I've been pondering a few things, and I'd like to get some opinions as to the achievable top speeds for the "straights" at VIR.

Their web page says they are 3000 ft. and 4000 ft.

4.4 vs 4.9 FD (with a 5th gear of 0.848), or a 4.4 with a GSR gearbox.
Redline @~8900

How about if you had ~400 whp and ~300 lb/ft of tq and wanted to play with "larger displacement" cars?

Other tracks to consider would be the downhill back straight at Mid-Ohio and Road America in general.

In the immediate future the track tire will be a 205/55/16 with a diameter of 24.9".

 

Do you think you could hit 158.7 MPH on the long straights? That would be with a 4.9 FD.

4.7 would put you at 162ish.

4.4 would put you at 176.7.

All with stock ITR gearing and a redline of 8900.

BTW, a GSR gearbox has a 4.4 stock.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88 rex &raquo;</TD></TR><TR><TD CLASS="quote">4.4 would put you at 176.7.
All with stock ITR gearing and a redline of 8900. </TD></TR></TABLE>

Yeah, but the second part of the equation is aero drag and the power required to overcome it (depending on whether you're going down a hill or not like at Mid-Ohio).

I'm looking into a stock ITR box depending on the track, and the motor in use.

An 8 point cage, seats and belts aren't out of the question, eventually.

 

I can't really help you all that much there. I can only go by what the calculator tells me.

I've never seen track duty BUT I recall Barry (apexinghonda) mentioning running out of gear at Road Atlanta with a 4.7. I don't think he's putting down 220 hp but he's considerably lighter than you since he's in a stripped/caged CRX. I don't know how long the straights are there, but I'm pretty sure they are longer than VIR.

When I asked about running out of gear at VIR on the straigths I was told I would be just fine with my 4.7. I've got a stock motor and a my car wieghs 2130 with me in it.

If I had to wager a guess I'd err on the side of acceleration and hope that the gears aren't THAT short that you are at the limit for half the length of the straight.

Dunno if that helps at all. Curious to see what others have to say.

 

What are Franza and Grandpa hitting on the straights with their K's? What about Chris F? Has he run VIR full flat-out?

 

hehe ... these are usually closely held secrets!

Oh! Wait! I should just get a 6-speed for it!

 

i hate mustangs!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!

 

with my stock ITR. (225-50-15 tires) im shifting into fifth on the front and back straits. i know its 125+ but i cant remember the exact speed.

 

IIRC I read that Willard was able to reach 130-135 on the straight with a stock R.
But I can't find the thread.

 

Im curious to know as well. Im sure its fast enough to scare me in my car.

&lt;&lt;&lt; b00st + 4.05FD + 0-130mph in 1320ish feet...should be interesting

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TheOnlyBrooklynITR &raquo;</TD></TR><TR><TD CLASS="quote">IIRC I read that Willard was able to reach 130-135 on the straight with a stock R.
But I can't find the thread.
</TD></TR></TABLE>

That sounds about right and Will can drive the hell out of a stock ITR, too. It has an awful lot to do with how well you get through oak tree, also. (I always thought I left too much time on the table through there because I suck.)

If I remember correctly, I think I would hit around 140-142 indicated on the back straight in the H2 car. With the H1 car, I'm guessing one could see 150+, although I haven't done any gear calculations to see what top speed could actually be achieved with the 6-speed/5.0 final combination.

Jason-
who's got his fingers crossed that there will be an Expo at full come June

 

I agree, that sounds about right for a really fast driver. I was using fifth gear and getting to the mid 120s there a few weeks ago on both straights. I know I'm not as fast as I could be through the turns leading onto both straights, partly because I'm not as fast as some other drivers, partly because this was only my second time at VIR and haven't yet gotten comfortable with going faster and getting on the gas sooner in oak tree and hog pen, which is what it takes to be faster at the end of both straights. Shorter gearing might help or hurt, depending on whether or not it prevents you from using a lower gear for quicker acceleration out of those turns at the start of the straights.

Those with little to no track experience probably won't need fifth gear at all. A stock USIM ITR reaches the indicated 8400 RPM redline at 117.6 mph, and the rev limiter allows you a few hundred RPM higher than that.

 

I have a recent car & driver that tested a bunch of cars at VIR including the new Z06 and Ford GT so I'll have to dig that up. I know none of the H1 cars will approach the top speeds of those cars so that will give you a good indication of the straight away speeds. Also remember Honda tach and speedos are terrible for being accurate. You are never traveling as fast as you think you are unless you got a set of 80 series tires on the car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">I have a recent car & driver that tested a bunch of cars at VIR including the new Z06 and Ford GT so I'll have to dig that up. I know none of the H1 cars will approach the top speeds of those cars so that will give you a good indication of the straight away speeds.</TD></TR></TABLE>

Remember, there's a difference between cars that are drag-limited, and cars that are gearing-limited - even more so when shorter gears are installed. It's easy to calculate the top speed at redline in the top gear, for any car. Whether or not the car can actually achieve this speed depends on whether it has enough power to overcome aerodynamic drag. In order to try it, you normally need a straightaway that's several miles long (or a facility with a high-banked oval). With shorter gearing, the top speed is reduced, so the car may become gearing-limited, and you may be able to achive that lower speed on a racetrack straight under a mile long.

In the stock USIM ITR, the top speed at 8400 RPM with the stock gears is 153.6 mph. I'm not positive, but I think you can't get over the mid 140's with a stock car. Throw in the 4.928 ATS final drive gear, and the top speed becomes 137.1 mph, and a good driver may be able to hit it on a track with long straights, like VIR, Road America, or Road Atlanta (probably not Mid-Ohio though).

