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Old 10-06-2007, 08:36 PM   #2071
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Originally Posted by Diffdude View Post
Kropy,
Thank you for the compliment. I'm just sad that bad shock caps made it to our customers.
It is too bad, no doubt, but I'm confident that everybody understands (at least everybody who's a real customer anyway) that stuff happens, whether it's beyond the company's control, something slipped through the cracks etc.

What distinguishes IRS and you, personally, is the exemplary manner in which you've stepped in front of the problem and made it go away the best you genuinely could.

THAT'S why I've got a ton of IRS stuff in my rides and wouldn't hesitate a minute to buy more myself or provide absolute recommendation others do likewise.

Kinda cool how class acts like to deal with each other. Dave and Jason, Dave and Eric, etc. And makes it nice for we end-users as well.
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Old 10-07-2007, 05:52 AM   #2072
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Thanks bro
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Old 10-07-2007, 09:47 PM   #2073
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i finally got to run my car on the track today, ran it for a few packs and it got better each run..
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Old 10-07-2007, 10:11 PM   #2074
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I ran a few practice packs in my DB12R today with a 19T brushed motor on med-grip carpet. Once I geared the car correctly, my lap times were in the mid 9 second range with a few 9.1 and 9.2 laps. The fastest guy at the track can put down low 8's and some of the other fast guys are consistently in the mid-high 8's.

I ran the setup per the instructions with the exception of the caster blocks in which I used 5* instead of 10*. Because I'm new to 1/12th scale, it was recommended that I didn't start with 10* as the car will most likely be way too twitchy. For tires, I used Jaco Prisms in Yellow-R and Purple-F. The car had a lot of on-power push and was very "jerky" through the corners when on mid-throttle. When turning on power, I could also see the front inside tire lifting at times and would then get an occaisional traction roll. I changed to a Lilac-F tire set and also changed the damper tube oil from 5k weight to 10k. The car felt a little easier to drive but didn't drop the lap times any.

Unfortunately I had to pack it up after that last change and didn't have more time for testing. What do you guys suggest as my next steps?

Thanks in advance.
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Old 10-08-2007, 02:03 AM   #2075
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I was kinda in th same boat as Chemical. Today was my first tiem out with teh DB12r. I had the exact base setup and i could not drive it to save my life..at all. The car was very hard to drive, it went down the straight differently each time i drove it, some times it would turn the corner great, then the next time i was like a bomb hit. Its my first time running 12th pretty much, but i shouldn't of been that hard. the rear end was breaking traction all over teh place, it would some times do a really fast donut in the corner. A guy put it on his tweak station and it was WAY! off. But i see you guys using no tweek screws.

Another thing, lets say i was coast slow then just gun it, every time the car would shift to one side or kind of fishtale.. Guys at te track said my dif was to tight? so i stopped it by a guy and he adjusted it good, but it was still doing it?

Correct me, but when holding both tires, how hard do you want it to be to slip the diff?

But in the end, the 3rd qualifier and the main, i didnt even race it

I dunno what i did wrong putin it together.

kinda boggles me the tweek was way off to begin with. I had a guy work on it on the tweek station.. and he ended up having to screw down teh tweek screws to make the tweek come in?

I need some build help! Im tempted to just send the car to jason and fix her. lol

