RB25 Tomei 256 poncams vs HKS 256/264

[LaurelPWR]

Hey guys. Apologies in advance for the age old topic and question, but I'm having a very hard time finding any of the old threads and results on SAU about this and other skyline forums aren't much help either. Even google search results aren't yielding any solid information.

 

What I want to know is, how do the rb25 s1/2 HKS 256 8.8 / 264 9.0 "drop in" cams compare to Tomei 256 8.5 / 256 8.5 pon cams as far as boost response is concerned ??

I currently use the poncams and I'm wondering if I install a set of the hks or even just a hks exhaust cam, can I gain a little more mid range and peak without loosing any response...

 

The only sort of info I have been finding is people speculating about a set up they "know of" or "a mates car used these and made heaps of power"...

Obviously a before and after dyno comparison on a same car, same dyno & same day with the two different brand of cams would be ideal but I highly doubt that info is out there..

 

My set up is s1 rb25 with HKS 2835 pro S .87a/r internally gated on e85 making 470whp on 24psi

 

Any links of help is greatly appreciated lads [emoji1365]

 

[klutched]

Maybe wait for Kelfords new cam coming out soon Might be a little bit big for you though.

[GTSBoy]

I was going to say....why bugger about with the brand name Jap cams when Kelford and even Camtech have excellent choices and local support?

[Lithium]

2 hours ago, klutched said:

Maybe wait for Kelfords new cam coming out soon Might be a little bit big for you though.

What new cam?  Got any more info than that?

[LaurelPWR]

I was going to say....why bugger about with the brand name Jap cams when Kelford and even Camtech have excellent choices and local support?

 

 

I'm open to any and all brands if I can retain VCT and keep my current responsiveness !!!!!

Please feel free to school me (:

[klutched]

1 hour ago, Lithium said:

What new cam?  Got any more info than that?

I'll be running them in my new motor. Still about a month away from being available. They're a 264/272 10mm VCT combo! They should be an awesome cam if you're chasing decent numbers. First cam that I know of that is more than 9mm lift while still retaining VCT. 

Downside is it's obviously not going to be a drop in cam with 10mm lift, so head clearancing will be required. 

[Komdotkom]

I just put a set of Kelfords in mine, let me know if you want a set of HKS 256/264 cheap.

[LaurelPWR]

I just put a set of Kelfords in mine, let me know if you want a set of HKS 256/264 cheap.

Ok thanks mate
You have Pm

[LaurelPWR]

I'll be running them in my new motor. Still about a month away from being available. They're a 264/272 10mm VCT combo! They should be an awesome cam if you're chasing decent numbers. First cam that I know of that is more than 9mm lift while still retaining VCT. 
Downside is it's obviously not going to be a drop in cam with 10mm lift, so head clearancing will be required. 

Very interested to see what you get out of those [emoji848]

[LaurelPWR]

These results from the RB25 dyno thread are pretty decent as far as response is concerned and that's a pretty decent top end figure too for that boost level on only 23psi & p98 fuel [emoji848]
looks very poncam-like.

I guess hub dyno results are a little stretched tho..

[Lithium]

That's a really good result, even on a hubber.  Nice!   

[LaurelPWR]

That's a really good result, even on a hubber.  Nice!   

What do you think Lith, can I keep my current response and get some small gains with the hks drop ins?

[LaurelPWR]

Another set of old results from the RB25 dyno thread that look quite promising for poncam-like response with a decent top end for the given turbo/boost and fuel.

Starting to think I I may be able to realise my girl [emoji848]

[LaurelPWR]

Another set of old results from the RB25 dyno thread that look quite promising for poncam-like response with a decent top end for the given turbo/boost and fuel.

Starting to think I I may be able to realise my girl [emoji848]

Better pic of the dyno without the power figures cut off...

[LaurelPWR]

Here's another very similar result:

[klutched]

This is my graph, ran 11.6 @126mph with manual, 11.2 @124mph with powerglide (did run a 126mph).

RB25DET, Tomei HG, ARP Headstuds, Gt3076r-wg, Tomei 256 drop ins, Custom 3" dump, decat, 3" cat back with muffler, 45mm Hypergate, CRG Manifold.

[LaurelPWR]

This is my graph, ran 11.6 @126mph with manual, 11.2 @124mph with powerglide (did run a 126mph).
RB25DET, Tomei HG, ARP Headstuds, Gt3076r-wg, Tomei 256 drop ins, Custom 3" dump, decat, 3" cat back with muffler, 45mm Hypergate, CRG Manifold.

Thanks for the post man. I'm only really after HKS 256/264 cam results though...
I have poncams now and theres literally hundreds of poncam results around the net.

Is your turbo internal gate?

[GTSBoy]

I think this obsession over the specific brand of cam is a bit odd.  Regardless of whether there was some interesting differences in the profiles between the HKS cams and the Poncams at the same ~256° duration, the fact remains that they are both 256° and there are a million other things that influence what the dyno curves and 400 times will come out looking like.  Things like how they've been dialled in, exhaust manifold, turbo choice, and a bunch of others are going to be far far more significant than the lobes on the cams.

[LaurelPWR]

I think this obsession over the specific brand of cam is a bit odd.  Regardless of whether there was some interesting differences in the profiles between the HKS cams and the Poncams at the same ~256° duration, the fact remains that they are both 256° and there are a million other things that influence what the dyno curves and 400 times will come out looking like.  Things like how they've been dialled in, exhaust manifold, turbo choice, and a bunch of others are going to be far far more significant than the lobes on the cams.

My question has nothing to do with the brand...
When I state the brand, I'm referring to the specs of that particular brand not the brand itself my dude.
Yes Tomei make 256 and so does HKS, but once again... I'm referring to the staggered 256/264 hks cams vs Tomei 256/256 so there is a difference and will be a certain characteristic relating each of the cam types in rb25 set ups that have same/same turbos and bolt ons as seen in the graphs I've posted above. One thing that's interesting is that hks cams do seem to bring boost on earlier compared to the poncams and make slightly more peak for same boost levels but bottem to mid power seems to be much the same in a fair few of the results.
Another thing I've noticed is the hks staggered seem to do a better job with internal gate boost control but when externally gates the poncams are pretty equal.

[GTSBoy]

Fair enough.  I'd actually glossed over the fact that the HKS cams were staggered.  My opinion on the matter of staggered cams with bigger exhausts on turbo engines leads towards discussion of fixing the problem that requires a staggered cam instead of the band-aid solution.  External gates &/or bigger rear housings &/or better ex manifolds being the non-band-aid solutions.