SPF at Road America - How Fast?

Re: ZFQ new proposed GT40 transaxle

:icon_bs:

Tom--I was there and saw it myself.

Kirby Schrader, who wasn't even trying very hard, hit 175 mph or thereabouts in his Superformance during the no-helmet parade laps!

There's video on Youtube of a Can Am car hitting 189 mph at the end of the same straight.

Road America is a big, FAST track! :thumbsup:
 

Ron Earp

Admin
Re: ZFQ new proposed GT40 transaxle

Pretty easy to find out what the cars run there. What group are they in the Brian Redman weekend? The results will be on MyLaps.

I've never raced up there but would like to. For reference the winning Spec Miata time there at the boreoffs this year was 2:44, equating to a average speed of 87.32 mph. These cars top out around 125mph there. Clearly this track does not reward momentum cars like a Miata.
 
Re: ZFQ new proposed GT40 transaxle

Tom--I was there and saw it myself.

Kirby Schrader, who wasn't even trying very hard, hit 175 mph or thereabouts in his Superformance during the no-helmet parade laps!

There's video on Youtube of a Can Am car hitting 189 mph at the end of the same straight.

Road America is a big, FAST track! :thumbsup:
I'm curious how you "saw" it going 190+? Was this by GPS or other telemetry?

Was that 175 on Kirby's speedo??? Gotta question a sanctioning body that would allow 175mph on parade laps.

LOL...that CanAm (at 1600#) had over 1000 HP, and he still didn't make 190.

The Audi ALMS P1 cars hit 195 before Canada, and that's only because they go thru the kink at 165. I'm sure the aero slows them down at the far end, but it's that same aero that allows them to flat it thru the kink.
 
Radar gunned the Shadow (vintage can-am) several years ago at 199mph on the second long straight. It consistantly hit 195-197mph.

Brian
 

Jack Houpe

GT40s Supporter
Tom, it was group 11 race laps not parade, there wasn't any speed limit, I easily hit 150 in the straight 1 time, then that first corner came up a little to fast and my brake adjustment was to much to the front of the car so the rest of the race I acted like I was on a Sunday drive and just let people take pictures for the rest of the race.
 

Kirby Schrader

They're mostly silver
Lifetime Supporter
Re: ZFQ new proposed GT40 transaxle

Before this gets a little out of hand...

No, I did NOT do anything of the sort during the parade laps. This was during the Group 11 run on Sunday morning where we all had to wear helmets, etc.

I was on the track three times... On Saturday, Group 11.
On Sunday morning early with no helmets and touring around.
On Sunday later in Group 11 again.

The pace car had pulled off and I thought I'd see what it would do on the front straight. I backed off early since I had no idea how the car would stop from that speed and there was a corner approaching.

With the setup I have, theoretically the car should do over 200mph before redline at 7,000rpm. I have a .652 5th.

I saw the speedo going past 170 and that's when I chickened out. The speedometer is a electronic unit which we calibrated on 'Jack's 2 mile calibration strip' in Arkansas. It is pretty close based on further driving on the freeway between mile markers.

FWIW,
Kirby


Tom--I was there and saw it myself.

Kirby Schrader, who wasn't even trying very hard, hit 175 mph or thereabouts in his Superformance during the no-helmet parade laps!

There's video on Youtube of a Can Am car hitting 189 mph at the end of the same straight.

Road America is a big, FAST track! :thumbsup:
 
Hi Guys

Dennis Olthoff's SPF has 540 RW HP and higher profile rear tires for the race and he is one hell of a driver.

Regards

Chris.
 
Finally a chance to chime in.
At Road America I was just touching 6200 rpm. With the tire diameter and gearing it calculates to 174 mph.
The bias ply Good Years do grow slightly at speed so I would guess 175 would be accurate.

At Road Atlanta we were just over 6000 rpm on the back straight with the same tires and gearing.

Cheers
Dennis.
 
So Dennis, Chris was using a bit of fishermans 'Creative HP' when he credited you with *190 mph plus*? :)

@ about 28.2 mph per 1000 it would need to be up @ nearly 6800 for 190mph.
 
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Dennis and Kirby

Thanks for setting the record straight. "The tales grow taller on down the line" is a profound statement. It's often misunderstood how exponentially harder it is to reach 190 on a closed course straightaway than 175 (or even 175 versus 150). I learned a long time ago to never trust lap times taken from a stopwatch or top speeds taken from someone's speedometer. Show me the telemetry or GPS.

