My 997.1 with EVOMSit, Cargraphic exhaust, GT3 throttle body + Werks plenum seems to have a torque curve similar to most dyno sheets I've seen with max torque somewhere between 3500 and 4000 rpm.

What I really want is max torque below 3000 rpm and the question is how best to achieve that. The car has more than enough top end power so I would gladly sacrifice some (blasphemy, I know) for more low end. At this point it seems that headers or turbos would be the next upgrade. My preference would be headers but internet wisdom (oxymoron?) is divided on whether long tube or short tube headers are best for turbo spool. Upgraded VTG turbos would be a bigger commitment and it seems that these turbos target high end HP over low end torque in addition to requiring all the supporting modes of intercoolers etc.

Ideally, I'd like to see a tuner develop a kit strictly for low end torque. Any takers?

 

Since upgrading from the EVT580 to the EVT700 (including headers and VTG turbos) I have noticed the turbos start spooling at a much lower rpm. 3000rpm seems to be the switch point from nice and calm to kick-in-the-pants torque. I plan on a dyno in the near future. Unfortunately, never had a stock or EVT580 dyno done...

 

Switching back to Stock TB/Plenum should give you bottom end.

 

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Even with stock TB and plenum, I don't think you will achieve peak tq below 3K in 3/4 gears. Imho, you will need different turbos for that.

 

I might swap out the TB and log some Durametric runs to verify but I don't think it should make a big difference. Sharky recommended the TB/plenum to me over headers for boost response improvement.

Upgraded turbos pretty much means going to full EVT700 if I want to stay with an evoms package, and that's overkill for what I'm after. I'm not crazy about mixing and matching turbos and software from different tuners so it looks like my best option is going to the EVT600 package. Interestingly, the EVT600 shows a 500rpm earlier torque peak than the EVT580 with the only difference between the packages being headers.

 

That's a nice gain for headers (and who said headers don't do anything--lol). I'm wondering if the tune is tweaked a bit too?

 

The fastest spooling turbo I know of (even has good top end) is the Tial Alpha 28. With all the supporting mods in third gear, they start max spool at 3100 or so with a really amazing 0.955g at 59 mph (3700 or so). See first graph. There the g (green) line has essentially a 1:1 relationship with torque. I dont know any turbo that can spin early enough to give max torque below 3000 though. The A28 will outspool modded VTGs usually. See second graph...

Switzer uses these turbos in his P800 kit.