R34 Rb25 Neo Valvesprings And Hardware?

[CHRIS MW33]

8 minutes ago, admS15 said:

Dude you said on the previous page drag only and daily. Wtf. So if you intend on driving it at all on the road you would be a fool to remove vct. Clearly u have your mind made up. Good luck to you but my crystal ball says that you'll look back in the future and think those guys where right. So, will this thing be driven on the street or not? That should be what your decision is based around. Also vct will not hurt performance on the drag strip.

Sorry I daily My Car to work on the highway for about 10mins and park. It will drive on the highway and back home. Rest is drag racing. 

No love lost to vct.

Rb26 had no vct and their large cams don't kill the driving experience.

but for me it can go. U can keep yours. I have 2 engines with vct I will take one off and put in larger cams.

[Dose Pipe Sutututu]

RB26 motors are rubbish thus people for HKS VCAM to them.

Also like I said earlier you can adjust the VCT cut off point. It's not fixed at 4700rpm and can be raised till torque starts to decay heavily. FWIW if you bother to absorb any useful information, my VCT is set to turn off at 5500rpm.

You sound like you're American like what I said in the PM.

[CHRIS MW33]

According to you.

Ur mind is set similar.... Let's agree to disagree. Not many Ppl can agree with Rb26 being rubbish. But maybe I need an American to say different. Japs put rubbish in the gtr. Smh

I have tried the shut off at higher rpm 4700rpm was still best.

no diss bud but theres more than one way to skin a cat

[Dose Pipe Sutututu]

You obviously don't tune cars nor have any knowledge of how-to operate a dyno.

[CHRIS MW33]

14 minutes ago, Dose Pipe Sutututu said:

You obviously don't tune cars nor have any knowledge of how-to operate a dyno.

I do tune cars but no I don't use an accurate dyno. I use virtual Dyno. 

but show me one drag car using vcam that does well and I will retain vct. 

You are thinking of time attack and circuit racing, how many drag cars have you tuned that actually utilize vct?  

no need to try to be disrespectful.

As I said let's agree to disagree.

and lets continue to enjoy the awesome forum.

[Guilt-Toy]

2 hours ago, CHRIS MW33 said:

I do tune cars but no I don't use an accurate dyno. I use virtual Dyno. 

but show me one drag car using vcam that does well and I will retain vct. 

You are thinking of time attack and circuit racing, how many drag cars have you tuned that actually utilize vct?  

no need to try to be disrespectful.

As I said let's agree to disagree.

and lets continue to enjoy the awesome forum.

I find it easier to just ignore that jokers posts,  but sometimes he comes up with some classics like this one to keep us entertained,  lol I nearly fell off my chair for that one.

[CHRIS MW33]

why did it not just read SAU non drag forum? simply conform to a box of not knowing. my last dyno made 476hp very close to virtual dyno results. i simply use the tool and compare results.

does anyone ever remove vct in this forum? restricted to one type of cam the 260 9.1 poncam.............

let me out the box.....i dont want to be confined mentally. 

thanks

[CHRIS MW33]

i will ask again where is your vct shut off point compared to the rpm range your recovery rpm after an up shift? with regards a drag situation.

 

[Lithium]

9 hours ago, CHRIS MW33 said:

but show me one drag car using vcam that does well and I will retain vct. 

Not "V-Cam" but the exact same technology - does this count?

I'm not here for trolling at all, just from my perspective it looks like you have the wrong end of the stick so just doing due diligence and will leave you to it if you have considered everything and aren't compromising yourself due to not knowing.

I get the impression you are shooting for only 500hp?  If so, then comparing with "drag cars" etc is irrelevant - they NEED 9000rpm to achieve the flow and powerband required to get down the strip fast.  For 500hp from an RB25 you REALLY don't need those rpm, in fact you are making life very hard for yourself.   Realistically you can make 500hp with the Tomei VCT friendly cams and a turbo which is on at a point where VCT is VERY helpful to drag racing as well as drivability as well as making it easier to launch and keep everything on steam.   Fwiw I've not tuned an RB25 where the optimal VCT turn off point is at all as low as 4700rpm.  The fact you said that "4700rpm" change over point is optimal for all cams and situations is what triggered me to suspect your knowledge on these motors and tuning is such that you may be spending much more money and making a much more "difficult" build for yourself than you need to be to achieve the power targets you are after.

If you are actually aiming for something WAY north of that then things make more sense, or alternately if know you are building something much laggier and more unreliable than you need to for those results then sweet as - I just like to see people put their money and effort into something they don't regret, so just pointing it out that for 500hp these days you don't have to have everything happening >5000rpm and have something with no VCT and potential for suspect reliability to achieve that.

