The 2011+ Mustang Thread

[BigDan]

Originally Posted by Speedy1975

Are we seeing mutiple GT500s bone stock with slicks and skinnes running times and speeds like that? And by bone stock does that mean full interior, trunk and all that jazz as well?

Yes and yes

There is about 5 or so members on SVTP running 11.5 and under on stock powered and stock weight GT500's. There is even a member with a stock eaton with the stock pulley running well into the 10's.

[THE EVIL TW1N]

Originally Posted by thePill

GM would have to get the ZL1's weight down to 4000lbs if the MH3 was rated 620lb-ft at 4000lbs. I get between 4105 and 4155lbs with a manual (best case/worst case). I am assuming in the 4015lb figure that maximum weight was saved in the exhaust but that would be from an aftermarket source. OEM weights would be higher no doubt due to emission requirements and the pieces that come with that.

why would they have to get the weight down? 4100-4150lbs sounds about right for the ZL1. couldnt they just use the MH3 since its stronger than the MG9? it would probably be rated a bit lower (600ish tq??) @ 4100lbs, no?

[thePill]

Warning: This is a book...

GM chose the MG9 obviously because it is matched with the LSA, and that’s the engine they wanted because it is about $8,000 cheaper than the LS9 and easier than building and recertifying an LS3. GM stated it would be "at least" 550 horsepower and in all fairness, torque scales pretty evenly with horsepower in the LSA (LS motors in general). Undoubtedly, the ZL1 was going to produce the extra horsepower (and torque) by having the transmission rerated just as the old TR6060 MM6 was rated at 470lb-ft and later rerated at 500. I doubt they would have exceeded the 551 rating even though the ZL1 will weigh less than 4255lbs unless the transmission was rerated. The old/new MM6 had the same gearset and was rated at the same 4000lb vehicle weight, it would have been the same situation as now.

The transmission has limits though, and I initially thought that if the MM6 can do it, so can the MG9. The MM6 could have easily been rerated because of the 3130-3190lb curb weight of the Z06. I cannot confirm whether or not the Z06 used both old and new MM6’s or not but the LS7 HP/TQ still produces 505hp/470tq. Even still, the MM6 transmission was rerated, maybe a future LS7 bump to say maybe 535hp/500tq. Now same situation, different transmissions. The ZL1 will be lighter than the CTS-V and to its advantage, the transmission was rated for the CTS-V at 551 at 4255lbs. The MG9 could be rerated at a lower weight and actually handle a higher torque rating and obviously, actual torque. I can’t really use the MM6 as a standard because the transmission’s weight rating looks like a generic standard. In order for the MG9’s torque rating to go up, the actual vehicles weight has to come down and thereafter, be revalidated.

Disclaimer: I absolutely hate doing this but, in order to get a guesstimation on how much a transmission torque rating could reach by reducing weight, I have to use the SS’s M10 vs. the CTS-V’s MG9. I know they are completely different gearset’s and that would have a great effect on the final numbers but it’s the only numbers that are solid.

The M10’s rating is 430lb-ft at 3860lbs and the MG9’s rated at 550lb-ft (rounded down) at 4255lbs.
That is a 395lb and 120lb-ft difference between the two, so for every 99lbs (98.75) that is reduced, the transmission would be capable of an additional 30lb-ft rating.

4255lbs=550lb-ft
4156lbs=580lb-ft
4057lbs=610lb-ft

I think we can stop there, I do not see the ZL1 being sub 4000lbs, although you could go another 50lbs less for another 15lb-ft (4008lbs=625lb-ft). So what does that equal as far as an engine rating? If the LSA’s HP and TQ scales almost evenly, it would be about 631hp/625lb-ft at a 4008lb vehicle weight using an modified LSA and revalidated TR6060 MG9.


Again, this is ROUGH, but I had a lot of fun with this….One thing makes me uncomfortable with my theory though, Are they intending the ZL1 to weigh even closer to the 4255lbs than what I figured?

[thePill]

Originally Posted by THE EVIL TW1N

why would they have to get the weight down? 4100-4150lbs sounds about right for the ZL1. couldnt they just use the MH3 since its stronger than the MG9? it would probably be rated a bit lower (600ish tq??) @ 4100lbs, no?

