What did you do to your 996TT today?
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Join Date: Feb 2021
Location: Satan's Armpit, aka Houston, TX
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Yogibara (03-16-2023)
If it's a high end wrap, I bet you would.
Paul, I'd like to see your graphs with rpm on the lower axis. That way it's easier to see when the turbos are spooling and then compare the how they're spooling compared to the k24's. While I definitely appreciate how the k16's spool, I'm willing to give up 500rpm of spool down low for the ability to carry power all the way to 7000rpm
6750 = 133
6500 = 128
6000 = 118
5000 = 99
4500 = 89
4000 = 79
3500 = 69
3000 = 59
Peak torque on K16s on Paul's graph looks to be right at a max of 562 ft.lbs at 76mph (3850rpm). That's solid...
To get a real apples to apples comparisson, Paul would need to get his tune optimized and then both of you would need to do a back to back run, same dyno, same time, same conditions. Would be really cool to see a "real" comparisson of stock K16 to K24 on basically identical stock block engines. I'm not really sure that's been done before under identical back to back conditions. Do I smell a dyno day?? I'll join you guys and bring my GT3 and round out the pack. I'd be curious to get that dynoed also. Maybe we could even throw Pauls GT4RS into the mix.
Last edited by powdrhound; 03-16-2023 at 02:22 AM.
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A little rough pencil work on the two graphs between k16's and k24's shows the k16's well ahead until ~4000 rpm, so for about 1500 rpm the k16's have quite a bit more hp and torque. The crossover point is right around 4200 rpm, then the k24's absolutely wallop the k16's from there to 7000 rpm. So the k24's give a much broader power band, making substantially more power over the k16's for ~3000rpm vs the 1500 rpm advantage the k16's have down low.
Obviously a lot of this is personal preference and how you're driving/using the car. In stop and go traffic, or low speed driving, the k16's will feel and perform better. Some of that can be alleviated on the k24's by staying one gear down and keeping the rpm's up. On a race track, where you're up higher in the rpm range for the vast proportion of the time, the k24's give a far larger, broader power band while also delivering substantial gains over the k16's. My car is making almost 200hp more than Paul's for 2000 rpm up top, that's pretty huge.
Personally, I really hate the feeling of a motor that's a dying quail. Ie: power falling off as rpms rise. I much prefer the feeling of power rising the red line and am willing to sacrifice some hp down low to get it. I'm really happy with the fact that I've got a flat power band all the way to 7000 rpm. With any luck it'll warm up today and the roads will be dry tomorrow so I can go pick up my car.
Obviously a lot of this is personal preference and how you're driving/using the car. In stop and go traffic, or low speed driving, the k16's will feel and perform better. Some of that can be alleviated on the k24's by staying one gear down and keeping the rpm's up. On a race track, where you're up higher in the rpm range for the vast proportion of the time, the k24's give a far larger, broader power band while also delivering substantial gains over the k16's. My car is making almost 200hp more than Paul's for 2000 rpm up top, that's pretty huge.
Personally, I really hate the feeling of a motor that's a dying quail. Ie: power falling off as rpms rise. I much prefer the feeling of power rising the red line and am willing to sacrifice some hp down low to get it. I'm really happy with the fact that I've got a flat power band all the way to 7000 rpm. With any luck it'll warm up today and the roads will be dry tomorrow so I can go pick up my car.
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making me really reconsider the billet k16s i have and stepping up to billet 24s...
A little rough pencil work on the two graphs between k16's and k24's shows the k16's well ahead until ~4000 rpm, so for about 1500 rpm the k16's have quite a bit more hp and torque. The crossover point is right around 4200 rpm, then the k24's absolutely wallop the k16's from there to 7000 rpm. So the k24's give a much broader power band, making substantially more power over the k16's for ~3000rpm vs the 1500 rpm advantage the k16's have down low.
Obviously a lot of this is personal preference and how you're driving/using the car. In stop and go traffic, or low speed driving, the k16's will feel and perform better. Some of that can be alleviated on the k24's by staying one gear down and keeping the rpm's up. On a race track, where you're up higher in the rpm range for the vast proportion of the time, the k24's give a far larger, broader power band while also delivering substantial gains over the k16's. My car is making almost 200hp more than Paul's for 2000 rpm up top, that's pretty huge.
Personally, I really hate the feeling of a motor that's a dying quail. Ie: power falling off as rpms rise. I much prefer the feeling of power rising the red line and am willing to sacrifice some hp down low to get it. I'm really happy with the fact that I've got a flat power band all the way to 7000 rpm. With any luck it'll warm up today and the roads will be dry tomorrow so I can go pick up my car.
Obviously a lot of this is personal preference and how you're driving/using the car. In stop and go traffic, or low speed driving, the k16's will feel and perform better. Some of that can be alleviated on the k24's by staying one gear down and keeping the rpm's up. On a race track, where you're up higher in the rpm range for the vast proportion of the time, the k24's give a far larger, broader power band while also delivering substantial gains over the k16's. My car is making almost 200hp more than Paul's for 2000 rpm up top, that's pretty huge.
Personally, I really hate the feeling of a motor that's a dying quail. Ie: power falling off as rpms rise. I much prefer the feeling of power rising the red line and am willing to sacrifice some hp down low to get it. I'm really happy with the fact that I've got a flat power band all the way to 7000 rpm. With any luck it'll warm up today and the roads will be dry tomorrow so I can go pick up my car.
Last edited by powdrhound; 03-16-2023 at 11:47 AM.
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That's what I figured, although my shifting with the k16's was a bit lazy. I'll probably drop down into 2nd gear for more turns with the k24's than I did with the k16's. I'm hoping to break the 2:00 minute barrier this season, I almost did it with the k16's last year.
Three Wheelin'
Nice numbers on the K24s. Playing with the variocam timing can make the K16s hang in there just a little longer, but even with that mine still started falling off fairly quick above 5700. Would be really cool to see a K24 setup with variocam optimized.
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From what I understand you can't play with the variocam stuff on the stock ECU, that you have to go to a Motec or something. I know John saw something nuts like +100whp by playing with the variocam on his car.
Three Wheelin'
Correct, those tables cannot be modified in the stock ECU. You have to go standalone or use some sort of external controller to take that away from the stock ECU. I would imagine a Motec dash running on stock ECU could control it, but it'd be more work than most people want to bother with and probably just as easy/cost effective to go with a standalone.
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I did want to try and get a baseline dyno pull on the 4RS anyway, and another with the Soul downpipe I've ordered that eliminates the secondary cat and the funky-shaped-but-empty particulate filter chamber, plus I do think it's time for a custom tune on the Arctic Turbo.
2:00min is a solid time that few 996TT can break on R-comps but it's doable. Not sure what Paul has run but I would imagine your cars are fairly similar. Chas is down to 1:55s but his car is starting to morph in to a dedicated track car. Every second below 2:00 becomes exponentially more expensive....
YES!
I did want to try and get a baseline dyno pull on the 4RS anyway, and another with the Soul downpipe I've ordered that eliminates the secondary cat and the funky-shaped-but-empty particulate filter chamber, plus I do think it's time for a custom tune on the Arctic Turbo.
I did want to try and get a baseline dyno pull on the 4RS anyway, and another with the Soul downpipe I've ordered that eliminates the secondary cat and the funky-shaped-but-empty particulate filter chamber, plus I do think it's time for a custom tune on the Arctic Turbo.