[iruvyouskyrine]

I make over 500 Australian HP and use the baby Neo cams (232/232 IIRC) and as such retain VCT. I really don't know why people delete VCT from RB25's when shooting for anything less than 600 HP

[Kinkstaah]

Yeah, for what you are asking there is no benefit, none at all, to even consider changing the stock cam.
And ABSOLUTELY NEVER removing VCT.

I mean, sure if you have a 5000RPM stall converter in the car, and you rev it to the point where VCT disengages naturally there may be no benefit of VCT... but if you spend any time below the disengage point, you will get benefit from it, and if you pick up 1 or 2 tenths anywhere I can't imagine a situation you'd want it more than in a drag application

[CHRIS MW33]

2 hours ago, Lithium said:

Not "V-Cam" but the exact same technology - does this count?

I'm not here for trolling at all, just from my perspective it looks like you have the wrong end of the stick so just doing due diligence and will leave you to it if you have considered everything and aren't compromising yourself due to not knowing.

I get the impression you are shooting for only 500hp?  If so, then comparing with "drag cars" etc is irrelevant - they NEED 9000rpm to achieve the flow and powerband required to get down the strip fast.  For 500hp from an RB25 you REALLY don't need those rpm, in fact you are making life very hard for yourself.   Realistically you can make 500hp with the Tomei VCT friendly cams and a turbo which is on at a point where VCT is VERY helpful to drag racing as well as drivability as well as making it easier to launch and keep everything on steam.   Fwiw I've not tuned an RB25 where the optimal VCT turn off point is at all as low as 4700rpm.  The fact you said that "4700rpm" change over point is optimal for all cams and situations is what triggered me to suspect your knowledge on these motors and tuning is such that you may be spending much more money and making a much more "difficult" build for yourself than you need to be to achieve the power targets you are after.

If you are actually aiming for something WAY north of that then things make more sense, or alternately if know you are building something much laggier and more unreliable than you need to for those results then sweet as - I just like to see people put their money and effort into something they don't regret, so just pointing it out that for 500hp these days you don't have to have everything happening >5000rpm and have something with no VCT and potential for suspect reliability to achieve that.

thanks right now im making 476hp i am looking to make more. i want more rpm, full boost is at 5.5k rpm a shift point is 8k right now. when i shift it is above 5.5k rpm so no vct.

i have the s2 engine in currently but i have heard the neo is better i will try same components on the neo and see the results.

 

thanks

[CHRIS MW33]

1 hour ago, iruvyouskyrine said:

I make over 500 Australian HP and use the baby Neo cams (232/232 IIRC) and as such retain VCT. I really don't know why people delete VCT from RB25's when shooting for anything less than 600 HP

thanks similar im making about that much with s2 engine and cams with vct slightly more duration with less lift.. thanks

[CHRIS MW33]

Just now, Kinkstaah said:

Yeah, for what you are asking there is no benefit, none at all, to even consider changing the stock cam.
And ABSOLUTELY NEVER removing VCT.

I mean, sure if you have a 5000RPM stall converter in the car, and you rev it to the point where VCT disengages naturally there may be no benefit of VCT... but if you spend any time below the disengage point, you will get benefit from it, and if you pick up 1 or 2 tenths anywhere I can't imagine a situation you'd want it more than in a drag application

lol thanks understood.maybe a miss change, i got u will consider. 

[Lithium]

11 minutes ago, CHRIS MW33 said:

thanks right now im making 476hp i am looking to make more. i want more rpm, full boost is at 5.5k rpm a shift point is 8k right now. when i shift it is above 5.5k rpm so no vct.

OK - if you are aiming for the kind of power a turbo which makes full boost that late makes then the cams/no VCT discussion makes more sense.  Again, was just doing my due diligence
 

[CHRIS MW33]

Just now, Lithium said:

OK - if you are aiming for the kind of power a turbo which makes full boost that late makes then the cams/no VCT discussion makes more sense.  Again, was just doing my due diligence
 

understood 

thanks for the input

[Guilt-Toy]

6 hours ago, CHRIS MW33 said:

understood 

thanks for the input

You are more then welcome on these forums mate,  and what you are saying makes sense to me,  I totally agree with you 100% that VCT is not needed on a setup like yours to get down the drag strip fast.

Once you are off the 2 step and powering down the track the VCT would be of no benefit at all on a 9krpm 900hp drag engine.

You mentioned that you have been playing with the virtual dyno,  out of interest how close did you get?  any pics of the results of a dyno run and the virtual plot?

A dyno is just a tuning tool,  and just because you have a dyno or know how to use one does not mean you are automatically a good tuner,  Shane T who I have met in person can punch out amazing tunes remotely without a dyno with his advanced knowledge of how to process his datalogs.  

