Dragster Drivetrain Angle

MR RACING · Sep 19, 2011

figured it out
if you want to line up drivetrain and
keep weight low as possible
something has to give
there she goes!
NOSE DOWN!

marlboro180 · Sep 19, 2011

Ni:fing32:ce, that'll help keep the C.G. low.

Ingersoll444 · Sep 19, 2011

Ujoints like to have a little angle to them. Just match the front and rear angle, and your good to go.

MR RACING · Sep 19, 2011

marlboro man & ingersol
the guy that posted how he built dragster
left a lot out
it's ok with me it's not supposed to be a manual or anything
it's a head scratcher how to
attach tranny to rearend
he's using what looks like 1 speed clutch drive
maybe we'll just use one u joint for the whole deal

Tencubed · Sep 19, 2011

You're bound to get vibration with just one U-Joint from everything I've read or experienced.

The rear end pinion and the output shaft of the transmission/clutch have to be parallel with a little difference in height and/or side to side offset for the U-Joints to function smoothly.

As ingersol444 pointed out, "Ujoints like to have a little angle to them. Just match the front and rear angle, and your good to go.". Good advice and well worth listening to.

The U-Joints also have to be aligned on the driveshaft and everything balanced.

Course that's just my opinion.

Mike

neo71665 · Sep 19, 2011

Most of the front engine rail cars have direct drive setup with a slip clutch setup. The driveshaft mounts to the rearend. Everything is solid mounted to the frame so there should be no movement. The clutch has a petal but once you let up off it they slowly burn up allowing power to the wheels not all at once but as the clutch wears down. Drag racers are way different beast than anything on the street.

MR RACING · Sep 19, 2011

tencubed & neo
yes that guys hemi dragster has a clutch 1 speed
ours has 292 & fordomatic
what happens if we have 1
count 'em 1 ujoint for
both transmission and rearend?
it will be all aligned
that's a fixture you make in dragster pic
to line everything up
we can make one

MR RACING · Sep 19, 2011

neo & mike
we need to get that drivetrain
back towards rear as much as possible
front end will be long
to get a mid engine effect
but we can't make it too long
about 24 or 30 inches of empty space
in front of engine to frontend
like early Chrisman cars
that's what made them fast & leave hard

Kbeitz · Sep 20, 2011

Tencubed said:
You're bound to get vibration with just one U-Joint from everything I've read or experienced.

The rear end pinion and the output shaft of the transmission/clutch have to be parallel with a little difference in height and/or side to side offset for the U-Joints to function smoothly.

As ingersol444 pointed out, "Ujoints like to have a little angle to them. Just match the front and rear angle, and your good to go.". Good advice and well worth listening to.

The U-Joints also have to be aligned on the driveshaft and everything balanced.

Course that's just my opinion.

Mike

Yea... I learned that the hard way...

Tencubed · Sep 20, 2011

Kbeitz said:
Yea... I learned that the hard way...

Yup Kevin, you, me and quite a few other folks that wouldn't listen or didn't check before building something. :banghead3

All about re-inventing the wheel, or something to that effect, I do believe.:fing32:

Mike

MR RACING · Sep 21, 2011

kbeitz & tencubed
looked at using one u joint before
we found couplers
couplers are in other post
u joint would work fine anyway
this is solid mount drivetrain
all of it!
maybe we'd keep rubber trans mount
let automatic transmission case flex but
that wouldn't make no never mind
u joint would hold it

neo71665 · Sep 21, 2011

If you run solid motor mounts you have to run a solid trans mount. You start mixing them you will be breaking cases. If you run those couplers you have to run solid mounts cause they don't have the play in them a u joint does.

MR RACING · Sep 21, 2011

neo
ok
back to the downward angle of drivetrain
saw more pictures of dragsters and
that's how they did it
because differential is so high
because slicks raise it up
what kind of problems does tilting engine
down in front cause?
if any

neo71665 · Sep 21, 2011

Says it better than I could so here

http://www.roadkillcustoms.com/hot-rods-rat-rods/hot-rod-engine-pinion-angle.asp

When your in the pits at a race most every rail car I've ever seen is on stands. I'm sure most of it is to raise it up to be easier to work on but they also level the chassis out. Also when going down track you can adjust the wheelie bars so it be be leveled out more.

MR RACING · Sep 21, 2011

neo
i think they are talking about something else
slicks are 32" tall
centerline is 16"
go down about 2" because pinion exits
a little lower than center of differential
that's 14" above the groundplane!
all these dragsters that have
drivetrain nosedown
they worked it out a long time ago
it would work

neo71665 · Sep 21, 2011

Slicks come in more than one size, you can also get rear ends with different pinions. You missed the main point of the site. Set your ride hight and then set the engine to run with the rearend. Being a purpose built racer you can cheat some things and make it work. When we built our truck I chopped out the whole trans tunnel to put a deeper one in for 2 reasons, ease of getting the trans swapped out and so I could set the engine more level.

MR RACING · Sep 21, 2011

neo
let's keep this on track
see the DRAGSTER?
see the SLICKS raise the differential up?
see how the builder tilted drivetrain down
to keep center of gravity low?
you can click on picture to
make it bigger and see better

Ingersoll444 · Sep 21, 2011

MR RACING said:
neo
ok
back to the downward angle of drivetrain
saw more pictures of dragsters and
that's how they did it
because differential is so high
because slicks raise it up
what kind of problems does tilting engine
down in front cause?
if any

Most have been tilted up.... but as long as the carb is pretty much level, and the oil pickup doesnt run dry your good to go...

neo71665 · Sep 21, 2011

Find the tires you want. Remember they will grow taller the faster they spin. Set your pinion angle with that in mind. Now if you are running a coupler your drive line angle will depend on that, don't worry about exacts right now. Now figure out the carb angle and if the oil pickup is gonna stay under oil. Carb angle can be adjusted by running an angled spacer easy enough. The pickup might require a bit of work. I know on chevys its easy with the rear pickup but some others have a front sump. Once again you have to remember as you take off the rear will come up from tires expanding and the engine will level out as weight transfers and the front comes off the ground. Static height where you are building it will be way different from racing heights. Most drag cars purpose built look and set up for racing and not as its sitting in the shop.

MR RACING · Sep 21, 2011

ingersol & neo
got it
the local machine shop can
make the jig to line things up
it's that tube in the picture
it goes thru bare block and
rear end pinion bearing housing
and you allow for length of tranny
it stays in while we make
engine mounts tranny mounts and
rear end plates generally like
the ones this guy made

Dragster Drivetrain Angle

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