Jump to content
SAU Community

Dialing In Poncams On Rb30dett

James_03

By James_03,
in Engines & Forced Induction

 Share

Recommended Posts

James_03 Mentor

James_03

Posted
Posted

Hey guys,

Last weekend I removed my standard gtr camshafts and replaced them with a set of 260 poncams on my rb30dett. I have them at 0 inlet 0 exhaust at the moment. The power delivery is ok, but definately better with the standard gtr cams. I also cannot get it to idle anymore with it hunting back and forth 200rpm then eventually stalling, is it normal to loose the ability for it to idle?

I know that a tune will more than likely need to take place now, but just curious to see if people have had better success with these cams by dialing them in using a different setting other than 0,0?

How much is the tune dependant on taking advantage of the cams? I just want to know if there is anything I can do to improve response/idle without playing with the tune.

Basically my worry is that I will have to cough for another dyno run just to get my stable idle back, and I just don't know if the gains are going to be worth it, especially if the whole tune will need to be done again.

The tune I have now with the gtr cams is very good and somewhat refined now, it spat out 250rwkw on 14psi, and response was great.

Link to comment
https://www.sau.com.au/forums/topic/278926-dialing-in-poncams-on-rb30dett/
Share on other sites
James_03 Mentor

James_03

Posted
  • Author
Posted

Yeah that's cool. I didn't think the change in 260's would be drastic enough to leave me with no idle but :D

Makes sense but all the same.

Ill just leave them at 0,0 and get another tune on it then. I searched yesterday and a couple of ppl had posted recommending +2 in -4 ex, so I thought it was worth asking.

Sydneykid Grand Master

Sydneykid

Posted
Posted

Generally with Poncams the 0/0 ends up being the best all round position. The -2/+4 ends up with slightly more torque due to slightly more boost at slightly lower rpm. Note the multiple use of the word "slightly", it's generaly not dramatic, but it is noticeable. Of course you get nothing for nothing, you will sacrifice a slight (that word again) amount of top end.

Cheers

Gary

James_03 Mentor

James_03

Posted
  • Author
Posted
Generally with Poncams the 0/0 ends up being the best all round position. The -2/+4 ends up with slightly more torque due to slightly more boost at slightly lower rpm. Note the multiple use of the word "slightly", it's generaly not dramatic, but it is noticeable. Of course you get nothing for nothing, you will sacrifice a slight (that word again) amount of top end.

Cheers

Gary

Thanks for that Gary, info I was after.

Sydneykid Grand Master

Sydneykid

Posted
Posted
Degreeing them properly would be a good start.

http://www.skylinesaustralia.com/forums/De...ts-t240804.html

Please Paul, help me out here with what that actually achieves? I set the cams at a perfect 0 then I stick the car on the dyno and move the cam timing around till I get the desired result. So why does it matter where I started from (perfect 0) when all that I am interested in is getting the power curve on the dyno that I want? I can understand the process for a control engine, say Formual Ford or Formula 3, where it is important to precisely duplicate the desired cam timing. But the reason for spending time so much time and effort getting it perfect only to go and change it escapes me.

Cheers

Gary

  • 2 weeks later...
Dale FZ1 Veteran

Dale FZ1

Posted
Posted (edited)

Question directed at both Gary and Paul:

running a 25 head with custom grind non-VVT cams and hydraulic lifters

Is the process in dialing the cams in any different, or any more (or less) worthwhile than with solid lifters?

A mate suggested that the hydraulic setup introduces a level of imprecision not experienced once a solid setup is used. His suggestion is to follow the route advocated by Gary, while I'd steered towards making the adjustments while the engine is still on a stand and access easy.

As always it's a different path towards the same/similar end, but interested whether hydraulics tend to confound attempts to get them dialed in by conventional means.

Edited by Dale FZ1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • soviet_merlin
      Duncan's V37.......race car?

      By soviet_merlin · Posted

      Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
    • Murray_Calavera
      Jacks that fit under GTR lips that can reach the subframe?

      By Murray_Calavera · Posted

      My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Duncan
      Chris' Toyota Mark ii JZX110

      By Duncan · Posted

      Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
    • Duncan
      Jacks that fit under GTR lips that can reach the subframe?

      By Duncan · Posted

      BTW I measured the jack I have, it is 70mm at the saddle but you only have about 700 until it returns to 150mm high at the cylinder so it is good but no magic bullet.
×
×
  • Create New...