Also, I was running Lilac's and yellows... and it was a fresh layout so it was lowbite.. I think i shoudl of used dblpink and pinks. Forgot i had them tires.
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Old 10-08-2007, 03:16 AM   #2076
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Well I don't have a DB12 yet...yet...but can offer some suggestions. First off did you balance the car out? Tweak adjustments are usually for a weight imbalance due to electronics placement. You may actually need to add weight to balance the car depending on the electronics you use. BL controllers, for example, can be very heavy and hard to counter balance with the reciever and servo placement. As far as it feeling different down the straight that could be the tweak...but often I find it is wander in the steering. The ball cups or servo saver could be loose causing some wander. I even had 1 brand new Airtronics 94145 servo whose gear mesh was so loose it caused wander. Ball cups can be corrected a couple of different ways. The most known is probably using an o-ring on the ball stud...but this can be binding as well. A better method is to use a little bit of cotton in the ball cup to take up the slop. This works great on taking up the slop but I'd reccomend not using it on the shock. I tried it a couple times and even though it felt like there was no binding the car handled funny until I took the cotton out of the shock ball cups. Diff settings for me depends on the amount of traction and how heavy your throttle trigger is. Under loose conditions setting the diff to slip for about a foot under acceleration can help when putting the power down. But it can also cause oversteer in the corners. While a tight diff can help tone down the corners by inducing some push, it also makes it more difficult to control under hard acceleration. On a high grip track personally I prefer to back off the diff until it slips then tighten it a little bit at a time just until it stops slipping under hard acceleration. You should also look for binding in the side flex plate pivot balls. I'm not sure if it possible to over tighten these or not but in general binding on the side links of a link car can cause some very strange handling characteristics.
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Old 10-08-2007, 03:25 AM   #2077
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Ben and chemical x,

Did you guys ream out the front steering blocks after installing the front axles? If not this will tweak the car badly because the spindles need to move freely on the kingpin. If you like, You can send the car to me with your radio gear installed and i will go through the car for you and find what the problem is. The car is definately bound up somewhere. It should not be tweaked. Let me know if you would like to send it and i will get on it immediately
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Old 10-08-2007, 03:51 AM   #2078
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Hey J, Yes, i reamed them out, but how reamed do i need them? i can turn them with alittle force.. do you want to ream them so they freefall down teh kingpins? If your going to do it, Ill send some NIP ones i got from you last week to ream out also.

PM me your address, I will send it out to you, I dont need it back until Sunday, the 26th. I have the micro RX in there, you have spectrum, right? so you can just bind it to your radio.

Jason, Ill call you at t shop this morning, sooner teh better, i havent went to sleep yet. I just called there, a guy said youll be there in about 20 min
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Old 10-08-2007, 04:07 AM   #2079
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I am leaving in about 10 minutes. I will be in about 7:30. YOu can send the car to me and i will find the problem. There is no charge for this if you were wondering. It is a service i offer for customers if they have any problems getting the car set up. I will be able to ship it back to you the next day
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Old 10-08-2007, 05:20 AM   #2080
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Hey guys,

I spoke with ben and found out that there is a mistake in the instruction manual. The manual tells you to install the left side clamping hub with the longer boss facing the bearing. You actually want the small boss facing the bearing. This will allow you to run even amount of shims per side. We found that his axle was shimmed 2.5mm off center which is what made the car irratic and show as being tweaked on the tweak station. I will make the change to the instruction manual immediately. I am very sorry for this. If anyone is having similar problems, please check the clamping hub direction and check that the rear axle is centered.
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Old 10-08-2007, 07:20 AM   #2081
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BShore- Did you check the Axle spacing?? It sounds like that's off, and I bet that it is off on Chem X's car also.

ChemX- back on page 46/47 you asked for Cheston's setup, did you ever get it? What setup are you running now?

Last edited by darnold; 10-08-2007 at 08:38 AM.
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Old 10-08-2007, 09:53 AM   #2082
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Anyone tried the CRC Pro Strut front end on the car yet?

Quote:
Running out of ideas on how to get his car competitive, he dropped off his Corally in the CRC pits and asked us to give the new CRC Pro Strut a try on his car. We put a Pro Strut front end on his car (yes, CRC guys working on the Corally!).

Until that point, Marc's best lap was a 10.3. On his 3rd lap after installing the Pro Strut, he nailed down a 9.9 and came back from practice with a big smile on his face. His car felt great and he went from off the pace to contender, just that easy. Shortly after that, a few other Team Corally drivers were busy fitting their cars with the front end.

Obviously, the Pro Strut was on the CRC Generation X cars. Three cars made both the stock and modified A-mains.

Don't be afriad to give the Pro Strut a go.
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Old 10-08-2007, 09:56 AM   #2083
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I have been running that front end on the car since the beginning
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Old 10-08-2007, 10:47 AM   #2084
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Thanks for the feedback guys. Here is some more info on how I built my car.

