Great write up. Either way, im sure ill be satisfied with a Vortech 2.87 pulley and all the supporting mods...

Turbo's will definately have that flat, more desired torque line. But there's something about a linear powerband that always attracted me; you have no choice to redline all the way just to build full boost

For the stock block, I think I would be satisfied with 430whp/350wtq.

Either way, Vortech has always been a favorite FI kit for those in California who want a reliable kit with good power, AND carb legal (although you can easily change that with a different pulley).

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the vortech always has a pretty flat curve

turbos only have flat torque curves if they're at low boost or have gone to extensive trouble with exhausts, turbo sizes, and tuning to try to flatten the torque of a high boost turbo setup

otherwise most turbos for this engine, especially the single turbos have a torque curve that looks like a hill - starts low, goes way up, then drops way down

 

+1 A free flowing exhaust can help flatten the torque curve by relieving back-pressure

 

sweet write up! thumbs up

 

Yeah my curve is quite flat right now but I'm only at 8psi.

 

Great right up Andy. You have answered quite a few questions about the SC versus TT comparisons. I won't be to far behind before I jump on the FI wagon.

 

thanks...hopefully if people actually use the search function it can be helpful

 

Respectfully disagree....

It's all about area under the curve and not about peak HP/TQ. A turbocharged car will outrun an SC car any day even with slightly lower peak numbers. If you actually calculate the area under the curve, you will see that a turbocharged car actually has more average HP/TQ per RPM than an SC car (talking similar ballpark peak numbers) and this means that the turbo will be faster and have more power throughout the rpm band making it a much quicker car.

The BUTT DYNO is actually a lot more accurate than many think... the thrust you feel when the turbo(s) kick in is not phsycological... it's actually all that torque kicking in at a very low rpm while the SC is still building torque and that's why you don't feel that punch with an SC.

That's my 2 cents.

Great write up BTW to the original poster.

 

well I'd normally say area under the curve is always faster too, but I don't think it would be in this case. The vortech will have 330 tq by 4500-5000 rpms, and it would normally stay there until redline, but in this case it must have gradually dropped to around 295 tq at 6600 rpms, hence the 370whp - maybe the belt was slipping?

in this case with the greddy kit, there's going to be a lot more power before 4500 rpms than the vortech, but at its peak it'll be 300 tq probably somewhere around 4000-4500 rpms and then we all know the tq drops hard if he's making 320whp at redline which would be around 255 tq at 6600 rpms

hp = (tq x rpm)/5252
is how I'm converting hp into tq

so they cross at around 4500 rpms and then the vortech has the advantage after that actually making 30-40 more tq than the greddy all the way to redline.



let's also not forget that the power below 4000 rpms is pretty much worthless in a race. If you launch the car hard, you're either going to be launching above 4000 rpms or if you start below that, you'll only be there for a tiny bit.

here's roughly where you spend your time in each gear if you shift at redline (may vary depending on how quick you can shift)

1st gear: idle to 6600 rpms
2nd gear: 4000-6600 rpms
3rd gear: 4500-6600 rpms
4th gear: 5000-6600 rpms
5th gear: 5050-6600 rpms
6th gear: 5100-6600 rpms


I really think the previous vortech setup would win in this particular case since it spends most of the race in the upper powerband where the 370/330 vortech is already making more whp and tq than the 320/300 greddy


there's a thread going right now on my350z.com about how a 400whp vortech is just a little slower than a 400whp turbo car. But give the vortech a 50whp advantage and I think that tips the scale completely in favor of the vortech

 

I'm not an expert by any means, but I would favor the 370/330 Vortech G/Z over a 320/300 G/Z ST/TT in a 1/4 mile race... if theoretically everything else is equal in regards to driver & conditions.

When you state very low RPM, what type of acceleration are you really refering to? Because on stock gearing, everytime you redline, the next gear falls into around 5000RPM's, which isn't very low RPM's. I'm assuming you're talking about daily driving, where a TT's torque is obviously much more apperant than an SC due to the TT's low end torque & power curve.

I agree, with the same peak power & torque, it's a TT or ST car that's going to have the significant edge in acceleration.

I know enough about how SC's and TT's work, but not where I can predict the outcome just by seeing the hp/tq numbers & power curve

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it's impossible to have 300 tq at redline and 320whp at redline. It's either one or the other, but not both at the same time

Maybe the peak whp was at 6300 rpms or something? If so, then that'd mean that there's 266 tq at 6300 rpms. There's no way around it, the tq started dropping as the rpms rose

If the tq hit 300 and stayed there, then 376whp would be made at 6600 rpms

can the chart be posted up have it looked over again?

 

you're right...I deleted my post as soon as I posted...I'll post up the plot as soon as I find it. My plot only goes up to 6300 though because of the 5AT so 320 whp would yield 267 tq, roughly.

 

for the sake of some sort of visual aid, here's what I'm guessing the two charts would roughly look like compared to each other

What's not really being shown here is if the greddy started the dyno earlier, it'd extend to the left and have roughly 50 more tq than the vortech before between 2300-3500 rpms

greddy = red
vortech = blue

(this is all going to be stupid old news once the greddy TT hits 600whp)

 

4 psi plot...boost was dropping off to 3.5psi at 5200 to redline at the time. None of this really matters, though, as I am going to get a dyno at 8psi next week

 

old Vortech dyno