Dyno results from “Bonneville” motor, 765 WHP, 900 CHP
03-10-2011, 03:20 PM
#151
Rennlist Member
231mph. / 60
3.85miles per min
x 5280 = ft per min = 20328
x 12 = Inches per min = 2438936
/ 90" for circumference = 2710 RPM at the wheels!
x 2.2 for ratio of the rear end, thats 6000rpm
or, for 7000rpm, thats 271mph
so, if you count on 8-10% slip, you will need 7000rpm to hit 231mph
28.5diameter = Pi x Diameter= 89.5"
3.85miles per min
x 5280 = ft per min = 20328
x 12 = Inches per min = 2438936
/ 90" for circumference = 2710 RPM at the wheels!
x 2.2 for ratio of the rear end, thats 6000rpm
or, for 7000rpm, thats 271mph
so, if you count on 8-10% slip, you will need 7000rpm to hit 231mph
28.5diameter = Pi x Diameter= 89.5"
03-10-2011, 04:19 PM
#152
Burning Brakes
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you cant go 190mph at 7000rpm in 4th gear. you may in your calculations, but your calculations include some gross errors in ratios. the manual doesnt have a typo, it is correct. we have posted this stuff many times before. we also know there is a difference in tire diamter from 26" as I use to 27.5" as Carl uses. Its about 6% diff. so, if i hit 155 in 4th, carl will hit 163mph in 4th. And, if you go to 7000rpm over my 6500rpm, that puts it about 175 mph in 4th.
Car, if you saw 195mph on the dyno in 4th, verifying your numbers thatwere missing the layshaft ratios, someone was smokin something!
Mark, it may seem like too much of an RPM drop, but that is the beauty of the 2.2 box. 50% rpm drop from 4th to 5th. all other ratios, rpm end up about 72% of the prior pre shift rpm
Car, if you saw 195mph on the dyno in 4th, verifying your numbers thatwere missing the layshaft ratios, someone was smokin something!
Mark, it may seem like too much of an RPM drop, but that is the beauty of the 2.2 box. 50% rpm drop from 4th to 5th. all other ratios, rpm end up about 72% of the prior pre shift rpm
03-10-2011, 05:23 PM
#153
Developer
Thread Starter
Kibort - thanks! I didnt know that and that does explain the Tech Spec book.
But I have yet to understand then why we saw 198MPH at 6800 rpm in 4th with these tires. And we did.
Whatever - I am going back with the big wide tires, and we will note what we get this time.
But I have yet to understand then why we saw 198MPH at 6800 rpm in 4th with these tires. And we did.
Whatever - I am going back with the big wide tires, and we will note what we get this time.
03-10-2011, 05:42 PM
#154
Three Wheelin'
The most important thing is it goes straight & stays on the ground. If it doesn't track well, nothing else matters.
This is well worth looking at and contacting them for chassis advice.
http://www.kugelkomponents.com/bonne...ville_news.php
I read somewhere that their car weighs something like 4800 lbs +-. They also modified the shock towers to add caster (keeps it straight) & greatly stiffened up the rear suspension
so it didn't squat at speed. Note that they used the stock small spoiler.
This is well worth looking at and contacting them for chassis advice.
http://www.kugelkomponents.com/bonne...ville_news.php
I read somewhere that their car weighs something like 4800 lbs +-. They also modified the shock towers to add caster (keeps it straight) & greatly stiffened up the rear suspension
so it didn't squat at speed. Note that they used the stock small spoiler.
03-10-2011, 06:10 PM
#155
Developer
Thread Starter
Yes, adding max caster is common, as are chopped and customized spindles.
Here is one of those places where it's "compromise time"
This car is a road racer turned land speed racer temporarily. We have every intention of returning to road racing after this.
So how far do we want to go in making this a dedicated purpose-built land speed car? Answer: not so far that I cant get back.
There will be compromises, it will be something less than a dead-nuts land speed racer but hopefully good enough to do the job.
Here is one of those places where it's "compromise time"
This car is a road racer turned land speed racer temporarily. We have every intention of returning to road racing after this.
So how far do we want to go in making this a dedicated purpose-built land speed car? Answer: not so far that I cant get back.
There will be compromises, it will be something less than a dead-nuts land speed racer but hopefully good enough to do the job.
Last edited by Carl Fausett; 03-10-2011 at 08:58 PM.
03-10-2011, 07:04 PM
#156
Rennlist Member
Its not going to squat at speed, as there will be plenty of lift making this car actually lighter.
The most important thing is it goes straight & stays on the ground. If it doesn't track well, nothing else matters.
This is well worth looking at and contacting them for chassis advice.
http://www.kugelkomponents.com/bonne...ville_news.php
I read somewhere that their car weighs something like 4800 lbs +-. They also modified the shock towers to add caster (keeps it straight) & greatly stiffened up the rear suspension
so it didn't squat at speed. Note that they used the stock small spoiler.
