The gear ratios wouldn't do it as the GT manual is crossing near perfectly at the top of 4th.

Also, more traction can often/typically lower the mph. Look at what MM&FF did with street tires vs. slicks (112mph vs. 109mph) and I don't think there was any significant tire diameter difference.

For all intents and purposes, trap speeds represent power. We are not spliting hairs here talking about 110mph vs. 111mph. We are talking 112mph vs. 116mph.

In my opinion, the 116mph numbers are complete BS and must be the result of a GPS measurement or something similar. The power is not there for that kind of trap speed and we would have seen a lot of other times closer to it if it were.

 

You are correct. The 3.73's are geared perfectly for the 1/4......just like the like the lightning was.

 

The 115 trap speed is not BS. There is a copy of the timeslip (saw it on Camaro5).

However, I do enjoy just sitting back and watching all of this happening. Fun times in PonyCar land.

 

Disagree. I held the same position (3.73 being optimum) for a long time, and can assure you that I am a BIG fan of big gears (routinely run 4.56s on the street, and have run 4.88s) but was finally convinced otherwise. If your curious, read here: http://forums.themustangsource.com/s...d.php?t=482773

Especially page 2. There are other threads with similar content, if interested.

And then go out and look at who's running quicker (and better MPH) in stock trim: 3.73 geared cars, or 3.31 (don't know of any 3.55s yet).

Modified....all bets are off. Simply moving the rev limiter up would mean all bets are off.

EDIT: Here's a handy breakdown. 4th gear, 7000 rpm:

3.73 - 111.5 mph (18" All-Seasons 765 rpm) - 111.1 mph (19" All-Seasons 768 rpm) - 111.8 mph (19" Summer Rubber 763 rpm)

3.55 - 117.2 mph (18" All-Seasons 765 rpm) - 116.7 mph (19" All-Seasons 768 rpm) - 117.5 mph (19" Summer Rubber 763 rpm)

3.31 - 125.7 mph (18" All-Seasons 765 rpm) - 125.2 mph (19" All-Seasons 768 rpm) - 126.0 mph (19" Summer Rubber 763 rpm)

 

Interesting. So the 3.73's could use a little bump in rev limiter and 3.55's should be better than 3.31's.

 

So 115 and 116mph trap speeds should mean we will be seeing dyno numbers up around 385-395rwhp? That's a ballpark based on 03/04' Cobra traps, weight, dyno numbers. I haven't see any that high, are there some?

 

Trap speed is also affected by weight. The 03/04 Cobra was heavier than the 2010 GT.

 

Bumping the rev limiter would be of great help to 3.73s.

Most dynos runs are in the low 370s SAE. The A6 that went 12.73 @ 115 dyno'd at 362 SAE - which is a bit surprising given that it is an automatic. About that car...I think most folks are skeptical of the MPH (I am just a little), even though he ran 114-115 in both lanes, against a 5th Gen SS at least once. Nobody is accusing him of cheating, it is just somewhat hard to fathom. Even so, the ET is reasonable, and who really knows what kind of trap speed the cars will turn....this is the only A6 we've heard from.

Bob

 

115 mph traps are LS3 Corvette territory, which really makes you scratch your head. Still, timeslips are timeslips.

 

So if I was going to get a Mustang and add a supercharger to it would the 3.55 gears be better for the street than the 3.73?'s It seems 3.73's would just sit and spin and be an extremely short gear with a supercharger? I'm liking the new edelbrock superchargers and I've heard that Roush is testing superchargers for the 5.0.

 

I personally wouldn't put a blower on a stock 5.0 (or LS3/L99 for that matter), but if I did, I'd stick with the 3.31 gear, given the very aggressive transmission gearing.

 

115?

Sacramento dragstrip (where the run took place) has been having trap speed issues for YEARS. NHRA had them change their setup several years ago due to trap speeds being 5-6mph too high. They moved the beams closer together, and now it's only off 3-4mph.

To anyone that thinks 115mph traps from a stock automatic GT is plausible?

 

I think that what gets forgotten sometimes in the internet bench racing is that the standards for how a 1/4 mile and especially trap speed isn't as regulated as we would like across the nations tracks. It's not like NHRA Pro Stock recrods Mike Edwards 6.509 sec. ET at Richmond last year or Greg Andersons 212.46 mph pass in Charlotte a few months ago. Would the auto '11 GT run 115mph through the traps if the NHRA had a National Event weekend at Sacramento??

 

Huh, was thinking RDI (but they are IHRA), its confusing to see people refer to Dinwiddie as Richmond (since RDI is just a hope and a skip from the Richmond International Airport and Dinwiddie is out in the middle of nowhere).

 

Well 115mph does seem a little fast to me but I wasn't there. Good points made all around... maybe the light boxes were a little funny or maybe a tailwind. Who knows.