 

[Lithium]

13 hours ago, Guilt-Toy said:

A dyno is just a tuning tool,  and just because you have a dyno or know how to use one does not mean you are automatically a good tuner,  Shane T who I have met in person can punch out amazing tunes remotely without a dyno with his advanced knowledge of how to process his datalogs.  

Exactly.  And Shane = advanced knowledge on basically everything he is working with, not just processing the datalogs.... I've had some pretty extensive conversations with him over the years and there is so much which happens before the engine is even fired and run to the point there is any data.  One of his strengths is despite the sheer guru/legend level he has reached he doesn't assume he is always going to be right, but tries his best to be - and he seems more open minded to that than people I've observed whose approach to tuning looks from my angle like drunk people trying fight an out of control fire.

What blows me away is so many people lack so much fundamental knowledge - they often see a few patterns without understanding, or trying to understand the underlying things which cause those patterns and try and apply them to everything they see without context and it results in bad advice and general "wisdom" being shared. 

We're all learning, guys.  Don't jump on everyone who says something which doesn't agree with your preference, experience or what you think you know.

Edited June 21, 2017 by Lithium

[discopotato03]

Just a couple of thoughts that come to mind - just thinking out loud .

I would have thought that a hydraulic bucket RB25 would be the least desirable version to take drag racing . I'm under the impression that hydro buckets are a low maint production item that don't lend themselves to high rev use . I can see value in using aftermarket plain buckets and shims - and cams to suit .

Basically it isn't really a 33 series top end then . If you can find one a Neo RB25T engine is better as in shim over bucket valve train but even they aren't something I'd like to regularly rev to 8000 plus . In std form Neo turbo's have better rods and pistons than R32/33 RB25Ts .

Imo the 26 valve train was the one that could take the most revs and be reliable , of course extra work to service shim under bucket valve trains . Also the 26 six throttle inlet is the way to have minimum pressure drop on the cold side .

What people are trying to tell you is that to have your approx 500 Hp and a usefull rev range , valve train rev limited , is to keep the VCT . If you set a sane rev limit of say 7500 and want a 4000 useful rev span then its going to need to be taking off at 3500 revs . I guess its easy to look at it from a revs going up to sky perspective but I kind of like seeing it from the top down rather than the mid rev range up . 

From what I read the hydraulic 25s don't cope well with lots of cam lift so to get the upper end breathing they use extended duration . Trouble is you reduce the usable rev range because it wakes up later - closer to a sane rev ceiling . The Neos can stand more aggressive lift ramps so (in theory) get better breathing with a bit more lift and a bit less duration .

Anyway theorizing aside if you wanted a high rev capable RB then IMO the RB26 , head anyway , is a better basis to start with . With 25s the Neos were the latest and more highly developed versions that made more power more reliably than the R33 version .

Just my take and my 2c spent .

[CHRIS MW33]

9 minutes ago, discopotato03 said:

Just a couple of thoughts that come to mind - just thinking out loud .

I would have thought that a hydraulic bucket RB25 would be the least desirable version to take drag racing . I'm under the impression that hydro buckets are a low maint production item that don't lend themselves to high rev use . I can see value in using aftermarket plain buckets and shims - and cams to suit .

Basically it isn't really a 33 series top end then . If you can find one a Neo RB25T engine is better as in shim over bucket valve train but even they aren't something I'd like to regularly rev to 8000 plus . In std form Neo turbo's have better rods and pistons than R32/33 RB25Ts .

Imo the 26 valve train was the one that could take the most revs and be reliable , of course extra work to service shim under bucket valve trains . Also the 26 six throttle inlet is the way to have minimum pressure drop on the cold side .

What people are trying to tell you is that to have your approx 500 Hp and a usefull rev range , valve train rev limited , is to keep the VCT . If you set a sane rev limit of say 7500 and want a 4000 useful rev span then its going to need to be taking off at 3500 revs . I guess its easy to look at it from a revs going up to sky perspective but I kind of like seeing it from the top down rather than the mid rev range up . 

From what I read the hydraulic 25s don't cope well with lots of cam lift so to get the upper end breathing they use extended duration . Trouble is you reduce the usable rev range because it wakes up later - closer to a sane rev ceiling . The Neos can stand more aggressive lift ramps so (in theory) get better breathing with a bit more lift and a bit less duration .

Anyway theorizing aside if you wanted a high rev capable RB then IMO the RB26 , head anyway , is a better basis to start with . With 25s the Neos were the latest and more highly developed versions that made more power more reliably than the R33 version .

Just my take and my 2c spent .

thank I have a neo in my garage, to install however I want to do mods while it's out one time should be looking to install in about 3 months. The s2 is currently in revs 8200 no issues but obviously I only do on drag days.

good advice