Cams To Suit My Car?

[SDEWY5]

Hey all, just thinking to myself, i have a decent bottom end in my car now, consisting of CP's, eagle rods. Im making 270rwkw on a GT3582R (i know its big for the application and power but i like it) with 620cc injectors. it makes this power on 16lb on a very conservative tune as i track it alot and wanted good reliability. My top end is stock as a rock. As i want to put some cams in i want to know wat sort of power increase i should expect on different cams (ie tomei, HKS, JUN) and cam gears on the same or similar boost level. Keep in mind i have only a limited understanding on how their duration and lift is suitable for different applications.

Basically if i were to throw in a set of Poncams and camgears with 16lb should i expect 280-290kw? more with larger cams?

Thanks

Chris.

Edit.

Also with solid lifters installed will that allow the car to rev higher for longer in the situation that the engine was balanced to do so? Just curious...i dont know jack shit when it comes to valvetrain in these cars, hoping to expand some of my knowledge here..

Edited March 13, 2009 by SDEWY5

[PM-R33]

Basic way to think about it, the larger the camshaft duration, the higher it will move your peak torque in the rev range. The larger amount of lift, the more power they will deliver.

That's a very simple way to think about it, but does apply.

Main thing you have to think about is whether or not you want to keep the VCT. Get rid of it and you will drop power down low.

So if you don't care about VCT, get a set of 264degree cams on intake and exhaust, or if you want to keep it, go a set of poncams, HKS (256 or 256/264).

You just dropping the cams in, or doing headwork? I highly suggest you do the valve springs at the same time, I found out that one the hard way...

EDIT: Yes solid lifters will allow you to run larger cams and have a safer peak RPM, 8000+ (aslong as the bottom end is balanced well). However the amount it costs to do the conversion is more than you would think.

Edited March 13, 2009 by PM-R33

[R31Nismoid]

If your tracking it IMO leave the stock cams.

I had as good response with my GT30 as people with aftermarket jobbies so i couldnt justify the expense to potentially see no gain.

As an interesting point, most of the circuit GTR's here in melb between 350-380rwkw all run stock cams on a tidied up head.

Several cars did have cams, and removed them and gained better response on the track, something you cant measure on a dyno

[arep3]

cost vs gain with cams, i found it chesper to stick with the stock cams. Benno has looked at this as well with the stock cams having more power in places. a bit of food for thought...

[SDEWY5]

thanks guys, i see. Greatly simplified for me. Well seeimg as my engine itself has next to no power before about 3900-4000 i thought the idea of having some larger duration cams wouldnt hurt it. Typically with solid lifters, what is involved in the conversion? is it a full head-off job? I don't care much for the VCT i dont think it works as it is at the moment. The solenoid on mine has a small (very small) oil leak.

Maybe i would be better off just getting a pair of cam gears? more cost effective over a full set of cams and the gears?

Thanks guys.

[PM-R33]

If your tracking it IMO leave the stock cams.

I had as good response with my GT30 as people with aftermarket jobbies so i couldnt justify the expense to potentially see no gain.

As an interesting point, most of the circuit GTR's here in melb between 350-380rwkw all run stock cams on a tidied up head.

Several cars did have cams, and removed them and gained better response on the track, something you cant measure on a dyno

cost vs gain with cams, i found it chesper to stick with the stock cams. Benno has looked at this as well with the stock cams having more power in places. a bit of food for thought...

You guys are talking about RB26's and aftermarket cams, not RB25's. Can't make that comparison as it's a completely different head and stock spec cams.

Edited March 13, 2009 by PM-R33

[PM-R33]

thanks guys, i see. Greatly simplified for me. Well seeimg as my engine itself has next to no power before about 3900-4000 i thought the idea of having some larger duration cams wouldnt hurt it. Typically with solid lifters, what is involved in the conversion? is it a full head-off job? I don't care much for the VCT i dont think it works as it is at the moment. The solenoid on mine has a small (very small) oil leak.

Maybe i would be better off just getting a pair of cam gears? more cost effective over a full set of cams and the gears?

Thanks guys.

Solid lifters, head off, entire rebuild. Better off getting a NEO or RB26 head and chucking it on.

Honestly, get your VCT working, i have mates that have got rid of it and are now regretting it. Cam gear (remember you can only run it on the exhaust side on the stock cams cause of the VCT) on the stock cams are a bit of a waste of time, the money for the time tuning for a few hours isn't worth the few kw's, if you gain any at all.

Honestly it's up to you and what you want the car for. It's more money then most people initially think (me included). If your going to go a decent set of cams, you need to do springs. For that you have to take the head off (can do it another way but it's easier just taking the head off). While the head off you might aswell clean it up a bit and redo the seals/guides. Put a gasket kit/head studs/exhaust studs and other bits and pieces ontop of that to put it all back together and your looking anywhere from $2500-$4000 depending on what cams/springs/gaskets/studs and work to the head you do. Is it worth it? I dunno, ill tell you in a week when mine gets retuned

Edited March 13, 2009 by PM-R33

[R31Nismoid]

I was talking RB25 with my example GT30

[arep3]

i didnt say anything about an RB26.

[PM-R33]

Well you said "I" and in your sig it says you have a GTR, hence why i thought u were talking about a RB26...

[STATUS]

Just finished doing the same thing on a R33 @ the shop.

Forget 256's for that turbo, we ended up getting a good gain with HKS 264 step ones and cam gear. 300rpm better response, 50nm through out mid and top end. Will chase up graphs.

all runs @16.5psi

Edited March 18, 2009 by URAS