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Top Speed Etc.

ArizonaBOSS

Because racecar.
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Arizona, USA
Here's a pretty good approximation of what the top speeds are going to be in each gear, at the currently-forecasted 7400RPM power peak...

BOSSredlines.png
 
I am wondering if the TracKey will remove the 155MPH speed limiter. I was hoping we won't have to get an after-market tune just to get rid of that. Odds are pretty good though that we'll end up going with after-market tunes, but time will tell.
 
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5 DOT 0 said:
What do you think the actual top speed will be stock? 170+? Assuming the Trackey adds another 20 hp.

The RPM will drop to roughly 4900 at the 5 to 6 shift. If we assume that the Boss and GT make about the same power until ~6000 rpm, after the shift we will be sitting at ~320rwhp which should be plenty to continue to pull in 6th at only 162mph. At 180mph the Boss will be at about 5500 rpm and making somewhere in the neighborhood of 350rwhp.

My speculation (alot of that in this post) is that the Boss will top out somewhere in the neighborhood of 180-185. While I do think with different gearing it could hit 190 or so, the stock gearing will not be conducive to a big top end.

I base this on the fact that the 2000R reportedly could hit 180 and makes ~350 rwhp as delivered (Boss should be much slicker).

Of course this would all be based on removal of the limiter.
 

ArizonaBOSS

Because racecar.
Moderator
8,540
2,369
Arizona, USA
I'm betting at least 170, but will the car ever see that speed? Probably not. In a race application, the .65 (or whatever) 6th gear is going to make the car lay down once you get into 6th. It will still pull, but not nearly as quick as it did in 5th. True road-racing transmissions usually have a .85-.80 range OD gear that allows them to really use that final gear on-track. So I'm pretty happy to see that the car should be able to hit 160 in 5th.

As far as the track key is concerned, I thought I heard something about it removing the top speed limiter (might have been on the SPEED special). I believe the FRPP Pro-Cal tune for the regular 5.0 does this. So I'd be shocked if the Red Key tune didn't eliminate it as well.

And regarding no HP bump--even if peak HP is unchanged, that doesn't mean it's not making more HP elsewhere in the powerband. Adding more torque across the rev range will make a big difference in how the car accelerates.

I will definitely be getting my BOSS on the dyno for some back-to-back pulls w/ the track key and without, but considering I'm taking delivery in Q4'11, there should be a host of people that beat me to this task.
 
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ArizonaGT said:
I'm betting at least 170, but will the car ever see that speed? Probably not. In a race application, the .65 (or whatever) 6th gear is going to make the car lay down once you get into 6th. It will still pull, but not nearly as quick as it did in 5th. True road-racing transmissions usually have a .85-.80 range OD gear that allows them to really use that final gear on-track. So I'm pretty happy to see that the car should be able to hit 160 in 5th.

agreed. although I don't expect to spend much time in 6th on track, lol.

With the gearing it will be interesting to see one of those 0-150 tests. It's geared like a 7 speed that's missing 6th and should be alot of fun and super quick through 5 gears.
 

ArizonaBOSS

Because racecar.
Moderator
8,540
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Arizona, USA
Yeah, not anticipating using 6th much (if at all) on track. Again, glad 5th tops out around 160. The combination of this powertrain and gearbox seems really potent.
 
ArizonaGT said:
Yeah, not anticipating using 6th much (if at all) on track. Again, glad 5th tops out around 160. The combination of this powertrain and gearbox seems really potent.
Sounds like you have a lot more track experience than I do. Are there any tracks out West where a Boss could hit 160 or anywhere close to that? Seems like other than Fontana that might be a stretch. Do they ever do track days on the oval at Fontana? I've done a Mario Andretti experience there where we hit 180-190 on the back straight.
 

ArizonaBOSS

Because racecar.
Moderator
8,540
2,369
Arizona, USA
5 DOT 0 said:
Sounds like you have a lot more track experience than I do. Are there any tracks out West where a Boss could hit 160 or anywhere close to that? Seems like other than Fontana that might be a stretch. Do they ever do track days on the oval at Fontana? I've done a Mario Andretti experience there where we hit 180-190 on the back straight.

I can just about crack 140 at Firebird Main at 6500rpm in 4th in the 427R racer. I think that's probably about as fast as it's going to get in the Southwest or West Coast in a car with this power-to-weight (9.0:1). Firebird main has a half mile straight with about a 50mph entry.

Only "Oval" I've ever been on was Phoenix International, but in the Roval configuration...best most cars get is about 115-120 on the straight before diving down across the apron onto the infield course.

I haven't had the chance to get out to any of the California tracks yet :-/
 
5 DOT 0 said:
ArizonaGT said:
Yeah, not anticipating using 6th much (if at all) on track. Again, glad 5th tops out around 160. The combination of this powertrain and gearbox seems really potent.
Sounds like you have a lot more track experience than I do. Are there any tracks out West where a Boss could hit 160 or anywhere close to that? Seems like other than Fontana that might be a stretch. Do they ever do track days on the oval at Fontana? I've done a Mario Andretti experience there where we hit 180-190 on the back straight.
Hitting over 160 on any track is tough. I'm making 575/545 rwhp/rwtq in my GT500 (~4000 lbs) with 3.73 gears and fifth is .80. At 6100 RPMs you break 160 MPH with a 305/35/18 tire. My rev limiter is set at 6500. The only track I can hit this at (and not launch off turn 1) is Brainerd International which has a MILE long front straightaway with a 60 degree banked Turn 1 that lower horsepower cars take flat out. My GT500 isn't caged, so I'm usually out of the throttle at about 160, although there's a little more there, but would require some braking into Turn 1 (and balls of steel) which will just cost you time anyway. BIR is advertised as the fastest (top speed) track in the US. I'm sure others might argue that point, but the fact is in a car making around 400 rwhp and weighing 3600 lbs, it's unlikely there will be much opportunity to get it past 160 on a road course. If you were to run something like the Texas Mile or out on the salt flats, then you might be able to push it past 170 or 180. Either way I'm hoping TracKey disables the speed limiter.
 
