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View Full Version : Cams for GT2540R on S14 Sr20det



fat200sx
04-21-2005, 02:39 AM
I was wondering what cams to go for, current setup on S14 sr20det

GT2540R 0.86AR with 38mm Ext. Wastegate
Stainless manifold
Z32 AFM
740cc Injectors
Power FC
70mm throttle body
FMIC
Splitfire ignition

What cams do you recommend? it is a daily driver and still want to have some power low down. I don't want to rev it past 7500rpm, i would rather get HKS cams

I have heard that if you run heavy duty springs the variable cam control will break, is this true?

I had the 0.64ar housing on this turbo and it was using the internal gate, the turbo would boost to 20psi but drop of to 15ps at readline has anyone had this problem???

Thanks for your help

Vapor
04-21-2005, 06:52 AM
max duration you can use is 256 with VTC. You can expect about 330-340whp with that setup.

killjoy
04-21-2005, 09:04 AM
Can't you just disable the vtc? I think I remember a buddy of mine with an s14 dyno with and without and it was 11 hp. Ditch that ****e and put in 264's.

Vapor
04-21-2005, 10:08 AM
a lot better mid range with VTC though. I'd keep it if possible

fat200sx
04-21-2005, 06:02 PM
What sort of power will this setup make. Some of you guys are making 400whp, but you guys are using larger cams.
How much power would i loose from this if i use Stage 1 HKS cams 256 int 264 exh ??

RocketScience
04-21-2005, 07:31 PM
max duration you can use is 256 with VTC. You can expect about 330-340whp with that setup.



Can you please explain this, I am running VTC and 264 VTC spec cams, and they have 272. I keep on hearing from some people on here that you can't go over 256 with VTC but I would like to know the theory behind this.

fat200sx
04-21-2005, 08:22 PM
From what I've been told you can run pretty much whatever cam you like, it's just when you use heavy duty springs, it causes the variable cam timing solinoid to break after a while of use. Apparently it leaves a very noticable hole in your midrange.

chunk
04-21-2005, 08:54 PM
max duration you can use is 256 with VTC. You can expect about 330-340whp with that setup.



That is untrue vapor. TODA makes cams up to 272' duration that allow the use of NVCS. Not sure but I believe they are not the only ones.

http://todaracing.com/products/nissan_sr20det/camshafts.html

RocketScience
04-21-2005, 09:01 PM
APEXi makes them as well.

KAkiller
04-21-2005, 09:08 PM
HKS Makes booth Step 2 and 3 intake camshafts for NVCS SR20DET in 264deg. I have the Step 2 264 In/Ex and gain roughly 30-40 HP. Sorry I do not have an exact # on the HP gain bc I also changed the headgasket and raise the boost.

fat200sx
04-21-2005, 09:32 PM
Hey KAKiller, Have you had any issues with VCT since installing those cams?? I assume you also did change to heavy duty springs? Did you lose much midrange?

RocketScience
04-21-2005, 11:39 PM
I can answer from my experience, I am running vtc with ferrea double springs and I have no issues, I rev to 8700 all the time and my NVCS/VTC is still working, mind you this a drag only car, so I don't know if it would have enough mileage on a drag engine to have a problem. But when it does run its balls to the wall harassment.

fat200sx
04-22-2005, 12:41 AM
I would be good to hear from anyone who has been using heavy duty valve springs on a daily driver with VCT to see what has happend to there VCT.

What would you reckon the top end difference would be between these two setups (with GT25/40r ex. gate):

HKS STG 1 256 INT 264 EXH
HKS STG 2 264 INT 272 EXH

KAkiller
04-22-2005, 12:54 PM
Hey KAKiller, Have you had any issues with VCT since installing those cams?? I assume you also did change to heavy duty springs? Did you lose much midrange?



I gained a ton of Mid Range and lost a little Low End. I do have the HKS newer Valve Springs. They changed them a few months back with some new coating/treating process to make them more durable. No problems with my NVCS working, because I'm using the HKS F-Con VPro Engine management I can acctually change the activation point of the NVCS. I haven't played with this feature yet, so all the dynos bellow are with stock NVCS engagement points.

Here is a dyno of my car with Cams and boost raised (~1.25bar). Vs my car with stock cams and boost (~1.0bar). A/F was 11:1 on 91 octane.

http://www.archangeldesigns.com/auto/dyno/ac_sr_cams_vs_nocams.jpg

Here are my dynos Non Corrected and SAE Corrected (Modifications are listed in these dyno charts).

Dyno NON Corrected (http://www.archangeldesigns.com/auto/dyno/dyno_nonecorrected.jpg)

Dyno SAE Corrected (http://www.archangeldesigns.com/auto/dyno/dyno_saecorrected.jpg)

BTW the car is Truly Daily Driven

fat200sx
04-25-2005, 01:23 AM
I can't believe the power you guys are geting out of the GT25/40r. I was on of the first people in Australia to put one of these on an SR (approx 4 years ago), and when it was time to get it tuned every shop I when to was telling me that it was crap and was trying to sell me a replacement. I guess it's a matter of finding the supporting mods to let you achieve this power level.

harlock_ssx
04-27-2005, 10:35 PM
I can't believe the power you guys are geting out of the GT25/40r. I was on of the first people in Australia to put one of these on an SR (approx 4 years ago), and when it was time to get it tuned every shop I when to was telling me that it was crap and was trying to sell me a replacement. I guess it's a matter of finding the supporting mods to let you achieve this power level.



I don't have any complaints! When I get back home from the trip I'm on, going to re-dyno again...shooting for 400 to the wheels with an internal wastegate, don't know if we can get there, but we're getting closer! I just swapped in a Q45 throttle body & 80mm intercooler piping, new diff with 4.38 gears, as well as a few trivial supporting parts, street tuned with a wideband O2 sensor since my last dyno test (355 rwhp with an extremely rich tune).

skillvia
04-28-2005, 08:55 PM
Can't you just disable the vtc? I think I remember a buddy of mine with an s14 dyno with and without and it was 11 hp. Ditch that ****e and put in 264's.


dump the VTC and just do large s13 cams.

SRFiveTen
04-28-2005, 11:55 PM
Can't you just disable the vtc? I think I remember a buddy of mine with an s14 dyno with and without and it was 11 hp. Ditch that ****e and put in 264's.


how would disabling a device which is disengaged above 5700rpm, affect peak horse power by 11hp?
do explain that ****e.

SRFiveTen
04-30-2005, 12:23 AM
bump because i really wanna know.

fat200sx
04-30-2005, 02:41 AM
I think he means it made an extra 11hp with the new cams and with VTC disabled.

Disabling VTC is pretty silly, especially on a street car, It does not affect top end.