-mid rpm at some sacrifice for top end power.
Tomei type Bs will give good mid-top end but at some sacrifice of bottom end.

I'm personally going -5s + Type Bs with e85 soon, and as I've lightened & tightened most of the drivetrain I'm hoping for the best of both worlds.
Currently I have 34R turbos with dialed in stock cams and it is almost too responsive.

From memory staggered setups usually favour the smaller exhaust ports to get more flow, so I'm not sure why those profiles you've noted are reversed,
 

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Yes, the head will need relief if you go over the tomei type B size. The cams I'm currently running are stock base circle @ 10mm lift. Clearancing the head for cams doesn't have to cost a ton of money--I did mine by myself within a couple hours using a 1/2" wide handheld belt sander and a dremel. :thumbsup:


It's hard to tell if you would have valve clearance issues or not. Depending on what pistons, head gasket thickness, and if your head has been shaved or block decked, etc. There's too many variables to give you a yes or no. Will you be pulling the head when you are working on it?
 

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I come back on this post because I begin a new step of my rb26 and I need some advice for the cam. I would take the tomei procam 270 10.8 in/ex. I read that this setup don't require to modify the head but I don't know if it's a good choise for a stock internal with only 2860-5 and other mods.

I would take this cam because the next year I will install a stroker kit and I would make 2 time purchase on cam's.

Another question, in addition of the valve spring typ B what I need to take for install these cam's ??
 

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Discussion Starter · #12 ·
Why this profile? Bigger numbers does not always mean it will be the best for you application. This profile does need head mods.

For your turbos Tomei type B would be best suited. No need for 270/10.8 cams on a stock setup.
 
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