TOPIC:

If I was closer, I could help you with a real 540 bl set. Sucks.

stingray-63 wrote:

If I was closer, I could help you with a real 540 bl set. Sucks.

I have a mate I can borrow several motors from.
Same chap I borrowed the cycle gps last year.
First I need to max out my current motor to see what it can do.

Installed the transmission today.
Now with the "normal" Frog" gearing, aka 50t spur and 18t pinion.
And I should be able to see the driveshafts now if the get thrown off...


Hopefully it stays like this the whole challenge. But I do have parts in worse case senario.


Added notes for my turnbuckles.
And I did add one leaf before the previous test, and I think this is the perfect amount of springs regarding ground clearance and tire to body clearance.


Also added heat shrink to the dogbones if I swap to those.


Turns out the gearbox joints for Frog is not the same as TL01 etc as the ball and pins on the dogbones are much thicker than TL01 etc.
Also I only have 1 long gearbox joint in my partsbin.
There is two partsnumbers for gearbox joints on ORV, the 9808037 and 9808070. The latter is slightly longer and have a line in the middle, the 37 ones are smooth.
Strange as them are using 9808038 dogbone and 9808039 wheelaxle.
I bet the longer ones are because the found out the dogbones can come out during driving, especially with the monsters.
Anyway only shop here in Norway had the 70 ones in stock and they were 3 times the cost of the 37 ones.
I did order the 9808037 and hopes the dogbones will stay put if I swap from hex driveshafts to dogbones.

Also rebuilt the second transmission, the one with Blackfoot gearing (52/16t).
Turns out the 0.5mm shim was too much, so was 0.2mm shim so diff needed no shim on this one.
Spur needed a 0.2mm shim, 0.4 was too much.
Gave the gears are coat of Molykote spray and it now turns butter smooth.
Before the silvercan got hot on 3s, not it turned with ease and stayed cool.
So a little slack is better than no slack.
For speedruns you want the tires and gearbox to turn as smooth/free as possible.
Should invest in ceramic ball bearings for next year...

My second run did not end any different than the first one.
But it got filmed and end result was 53mph / 85.29kph.
Think I will remove the diffuser next.

First thing I did today was removing the diffuser.
Then I installed a Mon-Tech touring wing sold by Schumacher. The only touring wing my LHS had it seems.

Simply bolted it on top of the lower level wing part that is part of the 2 level Zakseed wing.






The wing should give the downforce I'm looking for....

As you might saw in the video posted above, tracking did seem to be out a bit, or rather all over the place.
Was a bit strange as the first run it tracked about arrow straight.
Turns out the bolts that clamp the front suspension bracket to chassis had come slightly loose.
While I was there I swapped out the small tubes used previous and used a ORV transmission tube as it had the correct size.
The tube sticks out about half a millimeter so I used a 4mm washer then a 3mm washer to stop the tube from moving about.
Lower bolt is now is now changed to button head so it gets easier to remove if needed with my new OS 2.5 hex ball driver 


Front suspension now moves free without any slack 
Also changed the trailing arm stoppers that my mate ordered last week (9808040).
So now there is less slack at rear arms than it was.
Should make it easier to make it go straight.

Last Friday I did a run again and as usual at about 50mph the rear end sits down at right side and the quickly make the car to turn left and crash.
I replaced the gears with the normal gear set aka 50/18 gearing and installed the transmssion in the car again.

Saturday I ran several times with no luck whatsoever. 5 crashes with the same sympthom.
Lost the driveshafts one time but found them again thanks to the heat shrink I fitted to them.
But I did manage 70mph as best.


But came with a cost...
# Big split in the front spoiler where it joins the grill nearly all across the body.
Fixed this with Hody bodyfix and drywall tape.
# Stripped one of the hex driveshafts.
# Broke both spur and diff.
And I broke the body post supports as seen here


Also broke the HPI servo saver which has held up much better than the Tamiya ones (8 crashes so far - last year I broke 5 normal ones which was glued and 2x 51000)


Before I did my runs on Saturday I installed stiffer springs on the shocks and added a stabilizer bar, this is from Hotshot.
Fixed to chassis by two 5x3mm bearings, 2x 5mm wheelstoppers (plane) and a bit of fuel tube.
Used a pair of self tappers on the arms so they slide as suspension moves.
This did not help my cause of the crashes.


