When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Is that true over an entire 20-30 minute session, or just for a few laps?
--Ian
I only have limited data. All the times we tested 100's or 200's, we were comparing to each other, not Hoosiers. Hoosiers do generally shed heat better than any "street" tires. The anomaly in my experience is the A052. Good right down to the cord and doesn't seem to mind heat.
Does anyone have experience with the Goodyear Eagle F1 Supercar 3R?
There were a few guys from Mid Atlantic region at Pitt Race running them. And I talked to a very good Spec Corvette driver that was running them in TT3 at Mid Ohio this weekend. He was still adjusting to them, but he was setting his fastest times ever in the car. He said they're a little over 2 seconds faster than the RR's at Mid Ohio (He ran a 1:32.9 in TT3 on Pro today with them).
They're "100TW" so they fit within "Tires with a UTQG Treadwear rating 100 or greater or Toyo RR +0.6". The only 15" tire is a 205/50, but with rebates and junk they're $500 a set on Tire Rack currently.
I'm seriously considering giving them a try, since the RR's are a dead end, at least for TT. I've tried adjusting shocks, alignment, and pressures and feel like I'm pretty well optimized for the RR. They're just junk compared with my old RE71R's: lower Lat and Long G, slower warmup, vague response, require higher slip angle, etc. I'm competitive regionally with them, but they're not even close to being nationally competitive. Struggling to break out of the 44's at Mid Ohio Pro (which Sonny set the record @ 40.7). I was planning on ballasting up and switching to R7's next month, but these magical "3R's" seem like they may have Hoosier-like pace.
Last edited by engineered2win; 08-29-2021 at 07:46 PM.
SC3R are only a skosh slower than R7. Like less than a second on a 2.5 mile road course in a 9:1~15:1 lbs/hp car. At around half the price, they are the current "cheater" 100tw. Only tire under 200tw that's actually faster than a Super200. RR's are well behaved, cycle nice, steer nice, but they're basically RA1/NT01 compound in a fancy shallow tread slick casing. Never done RR v SC3R testing on the same day but scatter plot of data in my brain says they'd be 1~1.5s slower than R7 in same environment as first example.
Anecdotal again, but SC3R's are fast right down to the cord, sorta like an A052. They don't last long due to the soft compound and shallow tread, but they don't cycle out as rapidly as R7.
Anecdotal evidence seems to indicate the SC3Rs work best on heavy cars. Goodyear developed them for ~4000lb Camaros with gobs of hp/trq.
When I spoke with one of Goodyear’s top test engineers, he wasn’t sure if all of the performance would translate to a <2700lb car. The people I’ve heard having success with them have all been heavy TT2-TT4 cars. I’m eager to test them on a TT5 car…
Key changes are:
-ST6 down to 19:1 P:W
-Allowed ballast up to 300lbs
-Cable actuated throttles get a .2 credit
-New tire modifiers based on model, not UTQG
-A new credit for running tires smaller than you're allowed
I got a reply back from Greg on why only ST/TT6 was changing the W:P minimum from 18.0 -> 19.0:
It is to encourage the move to the +1.6 tires, allow other NASA Spec tire classes to cross over still, and make it so those already on +0.6 tires don’t have to do any changes to their cars. ST6 almost became a Spec tire class with a +1.6 tire, and it likely still will in the future.
I was initially pretty pissed when I breezed through the 2022 rules, but after thinking about it some more it does make some sense. However, I have no idea why they didn't apply a correction to ST/TT5 as well. So the delta between 5 and 6 will be increasing.
I ran some calcs and it'll be interesting if the +1.6 for the RR will be sufficient to be competitive with the R7, because the previous +0.6 certainly wasn't sufficient: R7 - 205/50:
2450lb
127hp max avg
+0.2 Mech TB
+0.3 <226mm section width
+0.4 BTM aero
-0.4 Comp weight
-0.7 Double A-arm
19.09 corrected W:P
200TW (A052?) - 205/50:
2450lb
134hp max avg
+0.2 Mech TB
+1.0 Tire
+0.3 <226mm section width
+0.4 BTM Aero
-0.4 Comp weight
-0.7 Double A-arm
19.08 corrected W:P
RR (Powaaa!!!) - 205/50:
2450lb
139hp max avg
+0.2 Mech TB
+1.6 Tire
+0.3 <226mm section width
+0.4 BTM Aero
-0.4 Comp weight
-0.7 Double A-arm
19.03 corrected W:P
This is assuming you run 2450lb comp weight to get the extra +0.3 modifier for section width (2400-2749lb CW) and the extra +0.1 for comp weigh(2450lb). So with the RR you get an additional 12hp over the R7 and 5hp from the 200TW keeping the comp weight and chassis modifiers constant. I'm currently at 129hp max avg and on the stock ECU, so I definitely need to go to a standalone to take advantage of any additional power.
