Camshafts For 700hp Rb26/30

[shanef]

Hi all,

I need some guidance as to what camshafts and what size i would need for the new engine i'm building.

The engine consists of a 32gtr head on a series 2 rb30 bottom end. The head will have extensive port and polishing and be capable of flowing 700hp+. The car will be used for track duties but be a streeter aswell, that means i dont want undrivable lumpy cams.

I was looking at a set of Tomei Pro Cams, 290 duration with 11.5mm lift.

Is this too big? I also know i'll need lifters, springs and guides to suit the lift.

I dont really know much about cams so any help is much appreciated!

cheers

Shane

[pnblight]

Hi all,

I need some guidance as to what camshafts and what size i would need for the new engine i'm building.

The engine consists of a 32gtr head on a series 2 rb30 bottom end. The head will have extensive port and polishing and be capable of flowing 700hp+. The car will be used for track duties but be a streeter aswell, that means i dont want undrivable lumpy cams.

I was looking at a set of Tomei Pro Cams, 290 duration with 11.5mm lift.

Is this too big? I also know i'll need lifters, springs and guides to suit the lift.

I dont really know much about cams so any help is much appreciated!

cheers

Shane

Dude there way to big

700hp do you mean (bhp or rwhp?)

As to make 700bhp you only need tomei poncams 260 9.15mm (std will make 600bhp) the 260 poncams are a perfect street/track cam if your more drag/street i would think 270 10.25mm would be perfect as i know of a number of guys running the HKS version of this for this style duty.

290 is about as big as tomei go meaning its for a full drag 1200bhp drag car and would not be streetable and the lift would be very hard on running gear requiring high maintain.

pete

[sky30]

Dude there way to big

700hp do you mean (bhp or rwhp?)

As to make 700bhp you only need tomei poncams 260 9.15mm (std will make 600bhp) the 260 poncams are a perfect street/track cam if your more drag/street i would think 270 10.25mm would be perfect as i know of a number of guys running the HKS version of this for this style duty.

290 is about as big as tomei go meaning its for a full drag 1200bhp drag car and would not be streetable and the lift would be very hard on running gear requiring high maintain.

pete

Anyone know:- Can 270 degree 10.3mm lift cams be run with stock lifters and stock springs?

Also Pete:- how much diference in midrange did the 270/10.25mm cams have compared to the

260/ 9.15mm ??

[shanef]

Dude there way to big

700hp do you mean (bhp or rwhp?)

As to make 700bhp you only need tomei poncams 260 9.15mm (std will make 600bhp) the 260 poncams are a perfect street/track cam if your more drag/street i would think 270 10.25mm would be perfect as i know of a number of guys running the HKS version of this for this style duty.

290 is about as big as tomei go meaning its for a full drag 1200bhp drag car and would not be streetable and the lift would be very hard on running gear requiring high maintain.

pete

i'm after 700hp at the flywheel

turbo i'll be running is the garrett t04Z (if its gonna make the required power)

so what would the 260deg 10.8mm lift cams be like?

[pnblight]

i'm after 700hp at the flywheel

turbo i'll be running is the garrett t04Z (if its gonna make the required power)

so what would the 260deg 10.8mm lift cams be like?

ok the t04z will make 700bhp when setup properly 260 deg 10.8mm would work fine but i think with a turbo that size i would most likely lean toward the 270deg 10.25mm (the more lift you run the more wear (maintain))as your setup is more towards the drag and outright hp setup then a track (ciruit)/streeter. There a r32 in wa running very close to this setup making good power and drag times BUT the power delivery misses some bottom end but hits very hard mid range which kills gearboxes (costly) and is not very helpfully for a fast track car (circuit), but the combo works but you need to be thinking beyond 700bhp as you right on the limit of alot of the other running gear (ie gearbox) which can add big dollars to the build.

pete

[Swiper the Fox]

i'm after 700hp at the flywheel

turbo i'll be running is the garrett t04Z (if its gonna make the required power)

so what would the 260deg 10.8mm lift cams be like?