After I came home I swapped to the second transmission with Blackfoot gears so the topspeed is now at 90mph.

I have now removed the shocks altogether to elimate the rear sag which causes the crashes.


Used RC4WD rod ends and Hot Racing M3 links to get the length needed.
There si a few millimeter give in total so it's not totally rigd.


This has allowed me to fit the body as low as possible.
When the front suspension is maxed out the front spoiler will touch the ground.
I don't want it higher in case the wind grabs the frontend. I hope the downforce is just pushing the body down to near max travel so the front spoiler will hoover over the ground.


I have been recomended to change my front tires due too much grip which is not good at speed.
So now I have fitted T3-01 front tires onto the Rush wheels which is M size.
Turns out regular M chassis wheels is one bead wider than the T3-01 front wheels so I have skipped to mount them onto the inner bead.
These was glued today.
Battery holder box was moved a bit backwards as the body repair now made it impossible to mount the body in the location I had it. Moved back about 5mm.


I have also now swapped over to modern gearbox joints and fitted the Xtra Speed cvd driveshafts.
Several has broken the Tamiya cvd ones so I hope these will hold up.


I'm still on the lockout for wheelhex with 5mm hole all the way and it needs to be 5mm wide with center setscrew. Current ones are a bit too woobly.

Not pictured, but I have also added a strut for the rear wing to hinder to bend backwards and make it more effective.
If that's not enough I will cut remaining lip on the rear of the body for smooth airflow through the body.

And today I rebuilt the gearbox with 50/18 gearing.
Both spurgear and a bit of diff was stripped this time.


I did find plenty of Frog spur gears in my parts bin. But no Frog diff!
But turns out Hotshot uses the same diff as Frog, only stamped Hotshot instead of Frog.
Luckely I had several Hotshot diffs in my spare parts bin 
So now my second transmission is fitted with the 49t speed spur.
If the car now behaves and goes straight without crashing I will install the speed transmission.
So far the brushless top speed in brushless class is 86mph.
I hope for 100mph + with speed gears in the end 

And first Scoreboard Sunday was posted this Sunday.
I'm not on the list yet due to my crashes (new rule this year, crashes don't count), but I hope to get back strong next week 
But I'm included in the into clip in the Scoreboard Sunday video 



 

Before I headed out today I chopped off the remaining of that lip on the rear of the body to make wind flow more freely.


And picture of the strut for the wing I made yesterday.


I did a bit testing at the location of the run tonight and my mate noticed it locked the rear wheels as it come off the road.
Think the esc is doing something weird.
Did a few test passes at around 40mph and it it was like the other times.
Then I turned off the 5% drag brake and it imediatly became better to drive.
After that I added a small bit of gyro.

My first PB this evening was 70mph and it for once drove straight!
I only did brake a touch too much and it slid off the road but it was in one piece and could drive back.



And video from said run


I also did a new PB straight after that at 75mph.
Sadly it transformed into plane mode again.
But I think I was too quick on the throttle so I need to be more gentler.
Broke the servo horn.

The 75mph run


But now I know what I need to do.
More gentle on the throttle, torque wants to make it spin out, ease of the throttle and then only brake when it gets down to slow speed.
ABS is on, but it will still lock up even at 25% total brakes, or slide as in the 70mph run...

When I nail the runs I will install the speed transmission and I expect in nabourhood of 100mph + (160kph).
Problem is my vision is not great at long distances anymore and I really should start about 1/4 mile (402m) from me let off throttle when passing me and coasting for the next 100 meters or so before any braking.

Yeahhhh 5mph more by removing the rear. Congrats bro. You could give a little camber on the front. Like -1° to stabilize the front.

stingray-63 wrote:

Yeahhhh 5mph more by removing the rear. Congrats bro. You could give a little camber on the front. Like -1° to stabilize the front.
 

It has a good amount of camber when the suspension compresses. Also has toe-out that helps with making it stable, this adjust to near zero toe out when the suspension compresses.
And I think I found the problem why it now goes to the right.
Found knackered bearings on front right wheel.
Changed and lubed the new bearings and also fitted a new servo saver.

And best part my 70mph run was approved by Fil as I had slowed down quite a bit when it slid off.
If it goes straight now I will swap to my speed transmission and hopefully get a 100mph+ run at the end.

Several badwords in my mouth but I can't wait to see these dragruns.🤞🤞🤞🤞