SCREAMER's IFS Bomber "Qwiksilver"

[Terrible1]

This is one bada** build Screamer! Can't wait to see this rig run! I'll admit between you and Bilinvic, I can't help but "borrow" ideas from you guys!

[SCREAMER]

This morning I was able to get the front suspension finished up. I installed the VP upper shock adjuster (the black plate) which moves the tops of the shocks further outboard and reduces leverage on the shock while increasing the spring rate. Due to the altered geometry, I had to switch to a shorter shock because the 2661 big bores were overextending the front suspension causing binding on the links. I installed a set of 2660 big bores I had which are 3.5 inches eye to eye as opposed to the 3.75 length of the 2661. Axial 14x54mm springs fit these Traxxas 2660 shocks perfectly with just enough preload to keep the spring seated. I wanted to show one last pic before putting all of the panels on. This is a good view of the packaging of all the components using DMG's kit. I used an Axial radio box to house the receiver and it tucked into the driver side area perfectly with a single round clamp holding it to the floor. You can also see the front driveline path and the proximity of the servo and trans. It's compact but everything clears with ease. I'll be headed out in a couple hours to get some wheel time in. I couldn't be more excited that I finally get to drive it. I'll post up my initial thoughts as soon as I get home.

[jamesthe1v]

I HATE WAITING

[SCREAMER]

Sorry for the delay guys, here's my initial thoughts. Yesterday's first test was very informative. Before going out, I tried to choose the spring weights and shock oil I thought were at least close but it's difficult to make a good guess based on living room testing. Needles to say, my guessing could use some work. As soon as Qwiksilver hit dirt, I could tell that I was under dampened in the front and under sprung in the rear. I was at least smart enough to take some extra springs with me knowing it takes 1 screw and 2 minutes to swap one out. Not much I could do about the bouncy front end but getting the next stiffer spring on the rear made a huge difference. I'm kind of surprised that the suspension characteristics were so far off from when Qwiksilver had a solid front axle but I guess I shouldn't be. One other thing I noticed is that the passenger side is significantly heavier than the drivers side due to the motor and servo both being together on that side. I added 1/4 inch of preload to the front right shock and she leveled right out.

After getting the right spring rates on the rear, things settled down quite a bit. The first thing I noticed was how plush the front end was compared to the rear. I think I might also be over dampened in the rear now but it was really something to see the front suspension soak up everything, big and small, and not transfer any of it to the chassis. Planted, is the best word I can use to describe the way the front feels. I think just 5 wt heavier on the front shock oil and she'll be perfect. I'm also going to soften the rear damping by 7-10wt lighter oil.

The motor, trans, ESC, and servo were all flawless and I think I really like these Flat Iron XLs. I'm happy with the 56/13 gearing but I may switch from medium startup power on the ESC to low startup power and maybe add more punch control. On a couple full throttle bumps from a dead stop, I had some cogging. Not real bad just enough to notice and I have to fix it.

I had a couple rollovers, nothing bad, but there was one very elegant cartwheel in particular that had me wincing until she came to a stop on her roof. I was absolutely sure I bent another axle but to my delight, everything stayed square and straight. The DMG IFS is a very stout package. Combined with the excellent RPM arms taking all the abuse, I feel this is a bombproof front end.

I'm going to work on the shocks today and try to get back out either today but definitely tomorrow. Results so far are very promising. I'll report back right after the next run.

[bilinvic]

It must feel good to have one of three IFS Bombers in the world....I can't wait to be #4. Your posts have been incredibly informative and I have read them over and over many times!!!! lol

[jwall046]

I wish I could build one of these!
So awesome!

J.A.W - just another wraith &
a Bomber!

[Terrible1]

Great info! I'm planning on a conversion build myself (hopefully sooner rather than later) so this is definitely a thread I'll be keeping tabs on. I'm curious where you end up with the suspension too, that's always an area I seem to struggle with the most in set up.

