Cam Gears - How Much Gain?

[shanef]

As per title, i'm intersted to hear how much of a gain cam gears will give me. I've got a stock RB26 head on a freshly built RB30 bottom end, and atm running R34 v-spec turbos and want to know how much of a gain i would see by adding cam gears now. Other mods include: Power FC, Blitz ID-III, 3" turbo back, Sard 800cc injectors, Bosche 044 pump

Early next year the rest of the head & valve train will be upgraded, but if the gain by adding cam gears is not bad, i'll grab some cam gears now.

Also between the brands, HKS, JUN, TOMEI & TRUST, are there any differences between them? I've heard a couple experiences where with the HKS cams, they have slipped due to the coating on the gears, has anyone experienced something similar? Also keeping in mind i will be persueing some big power, 800awhp, if that may factor into which ones to get.

Keen to hear everybody's thoughts and opinions

cheers

Shane

[[200]]

Cam Gear dyno results Edited October 26, 2006 by [200]

[shanef]

hrmm interesting - Original post edited to include more mod details

[[200]]

I posted the link from someone else's experience.

Hopefully it will help.

[R31Nismoid]

' date='26 Oct 2006, 08:22 PM' post='2618431']

Cam Gear dyno results

Thats an RB25 NEO writeup, not relevant for the RB26

Shane - people have gained upto 25kw through the midrange on similar setups to what you have.

Peak power doesnt really alter, its the midrange that sees the gains.

I think Beer Baron netted ~25kw as have others before him.

You dont need brand name ones either, you can have the stock ones chopped and modded, costs less than $150. Or about half the price of "colourful" cam gears which do the same thing

[Gav]

With and experienced tuner who has a feel for such things you will be amazed at the difference altering the cam timing cam do for the RB26.

In my case it really changed the boost threshold of the notoriously laggy GT-RS terbs that I run. As said before, to end doesn't really seem to suffer much. As there is no such thing as a "free ride" what I suspect does suffer is exhaust emmissions and this is why there are power/torque gains to be made over factory cam timing settings.

That said, you have a large displacement and small terb combo already so you already should have a responsive setup. Never the less, I'm sure the extra tuning/labour costs of experimenting with cam timing will pay dividends.

Good luck and keep us posted!

[frankxinyu]

shane i have very similar setup on mine. i use Tomei ones.

i gain quite a bit of power actually by adding them. i can not tell you how much as i changed the ecu at the same time. but there is a gain for sure.

definately worth doing.

[[200]]

My mistake, sorry.

[frankxinyu]

ok power figures....

on this 4wd dyno i got 235AWHP at 10 psi using stock computer running really rich.

on my tuner's RWD dyno which has a very low reading:

same setup 221RWHP @ 10psi stock ecu

280RWHP @ 12psi on power fc with cam gears dialed in on an extremly conservative tune.( max knock 20 on a 35 degree afternoon)

i assume it would clock somewhere near 300AWHP @ the other dyno..so i gained about 60hp at the wheels by using power fc+ cam gears+2psi extra boost. i was happy with the result

[Warpspeed]

How much gain ?

Well that depends on where the cams are to begin with. By doing a twin cam conversion on an RB30, the cam positions could both now be miles away from what it was on the original engine.

It is a meaningless question. Like saying I am now completely lost, how far is it EXACTLY from here to back home?

The very first thing you should be doing is very accurately measuring the exact valve opening and closing points with a dial indicator and a degree wheel. Then, if the cams are not where you want them, use adjustable cam gears to move them to where you think would be optimum.

How much lost power you can recover depends on how far out the cam timing is to begin with.

Edited October 27, 2006 by Warpspeed

[shanef]

by gain i meant power gain by adding cam gears and getting them tuned

the engine has been freshly built, and i'm waiting on some sump gear to arrive before the engine goes back in, and thought seeing as the timing hasn't been set yet, i can add the gears now.

thanks guys, it seems they will yield a decent result, so its off to purchase some new gears

P.S nismoid, aftermarket gears weigh 336g, and stocko's are made out of 'steel' so the saved weight down the track with the other upgraded valve train will be worth it (add ur thoughts please)

[R31Nismoid]

Not sure about the weight... didnt know there was much difference.

I think there was some issue with the HKS ones "loosing" meat on the teeth or something a while back.

I'll try find the thread about it.

I guess it would make a difference, which way i dont know though as i dont know how weight would affect that stuff at all

[mokompri]

Not sure about the weight... didnt know there was much difference.

I think there was some issue with the HKS ones "loosing" meat on the teeth or something a while back.

I'll try find the thread about it.

I guess it would make a difference, which way i dont know though as i dont know how weight would affect that stuff at all

yeah i remember that thread, apparently HKS have changed the material their cam gears are made of so they dont have this issue anymore, i think SK mentioned this.

its rotating mass, so it will make a difference, whether you can 'feel' it is another story, sort of equivalent to cars running hollow camshafts to reduce rotating mass of valvetrain, so it will be worth something however small.

[R31Nismoid]

hrm... cant find it... but im glad someone else remembers it at least

But i dont remember anything about the material being changed though.

[shanef]

what i heard was, that the metal used for the 'inside' of the cam gear (the purple coloured metal on the HKS gear) is dualumin but the outside metal, where the teeth are (the blue coloured metal) is/may be of a different type, and sometimes the belt would slip, which would lead things to go bang. but that's jsut waht i heard