I'm also not sure whether running a 225/45 over a 205/50 is worth the 0.3 modifier. I think that may only work with the RR, since I highly doubt <140whp is sufficient to generate the slip angles required for peak grip on a R7. The 200TW's might be on the fence, but availability is limited in 225/45's. There are a bunch in 225/50, but then you're impacting ride height(aero negative impact), gearing, and wheel well clearances.
Last edited by engineered2win; 12-05-2021 at 11:27 AM.
allow other NASA Spec tire classes to cross over still
Except for the appearance package lips, skirts and spoilers on all the Spec Miata and Spec E30...
I wish we got an OEM aero or airdam allowance in exchange for losing BTM. THAT would actually allow crossover in the event of low car count. Then we're a very small step from eradicating Honda Challenge, GTS and AI/AIX so they can all roll into ST...
This is assuming you run 2450lb comp weight to get the extra +0.3 modifier for section width (2400-2749lb CW) and the extra +0.1 for comp weigh(2450lb). So with the RR you get an additional 12hp over the R7 and 5hp from the 200TW keeping the comp weight and chassis modifiers constant. I'm currently at 129hp max avg and on the stock ECU, so I definitely need to go to a standalone to take advantage of any additional power.
I'm also not sure whether running a 225/45 over a 205/50 is worth the 0.3 modifier. I think that may only work with the RR, since I highly doubt <140whp is sufficient to generate the slip angles required for peak grip on a R7. The 200TW's might be on the fence, but availability is limited in 225/45's. There are a bunch in 225/50, but then you're impacting ride height(aero negative impact), gearing, and wheel well clearances.
This setup can be run with a 225/45 RR on a 9" wheel. It fits the 226mm template. So the +0.3 modifier can still be retained with a slightly wider tire.
I was already running RRs due to being too poor for Hoosiers, so thankfully the new 19:1 is a wash for me with the +1.6 RR credit. I will get to drop some weight though with the new +0.2 throttle body credit. My horsepower number is fixed due to still being on stock ECU.
I have measured as well. Hard to get the camera to focus, but plenty of room. The template doesn't even come close to staying in place and doesn't touch the sidewall at all. Falls right off if not being held. Mounted on 15x9 Dekagram.
I posted this over in my build thread, but curious about what some of you think about my first TT6 powerband. I'm probably going to shot for 2405# at 135HP so I have 6HP I can add.
Car dyno'd at 137 max HP with a 129 average HP. Is this good enough and I should just send it or is it worth getting it professionally tuned? Current engine setup: - BP4W with unknow mileage (don't think it is original to car) - MS3 mini - Squaretop intake manifold
- BP5A intake cam - DIY intake - Racing Beat header, midpipe, & muffler
Are you really running 15afr, b/c that's absurdly lean. You might actually pick up some power by going richer, but mainly will have a more det proof setup that will last a long time. In a power/weight class, especially with AVG hp formula, I see no point in running bleeding edge AFR. Just make a safe tune and adjust weight as necessary if your power even changes, it probably won't even targeting 12.6-12.8. Other than that power looks pretty decent to me. Similar to my street tuned setup when I was running TT6 (MS3 Basic, BP4W with VICS and BP5A cam). A better tune could probably fill in the mid range, have certainly seen folks with similar setups and better looking midrange than what yours/mine show. I was experimenting with running fairly lean back then, but don't think it was really worth much. If you're really min/maxing you could go so far as to run flatter vs peaky power based on the the track itself (Ex. small track no hairpins no long straights vs big track long straights hairpins).
My bad... the mobil dyno at the track wasn't measuring AFR but I'm targeting 12.5 - 12.8 WOT.
Makes more senes. Yeah, if you really want to eek out more mid-range either gonna have to figure it out, talk to someone that has figured it out, or find a good tuner (and potentially change some parts around). But I don't think your current dyno is going to stop you from winning/setting records all else being setup well (suspension, driver, etc).
Is Megasquirt usually only good for about 3-5 HP? I know every dyno is different and that location and weather change results as well, but my car makes 133 max HP with 130 NASA avg on stock ECU. I've been considering Megasquirt for a bit now, but not sure the 3-5 HP really does me much, at least in TT6. I know I'll need a tunable ECU for sure if I start modding heavier to try to get into TT5.
Is Megasquirt usually only good for about 3-5 HP? I know every dyno is different and that location and weather change results as well, but my car makes 133 max HP with 130 NASA avg on stock ECU. I've been considering Megasquirt for a bit now, but not sure the 3-5 HP really does me much, at least in TT6. I know I'll need a tunable ECU for sure if I start modding heavier to try to get into TT5.
Depends on fuel and the mods you have. Besides being able to raise the rev limiter you're also going to find a lot more mid range torque. Which if you are using a 5 speed x 4.3, pays even bigger dividends than peak power. We ran a 6x4.3 and tuned for a very narrow power band. With the current rule set that's the optimum strategy to have higher average power on track. Measured power as part of the average fell way below the range we were actually using ;
TLDR ECU in ST6 is as much about power band shaping as peak power gains.
06-01-2021, 10:25 PM
0
