# Serious JL / AW Thunderjet Chassi tune up tips



## gonegonzo (Jan 18, 2006)

I'd like to start this post for those of us that would be interested in building a competitive JL / AW Thunderjet racer.

Being somewhat new to pancake motored slots , I really have no hi tech advice to offer. I can work on them like anyone else but the knowledge that some of you have would make me look like a fool.

OK T-Jet mechanics , Combining the Aurora and JL / AW parts is quite common place ( or so I hear ) , so let's let that be an option.

What top plates can you interchange with these chassis ?

What "arms " can be used ?

What wheel sets are suited for these chassis' ?

What can be done to re-align the axle holes ? I'm sure even the most wobbled out chassis can be saved !

Has anyone tried running stock Aurora skinny wheels and tires on these chassis ? What was the outcome ?

What about metal gears ? Most run them until the plastic gears mesh into dust and toss the chassis. Would metal gearing make them as desireable as the favored Aurora T-Jet ?

I'm sure I haven't even scartched the surface as to the tuning of these pesky toys. However I do have quite a few of them and would rather make them runners than canablize them for the magnets.

I will now humbly turn this post over to the more expeienced mechanics.

Thx , Gonzo


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## dlw (Aug 17, 1999)

Well, on the top plates, Auroras won't work.....The tabs don't line up right. But you can use Moder Motoring top plates (if needed).

Arms is a matter of preference.


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## SuperFist (Aug 7, 2005)

On Thunderjets first you want to start out with a chassis that's straight and not twisted,
by checking it on a set up block or a piece of track.
All 4 wheels need to be making contact.
It's a waste of your good parts, time and money to tune one that don't.

When I find a T-Jet or Thunderjet chassis that's twisted, it goes straight into the trash.
I refuse to even give them away,
because I'd be screwing someone by giving them a piece of crap.

__________________


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## Tjettom (Jan 1, 2008)

Say Super, Have you ever tried straightening them like boiling them with an RTHO aluminum jig? I have one of Rick's jigs but since I haven't used it yet I was wondering if the time and out come is significant or not...Thanks and hope to hear any input from others as I do have many twisted but other wise good chassis...
Hate to pitch em if the jig trick is worth while......

Tjets forever,
Tjettom Baker Central Illinois


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## partspig (Mar 12, 2003)

Hey SuperFist, throw them t-jet chassis my way! I'll take every crooked one you have off of your hands. That way you won't have to worry about giving away crap to a bunch of guys, just me!


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## SuperFist (Aug 7, 2005)

One of the guys I race with has a RTHO boiling jig.
When chassis are twisted if they're straightened the parallel alignment of the armature and cluster gear shaft holes between the deck and the chassis won't be right and the gears won't mesh good.

Start out with a good true chassis for building a racer.
All my chassis are good otherwise I wouldn't need them.

__________________


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## mahorsc (Mar 26, 2008)

we race jl/aw in the southern sports here on east coast and have a ball
here in charleston sc we run alot of diff cars
the arms will work in both chassis'
any wheel set will work i run wizard,rtho, zoomin and i just got one from brp for the wiz shoe set up i will let u know how it works
as far as the chassis wobble i put bbs on both sides of the hole and us a micrometer to squeeze which tightens hole i have 1 chassis that has may 10000 laps and is still fairly tight it gets ran every time we are on an oval because it is the fastest car in the series 
we also run them with skinny tire double flange rims they are as fast as any
and dont handle to bad (but not as good as a t-jet)
i have not tryed to run brass gears only plastic-but i have built close to 50 of these cars and only trashed 1 gear in the last 5 yrs of running jl's-that was because the gear were not right

some other tips if you run 504 shoes notch chassis just a hair at front and the shoes will fit with out bending frt of shoe-these shoes will lower et buy a bunch
wiz shoe fit great but dont seem as fast but make the cars handle like crazy i am still trying to get speed from them i am sure it is just a small adj some where
just started to exp with 502 seem ok but not finished testing

the aw chassis seem to be better than jl but if they are flat and gears are set up right and smooth they are even on speed 
i lap gears just like a t-jet

thats all i can think of right now 
any question let me know
kevin


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## SuperFist (Aug 7, 2005)

Dose anyone know where you can get BSRT 502G & 502S pickup shoes ?

I can't find them anywhere.

__________________


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## mahorsc (Mar 26, 2008)

o-- i forgot throw rear axle away most are bent or bend when putting wheels back on 
1 good wall hit also bends axle
i use drill blank or afx axles


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## gonegonzo (Jan 18, 2006)

Youhave some valid points there Super. That's probably the right way to look at a racing chassis. However , you could look thru a case of xchassis' and not find a perfect one, especiallythe JL / AW chassis.

