Rb26 Question

[donkey]

hello there,

rb26 garrett -5's, with all the other bits and pieces

would anyone like to help me out with advice on when it is a good time to change the ol' cams,

i have about 320AWKW at 18lbs, going to wind boost to about 20lbs for a bit, and was thinking the next step would be cams? if so what is the pick of the bunch for low down power/torque? i see poncams seem to be one of the fav choices,

what roughly AWKW does it make sense to upgade?

thanks for any help

[Bakes]

Dont think you need them at that power level. Cars with 400AWKW seem to have them done.

[donkey]

  Bakes said:

Dont think you need them at that power level. Cars with 400AWKW seem to have them done.

yeah have read on this forum about not needing to touch them to around that power, but some others say they are a great updrade for low down power?

[Swiper the Fox]

  donkey said:

yeah have read on this forum about not needing to touch them to around that power, but some others say they are a great updrade for low down power?

For that power and stock rev limit cams are a waste of $$ and will do nothing for low down power.

Cam gears on stockers works well though...ive had great results with them.

[Bakes]

If you havent got cam gears already there is a group buy coming up for Tomei Cam Gears, very cheap. Go to the Group Buys Section.

[donkey]

hey thanks for advice, yeah cam gears was one of the first mods i got

[Swiper the Fox]

  donkey said:

hey thanks for advice, yeah cam gears was one of the first mods i got

how/where are they set to?

[rev210]

  DiRTgarage said:

For that power and stock rev limit cams are a waste of $$ and will do nothing for low down power.

Cam gears on stockers works well though...ive had great results with them.

The cam gears alone are great value. Even on stock turbos.

I understand the standard cams have a following with some reputable tuners. There are also a number of people who have upgraded and found better power delivery.

Whether it's the -5's or even stock turbos, taking the tuner as your guide is the best bet. If they are sure of the stock cam optimum setup then go with that and you get the best value.

Personally, on the unported head standard motor, I would take the pepsi challenge any day to get more power everywhere over well adjusted stock cams with a set of tomei poncams. However it took quite a bit of fiddling on the dyno last time to get the best out of them (mates rates dyno though).

I'll be giving the tomei cam upgrade a go again shortly and this time I will get the settings down for others to draw from.

[donkey]

hmmm, was going to get the boost turned up to 20lbs and see how that feels (on standard internal motor, rev limit 7500, have a profect b so will also run 15lbs) am a lil bored on 320 AWKW, dont know how much power 20lbs will produce, but im sure more then enough for me, then when motor gets tired go forged rebuild but maybe just leave the cams?

ps. sorry dont know what cams are dialled too

Edited January 11, 2009 by donkey

[Swiper the Fox]

  rev210 said:

The cam gears alone are great value. Even on stock turbos.

I understand the standard cams have a following with some reputable tuners. There are also a number of people who have upgraded and found better power delivery.

Whether it's the -5's or even stock turbos, taking the tuner as your guide is the best bet. If they are sure of the stock cam optimum setup then go with that and you get the best value.

Personally, on the unported head standard motor, I would take the pepsi challenge any day to get more power everywhere over well adjusted stock cams with a set of tomei poncams. However it took quite a bit of fiddling on the dyno last time to get the best out of them (mates rates dyno though).

I'll be giving the tomei cam upgrade a go again shortly and this time I will get the settings down for others to draw from.

I have actually witnessed in person on two cars that have removed poncams ONLY and lost only a couple of top-end KW but gained everywhere else in the rev range by refitting and dialing in stockers. Both cars had two different low mount turbo combinations...but to help your point i dont believe that the poncams were dialed into optimum position (well lets just say they werent set where i would run them).

[donkey]

i think i will just stick with the standard cams, really dont want to through away thousands of dollars for not much gain, im looking for torque not massive KW's

[Swiper the Fox]

  donkey said:

i think i will just stick with the standard cams, really dont want to through away thousands of dollars for not much gain, im looking for torque not massive KW's

again...where are the vernier gears set to at the moment?

