RE: FG 1/5 scale drag car

RE: FG 1/5 scale drag car
View related threads: (in this forum | in all forums)

Logged in as Guest

Users viewing this topic: none

Printable Version

All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Drag Racing >> RE: FG 1/5 scale drag car

Page: << < prev 1 [2] 3 next > >>

Login

Message

<< Older Topic Newer Topic >>

RE: FG 1/5 scale drag car - 8/1/2007 2:48:39 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

I'll try to get a good picture this weekend at the drag strip or at our practice track.

If it will go 3 seconds or quicker I would be amazed. I guess my F1 did do 3.5 at 37mph.

_____________________________

Performance RC

(in reply to M.R. Ogle)

RE: FG 1/5 scale drag car - 8/1/2007 4:20:19 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

Well, I never replied to this the first time around, but I guess I always liked the 80's style cars. The first time I went to the drag strip with my Dad was in a 65 Shelby Mustang that happened to be brand new at the time and I raced through the 70's and 80's. My personal best was about 9.90 at about 130mph on a bike. The 80's old school was good for me.

_____________________________

Performance RC

(in reply to aer-wubby)

RE: FG 1/5 scale drag car - 8/3/2007 4:32:39 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

M.R. Ogle,
Here are a couple pictures of my car, will they work to photo shop?
Hope that the weather holds for the race this weekend, they are talking rain.

Attachments

Click to see fullsize image.

Click for fullsize

Click to see fullsize image.

Click for fullsize

Click to see fullsize image.

Click for fullsize

_____________________________

Performance RC

(in reply to Performance RC)

RE: FG 1/5 scale drag car - 8/3/2007 6:57:04 AM

Posts: 130
Joined: 4/18/2005
From: Mount Vernon, IL, IL, USA
Status: offline

That'll work....

You're gettin' pretty crossed up during your burnout, though...

Attachments

Click to see fullsize image.

Click for fullsize

_____________________________

Mike
Grand Motorsports.com

(in reply to Performance RC)

RE: FG 1/5 scale drag car - 8/3/2007 1:49:19 PM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

Wow! is that cool! You must have that down you did it so fast.
I see a new backdrop for my desktop. Thanks.

_____________________________

Performance RC

(in reply to M.R. Ogle)

RE: FG 1/5 scale drag car - 8/3/2007 11:15:54 PM

Posts: 9895
Joined: 4/15/2003
From: ..., PA, USA
Status: offline

quote:

ORIGINAL: M.R. Ogle

That'll work....

You're gettin' pretty crossed up during your burnout, though...

Very nice - love your work.

_____________________________

http://studysession.com
http://www.rcuniverse.com/forum/m_6346863/anchors_6346863/mpage_1/key_/anchor/tm.htm#6346863

(in reply to M.R. Ogle)

RE: FG 1/5 scale drag car - 8/8/2007 3:50:02 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

I spent the day Sunday at Mn. RC dragway. Just to see how it all worked they let me make a couple of runs with my car. It turned 3.4 at 41mph, and I think it needs some lower gearing yet.

_____________________________

Performance RC

(in reply to studysession)

RE: FG 1/5 scale drag car - 8/8/2007 5:55:16 AM

Posts: 130
Joined: 4/18/2005
From: Mount Vernon, IL, IL, USA
Status: offline

Right on!!! Just shave a couple tenths with gearing, and it'll be right there!! I'm getting ready to take mine back out to test, too... I'd be just fine with a 3.4 first time out!!!

_____________________________

Mike
Grand Motorsports.com

(in reply to Performance RC)

RE: FG 1/5 scale drag car - 8/19/2007 12:07:07 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

After I ran the car I realized that I need to gear the car down. I located the parts from a WCM dealer and I've been trying to figure out the top speed of the car with the lower gear. A math wiz friend of mine came up with this equation, does anyone have a easier way.

Here we go : peak RPM 20,000 divided by gear ratio (42/22=1.91) (20000/1.91=10471.2) divided by final drive (78/16=4.875 )(10471.2/4.875=2147.93) which is the RPM of the rear axel. Now we need to figuare out the roll out of the rear tire, my tires are 7" tall so we take 7x3.14= 21.98. Then take RPM of rear axel (2147.93x21.98=47211.50 then divide by 12to get feet instead of inches =3934.29) then multiply that by 60 to get minutes per hour (3934.29x60=236057.5) then divide by 5280 to get miles per hour (44.70mph).

Considering when I do the same equation with my present gear ratio I get a top speed of about 70mph, which I know the car will never pull in 132ft. What does everyone think, did we miss step or does it seem accurate.