This is well worth looking at and contacting them for chassis advice.
http://www.kugelkomponents.com/bonne...ville_news.php
I read somewhere that their car weighs something like 4800 lbs +-. They also modified the shock towers to add caster (keeps it straight) & greatly stiffened up the rear suspension
so it didn't squat at speed. Note that they used the stock small spoiler.
03-10-2011, 07:07 PM
#157
Rennlist Member
Good, now you got the right numbers. you need them on the way up to 230mph, but in the end, it doesnt really matter, as after 160, you are in 5th anyway, and your car will have no problem reaching 170mph in its sleep.
you didnt see 198mph, you saw a system that printed out 198mph because it was confused. garbage in garbage out as they say.
you can clearly do the math and see that the final ratio is 3.2:1 for 4th. its 50% of the 2.2 gear. you can spin the crank and prove it to yourself.
you probably left off the gear ratio on the dyno or used the wrong ones that you saw on your spreadsheet . that would explain it.
you didnt see 198mph, you saw a system that printed out 198mph because it was confused.
garbage in garbage out as they say.you can clearly do the math and see that the final ratio is 3.2:1 for 4th. its 50% of the 2.2 gear. you can spin the crank and prove it to yourself.
you probably left off the gear ratio on the dyno or used the wrong ones that you saw on your spreadsheet . that would explain it.
Kibort - thanks! I didnt know that and that does explain the Tech Spec book.
But I have yet to understand then why we saw 198MPH at 6800 rpm in 4th with these tires. And we did.
Whatever - I am going back with the big wide tires, and we will note what we get this time.
But I have yet to understand then why we saw 198MPH at 6800 rpm in 4th with these tires. And we did.
Whatever - I am going back with the big wide tires, and we will note what we get this time.
03-10-2011, 08:52 PM
#159
Developer
Thread Starter
you probably left off the gear ratio on the dyno or used the wrong ones that you saw on your spreadsheet . that would explain it.
If you look at the next chart I posted in 128, where we could include the layshaft calc, I think you will see we had the right numbers.
But I wanted to thank you for your input. You said everybody was jumping on you and I was sorry for that. I don't know it all am always happy to learn more. Thank you for your input.
...and when I get to the dyno next, I do plan to ask them how they are calculating roller speed!
03-10-2011, 08:56 PM
#160
Developer
Thread Starter
but in the end, it doesnt really matter, as after 160, you are in 5th anyway, and your car will have no problem reaching 170mph in its sleep.
03-10-2011, 09:09 PM
#161
Developer
Thread Starter
Can anybody recommend an in-car GPS that will display my speed in large letters?
With a dash mount?
The speedometer will be useless and it would be nice to know my speed before I get back to the pits.
If the display is large enough the in-car video camera might be able to see it and that would make the video a lot more interesting.
Instead of searching the internet, thought I'd ask here...
With a dash mount?
The speedometer will be useless and it would be nice to know my speed before I get back to the pits.
If the display is large enough the in-car video camera might be able to see it and that would make the video a lot more interesting.
Instead of searching the internet, thought I'd ask here...
03-10-2011, 09:37 PM
#162
Administrator - "Tyson"
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One of the full race systems would be cool that show everything from elevation to G-forces.
The G's would be really interesting to see when you launch the parachute
The G's would be really interesting to see when you launch the parachute
03-10-2011, 09:41 PM
#163
Chronic Tool Dropper
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Carl--
I have a 5" Garmin (1490T) that does the deed. Stores max speed too. Has an hour-plus on battery so no wiring to screw up. Has traffic monitoring and auto rerouting, handy for getting there and back in the tow rig through most metro areas.
There are GPS dongles that can plug into your data-gathering laptop too. That should supplement the speed-sensor pulses, and if they are both calibrated well, let you look at wheel-slip later. You are running a datagathering laptop or something, right?
I have a 5" Garmin (1490T) that does the deed. Stores max speed too. Has an hour-plus on battery so no wiring to screw up. Has traffic monitoring and auto rerouting, handy for getting there and back in the tow rig through most metro areas.
There are GPS dongles that can plug into your data-gathering laptop too. That should supplement the speed-sensor pulses, and if they are both calibrated well, let you look at wheel-slip later. You are running a datagathering laptop or something, right?
03-10-2011, 09:46 PM
#164
Developer
Thread Starter
I have x and Y forces integrated into my on-board video. We haven't spent the big bux for on-board intrumentation and logging yet - I have it picked out but there is always something more important to buy it seems.
I have GPS in my car and truck - I know what you mean, it will display speed but its so tiny the camera will never see it.
I have a friend that had one mounted in his racer with a pretty big display - big enough to catch at a glance - I'll go ask him.
I have GPS in my car and truck - I know what you mean, it will display speed but its so tiny the camera will never see it.
I have a friend that had one mounted in his racer with a pretty big display - big enough to catch at a glance - I'll go ask him.
03-10-2011, 09:51 PM
#165
Developer
Thread Starter