ST4/TT4 Thread
11-02-2016, 10:33 AM
#1
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ST4/TT4 Thread
So who is going to go this route? The 2017 rules are posted and seems like we could have a similar deal to STL if anyone takes advantage of it.
https://nasa-assets.s3.amazonaws.com...--10-31-16.pdf
FWD has quite a tax break at +.6 mod factor.
Todays PTE/PTD cars could become very fun by taking out your 200#s of ballast to make up for the extra Pwr:weight.
My my current car at 2210 can run at 192whp vs 141whp. While taking limitations off brakes, tire size up to 245 vs 205, and typical nice updates including NB subframe, spindles, and bumpsteer. Can do more than double adjustables and gear ratios are also open.
Fwd cars on 245s or smaller while under 2600# and over 2200# will have 1.1 additional factor on any rwd car. Enough for a free sequential/dog box, "A" tires, or 10-12whp.
Average hp is another piece of the puzzle.
https://nasa-assets.s3.amazonaws.com...--10-31-16.pdf
FWD has quite a tax break at +.6 mod factor.
Todays PTE/PTD cars could become very fun by taking out your 200#s of ballast to make up for the extra Pwr:weight.
My my current car at 2210 can run at 192whp vs 141whp. While taking limitations off brakes, tire size up to 245 vs 205, and typical nice updates including NB subframe, spindles, and bumpsteer. Can do more than double adjustables and gear ratios are also open.
Fwd cars on 245s or smaller while under 2600# and over 2200# will have 1.1 additional factor on any rwd car. Enough for a free sequential/dog box, "A" tires, or 10-12whp.
Average hp is another piece of the puzzle.
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11-02-2016, 01:22 PM
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Wow, I'm very surprised there wasn't a break for 225mm tires, hah.
This would be a very fun class to run, but a lot of development to get towards the pointy end of it.
2400lb NB @ 208rwhp ...... average. On 245 R7s, 15x10s, front air-dam & splitter, rear wing..... damn.
This would be a very fun class to run, but a lot of development to get towards the pointy end of it.
2400lb NB @ 208rwhp ...... average. On 245 R7s, 15x10s, front air-dam & splitter, rear wing..... damn.
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11-02-2016, 05:25 PM
#3
I only skimmed the rules twice, but I'm not seeing any way for a swapped miata with an aftermarket subframe to run ST4. Aftermarket subframes work in ST1-3 with the non-production mod factor, but that mod factor can't be used in ST4. Looks like unmodified OEM subframe is required.
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11-02-2016, 05:45 PM
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I only skimmed the rules twice, but I'm not seeing any way for a swapped miata with an aftermarket subframe to run ST4. Aftermarket subframes work in ST1-3 with the non-production mod factor, but that mod factor can't be used in ST4. Looks like unmodified OEM subframe is required.
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11-02-2016, 06:22 PM
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I only skimmed the rules twice, but I'm not seeing any way for a swapped miata with an aftermarket subframe to run ST4. Aftermarket subframes work in ST1-3 with the non-production mod factor, but that mod factor can't be used in ST4. Looks like unmodified OEM subframe is required.
"7.3.2 Restrictions and Limitations for Production Vehicles Only:
1c) Suspension sub-frames/suspension cross-members may be updated or backdated utilizing any OEM factory produced item that is a direct replacement piece for that model, regardless of year or street legality, provided that it can be installed in the same location and in the same manner as on the donor vehicle without modifications. "
1c) Suspension sub-frames/suspension cross-members may be updated or backdated utilizing any OEM factory produced item that is a direct replacement piece for that model, regardless of year or street legality, provided that it can be installed in the same location and in the same manner as on the donor vehicle without modifications. "
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11-03-2016, 09:01 AM
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Indeed... Though it might be difficult to get 205-210rwhp avg from an ecotec without cams/internal work, at least on a dynojet. I think there are gains to be made just by porting the head, which would really put the current ecotec swaps I've seen over 200rwhp(peak).
Even still, in ST with 245s and aero..... you'd probably be better off running 2550lbs+ @ 220rwhp avg.
