TTR EK4 S2 Project BEAST MODE

[Snook Man]

The ofna diff cups use the 8mm ball end for the bones and will work with your center bones
The distance between bearings is 29mm, but the bearing seat is not bumped out like yours so that’s probably the difference.
The main measurement are:
End of cup to cup – 78.75mm
Center of cup to cup – 69mm
Height from chassis deck to top of uprights (without top plate) – 51mm, spur protrudes lower than chassis deck so the deck needs a relief (If your deck isn’t cut you would need to cut it or shim up the CD for clearance)
Center of spur measured from inside edge of rear upright- 6.75mm
Then you would need to measure the spread pattern of the uprights, the ofna has a wider spread in the front compared to the rear.
Gear ratio: If the stock spur is 60 and clutch bell 14 you would need the 12T clutch bell to get the closest ratio with the 51T spur.

 

[Nitrotrout]

Thanks for the measurements Snook. Every measurement on this spool
assembly is short. This is really an real odd ball contraption.
But noticed the Losi diff that sv250 suggested is a 50t design
and it seemed to fit in his EK4 with little or no modification so I so I ordered one.

 

[Nitrotrout]

Project update: Front suspension complete.
Front diff is rebuilt and topped off with 5k diff oil.


RED ANODIZED ERGAL ALUMINUM SERVO SAVER TOP PLATE,
STEERING SLIDER AND REAR TRANS. PLATE.

PLASTIC SHOCKS REPLACED WITH LOSI 8IGHT TRUGGY SHOCKS
HOME MADE BODY POSTS REPLACED WITH EK4 POSTS AND
ERGAL LOWER SHOCK MOUNTS ADDED

ERGAL FRONT KNUCKLES ADDED, ZIP TIE REPAIRED ROD END
AND BROKEN LOWER ARM REPLACED

]

 

[hulkmaxx]

Man these old school rigs are cool guys. If you break something how hard is it for you guys to get parts?

 

[Nitrotrout]

If you break something how hard is it for you guys to get parts?

The parts situation is not as bad as I thought. Most suspension parts
are the same parts used on the EB4 buggy. I have a stock pile of those.
Plus they're readily available on fleabay. I was able to order all engine parts I needed for rebuild.
I was even able to add some factory upgrade parts which was cool..
Plus I added several Losi 8ight Truggy parts, those should be
easily replaceable if need be..

 

[Rolex]

Good choice on changing out the cooling head. That is definitely a Thunder Tiger heli engine. I have the .46. In a heli they also have a shroud and a fan VERY similar to a lawn mower engine to provide cooling. Helis don't work nearly as hard as a ground vehicle so I can understand why they overheated, especially with that head.
Keep the photos coming. It's a really beautiful restoration so far.

 

[Nitrotrout]

Thanks for the kind words Rolex.
Even in the heli's these engines had cooling issues? LOL! I'm fascinated with this engine and I'm gonna try like hell to work out the bugs
and make it a solid performer. Trouble is I don't know anything about these motors. I'm learning as I go.
Here's what I know so far: Its rated at 18,000 rpms max, its rated at roughly 2.5 hp., it weighs 2 lbs requires a high oil,
low nitro fuel content, and it uses piston rings instead of sleeve pinch. According to Snookman it has a 4.28:1 final gear ratio.
I'm guessing these motors have a lot of bottom end grunt?

 

[hulkmaxx]

1800RPM max WOW that's really cranking just kidding I bet the torque it puts out is insane man!

 

[Nitrotrout]

Man I hope so. Its all a huge mystery to me. LOL
I have a LRP .30 on standby if it doesn't work out...hehe

 

[Rolex]

Even in the heli's these engines had cooling issues?

No, they didn't, that's why I explained that they had a cooling fan in the flywheel and a shroud that directed all that air directly over the head.
I never had a problem with mine and yes, ringed engine, high oil content, lots of smoke, and that's an airplane engine starter with the one-way heli starter shaft.
In a heli you're usually running in 'idle up' at a constant RPM and the rotor collective is doing all the work. In a ground vehicle the engine is always working hard and changing it's RPM.

 

[Nitrotrout]

I see what you're saying. And the engine is mounted in a vertical position.
That blows my mind.

 

[Nitrotrout]

Project update: Rear suspension complete
Diff is rebuilt and gone is the mushy plastic shocks and ginormous
rear bumper.

LOSI 8IGHT TRUGGY SHOCKS REPLACE THE 4 PLASTIC SHOCKS.
THE ERGAL ALUMINUM TOE IN BLOCK CAN BE CHANGED OUT
IN A FEW MINUTES WITH NO E -CLIPS TO DEAL WITH.

ERGAL ALUMINUM TRANS PLATE AND HUBS.
TITANIUM HINGE PINS WITH NO E-CLIPS

NON ADJUSTABLE GRUB SCREWS REPLACED WITH TITANIUM
ADJUSTABLE TURNBUCKLES

 

[Nitro Nerd]

I love it! Great job, sir. I deeply respect anyone's tenacity regardless of vehicle. It's how I am with my beloved Losi 810. Not the most popular rc vehicle in the world, but hands down my true love in this hobby. I've spent more time analyzing/building/testing with this than any of our vehicles....and I'll put it up against any , and I mean ANY ]nitro buggy out there. It's as close to a perfect nitro RC vehicle that I have and I've spared nothing at bringing out it's true potential. Everyone that sees it in action is like 'Daaayum! What the hell is that?' ha ha! In the rare event I ever get beat down, I know in my heart I've still won, because I'm driving a Losi 810! ;-)

So kudos to you on this - I love seeing this sort of passion. It's looking like mean machine!