_____________________________

Performance RC

(in reply to M.R. Ogle)

RE: FG 1/5 scale drag car - 8/19/2007 12:38:08 AM

Posts: 5996
Joined: 10/3/2004
From: Prairiville, LA, USA
Status: offline

quote:

ORIGINAL: warren528

FG PERFORMANCE RC,
Did you guys try this car, seen like it should hook pretty good with transbrake and rear tires. I would like to try your car against my modified 1/5 scale in 132' or more.
Warren528

Do you drag at Zephyr with Reggie?

_____________________________

Saldly, 98% of teens have switched to rap music, if you're part of the other 2% that like real hip-hop put this in your sig.

(in reply to warren528)

RE: FG 1/5 scale drag car - 8/19/2007 12:43:59 AM

Posts: 130
Joined: 4/18/2005
From: Mount Vernon, IL, IL, USA
Status: offline

I've seen many, many different formulas and calculations over the years to try to predict on-track performance... and let me say this... they simply don't work...unless you're running in outer space with no gravity, no friction or parasitic drivetrain drag, at "peak" rpm, and with no pesky air molecules to slow you down. Which you're not.... not even considering the engine's changing torque curve in just a 132-foot run.

Run the car, make a gear change... run it again... that'll tell you whether you're going the right way or the wrong way. No amount of time behind the calculator will ever be able to figure out your ET or speed that you'll actually get on your time slip.

Believe me. I guessed wrong the first time out with my car, so i re-geared my car three times... just read the time slip. and kept bumping up the foinal drive ratio until the ET stopped dropping and the mph stopped climbing.

There's NO SUBSTITUTE for real track time.

_____________________________

Mike
Grand Motorsports.com

(in reply to Performance RC)

RE: FG 1/5 scale drag car - 8/30/2007 1:51:06 AM

Posts: 23
Joined: 2/8/2005
From: Frisco, TX, USA
Status: offline

You interested in making the wheels and tires for the open market?

(in reply to M.R. Ogle)

RE: FG 1/5 scale drag car - 9/16/2007 5:08:25 PM

stealth assassin

Posts: 57
Joined: 9/26/2006
From: Jackson, MS, USA
Status: offline

quote:

ORIGINAL: Paul Songas

The track link is www.mnrcdragracing.20m.com

We run the standard 132 foot track.

I thought 264' was the 1/4 mile scaled down to 1/5.

Anyways just asking...

(in reply to Paul Songas)

RE: FG 1/5 scale drag car - 9/16/2007 6:05:30 PM

Posts: 39
Joined: 5/13/2004
From: Blaine, MN, USA
Status: offline

Our track is 1/10 scale.

_____________________________

RAE/Grand Motorsports
Co-Owner MN RC Dragway

(in reply to stealth assassin)

RE: FG 1/5 scale drag car - 10/3/2007 3:36:23 AM

Posts: 60
Joined: 12/2/2005
From: Isanti, MN, USA
Status: offline

Last time I ran the car I could tell it was geared for too much top end 20/42. So I regeared it to a 16/78, and now it jumps off the line. With the two speed should have about a 55mph top end.

Attachments

Click to see fullsize image.

Click for fullsize

Click to see fullsize image.

Click for fullsize

_____________________________

Performance RC

(in reply to Paul Songas)

RE: FG 1/5 scale drag car - 10/3/2007 10:14:07 PM

Posts: 130
Joined: 4/18/2005
From: Mount Vernon, IL, IL, USA
Status: offline

Here's what I've done in research for gearing on the 23CC drag cars:

I think I'm getting there, figuring out the correct final drive ratio for my car. It has two primary gears, then pulleys from the halfshaft to the rear axle.

15/48 gears 16/72 pulleys..... (14.4:1) way too low, car spun it's tires hard but topped out at 65 feet.

15/48 gears 21/48 pulleys... (7.31:1) too high, stripped rear belt (at Minnesota).

21/40 gears 16/72 pulleys... (8.55:1) Better, ran at Chicago like this (best of 3.15 ET).

20/44 gears 16/72 pulleys... (9.9:1) Will try this ratio next time out

20/44 gears 14/72 pulleys...(11.3::1) May also try this combo. May be good on a treated track where the tires stay hooked up, and will work the clutch real hard.

This is what I've tried so far. I'm surprised that the sweet spot is so narrow on these motors, but they're pulling 25 pound cars through a centrifugal clutch, so you gotta pay close attention to what the car's telling you.

Of course, with a two-speed, you'll have more options, and you can gear low to come off the line hard, then shift up as to not run out of steam halfway down track. My car ran 3.15, which was pretty good, but Guy Hilleary was way under three seconds with his, best of 2.78, I believe.

_____________________________

Mike
Grand Motorsports.com

(in reply to Performance RC)

RE: FG 1/5 scale drag car - 10/4/2007 1:51:48 AM