tub gt for racing

[markt311]

I know there's not a whole lot on here about GT's, but here's my tub GT. I'm going to be racing this truck, so the suspension has been updated with most of the newer GT's suspension arms and shock towers. It doesn't have the wide front axles yet or losi cvd axles to widen the rear. When my brother brought this truck over it was in pretty sad shape, wood screws everywhere, missing parts, just as it arrived from Ebay! I have it pretty much cleaned up and ready to go. We have a big state race this weekend so I'm going to give it a go with this old girl, I still have to get some different rod ends when the shop opens before the race. I love those old CVR motors, it runs great and has just enough power but not too much. Here's some pictures how it sits now.
Now I need to update my avatar since that truck is gone

[markt311]

I just got home from the Tennessee State Shootout now at 12:24AM, I left the house at 8am!! Long day to say the least. The day started out ok, I wrenched on the truck unil about 11 this morning since it rained a lot yesterday and the track was pretty sloppy. But the sun was out so the track was getting better. I put on some new ball ends on the front end. Went out for some dodging 1/8th scales, I mean practice , the truck was decent but pushing pretty bad. I looked the truck over before the first round of qualifying and I noticed the cap head screws I put on the captured rod ends for steering were rubbing the ballcups, so I put some button head screws in their place. In the first qual I was running in second but a stripped steering servo put me out. Thanks to a racer who let me borrow a servo (I actually had 2 people give me servos without me even asking!) I decided to put some different front tires on, borrowed from a fellow racer (thanks Todd). In the second qual I ran great the whole run and tq'ed, I was the only one to run 9 laps, I hoped that would hold up for one more round. Round 3 I drove bad, had 3 or 4 costly wrecks but no one beat my time so I ended up with top qualifier for the day with a fifteen year old truck!

The main started out ok, I made a dumb mistake and ended up in second place about 9 seconds back. This was a 20 minute main so I calmed myself down and just started focusing on my lines and jumps. I cut the lead down to about 4 seconds at about the 14 minute mark, we were all about to come in for our last pit stop. The leader had a slow stop and we came out of pit row with me about 3 feet behind the leader. Then it happened! Going down the back straight I heard the high pitched wail of the motor, uh oh, then I got drive again. I nursed it around for the next lap now thinking of saving second for myself. Of course it let go all together, I haven't pulled the trans apart but the spur gear is fine so I figure the idler gear let go or the diff loosened up. I ended up in fourth, but I will be back for revenge It was a fun day overall though

[dell]

what a great race report. it is nice to know that the tub still has it. with the right hop-ups that truck is just as good as the newer gt's. when that chassis came out it was thought that stiffer is better. fast forward to today and every body is looking for a chassis that will flex. I know the tub will flex in the wrong place, but there are some hop-ups to stop that without stopping the rest of the chassis from flexing. almost every 1/8 scale chassis make today is designed with flex in the chassis. most notable is the losi flex tune chassis for the losi 8 and losi 8 2.0.

[Lonestar]

Good job at the race, sorry to hear you didn't take the win!

stripped servo gear? interesting... when I looked at your truck I actually thought the stock servo arm looked a little wimpy... here's my suggestion - if you can afford it, get yourself a torquey, high-end metal gear servo (KO's have my, and most of the racers' I know, preference), and use the built-in servo saver as the elastic link in the chain...

The 635MG you currently have in there is not up to par with the rest of the truck imho... I know some people only swear by hitec, but the higher you go in the racing circles the least you find... a servo main output gear shouldn't strip in a car where the servo saver is in working order. that might be worth checking too.

Have fun with that old lady - Id also love to see Dynamite-converted LXT's battle on the track too

LAter
Paul

[markt311]

Lonestar- Thanks for the info, I did a little research and found the same info out you let me in on, that servo was sold to me by the LHS and after talking to a rep from HITEC that servo is meant for planes So I have a standard servo in there for now, loosened up the servo saver a little and have had zero issues in 2+ hours on the track. I'll be buying a couple torquie servos in the near future. I want to find a losi NXT or GTX (basically the same truck, one was after the dynamite deal started with Losi), I had one back in the day and it was a tank!!

Just a little update on the tub, we had the points series shootout race the weekend after the race I posted on earlier. We ended up with 6 entries in gas truck, including my brother who is runing a flat chassis gt prepped by me. I spent some serious time prepping this truck the week before the race, I countersunk the steering posts and drilled a 3rd hole for the nose plate and countersunk that hole. I also put some beefy rod ends on the truck to help bulletproof it and the Tebo camber link in the back definately hooked it up
I took the tranny out and realised the reason it stripped the spur was a combination of a really wierd worn top shaft and the 2 most forward holes in the trans case being stripped. I'm not sure if you can make it out in the picture, but the end of the topshaft is worn down like a bearing locked up at some point. This allowed the spur gear to rock a little and the trans holes being stripped let the whole trans move a little to the point the gear mesh got too loose and stripped the spur gear. I put all new gears in the trans and used 3mm screws in the tranny. I also put a new brake disc in it. I finished third this time because I didn't listen to my pit man and ran out of gas halfway through the race, oh well. The old school body was a hit with the racers and I had a steady stream of 1/8th racers looking nostalgic and telling stories of racing ten years ago, made some new friends!! I was very happy overall though. I ran the fastest lap of the day for gt's by a full second and my 2nd place qualifying spot was 15 seconds faster than my TQ the week before. I was pretty consistent throughout the day and although it looks like this truck is going to be retired now since I'm buying a GT2 from a buddy I think it had a very nice showing. now the pics

[justinspeed79]

Markt, I didn't notice the pic of the top shaft when you posted it on the GT forum, but it looks like it was shimmed wrong, and only the very end of the shaft was riding on the bearing. It could have been made worse by a bad bearing, or even caused the bearing to go bad. When you put it back together make sure you have one shim on each side. If you have any alignment issues with the spur/clutchbell, shim the clutchbell to get it lined up.

[markt311]

Justin you're right, when I pulled the trans apart it had no shims on the top shaft at all. I rebuilt it with all new parts except for the bearings (I cleaned those) and outdrives, I shimmed it when i put it back together with a new trans case. That transmission is in my brothers other gt now and its doing great now. I just need to spend some time with his truck to get it setup better. The tub might get setup to run dirt oval, it's up to him cause I have a gt2 now