Camshaft For Rb26 With Good Response And Idle..

[cobrAA]

Ok I guess It's important to mention that I will take the motor out and do a PARTIAL rebuilt, you know headgasket,forged piston and rods, crank collar, oil pump. basic rebuilt.

so I thought while I'm there, why not change the cams and gain a bit more power?

[Deano 1]

ive got Type B's in my car, DVS32R has standard cams in his car..... we have the same everything eles, pfc, n1 steel wheels turbos, same exhaust size, pritty much the same setup.

my car makes 300rwkw and comes on boost alil later,

his car makes 285rwkw and comes on boost earlier,..... my idle is a tiny bit lumpy and his idle is just norm. we can both post up our dyno sheets if need be......

[wolverine]

call me quick draw....

The Baron knocking a bad idea on the head before someone gets hurt...... you aren't Quick Draw you are El Kabong.

[Rolls]

How much does changing the cams effect the fuel economy for street driving? Are we talking a 5% increase, 50% .. etc?

[cobrAA]

How much does changing the cams effect the fuel economy for street driving? Are we talking a 5% increase, 50% .. etc?

That's a good question!! I want to know the answer too.

[NSNPWR]

the usual non-constructive stonewall response from nismoid.. perhaps he did mean midrange power.

type b's seem to be the way to go for better idle, both have the same 9.15mm lift, they're my choice

If he had his way mate we'd all be restricted to using stock cams, stock injectors, stock dump pipes and a pair of -9s to make 270rwkw...how boring.

Ive just fit a set of Type-Bs to my 32 GTR, little way off a tune as yet but seen some good results around the place and looking forward to some juicy mid-range gains.

All this talk of costs associated with an install...some basic tools and mechanical knowledge will have these in in a few hours, can do it without taking crank pulley off, just set to TDC and zip tie the gears to the belt...just dont over-torque the cap bolts................

Edited November 5, 2010 by NSNPWR

[Beer Baron]

you want good response. this is my old GTR post cam gear tuning. compare it to similar powered cars and see what power they are making at 100kmh, 120kmh etc. you can see a massive area under the curve. it doesn't make massive power but it was a pretty quick car. very quick for a car with "only" 270kw...

This car was standard RB26, standard head, standard cams, standard injectors, standard intercooler, standard turbos (possibly were N1s, not sure), power FC, 15psi, and a cat back exhaust (very free flowing).

as I said it does not make mega power but compare to other GTR graphs and see how well it does down low and how quick it ramps onto boost and the size of the area under the curve. before we even get half way along the scale it's making over 200kw. so it's making over 200kw atw from about 3,800rpm to redline.

[Beer Baron]

BTW, I am a big fan of cams for the right application. and in a GTR that really means either a circuit car who needs to beef up the 5,000rpm-8,000rpm range or a car with over 350kw that needs the thing to breathe deeply. on my own cars I've had cams. I had cams in my old GTR but it had lots of headwork, valve springs etc and was designed to run a higher than standard rev limit. at those rpms the cams are worthwhile.

[cobrAA]

I will post my dyno graph this week-end but I know i don't have speed vs. HP so I can't compare but we did a 500kms ride with 10 Skylines ( all different power) and I was, no doubt, the quicker. but if I can get a 40lbs increase in the 4000-6500rpm range, I can't see why it wouldn't make the car quicker? I'm down for this increase ''kick in the butt'' feeling

Edited November 5, 2010 by cobrAA

[NickR33]

How much does changing the cams effect the fuel economy for street driving? Are we talking a 5% increase, 50% .. etc?

all I know is I have 260º 10.8mm lift cams in my R and it sucks fuel like Jenna Jameson sucks teh cawk

is partially due to the high idle that's needed for lumpy cams but mostly due to the fact that you move the RPM the engine is most efficient at up towards redline... you can actually hear my car come on boost and then onto the cams... fair enough you can rev the thing to 9K if you really want... but if you like to do that you've obviously never paid for a rebuild on an RB

my tuner recommended I go back to stock when he rebuilt the motor but I like the personality of the car better with them... if I wanted quiet, fuel efficient and responsive I'd buy a grown up car

[NSNPWR]

you want good response. this is my old GTR post cam gear tuning. compare it to similar powered cars and see what power they are making at 100kmh, 120kmh etc. you can see a massive area under the curve. it doesn't make massive power but it was a pretty quick car. very quick for a car with "only" 270kw...

This car was standard RB26, standard head, standard cams, standard injectors, standard intercooler, standard turbos (possibly were N1s, not sure), power FC, 15psi, and a cat back exhaust (very free flowing).

Sorry mate, I wasnt meaning it like 'only 270rwkw'...just every post I read from him refers to stock this stock that, its all killa apparently and no one need do any mods to a stocko 26 to make good power bar some -9s...

Anyway, back on topic, has anyone had anything to do with tuning with these cams? Interested to know where people set the In/ex gears too, from what ive read, Inlet - 4 degree advance and Exhaust - 2 degrees retarded seems to quite common.

