FWD vs. RWD: VQ35 SC Dyno Comparo at 13psi
Thread Starter
Joined: Jan 2003
Posts: 378
From: Houston, Tx
FWD vs. RWD: VQ35 SC Dyno Comparo at 13psi
Sam at GT Motorsports put together a very nice SC 350z for one of this customers. His major mods include a Vortech T-trim SC, Return-style fuel system, and HKS FCon VPro. My mods include a swapped FWD VQ35 (on VQ30 timing eqiupment) Vortech SQ-trim on a very old school Engine Management System (stock ecu, FMU, J&S, and SAFC). The tuning capablities of FCon VPro are light years ahead of my EMS, but looks like it can still hang in there.
Sam's 91 Oct tune and my tune on 93 oct are literally identical. His may appear a little smoother, but mine corrected to a level 5 smoothing looks just a good. Note however that Sam's dyno is STD corrected and mine is SAE corrected. My STD adjusted dyno show a jump of about 10 hp all across the board.
The one key thing to note is that I don't have variable timing on the intake cam. As a results, Sam's dyno shows a ~10 wtq advantage at 3000, but slowly tapers to yield identical results at 4500 rpm (both have 300 whp and 350 wtq).
So, is the T-trim running out of steam just like my SQ-trim? Neither of us see any belt slip, yet both dyno's peak a bit above 6,000. While A/F is not shown in my graph, both us do drop our A/F to 11:1 as we hit redline.
Link to Sam's Thread at my350z.com
Sam's Dyno Sheet:

My Results:

.
Sam's 91 Oct tune and my tune on 93 oct are literally identical. His may appear a little smoother, but mine corrected to a level 5 smoothing looks just a good. Note however that Sam's dyno is STD corrected and mine is SAE corrected. My STD adjusted dyno show a jump of about 10 hp all across the board.
The one key thing to note is that I don't have variable timing on the intake cam. As a results, Sam's dyno shows a ~10 wtq advantage at 3000, but slowly tapers to yield identical results at 4500 rpm (both have 300 whp and 350 wtq).
So, is the T-trim running out of steam just like my SQ-trim? Neither of us see any belt slip, yet both dyno's peak a bit above 6,000. While A/F is not shown in my graph, both us do drop our A/F to 11:1 as we hit redline.
Link to Sam's Thread at my350z.com
Sam's Dyno Sheet:

My Results:

.
accoring to the guy i spoke to at vortech once you spin past something like 55,000 or 65,000 the efficency of the blower goes down the crapper. so its possible that both blowers suffer form that.
It could also be that maybe both motors just arent able to probally make use of the charged air being given to it due to some kind of im or head restrictions and that could be a cause of your power losses up high
It could also be that maybe both motors just arent able to probally make use of the charged air being given to it due to some kind of im or head restrictions and that could be a cause of your power losses up high
I am more familiar with ATI Prochargers. Prochager's C-2 have a much higher rpm redline(80,000rpm). The only time I have seen a Procharger drop near redline was on a Z running 18psi. On a VQ35, Prochargers run about 45,000-48,000 on 7psi stock pulley at 7,000rpm. Vortech V2's run about the same on a VQ35 at 8psi but with a much lower redline(50,000rpm). At 13psi, I would say both are pushing the Vortech over its max effiency.
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