home brew quarter sprint

Post your custom large scale projects completed or not here. These are home builds. No factory or mass produced cars please.
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Appreciate the comments, Emilio.

Since it's not practical to try to move all this to the drill press, I'll be hand drilling. A drill block will help keep the holes squared up & on center through the rails.

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Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

One down. Solid, very stiff torsionally. There will be more rivets as the crossmembers are added.

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Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

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Kaye
1/4 scale GOD
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Joined: March 8th, 2015, 9:33 am

Re: home brew quarter sprint

Post by Kaye »

This project is looking very good!
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Thanks for taking a look, Kaye & for the comments.


The all important centerline. Essential in building good, square frames.
I'm working off of a set of overall dimensions for quarter sprint cars that I found on line...wheelbase, overall length & width etc. However, I'm not building to anyone's set of rules or class specs.
Here's the lil 33cc that I've got setting kinda in the middle of it all...

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...not very visually compelling.
I'm thinking something that will have this type effect. Well, maby not that far out...but I do admit I really enjoy outrageous machines. :wink:

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Annnd I have some ideas turning over in my head.
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

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Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

I have located 2 motorcycle salvage operations within reasonable driving distance.
Going shopping for a drive train for this thing. :)
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

I'm adding an inner set of rails to manage the engine, driveline weight & torque.
Will be lightened to match the sides of the cage.

What I have shown here is 14 lbs. Not sure what driveline weight will be.
I'd like to see a total vehicle weight of around 100 lbs, with at least 20 hp in power...cause it's all about power to weight & I want it to jump up & down & spin around when I nail it!!
But I'm just semi-informed guessing at this point.

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Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Over the weekend, I looked at a nice 750 inline Honda 4 with 5 speed. Price was very attractive.
If it had been a few inches smaller, dimensionally, I would have probably brought it home with me.

After quite a bit of research, what I think I'd like to use is a ninja 250 twin by Kawasaki. 4 stroke, overhead cams, 10K redline.
They have been around since the 80's. Looking for an older one that's carburated & no computer junk on the engine...old school tunable.
Kaye
1/4 scale GOD
Posts: 639
Joined: March 8th, 2015, 9:33 am

Re: home brew quarter sprint

Post by Kaye »

250 twin Kawasaki = a lot of power for a model car!!

Kaye
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Yes, quite a bit of power.
I'm overbuilding it structurally to accommodate the power.

For comparison...a 410 winged sprint weighs around 1400 lb wet, with driver & is powered by 800+ hp engines.
This gives a power to weight ratio of 1.75 lbs per hp.

If my build weighs 150 lbs & has 35 hp, that is a power to weight ratio of
4.2 lbs per hp. Somewhat less than the 1:1.

To match the 1:1 specs, I'd need more like 55 to 60 hp. This is where the 4 cyl honda I looked at would have put it. But it was just too big to fit the chassis.
CALracing
1/4 scale guru
Posts: 371
Joined: August 16th, 2009, 2:49 am

Re: home brew quarter sprint

Post by CALracing »

Great Project!
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Thanks CAL.
Haven't been around much lately.
In the process of moving.
New shop will have 5X space of where I've been working. :) !!
Ognib
Newbie
Posts: 35
Joined: September 11th, 2016, 8:25 am

Re: home brew quarter sprint

Post by Ognib »

Getting settled into the new-to-me house & finally some time to start setting up the shop.

8' of new bench space, a build table in the center with access from four sides & a table for my benchtop mill.

And, my buddy & administrative assistant, Lou thu DAWG.
Attachments
quartersprint29.JPG
quartersprint28.JPG
quartersprint27.JPG
quartersprint26.JPG
Kaye
1/4 scale GOD
Posts: 639
Joined: March 8th, 2015, 9:33 am

Re: home brew quarter sprint

Post by Kaye »

Wonderful work space.
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