Edited November 5, 2010 by NSNPWR

[Beer Baron]

no need to apologise. I wasn't directly replying to you. I just meant 'only' 270kw in that these days it's not considered much power, but it's actually a decent amount of power for an otherwise fairly standard engine set-up. not long ago most people would kill for a genuine 270kw atw in just about any type of road car.

and yes wiith stock cams the sweet zone (best compromise between midrange power and peak power) seems to be around 4-6 degrees inlet advanced and 2-4 degrees exhaust retarded. where the exact sweet spot is for any car is a guess and why it's worth testing a few points. ie, inlet 3, exhaust 2, inlet 4 exhaust 2, etc etc you get the picture.

as far as tuning your type B poncams it seems to be a bit more hit an miss. many people say they are best left at 0 and 0 but some people have been happier with them after some time adjusting on a dyno. I do think it's worth spending a bit of $$ to get a few different positions tested on the dyno to see if you like the way it changes the power delivery.

anyway in this case I still think by far the best option this bloke has is just get the cam gears adjusted. it will give maximum result for minimum cash. If he really wants cams though just buy some. no one here will loose any sleep over it, but it does defeat the purpose of asking for advice is your mind is already made up...

[djr81]

... but it does defeat the purpose of asking for advice if your mind is already made up...

Gees man, that is the whole purpose of this forrum these days.

More seriously the problem with the type B Poncam is that it kills your torque at 4000rpm (114km/h on the dyno in 4th) without giving you a commensurate increase in top end because the cam lift is not as it could be.

[cobrAA]

no need to apologise. I wasn't directly replying to you. I just meant 'only' 270kw in that these days it's not considered much power, but it's actually a decent amount of power for an otherwise fairly standard engine set-up. not long ago most people would kill for a genuine 270kw atw in just about any type of road car.

and yes wiith stock cams the sweet zone (best compromise between midrange power and peak power) seems to be around 4-6 degrees inlet advanced and 2-4 degrees exhaust retarded. where the exact sweet spot is for any car is a guess and why it's worth testing a few points. ie, inlet 3, exhaust 2, inlet 4 exhaust 2, etc etc you get the picture.

as far as tuning your type B poncams it seems to be a bit more hit an miss. many people say they are best left at 0 and 0 but some people have been happier with them after some time adjusting on a dyno. I do think it's worth spending a bit of $$ to get a few different positions tested on the dyno to see if you like the way it changes the power delivery.

anyway in this case I still think by far the best option this bloke has is just get the cam gears adjusted. it will give maximum result for minimum cash. If he really wants cams though just buy some. no one here will loose any sleep over it, but it does defeat the purpose of asking for advice is your mind is already made up...

I saw your engine for sale.. Nice!!! But hey, you do have type-B and GTSS. did you run tthe type-b with the gt-ss?

Before making this thread my mind wasn't set and I'm still not set ( Also thinking about water-meth). However, I do like the idea of better mid-range and I do believe this will make the car more responsive and more powerful even if at peak I only get 10whp more.

And from reading what people have to says, it seems like the type-B will do that. I also read that PROCAM and greddy are ''better'' aka more HP but this is not my ultimate goal

[Nee-san]

I saw your engine for sale.. Nice!!! But hey, you do have type-B and GTSS. did you run tthe type-b with the gt-ss?

Before making this thread my mind wasn't set and I'm still not set ( Also thinking about water-meth). However, I do like the idea of better mid-range and I do believe this will make the car more responsive and more powerful even if at peak I only get 10whp more.

And from reading what people have to says, it seems like the type-B will do that. I also read that PROCAM and greddy are ''better'' aka more HP but this is not my ultimate goal

Have a think about whether all these extra ancillaries involved in the water meth kit and concurrently the weight and weigh up if it's actually worthwhile, benefit wise.

Not saying that it isn't, but it's always something to weigh up with these sort of decisions, the best kind of engineering is the one where you isolate what truly benefits your project and then disregard everything that isn't directly related to what your trying to achieve.

[r32-25t]

I have gt-ss turbos in mine and type b cams in it, I kinda regret changing the cams. but I'm looking at going 2.8 and put them in for when I finally kill the bottom end in my car and fit the 2.8 I have rapped in plastic in my garage

Only time will tell tho

[R.3.2.G.T.R]

I have gt-ss turbos in mine and type b cams in it, I kinda regret changing the cams. but I'm looking at going 2.8 and put them in for when I finally kill the bottom end in my car and fit the 2.8 I have rapped in plastic in my garage

Only time will tell tho

how does your car drive with the b cams compared to stocko?

[r32-25t]

It drives ok fine just lost a Bit of fuel economy and little bit down low, but a touch up on the tune should fix that, does have a nice idle now tho.

Edited November 8, 2010 by r32-25t

[Rolls]

It drives ok fine just lost a Bit of fuel economy and little bit down low, but a touch up on the tune should fix that, does have a nice idle now tho.

by nice you mean bad don't you? lol

how much worse is the fuel economy, do you have figures?

[NickR33]

Gees man, that is the whole purpose of this forrum these days.

More seriously the problem with the type B Poncam is that it kills your torque at 4000rpm (114km/h on the dyno in 4th) without giving you a commensurate increase in top end because the cam lift is not as it could be.

yeah I don't see the point in having more overlap if your not going for a decent amount of lift... the Procams have different lift options for the 260º... 9.15, 10.25 and 10.8... but then you need all the other gear to accommodate the extra lift