Im running 750hp+ at the flywheel...tomei 260 9.15mm cams were excellent match for the HKS 2530 turbo's i was running and power was high all the way to 8500rpm. Now ive upgraded to HKS GT-RS turbo's and will only go as far as 264deg cams to match these. In my opinion the Japanese "overcam" their engines and move the power delivery band past the turbo's efficiency range and the engines rpm capabilities.

[shanef]

thanks for that great info guys. certainly gives me something to think about.

another question. what twin turbs would give me this desired power? (the gtrs's?)

also i realise about the strain on driveline parts thats y i am capping the power at 700hp at the flywheel.

[Swiper the Fox]

thanks for that great info guys. certainly gives me something to think about.

another question. what twin turbs would give me this desired power? (the gtrs's?)

also i realise about the strain on driveline parts thats y i am capping the power at 700hp at the flywheel.

We used HKS 2530's to make over 400AWKW with pump gas and almost 450AWKW with C16....we are hoping to make over 450AWKW with GT-RS turbos on pump and almost 500AWKW on C16.

[shanef]

wat else was needed to extract that much power out of them?

[N I B]

These guys are so right so many ppl go for huge cams and turbos making crazy power but not running the times guys like DIRTgarage are with their milder parts giving huge average power.

260pon cams are very hard to beat for anything other than dyno queens or gutted drag cars with perfect trans setups.

Ive been very suprised to see the power curves weve been able to get with these cams.

[Swiper the Fox]

wat else was needed to extract that much power out of them?

Check out the full feature on our car in the last HPI GTR special....its the one with the orange Garage Saurus GTR on the cover.....too much to type here....lol

[shanef]

Check out the full feature on our car in the last HPI GTR special....its the one with the orange Garage Saurus GTR on the cover.....too much to type here....lol

slack lol...nah thanks for the pointers mate, will definately have to get the new HPI then...

lets hope all goes well and shes ready and running by jamboree this year!

does it cover the complete driveline ur running? or shall i need to pick ur brain some more?

[Sydneykid]

As the guys have pointed out, cam duration selection is all about the rpm range you want to use and maximising the average power. So look to your gearbox ratios as a guide. Lift is about how often you want to rebuild it. As always, you need to keep in mind how much money you want to spend.

cheers

[shanef]

pk, say i was to get TOMEI valve springs, valve guides, valve lifters and some custom stainless valves, would the maintanence be prolonged with this aftermarket pieces with high lift cams? ~10.5mm lift

the car will be used for track duties so i'd want low-mid range response, but saynig that i dont want the power to be like a light bulb, all on or all off.

cheers

shane

[Sydneykid]

pk, say i was to get TOMEI valve springs, valve guides, valve lifters and some custom stainless valves, would the maintanence be prolonged with this aftermarket pieces with high lift cams? ~10.5mm lift

the car will be used for track duties so i'd want low-mid range response, but saynig that i dont want the power to be like a light bulb, all on or all off.

cheers

shane

Hi Shane, the higher lift means the cams have steeper profiles needed to fit the lift (open and close) within the duration (time). This means the valves open and close faster. In addition you have to use higher rate valve springs to make sure that the valves close (follow) the cam lobe’s profile.

So you have faster and harder closing valves. Just like a rapid and heavy hitting hammer, this will eventually wear out the valve seats, pound them flat. In addition you will experience similar wear on the valves themselves. The quickest wear being the seat area where the valve seals on the seat. As this wears, the seat becomes wider and may even leak. Both of these costing noticeable horsepower.

The rapid pounding of the valve heads will eventually fatigue the valve stems around the head mushroom. Given sufficient repetition, the valve head will eventually fall off causing (at the very least) catastrophic damage to the piston and cylinder head.

Also you have faster opening valves with stronger valve springs resisting this opening. This means the cam lobes themselves and the buckets wear out faster. Higher lift also increases the angles on which the lobes affect the buckets. This side loading results in faster wear of the valve stem seals, which will leak oil into the combustion process and cause a loss of power and generally premature detonation.

