Which Camshafts?

[Nee-san]

I'de be interested to see those graphs, if it isnt too much trouble for you STATUS ?

Cheers,

Mitch.

[Swiper the Fox]

I'll do Racepace, you, Drifty all in a day

5lut

Edited January 13, 2010 by DiRTgarage

[discopotato03]

Just my 5c and I've never had an RB26 .

Having to budget for a build is frustrating but extra time often leads to decisions made from extra research .

To me the headwork should take the no 1 priority because cams and turbos bolt on/in - yeah I know about shimming .

IMO to make the power the engine has to breathe properly - and throw off the factory built in needs to be a production engine characteristics .

I think the question needs to be asked about those twin GTRS turbos - do you really need them to make that 370 kw . You could spend a lot of money making those turbos work but is that really the goal . You could put real big cams in it too but are they justified in making the power ask ?

You say you want this for a daily driven car so nice drive characteristics are a must . I dunno , maybe a really well done head/adequate cam combination and 2530 style turbos is the go not to have a cammy torqueless waiting waiting waiting wham engine .

Just lastly where does the 370 Kw number come from , many chase a number and don't like what it means to live with the compromises it can give .

Cheers A .

[Jamtime]

Ok so clearly I have just bought the wrong turbos for my setup. Sounds like the general consensus is -5s are the way to go for what I'm after. Sorry about the whole can of worms on the camshaft debate, thought it might have been a straight foward answer. I might just ask some locals in Townsville who have tried similar setup and guage their responses.

Also I've ordered a stoker kit and I'm not sure it'll be ideal. It's an HKS 2.8L step 0. Anyone know if this will be sufficient?

[PM-R33]

Go speak to Paul at Xtreme, probably the better person with RB26 knowledge in Townsville.

[N1GTR]

Step 0, that's the 450hp or so rated one?!

You may aswel save the money and just get a new crank from Nissan.

I know the step 0 is on sale currently at what seems a great price, but it's not really worth buying IMO.

[destrukshn]

So speaking about camshafts, who would like to shed some light on what should be run on HKS 2530s?

I'm curious about which cams should i run. The head is full worked, you're talking tomei lifters, type-b valve springs, retainers, tomei valve guides, tomei 1mm oversized valves, port and polished. I bought 272/272 (in&ex 10.25mm lift). I have cp pistons, eagles rods.

Would this be a better combo than my 264/264 (9.15mm lift)? How would the drive be? Would it lag more and have more top-end or just depending on tune? My car is tuned for 1.6bar at the moment and it feels quite responsive.

[R31Nismoid]

Ok so clearly I have just bought the wrong turbos for my setup. Sounds like the general consensus is -5s are the way to go for what I'm after. Sorry about the whole can of worms on the camshaft debate, thought it might have been a straight foward answer. I might just ask some locals in Townsville who have tried similar setup and guage their responses.

Also I've ordered a stoker kit and I'm not sure it'll be ideal. It's an HKS 2.8L step 0. Anyone know if this will be sufficient?

Aye - big can-o-worm. But then we haven't had a thread like this for a while

So ye -5's for sure.

Cams then comes down to whoever is doing your head work, so pretty much leave it in their hands as they are the ones doing it.

[bigmikespec]

Can someone just start an "epic" RB26 cam thread please so it can all be sorted. Even if nothing gets sorted at least it will be good entertainment value reading it.

[Ziller]

I've had 4 different engines in my car now but never a 2.8 stroker so I cant make comment, as far as a 2.6 go's I've had Garrett 2871-7s, 2871-10s similar to a GT-RS all with 260 x 260 9.15 cam shafts with a STD head and Tomei springs, now running 2860-5s with STD cam shafts.

Maybe down a bit in top end but the response has left me gob smacked, now that's an every day driver!, personal choice really, but I aint never going back!!!!

[zebra]

Zebra your coventional thinking you have quoted is correct on a vacuum drawing engine (atmo). It doesn't necessarily go the same way with forced induction. Would you run a small cam in an atmo engine that runs 15:1 static comp and expect it to make lots of power early...no way. How do you expect to get good cylinder fill and properly burn the mixture.

While I understand that having "more" cam under +ve pressure is benificial in making more torque.

But what about off boost drivng which is 90% of the time for most street cars.

For e.g. your car paul, if you did a 5th gear rolling run from say 2000rpm against an identical car (same turbo, head work etc) but it had 260deg cams which do you think would accelerate harder OFF boost? My rekoning is that a street car needs to have good pull down low off boost so that there is no need to be constantly down shifting up hills etc while running around town.

I hope Im making sence here? lol

in a race car (particually drag cars which really should never be off boost during a run) It is definatley better to have that huge amount of cylinder filling that big lift / long duration cams prove to make the on boost grunt needed.

[Swiper the Fox]

While I understand that having "more" cam under +ve pressure is benificial in making more torque.

But what about off boost drivng which is 90% of the time for most street cars.