Read above...

[thePill]

Originally Posted by THE EVIL TW1N

why would they have to get the weight down? 4100-4150lbs sounds about right for the ZL1. couldnt they just use the MH3 since its stronger than the MG9? it would probably be rated a bit lower (600ish tq??) @ 4100lbs, no?

Transmissions are rated between force (which comes from the engine) and resistance (which comes from weight and traction). The clutch/torque converter, transmission, driveshaft and rearend are in the middle. Force vs. resistance, without resistance the transmission would have an infinite torque rating. Reducing the amount of resistance would grant the transmission extra leeway on torque input.

Edit: Also, I do not have the solid numbers on the MH3, if it was rated at 4000lbs even then the ZL1 would have to match that.

[thePill]

Now... How do we modify an LSA to produce those numbers, how much would it cost, how fast can GM recertify the engine and will they do it?

(hand raised)
Number 3!!!! I have a question!!!!

[BigDan]

Couldn't GM just use torque management when the trans is in a vulnerable situation to keep the current trans.

[thePill]

Originally Posted by BigDan

Couldn't GM just use torque management when the trans is in a vulnerable situation to keep the current trans.

It's not that the MG9 is vulnerable, it can handle loads of torque. It just needs to be rated as such. If you got an idea though, lets hear it and if I got anything wrong upstairs let me know.

Edit: I am burnt out...

[Mr. Wyndham]

Originally Posted by thePill

Now... How do we modify an LSA to produce those numbers, how much would it cost, how fast can GM recertify the engine and will they do it?

(hand raised)
Number 3!!!! I have a question!!!!

Modifying the LSA to big power is as easy as farting into the throttle body...talk about a responsive motor.....certifying it? Hmmmmmm......now there's the trick.

[thePill]

Originally Posted by Dragoneye

Modifying the LSA to big power is as easy as farting into the throttle body...talk about a responsive motor.....certifying it? Hmmmmmm......now there's the trick.

Time for me to do some engine certification research.

[Mr. Wyndham]

Originally Posted by thePill

Time for me to do some engine certification research.

Heh. So I'll see you in a few months? Just Kidding...

Recertification takes weeks, iirc. Not only the physical testing of the engine (which is beyond rigorous), but tons of data analysis...plus there's always the emissions question. If it can't pass - it's not built.

[thePill]

Originally Posted by Dragoneye

Heh. So I'll see you in a few months? Just Kidding...

Recertification takes weeks, iirc. Not only the physical testing of the engine (which is beyond rigorous), but tons of data analysis...plus there's always the emissions question. If it can't pass - it's not built.

I think I have to pay for SAE J2723... Is that correct?

and SAE J1349, SAE J1995 too .. Its like $65 dollars per file.. thats garbage...

[Mr. Wyndham]

Originally Posted by thePill

I think I have to pay for SAE J2723... Is that correct?

Yeah, I'm sorry -- there's internal testing and validation, and then there's SAE certification which makes things "official", and allows the company to put the little "SAE" logo next to their dyno graphs. This ensures there's no 'underrating', or 'cheating' on advertised power/torque. All SAE hp/tq figures are accurate to within (I think) 5% allowing for manufacturing variables.

They need to pay the society for the service, though - you're right: an expert/representative actually stands right there as it happens...GM has opted to have all their powertrains SAE certified.

[thePill]

Originally Posted by Dragoneye

Yeah, I'm sorry -- there's internal testing and validation, and then there's SAE certification which makes things "official", and allows the company to put the little "SAE" logo next to their dyno graphs. This ensures there's no 'underrating', or 'cheating' on advertised power/torque. All SAE hp/tq figures are accurate to within (I think) 5% allowing for manufacturing variables.

They need to pay the society for the service, though - you're right: an expert/representative actually stands right there as it happens...GM has opted to have all their powertrains SAE certified.

Well, I have come to the conclusion that the TR6060 MG9 is capable of managing the horsepower and torque to match the rumored power output of the 2013 GT500. The TR6060 accomplishes this by having the intended vehicle's curb weight reduced below the original rating of 4255lbs. The transmission would have to be revalidated and I remind you that this is a rough estimate, but it seems very reasonable to me.