This rapid wear factor why you don’t see huge horsepower GTR’s making 100’s of ¼ mile passes in a year. This is why you have drag engines that do little real kilometres, able to be built/tuned to make more power than circuit racing engines that have to last a season. An extreme example is a F1 engine, that is very lucky to do 1,000 k’s before a full rebuild is required. Or a top fuel drag engine that does one pass before a full rebuild is required.

So to answer your questions;

1. RB26 valves are already stainless

2. Stronger valve springs actually increase wear, not decrease it. I use valve springs just strong enough to control the valve, make it follow the lobe and resist the targeted boost pressure.

3. Personally in a circuit race engine, I never use cams over 10.3 mm lift to minimise the side loading and the valve seat wear

Hopefully that answered your questions

cheers

[pnblight]

Hi Shane,

All the info in here is very good and i think you should be starting to get a feel for what is needed for a good package to suit your purposes.

the car will be used for track duties so i'd want low-mid range response, but saynig that i dont want the power to be like a light bulb, all on or all off.

In this case i would guide you toward twins for the linear power delivery and low end responce

I will tell you this is only my opinion from time tuning and testing

HKS turbos and Garret units ae all awesome

HKS GTRS

HKS 2530

Garret GT2560R 707160-5

these unit will all serve you well

(and no i'm not saying a single cant be used well to achieve this it's just the twin are more user friendly in a circuit enviroment)

I'm not sure on the 700bhp but if you can keep your power to and around the low 500's rwhp good have a chance for keeping the std run gear and box and please dont judge a 500rwhp+ car until been in one for a ride, more power then you'll even need for track duties.

To achieve a reliable 500rwhp+ car will need sum real dollars and time and effort let alone gear. But shit man there nothing else like i have driven lol.

One area you will have to address for such a powerfully car will be heat control as the more power the more heat is generated and has to be delt with. Nice radiator and oil cooler is a great start and even a low temp Nismo thermostat won't hurt. Another good investment is a custom large baffled sump.

pete

ps One small tip please buy yourself some new tomei or arp etc cam stud bolts as they are a weak point when you start running high lift cams.

[Swiper the Fox]

slack lol...nah thanks for the pointers mate, will definately have to get the new HPI then...

lets hope all goes well and shes ready and running by jamboree this year!

does it cover the complete driveline ur running? or shall i need to pick ur brain some more?

The issue is about 6 months old so look back through your old ones....i got it as a free giveaway with this months issue.

on the driveline...i run a 1.5 way front LSD...Jim Berry Race clutch....OS giken 5speed gearbox (helical)....and STD rear diff (still hanging in there)

[shanef]

Hi Shane,

All the info in here is very good and i think you should be starting to get a feel for what is needed for a good package to suit your purposes.

In this case i would guide you toward twins for the linear power delivery and low end responce

I will tell you this is only my opinion from time tuning and testing

HKS turbos and Garret units ae all awesome

HKS GTRS

HKS 2530

Garret GT2560R 707160-5

these unit will all serve you well

(and no i'm not saying a single cant be used well to achieve this it's just the twin are more user friendly in a circuit enviroment)

I'm not sure on the 700bhp but if you can keep your power to and around the low 500's rwhp good have a chance for keeping the std run gear and box and please dont judge a 500rwhp+ car until been in one for a ride, more power then you'll even need for track duties.

To achieve a reliable 500rwhp+ car will need sum real dollars and time and effort let alone gear. But shit man there nothing else like i have driven lol.

One area you will have to address for such a powerfully car will be heat control as the more power the more heat is generated and has to be delt with. Nice radiator and oil cooler is a great start and even a low temp Nismo thermostat won't hurt. Another good investment is a custom large baffled sump.

pete

ps One small tip please buy yourself some new tomei or arp etc cam stud bolts as they are a weak point when you start running high lift cams.

thanks pete most appreciated. Looks like i'll be keeping the twins. I've been in and driven a 400rwkw gtst and hell it was scary, only drove it for a short aquirt but it was enough to get the bug growing .