For e.g. your car paul, if you did a 5th gear rolling run from say 2000rpm against an identical car (same turbo, head work etc) but it had 260deg cams which do you think would accelerate harder OFF boost? My rekoning is that a street car needs to have good pull down low off boost so that there is no need to be constantly down shifting up hills etc while running around town.

I hope Im making sence here? lol

in a race car (particually drag cars which really should never be off boost during a run) It is definatley better to have that huge amount of cylinder filling that big lift / long duration cams prove to make the on boost grunt needed.

With that sort of talk you should be in here...

http://www.skylinesaustralia.com/forums/Na...-Perfo-f53.html

Why not just sell the skyline and drive a diesel truck? we dont buy/modify these things to putt around off boost.

honestly my car is great down low 1200+nm of tractive effort at 4500 is pretty impressive...thats well built V8 territory.

Ziller you are spot on...STD head = small cams...there is no point even bothering with larger camshafts when they have little to assist them. Thats why there is also no point using RS's if you are not willing to spend the required $$ on the head. Building and designing combo's for these engines is all about matching the components to work together...a mis-match in one area will be exposed through poor results/performance.

Edited January 14, 2010 by DiRTgarage

[bloodzkull]

when i had my gtr motor rebuilt the only extra (performance) work done was a bit of porting, port matched manifolds and a set of 264/272 cams, can't remember the lift but only a little above stock.

i found that full boost came on a little earlier (maybe 200rpm) made 40kw more at the wheels and the responce on and off throttle was better. this was with -5's. curious if i could have had a better cam choice.

as far as off boost responce, well i was making positive pressure by 2000-2200 and 8psi by 3, from there it came on a bit slower but very linear.

[Ziller]

With that sort of talk you should be in here...

http://www.skylinesaustralia.com/forums/Na...-Perfo-f53.html

Why not just sell the skyline and drive a diesel truck? we dont buy/modify these things to putt around off boost.

honestly my car is great down low 1200+nm of tractive effort at 4500 is pretty impressive...thats well built V8 territory.

Ziller you are spot on...STD head = small cams...there is no point even bothering with larger camshafts when they have little to assist them. Thats why there is also no point using RS's if you are not willing to spend the required $ on the head. Building and designing combo's for these engines is all about matching the components to work together...a mis-match in one area will be exposed through poor results/performance.

Now you tell me!, Hehe don't ya just love these cars!

Best of luck with the development of your beast. Cheers Brother!

[livicuru]

Ok so clearly I have just bought the wrong turbos for my setup. Sounds like the general consensus is -5s are the way to go for what I'm after. Sorry about the whole can of worms on the camshaft debate, thought it might have been a straight foward answer. I might just ask some locals in Townsville who have tried similar setup and guage their responses.

Also I've ordered a stoker kit and I'm not sure it'll be ideal. It's an HKS 2.8L step 0. Anyone know if this will be sufficient?

Hey Jam

Just saw your now selling you RS's and losing $500 on them..............Man if you have already ordered a 2.8L stroker etc dont turn back. I have x2 GT3582r high mounts with smaller rear ex/housings + ext. gates (+ plus bigger cams / no head work), Im sure these will come on bit later than your Rs's, but hey when they come on its all over. Yeh its a different drive than the snappy 2530's and need to keep Revs up a little more, but hey thats the whole idea of having 4wd!..

so i guess your Rs's are only gonna spool up quicker compared to mine.....Aim for 400kw my friend and stick to what you have

[SimonR32]

Hey Jam

Just saw your now selling you RS's and losing $500 on them..............Man if you have already ordered a 2.8L stroker etc dont turn back. I have x2 GT3582r high mounts with smaller rear ex/housings + ext. gates (+ plus bigger cams / no head work), Im sure these will come on bit later than your Rs's, but hey when they come on its all over. Yeh its a different drive than the snappy 2530's and need to keep Revs up a little more, but hey thats the whole idea of having 4wd!..

so i guess your Rs's are only gonna spool up quicker compared to mine.....Aim for 400kw my friend and stick to what you have

im sorry but yours sounds like one of the worst setups i've ever heard of on a rb

Edited January 14, 2010 by Cerbera

[Mr. Untouchable]

haha Sun dial boost guage

[zebra]

With that sort of talk you should be in here...

http://www.skylinesaustralia.com/forums/Na...-Perfo-f53.html

Why not just sell the skyline and drive a diesel truck? we dont buy/modify these things to putt around off boost.

Lol I completley agree with you there. but isnt this guy building a street car...id be willing to sacrifice some top end in a street car for better (in theory) fuel economy and low down drivability.

[The Bogan]

A worked motor with fuel economy and low down drivability, I would like to see that.

[Swiper the Fox]

A worked motor with fuel economy and low down drivability, I would like to see that.

low gown driveability and response are the things to cling to for satisfaction when a combo just doesn't cut the numbers.