That's one of the points of this post , to seriously tune and save even the not so perfect chassis and learn what parts can fit where etc etc . 

I haven't ran into any miss aligned bores with boiling a chassis yet. However, I was warned against boiling a JL/AW chassis by one of the pro-builders. As he explained they are cast from a different chemistry than the oringinal Aroura pcs.

In this case if all four wheels don't touch evenly, to save the otherwise o.k. JL/AW chassis, I would suggest staggering the front tires to even up the paw prints. If you would determine for example that the chassis was .015 high on one point, you coud use a tire that is .030 larger in diameter on the high side to even it out. Since it's not recomended to boil this chassis it would be a way to save it. 

If anyone has had good luck or has any experience in boiling the JL / AW chassis, let us know now so we can clear that issue up for certain.

Kevin,

That's the kind of info we're looking for here. What we can do to inhance performance from the JL / AW chassis. I've ran the Southern Sportsman cars at a race in Pittsburgh a few years back and they were a lot of fun, cheap to build and with everyone running the same caliber equipment, very competitive.

Keep the pros and cons comming and we might discover we have some diamonds in the ruff slammed in the corner of our pit boxes. All they needed all of this time was polished off.

Hey Kevin, I hope to see you in Columbus in a few weeks.

Gonzo


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## mahorsc (Mar 26, 2008)

has far as boiling dont what i have found they kind of melt
you can if you watch carefully ---- but--- this goes for a t-jet also

they will return to origanal twist it may be the same day it maybe year from now butt it will return and its always at the wrong time like in the middle of a race 

i have several cars with staggered tires the work great there fun
but they are not my best race car 

cant wait for ohio i am having trigger withdraw


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## 00'HO (Nov 19, 2004)

*Hair Dryer ?*











Anybody try a hairdryer/heat gun on their chassis ?

http://www.daveshoraceway.com


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## gonegonzo (Jan 18, 2006)

I wasn't aware of Aurora chassis having a melt down too. That's good to know.

I wasn't aware that a chassis would return to their original twist either. In the middle of a race would be bad timing I agree. Do you think a hard crash is the cause. It all makes sence.

I went to Marks Model World in Canton , Ohio yesterday and bought some BSRT parts. He has some left .

Trigger finger withdrawl huh ? I actually take the summer of from racing slots. I'm just comming out of my hiatis for the Ohio race. It's a "not to miss" race ya know?

Gonzo


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## hartracerman (Jan 9, 2005)

I have boiled all of my aurora chassis and haven't had a problem. I kind of remember someone saying that by doing that it goes back to original form from being yanked out of the mold to early. The aurora plastic has a memory to go back to normal when done this way. So like the factory let it cool first.


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## hartracerman (Jan 9, 2005)

I forgot put it in a strainer or something else so it is raised from the bottom of the pan. It can get too hot if you let it stay at the bottom


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## LDThomas (Nov 30, 1999)

*Boil away...*

The plastic used by both Aurora and JL/R2/AW can withstand boiling with no problems. They don't melt at 212 degrees F. If someone destroyed a chassis while boiling it, it wasn't the water that caused the problem.

Those grades of resin have a memory. And boiling them will change that memory. I have been boiling chassis far longer than R/T has had his jig on the market and have yet to lose a single chassis. The key to a successful boil is to boil the chassis for at least 30 minutes (I prefer 45 minutes, just to be sure.) in a hard boil and then turn off the heat. Let the chassis sit in the pan and water while they all cool down to ambient temperature on their own. Don't try to speed up the process with cool water or anything like that. This process removes the old 'memory' and replaces it with the new 'set' that you have given the chassis. I have yet to have a chassis go back to its old shape if I boil it for 30-45 minutes and let it cool in the water. You are simply taking advantage of the physical traits of the plastic resin.

You have all seen how Bill Hall is able to reshape a car that has lost a pillar or such. He makes it very clear that you have to get the top back to its proper shape before you worry about replacing the pillar. And once you get it back into shape in a proper fashion, it will stay there. The same concept holds for a chassis.


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## Brixmix (Dec 2, 2007)

I agree with Larry I boil chassis for 30 to 40 mins and let it cool down in the water ( 1-2 hrs) and then dry off the chassis and let it sit in the jig for another couple of hrs at room temp. I have had good luck with this and it also kind of rehydrates the plastic and makes it a little more fexiable.

Good tip Larry !!


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