5 DOT 0 said:
That's pretty fast. The only track large track I've ever driven is Sears Point during a Formula Ford class I took with Skip Barber. We were hitting over 100 going into the first corner but that was the fastest those cars would go.
It is fast, thus my comment about balls of steel. Trust me there's a pucker factor for me, but a little fear can also keep you alive. I probably should cage the car to run there, but haven't. I might do so with the Boss since I'm planning to turn my GT500 into my daily driver again.

Life is full of risk. I have seen some pretty wicked (likely fatal) wrecks along the highway on several of my trips back from the track. The statistics say your risk of something bad happening is lower on a closed course than just everyday highway driving. No animals to jump out at you, everyone travelling the same direction and for the most part more capable drivers. More importantly, no one is texting or drunk!
 
5 DOT 0 said:
Cloud9, I bet that would be pretty hair, and fun, going into a banked corner like that at 160. But only after lots of practice.
Trust me I "waded" into the deep end. Staying in it just a little longer each lap until you're comfortable. I still slow just by letting off the throttle to around 145 as I enter the turn. The Porsches and BMWs typically top out there and will flat foot it all the way through, whereas I just "maintain" speed at about half throttle. I'm hoping I can be more "flat foot" in the Boss, but will have to see.
 
As we're talking about these top speeds, it occurred to me about the hood design on the Boss. I put hood pins in my GT500 because of the hood flutter I would get over about 130 mph. I just didn't want to worry about that thing coming up at high speeds. I like the re-design of the 2010+ GT500 where the hood sits inside the front grille and is not subject to the same buffeting as the 07-09 design. Looking at the Boss it seems to have the same type of overhanging hood as my GT500. I wonder if there's any risk of it flying open at high speeds? Not that it's a big deal to add hood pins, but just curious. It's probably the same design as the 2011 5.0?
 
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cloud9 said:
Hitting over 160 on any track is tough. I'm making 575/545 rwhp/rwtq in my GT500 (~4000 lbs) with 3.73 gears and fifth is .80. At 6100 RPMs you break 160 MPH with a 305/35/18 tire. My rev limiter is set at 6500. The only track I can hit this at (and not launch off turn 1) is Brainerd International which has a MILE long front straightaway with a 60 degree banked Turn 1 that lower horsepower cars take flat out. My GT500 isn't caged, so I'm usually out of the throttle at about 160, although there's a little more there, but would require some braking into Turn 1 (and balls of steel) which will just cost you time anyway. BIR is advertised as the fastest (top speed) track in the US. I'm sure others might argue that point, but the fact is in a car making around 400 rwhp and weighing 3600 lbs, it's unlikely there will be much opportunity to get it past 160 on a road course. If you were to run something like the Texas Mile or out on the salt flats, then you might be able to push it past 170 or 180. Either way I'm hoping TracKey disables the speed limiter.

good post
 
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cloud9 said:
As we're talking about these top speeds, it occurred to me about the hood design on the Boss. I put hood pins in my GT500 because of the hood flutter I would get over about 130 mph. I just didn't want to worry about that thing coming up at high speeds. I like the re-design of the 2010+ GT500 where the hood sits inside the front grille and is not subject to the same buffeting as the 07-09 design. Looking at the Boss it seems to have the same type of overhanging hood as my GT500. I wonder if there's any risk of it flying open at high speeds? Not that it's a big deal to add hood pins, but just curious. It's probably the same design as the 2011 5.0?

I went back and looked at the 302R and 302S and most appear to have hood pins. Although much of the flutter could be caused by a lack of stiffness at the center/back and there are some fairly significant differences in the new hoods that could make this a non issue. Namely the two deep creases around the center bulge that I imagine stiffen up the hood considerably vs the 07-09 GT500 hood.

2011_ford_mustang_2.jpg


vs.

images
 

ArizonaBOSS

Because racecar.
Moderator
8,540
2,369
Arizona, USA
cloud9 said:
As we're talking about these top speeds, it occurred to me about the hood design on the Boss. I put hood pins in my GT500 because of the hood flutter I would get over about 130 mph. I just didn't want to worry about that thing coming up at high speeds. I like the re-design of the 2010+ GT500 where the hood sits inside the front grille and is not subject to the same buffeting as the 07-09 design. Looking at the Boss it seems to have the same type of overhanging hood as my GT500. I wonder if there's any risk of it flying open at high speeds? Not that it's a big deal to add hood pins, but just curious. It's probably the same design as the 2011 5.0?

The BOSS and GT share the same hood and grille surround (although the BOSS grille surround is painted). If the GT doesn't have the hood flutter issue on 10+, the BOSS won't either.

The 302R and 302S use hood pins because they eliminate the stock latching system to save weight.
 
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cloud9 said:
As we're talking about these top speeds, it occurred to me about the hood design on the Boss. I put hood pins in my GT500 because of the hood flutter I would get over about 130 mph. I just didn't want to worry about that thing coming up at high speeds. I like the re-design of the 2010+ GT500 where the hood sits inside the front grille and is not subject to the same buffeting as the 07-09 design. Looking at the Boss it seems to have the same type of overhanging hood as my GT500. I wonder if there's any risk of it flying open at high speeds? Not that it's a big deal to add hood pins, but just curious. It's probably the same design as the 2011 5.0?

Good question - you might want to ask on a forum with racing GT owners to see what they've experienced
 

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