to cam or not to cam

[NickR33]

okay so my motor is currently being pulled out to get at the spun big end bearing...doh

my question is this, whilst the motor is open and the bottom end is getting a makeover should I upgrade the cams with something like the tomei poncams? Is there sufficient gains to be made with aftermarket cams on a car running the stock turbo? Would the money be better spent elsewhere?

Also it is my understanding that I will lose the advantage of the VVT if I upgrade cams? is there a way around this?

My mechanic has an opinion on this I just wanted to hear what everyone else has to say...

thanks

(motor is an RB25DET)

[cameron]

Tomei poncams are the biggest cam that will work with standard valve's, cam gears and VVT. They are certinely better then standard cams because their bigger.

Theirs a couple of guys on here with tomei poncams in their skyline they should give you a run down on what their like.

Jun

[Busky2k]

Dont forget, HKS Step 1 and 2 cams also work with VVT.

[Sydneykid]

We have the Tomei 260 degree Poncams in the R34 GTT, it makes more power EVERYWHERE than standard. I can highly recommend them, worth about 20 rwkw max power and give a ~25 rwkw average power increase.

Tip, we found adj exhaust cam pulley is not required, their std timing was spot on.

Hope that helps :wavey:

[Trust33]

Hey sk how are you going.I got a question for you.Is their still power to be coaxed from an adj exhaust cam pully when going cams?Or are they like you said dead spot on.

And sk i need ur help with wiring a z32afm into my r33gts-t S1 go to http://www.skylinesaustralia.com/forums/sh...ead.php?t=52564 if you know or can help me.

Cheers and sory for hijacking this thread.

[Bass Junky]

SK.

You're a bad man. You keep making me want to buy Poncams and everytime I decided against it, you post something like that and I want them again.

You suck.

Now some questions about them.

Is the 20kW increase with the standard turbo. When will my turbo run out of puff if I'm running these cams?

BASS OUT (I hate you SK )

[NickR33]

We have the Tomei 260 degree Poncams in the R34 GTT, it makes more power EVERYWHERE than standard.  I can highly recommend them, worth about 20 rwkw max power and give a ~25 rwkw average power increase.

Tip, we found adj exhaust cam pulley is not required, their std timing was spot on.

Hope that helps :wavey:

great!...providing the head doesn't require any TLC i can fit a set of these into my budget...yay

another question (I'm going to whore my own thread)

What power output would justify going for forged pistons?

I am going to leave rods standard as I can't forsee ever wanting 300rwkw+

If the pistons are in good shape would you bother changing them to the aftermarket variety...?

Thanks for the input guys :jump:

[Sydneykid]

SK.

You're a bad man.  You keep making me want to buy Poncams and everytime I decided against it, you post something like that and I want them again.

You suck.

Now some questions about them.

Is the 20kW increase with the standard turbo.  When will my turbo run out of puff if I'm running these cams?

BASS OUT (I hate you SK )

Me bad man, nope I just call 'em like I see 'em.

The old 20rwkw and standard turbo question, I don't have a real answer to that one. If you are at 1 bar and 200 and a bit rwkw then the turbo won't last to make the extra 20 rwkw anyway. Most likely the cams will lower the boost level by reducing the resistance. But at the same time give higher airflow for more power. I really don't know, haven't tried it, but it's logical.

Personally, I would upgrade the turbo before I did cams, but you already know that. :wavey:

[Bass Junky]

I know i know.

But I've always wanted cams. Maybe I should just pu them into my fantasy basket until I have a bigger snail.

[NickR33]

on a motor that is already out of the car there is minimal labour costs to install cams (esp. when your getting mates rates) so that just leaves the cost of the cams...approx $1,000+

but a minor turbo upgrade including support systems, fuel etc is going to cost $2,500+

cmon Bass Junky...you know you want to...

sooo... cams now, turbo later?

[Bass Junky]

I hate cars.

They cost too much money.

[Sydneykid]

great!...providing the head doesn't require any TLC i can fit a set of these into my budget...yay

another question (I'm going to whore my own thread)

What power output would justify going for forged pistons?

I am going to leave rods standard as I can't forsee ever wanting 300rwkw+

If the pistons are in good shape would you bother changing them to the aftermarket variety...?

Thanks for the input guys :jump:

My rule of thumb is 450 bhp (270rwkw), over that and I tend to do everything. This is because I just hate pulling RB engines out of Skylines, so I only like to do it once per car. So many guys have problems with pistons at or over that 250 rwkw mark, you can usually pin it down to tuning, but sometimes it's bad maintenance. Some might call it bad luck, but you really make you own luck as far as I am concerned.

My suggestion, if 300 rwkw is your max target, then I would go forged pistons and RB26 rods with ARP rod bolts. If you want to go over 300 rwkw, then I would go with forged rods as well. If you are happy with 250-270 rwkw then the std pistons may well be OK but you need to very confident in the tuning, keep up the maintenance and test often.

My 20 cents worth, with change :wavey:

[Sydneykid]

I hate cars.

They cost too much money.

Not compared to wife, children and house. :wavey:

[Bass Junky]

I've got two of those already.

Car's always fall into the want category, that's why they always seem expensive!

[NickR33]

no wife, children, or house... just a broken skyline:(

I thought I would squish the car bug before I started on the house... at this rate I may never get there...lol

[Bass Junky]

I think a Skyline is much like a wife and a child.

A wife because you are constantly a slave to your Skyline. Making sure that the thing is happy, has the right htings bought for it and sometimes giving it a good going over!!

A child because if you aren't nice to it, it will cry and crap on the floor of the garage.

[NickR33]

hahahaha sooo true, mine is a bit like the kid you knew at school who is always away sick...

Feel free to whore this thread people... I'm bored and Mondays suck!

[INASNT]

I thought I would squish the car bug before I started on the house... at this rate I may never get there...lol

I thought that also, but you will always end up buying something new for the car (well i do) and your house will never end up happening!! just do both at the same time

On another not if your getting tomei cams also considered getting a new tomei metal headgasket, as it will all have to be pulled apart anyway to fix ur problems.

[R33vit]

I think a Skyline is much like a wife and a child.

A wife because you are constantly a slave to your Skyline. Making sure that the thing is happy, has the right htings bought for it and sometimes giving it a good going over!!

Yes but the Skiline doesnt follow you around after a thasing :cuddle: :69:

[NickR33]

yeah I forgot to ask about other things to fix/replace whilst the motor is out?

Is it wise to use a head gasket to drop the compression a little when rebuilding? or is it only needed on big hp engines?