On the '91-96 NSX, the calculated top speed at redline is 186 mph, but the car will only go up to 168 mph.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">Also remember Honda tach and speedos are terrible for being accurate.</TD></TR></TABLE>

Don't know about the tach, but the speedos on all my Honda/Acura cars are quite accurate when I'm using the stock size tires.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">You are never traveling as fast as you think you are unless you got a set of 80 series tires on the car.</TD></TR></TABLE>

The accuracy of the speedometer depends on the outer diameter of the tire size, not just the aspect ratio. And I don't know of any tire sizes with an 80 aspect ratio that will fit our cars.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Back in Black &raquo;</TD></TR><TR><TD CLASS="quote">

With the H1 car, I'm guessing one could see 150+, although I haven't done any gear calculations to see what top speed could actually be achieved with the 6-speed/5.0 final combination.

Jason-
who's got his fingers crossed that there will be an Expo at full come June </TD></TR></TABLE>

k20a with the 5.06(crv fd) would have a gear limited top speed of close to 150(about 147-149 i believe)with a redline of 8500. If you are stretching your redline further than that...may god have mercy on your engine and obviously the top speed number is going to go up a little bit.

 

ive found in a stock R that shifting into 2nd at the oak tree is a real big help to reaching a top speed on the back strait.... one of my instructors told me that 2nd isnt necessary because its just added abuse to the tranny. i agreed with him at first because i knew that i was no competition for a drag race down the back strait. then as i got comfy with oak tree, i started using 2nd more, and man what a big big difference.

but i still am pondering whether or not i should shift into 2nd during turn 1/2.. because i come out of it kind of slow when im in 3rd.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">
How about if you had ~400 whp and ~300 lb/ft of tq and wanted to play with "larger displacement" cars?
</TD></TR></TABLE>

ED, what are you thinking of doing?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ross &raquo;</TD></TR><TR><TD CLASS="quote">ED, what are you thinking of doing?</TD></TR></TABLE>
I think he is thinking about his turbo motor that he still has sitting around

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by baonest &raquo;</TD></TR><TR><TD CLASS="quote">ive found in a stock R that shifting into 2nd at the oak tree is a real big help to reaching a top speed on the back strait....</TD></TR></TABLE>



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by baonest &raquo;</TD></TR><TR><TD CLASS="quote">one of my instructors told me that 2nd isnt necessary because its just added abuse to the tranny.</TD></TR></TABLE>

Huh?

The only reason NOT to use second would be if you're going through oak tree so fast that you wouldn't be in second long enough (IOW if you spent more time shifting in and out of second than it would save in terms of better acceleration). As long as you're far enough below 60 that it helps long enough - and I think it does (carries you well past the trackout point before you have to upshift to third) - then it's to your advantage to use it.

However, even though second may be beneficial for an ITR with stock gears, it's possible that one with a shorter FD gear may not find it beneficial at all (because the shift points, i.e. speeds, on such a car are lowered).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by baonest &raquo;</TD></TR><TR><TD CLASS="quote">but i still am pondering whether or not i should shift into 2nd during turn 1/2.. because i come out of it kind of slow when im in 3rd. </TD></TR></TABLE>

IMHO second gear is not helpful there (horseshoe) because you aren't going slow enough to use it for very long. I think that turn seems slower than it is, because you just hauled down from perhaps the fastest speed you achieve on the entire track. Yes, it's a slow 180-degree turn, but it's not as sharp a turn as oak tree.

 

I never needed 2nd gear for Oak Tree in anything other than an LS tranny-equipped car. I'd work on carrying more speed through there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ford Prefect &raquo;</TD></TR><TR><TD CLASS="quote">
I think he is thinking about his turbo motor that he still has sitting around </TD></TR></TABLE>

I sincerely hope ED is not thinking of removing Bradstard's perfectly built NA motor in favor of the turbo motor that wouldn't run more than a few laps without getting way too hot?

ED - the car is perfect as is. Resist the urge to expletive it up. Please.

And, all this talk about top speed @ VIR is purely theoretical until you have some real track time under your belt. Even with 400 or 500 whp, you won't be able to reach these speeds until you really know what you're doing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ross &raquo;</TD></TR><TR><TD CLASS="quote">And, all this talk about top speed @ VIR is purely theoretical until you have some real track time under your belt. Even with 400 or 500 whp, you won't be able to reach these speeds until you really know what you're doing.</TD></TR></TABLE>
Especially in your case, Ross, I wouldn't worry about top speed. I hear they've handcuffed you to Will for the duration of the event, just to be safe.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ross &raquo;</TD></TR><TR><TD CLASS="quote">And, all this talk about top speed @ VIR is purely theoretical until you have some real track time under your belt. Even with 400 or 500 whp, you won't be able to reach these speeds until you really know what you're doing.</TD></TR></TABLE>

Ross, why does this always become some type pf pissing match with you?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">
Ross, why does this always become some type pf pissing match with you?</TD></TR></TABLE>

In his defence, I think your top speed before Turn One is going to be governed by your ability to get through Hogpen well, and your courage through the ltitle kink if you hit a bump while passing somebody.

Ross should probably have removed the you and substituted an indefinite pronoun.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW DC2R &raquo;</TD></TR><TR><TD CLASS="quote">Im curious to know as well. Im sure its fast enough to scare me in my car.

&lt;&lt;&lt; b00st + 4.05FD + 0-130mph in 1320ish feet...should be interesting </TD></TR></TABLE>

... and big brakes to go with the big 'nads!

My point here being that due to the incresed acceleration potential a higher "top speed" can be reached in the same distance than with a lower/slower accelerating car.

But hey, I was just asking for some technical info.

And that turbo motor was doomed from the get-go because the un-named builder recognized a problem with the sleeved block and tried to fix it with multiple bottles of Bar's Leak stop (as per GE's instructions).

So, let's leave that sleeping dog lie!