[rev210]

  DiRTgarage said:

I have actually witnessed in person on two cars that have removed poncams ONLY and lost only a couple of top-end KW but gained everywhere else in the rev range by refitting and dialing in stockers. Both cars had two different low mount turbo combinations...but to help your point i dont believe that the poncams were dialed into optimum position (well lets just say they werent set where i would run them).

Yeah I've heard of a few more as well that have talked about poncams not getting the width of power like that.

I wonder if it is to do with the setting of the cams as you mention or if there is also some overcamming / profile mismatch going on if these examples are ones being ported /rebuilt motors . I think regardless that the off the shelf limitations we have with the RB's puts all engine setups at some sort of compromise. We don't have access to the variety of profiles or custom grind's other motors have. It is possible that the off the shelf Tomei's are optimised for stock head dynamics.

I've done the stocker dial in also and I'm a big fan of it as a great budget mod, you pick up power everywhere and the settings are pretty well established for the average motor.

The experience I had with the Tomei units however, made me a convert. I gained more power from as low as 3,000 rpm up. From 3,000rpm onwards I had a better power band than the best stock cam cam gear adjusted car dyno I've seen and by alot down low. My brother who is a big block hemi fan , I let drive the car before and after, was shocked by the pull the car had from the cams final setup, such that he commented he may have to buy a GTR.

[Swiper the Fox]

  rev210 said:

Yeah I've heard of a few more as well that have talked about poncams not getting the width of power like that.

I wonder if it is to do with the setting of the cams as you mention or if there is also some overcamming / profile mismatch going on if these examples are ones being ported /rebuilt motors . I think regardless that the off the shelf limitations we have with the RB's puts all engine setups at some sort of compromise. We don't have access to the variety of profiles or custom grind's other motors have. It is possible that the off the shelf Tomei's are optimised for stock head dynamics.

I've done the stocker dial in also and I'm a big fan of it as a great budget mod, you pick up power everywhere and the settings are pretty well established for the average motor.

The experience I had with the Tomei units however, made me a convert. I gained more power from as low as 3,000 rpm up. From 3,000rpm onwards I had a better power band than the best stock cam cam gear adjusted car dyno I've seen and by alot down low. My brother who is a big block hemi fan , I let drive the car before and after, was shocked by the pull the car had from the cams final setup, such that he commented he may have to buy a GTR.

how far did you retard the exhaust cam?

[donkey]

  DiRTgarage said:

again...where are the vernier gears set to at the moment?

again im sorry have no idea where they are set? can ask my mechanic

[rev210]

  DiRTgarage said:

how far did you retard the exhaust cam?

Hi, I found the scibblles in my pile o junk after a bit of a look. The exhaust timing was set to 8 degrees retard. Intake to 4 advanced.

[Swiper the Fox]

  rev210 said:

Hi, I found the scibblles in my pile o junk after a bit of a look. The exhaust timing was set to 8 degrees retard. Intake to 4 advanced.

thats a co-incidence

[rev210]

  DiRTgarage said:

thats a co-incidence

Ah you have tried this setting too?

I'm not 100% that's the setting I wound up with but, it was written down on a bit of paper that I was using for notes on the car at the dyno.

The cams were R34 units in an R32 as well, with my rather dodgy looking standard R32 CAS modification

[Swiper the Fox]

  rev210 said:

Ah you have tried this setting too?

I'm not 100% that's the setting I wound up with but, it was written down on a bit of paper that I was using for notes on the car at the dyno.

The cams were R34 units in an R32 as well, with my rather dodgy looking standard R32 CAS modification

Yeah i found that stockers worked the best there with overall gains...yes everywhere!

[R33GTRKid]

so if i had poncams with GTSS in an otherwise stock 26, would I dial in at 4,-8 also?