Front End Assembly:
When I setup the car, I took my time to make sure the front end was free but didn't have too much slack. I used a 1/8" drill bit to hand-ream out the steering knuckles. The upper arms were binding against the caster blocks when there was a shim on each side of the block. To correct this, I sanded a shim on each side (the one on the front side of the caster block) until the arm move and fell freely with very little front-to-back slop.

For installing the pivot balls, I don't have the CRC or IRS pivot ball tool, so I used a small hobby vise instead. The jaws on the vise are smooth and I used this to slowly press in the pivot balls making sure they were parallel the entire time. All four pivot balls move freely and don't have any slop in them.

For the steering linkage ball cups, I used the plastic bag trick to remove the slop but made sure I didn't go too far. To test them, I would check for no slop but made sure the linkage would freely fall when only connected to one side of the linkage.


Front End After Driving:
After driving the car for a couple packs and hitting the boards quite a few times, I have noticed additional slop in the front wheels. What I'm referring to is checking the front tires for camber slop when the chassis is lifted up. There is definitely more slop there now than when I first assembled the car. It appears that the steering knuckle is where the problem is but I still need to check for problems with the king pin in the pivot balls and/or any issues with the pivot balls and the arms.

Question: How much movement is acceptable on the front end? Is it ok for the camber to move +/- 1 degree? What about the steering toe? what's acceptable for that movement?


Rear End:
For the axle spacing, I did notice the clamping hub was backwards before I drove the car. I use an Integy setup board and lined up the balancing holes on the chassis with the center line on the setup board. That's where I noticed it when shimming the rear wheels. My car is using four axle shims on each side for the rear to get to 172mm while still keeping the chassis balancing hole centered on the board.

The diff is very smooth and it was difficult to move the spur gear while holding the rear wheels when I assembled the car. After driving the car for a couple packs, the spur gear was then able to move easier when holding the rear wheels so I tightened up the diff about 1/8th of a turn.


Balance:
I'm using an LRP QC2 ESC, a Spectrum Micro receiver, and an AMB PT in the car. With everything installed, including batteries and wiring, the car does balance when left static. I'm using the Hudy balancing pins as I don't have the IRS balancing balls yet. To compensate for any binding of the pin in the chassis hole, I would purposly tip the car to each side and made sure the "fall" point was even both left to right. I'm not sure how valid that test is but I did it anyway.


Tweak:
Before I drove the car, I put the car on a couple different tweak stations. I have a Speedmind bubble tweak station and the tweak was ok. I then used a buddy's Integy laser tweak station and the car was laser was splitting the center line in the middle. I also put it on another buddy's MIP bubble tweak station and it was off a bit. Not drastically, but some.

The reason I checked it on more than one station is because the rear pod isn't flat to the chassis when there is no load on the car. When you pick up the car and inspect the bottom, you can see that the rear pod isn't parallel to the chassis left to right. I haven't measured this difference yet with my calipers but to me, if you can visually see the difference, it's too much. When checking this, I made sure the motor wires weren't binding in any way either. I plan on rebuilding the L-plates to the chassis to see if this corrects it.

I find it strange that I can see the chassis difference but the tweak was ok (for the most part...) on the tweak stations.


Handling Question:
Aside from the specifics of my car, what would you guys do for a car that you can see the inside front tire lifting on high-speed turns? My thought is to stiffen up the side-to-side movement of the rear pod with either thicked dampening fluid and/or a heavier spring, T-plate, L-plate, etc (take your pick based on the chassis type). What do you guys think?

Thanks,
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Old 10-08-2007, 10:50 AM   #2085
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Quote:
Originally Posted by darnold View Post
ChemX- back on page 46/47 you asked for Cheston's setup, did you ever get it? What setup are you running now?
I never received Cheston's setup. Does anyone have it that they can send or post? Perhaps Cheston...

I will fill out the setup sheet later today and post it. This will accompany the previous post I just made on the assembly details of my car.
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