Even still, in ST with 245s and aero..... you'd probably be better off running 2550lbs+ @ 220rwhp avg.
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11-03-2016, 01:17 PM
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Originally Posted by The Rulebook
7.3.2 C:
2) Relocation of suspension mounting points is permitted in ST1, ST2, and ST3, provided that the modifications do not violate any of the other rules above. One possible method is via the use of modified mounting point brackets attached to OEM mounting locations. Relocation of suspension mounting points is not permitted in ST4.
2) Relocation of suspension mounting points is permitted in ST1, ST2, and ST3, provided that the modifications do not violate any of the other rules above. One possible method is via the use of modified mounting point brackets attached to OEM mounting locations. Relocation of suspension mounting points is not permitted in ST4.
That means NO NB subframe/spindles/bumpsteer in 4. Only in 3/2/1
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11-03-2016, 01:25 PM
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Excerpts:
Under:
2200 lbs = -0.3
2600 lbs = -0.2
3000 lbs = -0.1
Over:
3300 lbs = +0.1
3400 lbs = +0.2
3500 lbs = +0.3
3600 lbs = +0.4
3750 lbs = +0.5
3900 lbs = +0.6
245 or smaller = +.7
250 to 275mm = +0.3
windshield removal = -.3
OEM aero = +.4
Sequential = -1
A7/R1S/C91 = -1
__________________________________________________ ___
Imagine this:
OEM-aero, Ecotec, NB
12:1 base
12.2:1 2201-2599lbs
11.5:1 245 or smaller
11.1:1 Oem aero
200whp/2225lbs
Wow.
Under:
2200 lbs = -0.3
2600 lbs = -0.2
3000 lbs = -0.1
Over:
3300 lbs = +0.1
3400 lbs = +0.2
3500 lbs = +0.3
3600 lbs = +0.4
3750 lbs = +0.5
3900 lbs = +0.6
245 or smaller = +.7
250 to 275mm = +0.3
windshield removal = -.3
OEM aero = +.4
Sequential = -1
A7/R1S/C91 = -1
__________________________________________________ ___
Imagine this:
OEM-aero, Ecotec, NB
12:1 base
12.2:1 2201-2599lbs
11.5:1 245 or smaller
11.1:1 Oem aero
200whp/2225lbs
Wow.
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11-03-2016, 01:41 PM
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Excerpts:
Under:
2200 lbs = -0.3
2600 lbs = -0.2
3000 lbs = -0.1
Over:
3300 lbs = +0.1
3400 lbs = +0.2
3500 lbs = +0.3
3600 lbs = +0.4
3750 lbs = +0.5
3900 lbs = +0.6
245 or smaller = +.7
250 to 275mm = +0.3
windshield removal = -.3
OEM aero = +.4
Sequential = -1
A7/R1S/C91 = -1
__________________________________________________ ___
Imagine this:
OEM-aero, Ecotec, NB
12:1 base
12.2:1 2201-2599lbs
11.5:1 245 or smaller
11.1:1 Oem aero
200whp/2225lbs
Wow.
Under:
2200 lbs = -0.3
2600 lbs = -0.2
3000 lbs = -0.1
Over:
3300 lbs = +0.1
3400 lbs = +0.2
3500 lbs = +0.3
3600 lbs = +0.4
3750 lbs = +0.5
3900 lbs = +0.6
245 or smaller = +.7
250 to 275mm = +0.3
windshield removal = -.3
OEM aero = +.4
Sequential = -1
A7/R1S/C91 = -1
__________________________________________________ ___
Imagine this:
OEM-aero, Ecotec, NB
12:1 base
12.2:1 2201-2599lbs
11.5:1 245 or smaller
11.1:1 Oem aero
200whp/2225lbs
Wow.
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11-03-2016, 03:11 PM
#14
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I also don't see 200 "average" hp from an ecotech being easy or cheap.
I dont know the exact calculations for average hp, but with really good boost control you can add/remove power in specific locations and even tune your setup per track.
I dont know the exact calculations for average hp, but with really good boost control you can add/remove power in specific locations and even tune your setup per track.
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