Quote:
Originally Posted by sidewaysil80
it was a gt2871r .64 but i think the lag was due to the un dialed in cams and the greddy intake manifold. in additon i belive it only made 320whp at 19psi which REALLY leads me to belive the cams were way off. i'm just really wary of giving up all the low end i'm used to with my 28r...i already have an ems and all the bolt ons imaginable so it really comes down to turbo choice.
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Sounds like a crappy tune and cams are to blame for your car not makign the power and have the response you are lookign for. I'd honestly go with a .64 2871 (as it will spool equal a 28rs .86) and then you'll have the top end you want. However with that said, here is a car we recently dynod
Stock Engine, BC 264's, 7500 limit, light PnP, Greddy IM, GT28RS .86, Tubular Exhaust Manifold. Tuned at RT Tuning n PA. 18 or 19 psi IIRC
Makes some awesome power, but kinda light in torque.
Now compare that to my car for example (same dyno, similar conditions). JWT ECU, JWT S3 Cams, Greddy Manifold, 20 psi.
To me, even with the 1-2 psi difference, this is nearly a
60 ft lbs difference (not to mention the 40 hp difference)
Now here is another comparison for you, for sake of mind, and to show you what a difference cams would make
SR20DE (9.5:1 stock compression, so marginally better spool) Stock high port (similar to s14) manifold, Modified GTiR manifold with extrude hone and swain (similar to the factory RWD exhaust manifold), JWT ECU, JWT S3 cams, @ 17/18 psi (overlayed on my dyno)
Equal toque, but a severe difference in HP (and retention, that stock IM kills those cars). Regardless, the Sentra made similar HP to the other 240 I just posted (360 whp), but it too made almost 60 more ft lbs than that 240. Granted it lost top end power, but again the intake manifold is to blame.
So, like I said earlier, I'd opt for the 2871r in .64 turbine housing, and go from there. Also, let it be known that both my car, and the Sentra have stock heads, aside from the JWT S3 cams. I find it ironic that both our cars made a HUGE difference in torque compared to the BC ones.
Quote:
Originally Posted by sidewaysil80
have any gt2871r users tried a staggered valve setup AND a staggered cam setup to increase low end response and help it spool faster? or is that too much staggering lol, seriously though, could that have any adverse effects?
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I wouldn't even bother with staggering cams. JWT S3 or HKS 264 Step II's are the only way I'd go. JWT's are safe to 7850 on stock valvetrain, while HKS Step II's require springs.