RB26 Cam Question

[FLYSKY]

I am not that familar as cams goes so i am just asking for some advice on some cams.

i was thinking on some Mine's cam 252° IN/EX 10.05

http://www.mines-wave.com/JP/CATALOG/P_Eg_CAMSHAFT_SHORE_Pro2.html

but those r pretty expensive so i've also thought about some JUN bolt on Cams

http://www.junauto.co.jp/products/cylinderhead-part/camshaft/camshaft-rb26.en.html

can somebody tell me the differences for those cams and how they would work?

will be a light build engine for most street use, HKS GT2530 turbo's planned, turbine outlet pipes, front pipe, 600cc injectors,..
lookin for ~ 500 - 600hp

[Harvey]

I would go with Jun 264 in/EX with 9.15 lift. They will simply bolt on and work well with OEM valve train. OR you can go with Tomei pon cams Type B with 260in/ex also with 9.15 lift. http://www.tomei-p.co.jp/_2003web-ca...haft_rset.html They are pretty reasonable in price as well. According to what tomei says the type B pon cams will be the best choice. or You can go Jun since they have similar specs. You will probably need to upgrade you valve train ($$$$) with the Mines cams.

[cobrAA]

I thought tomei was the only maker with bolt-on cams. owever, I'm wondering what 4 degrees of duration can really do to an engine of 450-500whp.

[Phastwon]

Stock cams are something like 248Deg and 8.5mm lift. So the mines with 10.05mm are opening a lot farther over the duration and restricting airflow less. I am running 264Deg 10.2mm lift HKS step 2 items. Anything over 10mm lift you are going to have to machine the head for clearance.

[GTR-Dad]

I run Jun 264/264 - 9.7 mm lift cams with all the other efficiency mods to remove airflow bottlenecks. Last season it dyno'd at 525 AWHP at 17 psi.
Dan

[FLYSKY]

thx for the Informations.

How does the cams exactly work and how do i know what the best cam would be for my engine?
from what i know how cams work is that the power in the low rpm section will be decrease a lil but the power in the higher rpm will be increase, so a friend recommented me if i change the cams i also should use a short transmission and rais the rpm to be faster with keeping the shift speed.

So if i want to go for about 500 - 600hp with HKS GT2530 i guess i shouldnt take the 248° Cams of JUN if they seem to be nearly like the stock cams with 8.8 lift but how about with the 9.15 lift?
how would i feel the differences with those cam specs?

JUN 248 IN/EX 9.15

JUN 256 IN/EX 9.15
JUN 264 IN/EX 9.15



TOMEI
Poncam
Type A 260 IN 9.15 - 252 EX 9.15
Type B 260 IN/EX 9.15
Poncam Type R
250 IN/EX 9.15

[FLYSKY]

I run Jun 264/264 - 9.7 mm lift cams with all the other efficiency mods to remove airflow bottlenecks. Last season it dyno'd at 525 AWHP at 17 psi.
Dan

what other mods have u got on u're car?

[GTRADDICT]

what other mods have u got on u're car?

His car is the envy of twin gtr's! 525 awhp on -5's @ 17 psi. Are you going for more? Not that you don't have enough!

[GTR-Dad]

what other mods have u got on u're car?

Following the airflow...
HKS Hard pipe intake
GT2860R-5 twins
Really decent FMIC - forget make/model
OEM intake plenum - ITB intact
Ported intake - surface left rough to promote mixing
JUN 264/265 x 9.7mm lift cams
OEM valves on previous tune (soon to be oversized Ferrea's with titanium retainers and suitable springs - 9000 rpm capable)
Ported exhaust - opened up, port matched to OEM exhaust mani (soon to be Tomei extreme) and polished
HKS dumps
Tomei downpipe
HKS exhaust

Supporting mods need to be in place to support the power, but these are the airflow improvements.

Are you going for more? Not that you don't have enough!

I doubt I'll tune to much more boost than last year, but I might rev higher with the new valvetrain. If I end up with more power lower down, I'll take it.
The nice thing about the setup I'm running is that power comes on very linearly and quite early in the rev band (considering the peak power) so drivability is really acceptable on the street and easy to handle on the circuit.

Oh, and I see it was 17.5 psi. Memory must be going...

Dan

[Bruizer]

I'd suggest smaller turbos ( like -7s or GT-SS or R34 N1s) and type A tomei cams, good for 500whp and LOTS of response!!!

Oh, if you have to do air care and have issues, tomei has type R cams which are easier to pass.

[FLYSKY]

aren't the -7 R34 GTR N1 one's?

[LuckyGTR]

yeah ! thats what i drive 502 whp at 18.5 psi wit n1 and grex cams alot alot of other goodies way to long to write lol

[FLYSKY]

i think that i will take Tomei Type B Poncam 260° IN/EX 9.15mm but still not sure about the turbo's i wanna run, i would like 2 get HKS GT2530 but i guess Garrett GT2860R -5 r pretty close to them and r not that expensive but i am also wondering how -7 would do on RB26.
I've heard -5 for quicker spool and -7 for more top end or so

[allwheeldrifter]

I've heard -5 for quicker spool and -7 for more top end or so

i heard the opposite

[FLYSKY]

dont know what was for what now but the one was for spool and the other for top end