Chris, sorry I had to throw the flag up on that one, bud. Certainly, that doesn't detract from the fine showing by Dennis, his SPF, and the ZFQ. Congrats to all.
 

Keith

Moderator
I just watched an old Fifth Gear on TV and saw a 25 year old absolutely stock looking Sierra Cosworth saloon car, 2 litres or so 4 banger turbo with some nitrous added go 206 mph on a 2 mile airfield runway - verified by independent timing and an incar camera with a specially fitted digital speedometer display.

He reckoned the horsepower was over 700 and it cost around £35,000 and 6 years of work to get it there. What surprised me is how stable the thing was (the driver only had one hand on the wheel) with zero aero aids apart from the small stock trunk lid variety.

Surely a much lighter 540 rwhp GT40 geared appropriately could achieve that with it's more slippery shape in under that distance?
 
I just watched an old Fifth Gear on TV and saw a 25 year old absolutely stock looking Sierra Cosworth saloon car, 2 litres or so 4 banger turbo with some nitrous added go 206 mph on a 2 mile airfield runway - verified by independent timing and an incar camera with a specially fitted digital speedometer display.

He reckoned the horsepower was over 700 and it cost around £35,000 and 6 years of work to get it there. What surprised me is how stable the thing was (the driver only had one hand on the wheel) with zero aero aids apart from the small stock trunk lid variety.

Surely a much lighter 540 rwhp GT40 geared appropriately could achieve that with it's more slippery shape in under that distance?

Keith, my guess is not the question of if an SPF will do 200, more was the question of if an SPF will do 200 on Road America.
 
Keith, my guess is not the question of if an SPF will do 200, more was the question of if an SPF will do 200 on Road America.

That's like asking how long is a piece of string? Gear ratio's, RPM's and HP
would tell the tale.. Road America is pretty fast on the straight.
 

Keith

Moderator
Keith, my guess is not the question of if an SPF will do 200, more was the question of if an SPF will do 200 on Road America.

Understood but having no idea what the actual length of the straightaway (sorry, hangover from my Talladega days :stunned:) main straight is. This Sierra achieved that from a standing start within 2 miles.

By the way, I am not dissing anyone's achievement here and not disbelieving any statements made, but the 200 mph question has come up with the '40's time and time again since I've been a member here for some 5 almost 6 years.

Understandable why owners should treat that as a magic figure given the Mulsanne history, just wondered if anyone has actually done it and what the kind of stats are from that effort.

Sorry if this is the wrong thread. If anyone IS interested further, then perhaps they could start a "200 mph" thread! I'll go with the majority on this one... bench racing is absolutely fine - it's what I do best now I'm fat old and falling to bits... :drunk:
 
Understood but having no idea what the actual length of the straightaway (sorry, hangover from my Talladega days :stunned:) main straight is. This Sierra achieved that from a standing start within 2 miles.

By the way, I am not dissing anyone's achievement here and not disbelieving any statements made, but the 200 mph question has come up with the '40's time and time again since I've been a member here for some 5 almost 6 years.

Understandable why owners should treat that as a magic figure given the Mulsanne history, just wondered if anyone has actually done it and what the kind of stats are from that effort.

Sorry if this is the wrong thread. If anyone IS interested further, then perhaps they could start a "200 mph" thread! I'll go with the majority on this one... bench racing is absolutely fine - it's what I do best now I'm fat old and falling to bits... :drunk:

Keith, fair enough. I would like to see if it is possible. I bet it is but that is me just bench racing.
 
Guys,

After having worked the speed traps on the back straight at Road America back in the early 1970s, the top speed of the Can Am cars never exceed 165 MPH (from memory). The cars were pushing somewhere around 500 hp, and are what they are.

The speed trap was located on the back straight, just before the brake markers heading down to corner 5, because it was faster than the main straight, which was much longer.

Presumably the higher speeds are achieved on the main straight?

Thanks
Dom
 
Guys,

After having worked the speed traps on the back straight at Road America back in the early 1970s, the top speed of the Can Am cars never exceed 165 MPH (from memory). The cars were pushing somewhere around 500 hp, and are what they are.

The speed trap was located on the back straight, just before the brake markers heading down to corner 5, because it was faster than the main straight, which was much longer.

Presumably the higher speeds are achieved on the main straight?

Thanks
Dom

You have to remember that fully the first 1/3 of the main straight is compromised by a substantial uphill grade.
 
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