[vtirocz]

Originally Posted by Idaho2018GTPremium

FBO E85 Gen 3 Coyotes are often near to or 500+ rwhp. ZL1s are what, 550-570 rwhp? With a little weight reduction and the rear end gearing advantage I mentioned earlier that you dug into here, it's not that far fetched that a FBO E85 A10 GT PP1 would hang with a stock ZL1 until 100ish mph. The additional hp of the ZL1 will ultimately win out as time goes on (since horsepower is work per unit time), as well as the environmental physics you mentioned when wind resistance and rolling resistance becomes more of an issue than vehicle weight.

3.55 gears provide a 24.5% torque advantage at the rear wheels compared to 2.85. And the Coyote has 1000 extra rpms to work with keeping the velocity at gear changes similar in the first few gears between the two cars.

Look at this theoretical torque delivered to the rear wheels calculation:

FBO E85 Mustang GT A10 PP1: Assume 500 crank ft-lbs torque (~440 rwtq):

2nd gear: 2.99, rear diff 3.55: 500 ft-lbs x 2.99 x 3.55 = 5,307 ft-lbs delivered to the rear wheels

Assume my car's weight with some weight reduction: 3,680 lbs w/ 1/2 tank of gas: 3680/5307 = 0.6934 lbs per ft-lbs

Stock ZL1: 650 ft-lbs: 2.99 2nd, 2.85 rear diff: 650 x 2.99 * 2.85 = 5,538 ft-lbs. to the rear wheels

Stock ZL1 A10 w/ 1/2 tank = 3,875 lbs: 3875/5538 = 0.6997 lbs per ft-lbs.

That is at torque peak in 2nd gear for each car. That should explain why, at least under certain circumstances, a FBO E85 GT A10 PP1 would hang right with a stock ZL1 as the GT would actually have a slight lbs/ft-lbs advantage (lower is better, just like with lbs/hp). However, eventually, the higher hp would win out as these close torque match occurrences become less frequent over time.

Those torque values are about 4% apart and when adjusting for weight, are within 1% of each other. That means, momentarily, the GT and ZL1 would accelerate at about the same rate in 2nd gear. The Coyote breathes well up top and the ZL1 is supercharged, so both have flat high rpm hp curves, so they will both accelerate at similar levels through 2nd gear. You could do the same calc at peak power (convert hp to torque) and see how they compare at the high end. This would hold up in 3rd and 4th gear as well. Eventually, those close torque matches will be less frequent, favoring the higher hp ZL1 over time.

Another caveat to this is at higher speeds, the cars might start to be in different gears for longer. For example, at 100 mph the ZL1 might still be in 4th because of the 2.85 gearing, while the GT shifts to 5th despite the rpm advantage the GT shares, it's not enough to overcome the difference in gearing. As those types of things start to happen, over time, the ZL1 pulls away. They occur in much shorter durations in low gears so they aren't very substantial.

Of course, all bets go out the window if you start to mod the ZL1.

Acceleration could be modeled, but to have any accuracy you'd need to use the power curve as an input rather than a single torque peak value. The "lb / (lb-ft)" metric is essentially meaningless.

For instance, your example implies I could take a stock 2.0T Camaro auto and simply swap the rear axle ratio to a theoretical 5.40:1 and it would hang with a ZL1 from an acceleration standpoint.

2.0T Camaro: 2nd gear = 3.04; Theoritical Axle ratio: 5.4; Torque Peak:
295 lb-ft results in 0.689 lb / (lb-ft).


I think we can all agree that is not realistic.

[vtirocz]

Originally Posted by RobbyBeefcake87

That launch technique is what I started doing this past weekend for my best times yet. Kind of followed all you fast guys advice. The time out before that I was slipping from idle or a little higher and getting to 60 a 2.2 which was way better than any rpm dump (I won't dump at the track at a high rpm at all though) or launch control got me in the past.

The jury is still put for me on NLS on the 1-2 shift. I took video at the track and it is so much more violent and aggressive by regular power shifting than nls... I still like nls on the 2-3 and 3-4 though or for roll racing.

Regarding your comments on NLS: That's surprising to me. I have quite a few passes using the feature and not using it and I don't think any of my passes while not using it were below 12.5s.

The NLS tune on the non-1LE SS cars is aggressive (6400rpm speed target vs. 5000rpm) and if track conditions aren't optimal can result in significant wheelspin on the 1-2 shift. On occasion, I do the 1-2 shift regularly (softer) to prevent this wheel spin on the shift. But for best times, I've found I need to use it on all shifts.

[shaffe]

Originally Posted by BlaqWhole

That makes sense. However there is a way we could see it. If 2 cars had diagnostic equipment attached and ran their cars while recording the data...and then overlayed that data on a split screen to show where each car is and the MPH, then we could see exactly what is happening and how it is happening. If the GT with those mods could get a good enough jump, then it would take the Zl1 even longer to catch it. Same with ZL1 vs HC videos that I have seen. In some of them, the HC was not able to catch the ZL1 at all because the ZL1 got that good of a jump. And of course, the faster you're going, the faster someone else will have to go to catch up.

Yes and no. Idaho explained it more technically then I could but eventually that aggressive gearing in the Mustang will hurt it more than help it especially at the speeds most roll races get to.

