rb30neo Ultimate street response

[AngryRB]

39 minutes ago, Dose Pipe Sutututu said:

Didn't you mention your VCT is cooked? I would be focusing my energy on fixing that.

It still works but its become noisy so ive stopped driving it.  

 

 

 

[AngryRB]

I emailed kelford and tighe cams, kelford just say that there cams wouldnt be any better but also say they can give stock like response whatever that means.. but i was expecting more depth and enthusiasm in the reply which is disappointing if they are experts in there field...

Tighe cams didnt respond at all... so after much reading of sau threads it would seem that lift is important but duration should be kept stock or to a 250deg..  

Info on cams is a bit hit and miss really and i beleive there is a sweet spot to be found.. so my current thought is i will try a set of 250deg 9.15lift from japan cause i have little faith in companies that give short or no responses... japanese atleast are passionate about engines it seems...

So maybe ill be the ginnea pig and give a direct comparison of 252 vs 260 on an RB3025... as i think stock cams lack lift to get max area under curve... 

Will also try advance a 252 intake..

Im out til is done.. cheers

 

 

[niZmO_Man]

Paging Piggaz lol

[Dose Pipe Sutututu]

keep your Poncams, fix your VCT, get a twin scroll rear housing, twin scroll manifold and enjoy car

[AngryRB]

52 minutes ago, Dose Pipe Sutututu said:

keep your Poncams, fix your VCT, get a twin scroll rear housing, twin scroll manifold and enjoy car

I had the twin scroll setup on RB25, it wasnt very impressive, alot of stuffing around and expense compared to a cam swap..

[Bond]

Why not just get a pair of stock cams for next to nothing and just see if you like the response and go from there? Also fix the VCT. Cheap option.

Edited July 12, 2018 by Bond

[discopotato03]

I agree with this .

I think you need to consider what people have achieved with the standard Neo turbo cams . Its great to theorise about valve lift but that's only one part of the camshaft story .

252 Neo Poncams are still going to have too much overlap for an engine you want to make good part throttle power with IMO . If it were me , and I wanted your preferences and had coin to spend , I'd consider using slightly oversized valves to make it breathe better and be nice all round .

If you want to see things from a factory perspective you could look at 1JZ vs 2JZ turbo cams because its sort of similar deal to 25DET vs 30DET . I haven't done this but I'm pretty sure 2JZ turbo cams don't look anything like Neo T Poncams - even the 252 9.15 ones .

  

[AngryRB]

Thanks for all the replies

The stock cams might be worth a go but then i lose lift so maybe weaken the         3.5-7K which is a fail...

So thinking if i can have the 260's ground back to like 244degrees or stock duration and would that make the ramp rate more aggressive..( i hear thats a good thing)

Tigh cams said they can reduce the duration but i dont know enough to understand how that affects overlap, ramp rates and what duration is the sweet spot.. 

Also, if duration is reduced too far eg 240, would i then have knock issues?

As i said from start, im only looking to improve response and shift curve to left, not lose any. 

Edited July 13, 2018 by AngryRB

[KiwiRS4T]

Sell the 260s get custom cams made to your requirements.

[fatz]

T51r

[AngryRB]

On 7/13/2018 at 6:37 PM, discopotato03 said:

I agree with this .

I think you need to consider what people have achieved with the standard Neo turbo cams . Its great to theorise about valve lift but that's only one part of the camshaft story .

252 Neo Poncams are still going to have too much overlap for an engine you want to make good part throttle power with IMO . If it were me , and I wanted your preferences and had coin to spend , I'd consider using slightly oversized valves to make it breathe better and be nice all round .

If you want to see things from a factory perspective you could look at 1JZ vs 2JZ turbo cams because its sort of similar deal to 25DET vs 30DET . I haven't done this but I'm pretty sure 2JZ turbo cams don't look anything like Neo T Poncams - even the 252 9.15 ones .

  

A few comparisons of other factory 3L factory cams but they have restrictive stock ex mani and lower comp probably.

2JZ has In 224 7.88 and Ex 233 8.4,

Z32 has In 248 8.5 Ex 248 8.5

Z33 has In 238 9.2 Ex 240 9.2

http://www.tomeiusa.com/_2003web-catalogue/e090_camshaft-specs.html

Neo cams are In 236 8.4 Ex 232 8.7 which are very close to RB26 cams, but neo has bit more lift.

The drop in duration from 240 in the r33 but extra lift is interesting as the compression was bumped up at same time.

I reckon the 260s are suited to 3500rpm onwards but at typical road conditions does rob response.  I noticed now that at 2k and accelerating out a corner im pretty sure its starting to surge.. makes a fluttering sound, that plus has always been hard to drive at a crawl or cruise as it jerks.. 

If this is reversion then the right duration will likely make a notable difference in response and drivability..

Be interesting to drive a 2JZ, they some low duration cams..

 

 

 

 

[dr phil]

R33 and R34 RB25DET are same 9:1 comp ratio. R34 has less cc in the head but also less dome in the piston.

 

[Dose Pipe Sutututu]

Convert to TS, fix VCT, retard the exhaust cam by maybe 2~3 degrees - Good power band, good response, rip skids, call it a day

[tridentt150v]

Look down.....on the left hand side of the drivers seat is a thing called a gear lever.....if you master how to use this then you can increase your street response without affecting top end power!!!

Seriously you are trying to split the atom....you already have a great motor and setup.  If that's not enough then try the std cams and reco'ed VCT like everyone suggests before selling any kidneys and buying stuff!!!