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43 minutes ago, ActionDan said:

Is 250 going to be too much or is that small enough of a bump up to improve mid to high rpm performance without losing anything down low or is there no such thing as a gain in the low/medium/high and anything you do is just moving the band left or right and that's that. 

 

I think I refer you back to my 1st reply.  I think 250 is a very gentle increase in duration and it should be possible to install them so that you have very small increase in overlap.

2 hours ago, ActionDan said:

I'm mostly interested in response and low to mid range torque, though some more top end wouldn't be a bad thing, I just don't want it at the expense of low to mid range, it's a street car.

Then putting in longer duration cams won't do what you're after.

Advance your intake cam further for more response... or single TS conversion.

20 minutes ago, KiwiRS4T said:

You will be lucky to find anyone who can give you a before and after comparing type R with stock cams because usually (not always) people incorporate new cams in a new build. There's nothing wrong with sound theory - a modest increase in duration and lift should, if tuned right , give you a modest increase in power up top. Increased duration should work against response low down.

 

I would keep the stock cams and get a better single.


No single happening here. Victoria = defect and I just CBF dealing with that headache. 

10 minutes ago, GTSBoy said:

I think I refer you back to my 1st reply.  I think 250 is a very gentle increase in duration and it should be possible to install them so that you have very small increase in overlap.

Thanks for the info. Am I right in saying the overlap is the issue in terms of losing downlow grunt? 

So if I were to advance the intake cam further and have the increased duration, could I get the improved response and some improved flow up top?

5 minutes ago, Dose Pipe Sutututu said:

Then putting in longer duration cams won't do what you're after.

Advance your intake cam further for more response... or single TS conversion.

As per the above, So if I were to advance the intake cam further and have the increased duration, could I get the improved response and some improved flow up top?

59 minutes ago, ActionDan said:


So if I were to advance the intake cam further and have the increased duration, could I get the improved response and some improved flow up top?

Effectively, yes.  If you leave the lobe centres at stock, then more duration = more overlap.  Overlap is the thing that tends to de-optimise the cams for lower rpm, because it gives a longer window for reversion and cross-talk between inlet and outlet.  There's nothing wrong with more overlap at higher rpm, because you effectively need it to overcome the timing problems involved in getting the gas to move through the head with the short timeframes available.

Longer valve events always favour higher rpm breathing rather than lower rpm breathing, and there's no avoiding that.  Installing the cams so that you minimise overlap is not actually going to make the best use of them for their higher rpm effectiveness, but it will minimise any negative impact on the low rpm behaviour.  Add the increased lift on to that and you should be able to get a small positive result down low coupled with a decent mid range benefit.

Edited by GTSBoy
  • Like 1
9 minutes ago, GTSBoy said:

Effectively, yes.  If you leave the lobe centres at stock, then more duration = more overlap.  Overlap is the thing that tends to de-optimise the cams for lower rpm, because it gives a longer window for reversion and cross-talk between inlet and outlet.  There's nothing wrong with more overlap at higher rpm, because you effectively need it to overcome the timing problems involved in getting the gas to move through the head with the short timeframes available.

Longer valve events always favour higher rpm breathing rather than lower rpm breathing, and there's no avoiding that.  Installing the cams so that you minimise overlap is not actually going to make the best use of them for their higher rpm effectiveness, but it will minimise any negative impact on the low rpm behaviour.  Add the increased lift on to that and you should be able to get a small positive result down low coupled with a decent mid range benefit.

OK I have it right in my head then, and acheiving that will be easier with the smaller increase in duration of the Type R vs the Type A. 

9 minutes ago, r32-25t said:

Vcam will give you everything you're after

Would need to go to new ECU, plat pro can't do it. Already spoke to Haltech. 

6 minutes ago, r32-25t said:

yes you will, but it will give you what you want 

$$$$$$$

1 minute ago, Piggaz said:

Where are your current cams set at? Considered just playing around with them to get the low endish twist you want without the major expense?

Not sure, off the top of my head, but they were dialed in with response/mid range in mind. 

its not cost effective when it doesn't give you what you're after.

as a few have said just advance the intake cam a few more degrees to shift power lower, that's the cost effective solution 

13 minutes ago, ActionDan said:

Understood. 

Now, as per the original question, who can show me before and afters with Type R cams :)

pm Michael (aka Xklaba), he went from B to R poncams, also posted his feedback on few threads on here

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