I remember my previous mustangs I put 4.10s in both of them and by around the 1000 ft mark they pretty much had nothing left in the tank

[RobbyBeefcake87]

Originally Posted by s346k

isnt bradenton the new atco? isn't that where the fast cars go in the winter to make hero passes now?

It's definitely a good track, the house of hook they call it, I've just always MPH'd higher in Orlando. Someone once mentioned a slight down hill gradient, idk if that is true, but Bradenton is definitely nicer and better prepped at any given night. That extra good prep doesn't really do anything for a slow stock ss 1le on stock rubber though lol.


Both hold big events though, both solid tracks. FL2k is always at BMP and I'm going to the big Cadillac Attack event at OSW in late January for the new LT class (spectate not race, my car is slow and stock.

FL humidity will keep BMP from being the new ATCO but I want to go back to Bradenton on a cold night in January, every cold week we've had here so far heats back up by the weekend to nothing lower than 70.

[Idaho2018GTPremium]

Originally Posted by vtirocz

Acceleration could be modeled, but to have any accuracy you'd need to use the power curve as an input rather than a single torque peak value. The "lb / (lb-ft)" metric is essentially meaningless.

For instance, your example implies I could take a stock 2.0T Camaro auto and simply swap the rear axle ratio to a theoretical 5.40:1 and it would hang with a ZL1 from an acceleration standpoint.

2.0T Camaro: 2nd gear = 3.04; Theoritical Axle ratio: 5.4; Torque Peak:
295 lb-ft results in 0.689 lb / (lb-ft).


I think we can all agree that is not realistic.

I agree - you'd have to plot the torque curve at ~50 or 100 rpm increments to see what is really going on, and then, overlay it with mph. I was trying to point out that it is only momentary. And it is true that for a brief moment, that little 5.4 rear diff 2.0T Camaro would accelerate as quickly as a ZL1. But only for that exact moment where there's a torque advantage through gearing. There's not enough power in that engine to make it last. A 500 rwhp GT has enough power to make that momentary acceleration capability more frequent and last longer, thus, it would hang longer. But ultimately, the ZL1's higher power would win out.

[RobbyBeefcake87]

Originally Posted by vtirocz

Regarding your comments on NLS: That's surprising to me. I have quite a few passes using the feature and not using it and I don't think any of my passes while not using it were below 12.5s.

The NLS tune on the non-1LE SS cars is aggressive (6400rpm speed target vs. 5000rpm) and if track conditions aren't optimal can result in significant wheelspin on the 1-2 shift. On occasion, I do the 1-2 shift regularly (softer) to prevent this wheel spin on the shift. But for best times, I've found I need to use it on all shifts.

Yea, I still need to test that out further because for the longest time I was convinced NLS was better without question but my last trip to the strip didn't really show me anything tangible.

I will say that I used to nls using the heads up display for rpm reference, and now that I'm running faster at the strip I use the tach which I feel lets me get a more accurate and larger reading of rpm. So maybe next time out I will nls using the tach for reference to get closer to 6500rpm. As I believe only looking at the HUD in the past, I many times shifted a little early to avoid accidentally hitting the limiter.

I also want to try the 1-2 with a regular power shift then nls 2-3 and 3-4. I have a hunch that will work out nicely.

[s346k]

Originally Posted by RobbyBeefcake87

...my car is slow and stock.

your car went 12.0 @ 120 stock?

[Martinjlm]

Just to lighten the mood a bit....

[arpad_m]

Originally Posted by Martinjlm

Just to lighten the mood a bit....

Just what the doctor ordered, a juicy holiday roast

[UnknownJinX]

Originally Posted by Martinjlm

Just to lighten the mood a bit....

Should be "a Mustang that doesn't crash into crowds."

Sent from toaster or something

[wnta1ss]

Originally Posted by s346k

your car went 12.0 @ 120 stock?

I believe that 120mph was with his 5.0 Mustang which is very much not stock (Procharger blower etc).

[s346k]

Originally Posted by wnta1ss

I believe that 120mph was with his 5.0 Mustang which is very much not stock (Procharger blower etc).

doubtful. a friend of mine has a 19 pp1 a10 car that went 11.5 @ 120 with a jlt cai and e85 only. that same car trapped 130 with a very soft 93 octane tune, 5 psi and a p1x.

[wnta1ss]

Originally Posted by s346k

doubtful. a friend of mine has a 19 pp1 a10 car that went 11.5 @ 120 with a jlt cai and e85 only. that same car trapped 130 with a very soft 93 octane tune, 5 psi and a p1x.

Yes indeed, it was his supercharged Mustang. I think his 2019 5.0 is an M6 and that could make a difference from your friend's A10. BTW I've seen an M6 Coyote with 600 supercharged hp (that's what he told me) on drag radials here and he only got 11.9@120 with his. Below is the text from when Robby answered Idaho2018's question about his Mustang trap speed:

Yea I know, that's why I took the car out really, I knew the 60 would kill it so just wanted to test for mph. I hit 120mph, which was alright and about where I wanted it to be, mind you this is Bradenton where a stock 18+ m6 5.0 is trapping 108-111. Orlando Speed Way would be better, always mph better there.

[s346k]

ah 10-4. i didn't know the m6 cars were that much slower. one of my other friends has an 18 m6 pp1 car, id put it around 118-119 with jlt & e85 only.