I put up the 700hp figure as a maximun i'd want the engine to be able to handle, but i'd never go above 600hp at the flywheel, just to give a bit of headroom.

I plan on replacing all the engine bolts with aftermarket higher strength ones that's for sure, as all this other good gear would just be a waste. No point in doing a job that isnt done properly.

I dont want to go replacing the gearbox as i'd looking at 8k for a ppg or the like one, that i'm not willing to do. (but saying that, if the standard one does break id have to change it). One question though, would a track car's running gear cop as much punishment as that from a drag car? I mean a track car u have to nurse the throttle more and ease the power on and not be all power for 10 secs and then nothing.

Heat control i am very aware of. This will make or break the engine. Trust intercooler, radiator, oil cooler, maybe even gearbox and diff coolers, and certainly some sort of aftermarket custom sump that is designed for the track use.

The issue is about 6 months old so look back through your old ones....i got it as a free giveaway with this months issue.

on the driveline...i run a 1.5 way front LSD...Jim Berry Race clutch....OS giken 5speed gearbox (helical)....and STD rear diff (still hanging in there)

Paul (am i correct in saying thats ur name? lol) is there any difference in application of a custom clutch from the likes of Jim Berry over say an ORC 700d twin plate clutch? or am i being neieve in saying they both should do the same job, if they r rated the same power.

Again guys i'd like to thank you alot for giving your time and ur advice, i appreciate it alot

cheers

Shane

[Swiper the Fox]

I dont want to go replacing the gearbox as i'd looking at 8k for a ppg or the like one, that i'm not willing to do. (but saying that, if the standard one does break id have to change it). One question though, would a track car's running gear cop as much punishment as that from a drag car? I mean a track car u have to nurse the throttle more and ease the power on and not be all power for 10 secs and then nothing.

Paul (am i correct in saying thats ur name? lol) is there any difference in application of a custom clutch from the likes of Jim Berry over say an ORC 700d twin plate clutch? or am i being neieve in saying they both should do the same job, if they r rated the same power.

Again guys i'd like to thank you alot for giving your time and ur advice, i appreciate it alot

cheers

Shane

Shane, i broke our STD box coming out of turn 9 at Eastern Creek...dont be fooled into thinking that circuit racing is kind on cars.

Ill give you a quick rundown on what you NEED (others are wish list)....rebuilt RB26 Cryo'd block, rods and crank. Aries forgies (my fav.) N1 oil and water pumps, tomei 260 cams, head gasket and sump baffles, ARP rod bolts, HKS 2530 turbo's and dumps, SARD 700cc injectors and reg.

On the clutch....I know ORC make killer clutches but....at your power i think the Jim Berry item is right there for value and performance against any clutch you care to name. (i know thats a big statement but trust me on this one)

Paul

EDIT...sorry Shane...just realised your running an RB30 bottom end....change the turbo's to HKS GT-RS's and the rods to Argo's

Edited April 19, 2006 by DiRTgarage

[R32 TT]

EDIT...sorry Shane...just realised your running an RB30 bottom end....change the turbo's to HKS GT-RS's and the rods to Argo's

Hi guys, I've been reading this thread with interest and a lot of questions asked are ones I had myself!

I am also building an RB26/30. I have ordered HKS cams of 264 degree and 10mm lift, so only a smidge bigger than Poncams.

I am thinking of going 707160-5 turbos (same as HKS2530).

I know this will limit my top end to about 600-650 flywheel hp. I don't mind so much as I am sure it will be torquey as in the mid range.

Is there likely any problem with this setup in terms of the internal wastegate for example (will it be able to expel the air from the RB30 to keep boost under control)

I know I could go GT-RS for more power - but I figure 2530's will spool ultra fast on a 3 Litre and this appeals to me.