[SCREAMER]

Ok guys quick update. I'm still working on dialing in the suspension but I'm a lot closer now then when I started. I don't want to muddle this thread anymore with the wrong choices so when I finally settle on a good combination, I will post my setup.

My testing was cut short today due to a problem I discovered with my VP VVDs. The passenger side drive pin at the output started pushing its way out of the ball end. Had it not been for the clicking sound it made when the pin hit the link mount on the shock tower, I would've kept driving until something broke. I'm so glad I caught it before the pin moved any farther. I'll contact VP right away and am sure they'll take care of me as they have in the past. I just have to decide if I want to swap in an Axial universal I have or wait until my BMRC one piece spool and Traxxas Slash CVDs show up. More to come.

[bilinvic]

I've read lots of folks prefer the Axial universal axles over the VP VVDs. I have the VVDs in all my 2.2 rigs and they have been great, must be something specific to the Yeti axles. I'm going to stick with the Yeti universal axles for now.

[SCREAMER]

I have had at least 4-5 sets of VVDs and this is my first issue so I'm sure it's just a bad pin. This was only the third run and the other side is still perfect. I would just try to press it back in but there's no doubt it'll work its way out again. I'll get her fixed up and back on the trail.

[luckster]

Bummer, The anticipation is not as bad for all of us enjoying your build as it has to be for you. But waiting for a new VVD is the smart thing to do. Great build man. Looks awesome.

[the DMG]

i had a pass thru pin back out on a inward MIP drive hub,
& it chewed off half of the upper link mounting area on the shock tower, before i got it stopped !!

on some of the yeti - EXO aftermarket shock towers,
they have vary little clearance in-between the drive cup & the shock tower !

i have had to grind the top & bottoms of the pass thru pins sticking out of the drive hub,
because they hit the shock tower - they had to be flush with the outer surface of the drive hub to clear the shock tower!!

watch 4 that also !!

[SCREAMER]

I did notice the proximity of the shock tower and outputs during assembly and there was at least 1-2mm of clearance on both sides. The VVD pins were perfectly flush with the outer diameter of the output when I installed them also. For some reason, this pin started to work its way out.

[cmbscx10]

Such an awesome read. Learning a lot even if i don't go IFS. Glad you caught that pin before catastrophic failure struck. I had 2 Axial Uni's bust on my Yeti when they where the too short version shafts. Not sure if they were ever updated but i would rather go VP as i like the fact that they can be rebuilt and are beefy. Hope VP takes care of you.

Now where are those vids?

[84yoda]

What about some loctite 648 compound to hold the pin in if it happens again?

[cmbscx10]

Originally Posted by 84yoda

What about some loctite 648 compound to hold the pin in if it happens again?

They may work (never tried) but for me that's a band aid. I would hold VP accountable and i have no doubt a replacement is in the mail tomorrow to Screamer.

[SCREAMER]

I decided to go ahead and replace the VP driveshafts with Axial Unis that I bought as spares. I just can't wait another week for something to happen, this rig needs to be ran. Here's a comparison shot of the VP VVD next to the Axial universal. It's obvious the reason I went with VP shafts initially was for strength in the form of better design and stronger materials, and I like that they're rebuildable. I'll see if these unis can stand up to the challenge.

[bilinvic]

Let's hope the Axial Uni's will withstand the punishment you are going to give them!

[maslin]

Make it work. No excuses.

[cmbscx10]

Originally Posted by SCREAMER

I decided to go ahead and replace the VP driveshafts with Axial Unis that I bought as spares. I just can't wait another week for something to happen, this rig needs to be ran. Here's a comparison shot of the VP VVD next to the Axial universal. It's obvious the reason I went with VP shafts initially was for strength in the form of better design and stronger materials, and I like that they're rebuildable. I'll see if these unis can stand up to the challenge.

What? VP is not overnighting them to you for their product failure? That's just wrong.

They sure are beefy suckers though and hope the Uni's work out.