Camshaft For Rb26 With Good Response And Idle..

[cobrAA]

I read every thread of the 8 pages on gtr.uk about camshaft.

- I have a RB26 with GT-SS. almost no lag, very responsive and I like it this way!

- So I'm looking at a camshaft that will give me more power without taking out the response or barely..

- I'm also looking for a good idle, (I'm aware that the smoothest idle would be my oem cams)

- Drop-in cams is a big + over cams that need custom works to fit.

Would the tomei poncam type-B be the perfect match for what I'm looking for?

Thanks!

[jangles]

head work? what power??

[R31Nismoid]

How do you expect cams to give you more power? In most situations they will just move the power curve.

Without head work etc, IMO its pointless and you certainly don't need to change them

[kristafa]

How do you expect cams to give you more power? In most situations they will just move the power curve.

Without head work etc, IMO its pointless and you certainly don't need to change them

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

[gtr fan]

Have you tried just using adjustable cam gears first?

[cobrAA]

Have you tried just using adjustable cam gears first?

I already have tomei cam gears fitted.

[STATUS]

with those turbos id just use a set of cam gears, advance up the intake 4-8 degrees and plot the results, then play with the exhaust but in small increments.

If not i found the Greddy procams 264 with 9.7mm lift to work real nice compared to the poncams but ive only compared them in engines making at least another 50rwkw over the gtss so it not a real help but a good cam comparison nonetheless..

[cobrAA]

How do you expect cams to give you more power? In most situations they will just move the power curve.

Without head work etc, IMO its pointless and you certainly don't need to change them

Well by looking at this chart from a supra tuner, it's pretty obvious that all 3 camshaft setup gives more power than the OEM setup.

I expect the samething to happen to a rb26.

[Owgasm]

Torque. Which is correct.

[R31Nismoid]

Supra 2JZ graph? Irrelevant for RB26's.

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

How was it non-constructive exactly?

We've told him before stocker cams are the way to go with that turbo selection for his use of the car (he does want ultimate response afterall).

So in saying that, ultimate response, the stock cams fit that bill perfectly combined with a set of cam gears (which a few have told him before also )

I mean end of the day if he wants, the Poncams will idle fine etc, barely noticeable however costly exercise should it ruin that which he set out to achieve.

[Beer Baron]

seriously if you want good response and good idle stock cams are the way to go. any cam is going to give you a slightly lumpier idle and going to move your peak torque UP the RPM scale. for GTSS probably the best option for what you want is cam gears. you say you have them but have they been tuned? I gained 30kw midrange in my old GTR with cam gear tuning and about 5kw peak power. so peak power change was quite small but the difference in the midrange and the transition onto boost was amazing.

so yeah, the best bet for you is cam gear tuning. or maybe a set of 34 N1 cams, they are a very mild upgrade.

[cobrAA]

seriously if you want good response and good idle stock cams are the way to go. any cam is going to give you a slightly lumpier idle and going to move your peak torque UP the RPM scale. for GTSS probably the best option for what you want is cam gears. you say you have them but have they been tuned? I gained 30kw midrange in my old GTR with cam gear tuning and about 5kw peak power. so peak power change was quite small but the difference in the midrange and the transition onto boost was amazing.

so yeah, the best bet for you is cam gear tuning. or maybe a set of 34 N1 cams, they are a very mild upgrade.

I know it sound stupid but I had tomei cam gears fitted on the dyno but the tuner never played with them. I bought these because i got them for 150$. However, when I went on the dyno, the tuner said he would have to charge me like 1-2 hours to get the best out of them and at 220$/hour. I said..well forget the cam tuning lol!

I wasn't expecting such a huge increase from cam gears tuning.

Like you said, with camshaft, I might only get 10whp more peak but if I can get 30lbs torque and 40whp more at midrange(3.5 to 6k) I think it's really worth it and it will make driving more fun.

[Beer Baron]

yeah but cams cost $800-$1000 for a pair, plus maybe $300 fitting, plus you will need a re-tune of the ecu AND adjust the cam gears to get the most out of them. so you're looking at nearly $2000 to do it properly.

for 2 hours of dyno time to set-up the cam gears you will get an excellent result for $400 and you wont loose any response (you will gain some) and your idle wont be much affected at all (slight change).

for what you want you'd be mad to go to all the expense of buying cams. especially since you already have cam gears and just need to spend 1-2hours to have them set-up.

[R31Nismoid]

So based labour/time price... You'll spend over $1500-$1700 to get the cams installed and then dialled in?

Or you could dial in the cam gears for $440

[R31Nismoid]

Ah fk the dick was faster

[noone]

A little off topic an might open a can of worms

but would the same advice be given for a built motor with minor headwork an 2530's???????

Would the bigger turbos give more relevance to bigger cam's

Just curious as to others opinions

[Beer Baron]

Ah fk the dick was faster

call me quick draw....

[Beer Baron]

A little off topic an might open a can of worms

but would the same advice be given for a built motor with minor headwork an 2530's???????

Would the bigger turbos give more relevance to bigger cam's

Just curious as to others opinions

yeah definitely look at cams with headwork and bigger turbos. but with small bolt ons and standard engine and head there is not a lot to be had. it will fatten up the area around 5,000rpm and give some top end gain but will be at the expense of low down response.

[Chris32R]

If not i found the Greddy procams 264 with 9.7mm lift to work real nice compared to the poncams but ive only compared them in engines making at least another 50rwkw over the gtss so it not a real help but a good cam comparison nonetheless..

Did you have to do any head modifications to get the Greddy cams to fit?

I always thought the poncams type b was the biggest you could go without modifying the head?

[djr81]

For my 10 cents worth the type B cams suck teh balls.

If you have a proper look you get the following:

Open Closed Centreline

Stock cams

14 degree overlap (commonly modded to 20 degrees)

Intake 240 degrees 7 BTDC 53 ABDC 113 degrees

Exhaust 250 degrees 65 BBDC 7 ATDC 118 degrees

Tomei Poncam A

31 degree overlap

Intake 260 degrees 20 BTDC 60 ABDC 110 degrees

Exhaust 252 degrees 61 BBDC 11 ATDC 115 degrees

Tomei Poncam B

35 degree overlap (modded to 33 degrees)

Intake 260 degrees 20 BTDC 60 ABDC 110 degrees

Exhaust 260 degrees 65 BBDC 15 ATDC 115 degrees

Note the only difference between type A & B is the exhaust cam. Having reverted from the type B to a smaller inlet & exhaust cam the thing goes much, much harder at 4000rpm without giving up anything worth worrying about at the top end when running approx 1 bar on 2860-5's.

But for what it is worth the type B's idle fine. The most common reason the RB26 will hunt at idle with them in is you have the idle screw adjusted too far out.

Lastly I wouldn't bother doing cams until you have the motor out. Only then is it worth thinking about.