 

[Nitrotrout]

Thanks Nitro, much appreciated! I'm not familiar with the Losi 810. Post some pics of it here if you'd like, I'd love to see it.
I'm a BIG fan of Losi products. The all time favorite in my fleet is my Losi XXXNT AD.
I guess it's because it was my first ever kit, and the most trouble free car I've ever owned.
I've added several Losi parts to this latest project here and there.
So many in fact that its no longer an EK-4, it's an EK-8ight.

I did a mock up of this thing and it looks bad to the bone. Performance wise, I dunno, thats TBD.
My expectations aren't that high, we'll see how it goes.. lol
Trial and error, trial and error, trial and error...

 

[Nitro Nerd]

That's how it is with my Savage. Run/break/analyze/fix/run/break (something new). Ha ha you're doing the right thing IMO...build it for durability then start focusing on performance. Lot's of times that can be handled simply with the right setup. Too many people build their vehicles all tricked out with polished aluminum everywhere (i.e. shelf queens) and don't give a thought about how the vehicle will perform. I like my vehicles to look as nice just like anyone, but we run our poop hard, and for us it's about durability, speed, and agility. I'm not hating on aluminum, but I think we can all agree 50% of the time it's about show without any real analysis on how it will make the car stronger, faster, and more agile. Some of the most durable cars out there have very little aluminum, and the parts that do are known points of failures. This instead of just throwing a bunch of aluminum crap everywhere because it looks 'bad-ass'. In my opinion, to make a vehicle durable you have to fully understand genesis of broken parts and go from there. To each is own but I go for performance over looks any day.

So yeah, keep testing and testing. That's how to do it!

 

[Nitrotrout]

Project update : Issues, issues, issues...
I got it all assembled only to find I installed the rear diff upside down.

Body posts don't protrude through the body enough for the body clips to fit through.

Engine cooling fins sit about 1 inch taller than the body roof.
Think I'm gonna have to cut the top 6 fins off to make it flush.

Rear drive shaft was too short with the Losi 8ight center diff and diff cups.
I sacrificed the diff cups off one of my EB4 buggies. Problem fixed.

Center diff mount had to be shimmed as the spur gear teeth protruded lower than the chassis plate.

Cheesy battery holder only accepts AA batteries, not hump back rechargeables.
EB4 S3 battery tray on order.

Dumb ass me, I ordered the Revo dish wheels forgetting all bout the funky
17mm hex pattern with their rims. I had to break out the Dremel to make them fit.

Theres several other petty issues I'm dealing with. I'm just too tired to list them all at the moment.

Positive notes: This truck looks nothing like it used to. Looks legit, no more cartoon looking nonsense.

I shaved a full pound off the total weight. I'm still not sure how that worked out as I replaced some plastic and some thinner aluminum parts with thicker, heavier 7075 aluminum parts.

I found a diamond in a

today.
This mysterious hitec servo I kept finding. I had no idea where it came from, I know I didn't buy it new, it looked slightly used. Turned out to be a servo that came in a completely trashed Tmaxx beater I bought for cheap off of fleabay.
Its a HS 7955TG servo with 333 oz. of torque @ 6v. Purchased new it costs more than I payed for the entire truck. Smooth as glass, no noises, now its a steering servo for my project.

 

[hulkmaxx]

Project update : Issues, issues, issues...
I got it all assembled only to find I installed the rear diff upside down.

Body posts don't protrude through the body enough for the body clips to fit through.

Engine cooling fins sit about 1 inch taller than the body roof.
Think I'm gonna have to cut the top 6 fins off to make it flush.

Rear drive shaft was too short with the Losi 8ight center diff and diff cups.
I sacrificed the diff cups off one of my EB4 buggies. Problem fixed.

Center diff mount had to be shimmed as the spur gear teeth protruded lower than the chassis plate.

Cheesy battery holder only accepts AA batteries, not hump back rechargeables.
EB4 S3 battery tray on order.

Dumb ass me, I ordered the Revo dish wheels forgetting all bout the funky
17mm hex pattern with their rims. I had to break out the Dremel to make them fit.

Theres several other petty issues I'm dealing with. I'm just too tired to list them all at the moment.

Positive notes: This truck looks nothing like it used to. Looks legit, no more cartoon looking nonsense.

I shaved a full pound off the total weight. I'm still not sure how that worked out as I replaced some plastic and some thinner aluminum parts with thicker, heavier 7075 aluminum parts.

I found a diamond in a

today.
This mysterious hitec servo I kept finding. I had no idea where it came from, I know I didn't buy it new, it looked slightly used. Turned out to be a servo that came in a completely trashed Tmaxx beater I bought for cheap off of fleabay.
Its a HS 7955TG servo with 333 oz. of torque @ 6v. Purchased new it costs more than I payed for the entire truck. Smooth as glass, no noises, now its a steering servo for my project.

Gotta love projects man this is usually how it goes LOL! But it sure is looking awesome bro! Kinda makes me wish I didn't trade off my GS truggy rig. And I doubt you will notice any kind of performance loss from the 7075 aluminum, sometimes aluminum isn't a bad thing in some areas on a rig.

 

[Nitro Nerd]

7955 is my favorite servo. I run them on one truggie, two buggies and have an extra one for backup. They are violent. I have had trouble with two of them, but since HiTec fixed they have been fine.

 

[WoodiE]

Well get these issues fixed and pictures posted... I wanna see!!!

 

[hulkmaxx]

I'm with Woodie pics please!