Yokomo YZ-2T 2WD ST truck
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#136

Okay and now for the update. Like I said we got to practice/test on the new layout because of the storm and lack of guys who showed.
I ran a few different buggy rear springs on the truck front and they were all too soft. Made the truck handle extremely well through the tight sections and the technical stuff, but was too soft for the sweeper and the jumps.
I was only able to get a 16.0 in the practice no matter how I set the truck up. Messed with roll centers, dropping the ride height and different pills. The 16.0 was my fast lap and that was it. There was a lot of consistent 16.2s and 16.3s but was only able to hit 16.0 every once in a while. I ran the track preferred proline prime in m4 compound with sauce each time and only made 1 change at a time to see the difference.
This past weekend I didn't change anything, went back to the setup I was running, threw the truck out there and again ran a 16.0 in the practice with the prime m4s. I thought I could get more grip out of different tires so I had a few prepped and ready to go. I tried the chainlinks in ultra soft sanded down to slicks and again ran a 16.0. The truck felt sluggish in the turns and pushed quite a bit with what felt like the same amount of forward bite. Then I threw on the tires in the picture above and it felt like there was a noticeable difference in the grip. First couple laps I was running 15.7s and 15.8s with only the occasional 16.0. That was the biggest change for me. I ran the same gearing and setup only difference was the tires. (About a month ago I gave these a shot and the back end was swinging around in the seweper and on the techical sections. The lap times were similar to what I was running at the time, it was just harder to drive so I went back to the other tires. In the mean time I scuffed the front some more and sanded the backs down to almost slicks and wanted to give that a go.)
Like I said, I instantly dropped time on my fast lap and was able to clear the middle doubles with no issue and didn't have to swing it wider or line it up just right like I did with the other tires. The truck had a lot more forward grip, but the truck turned/rotated too much for my liking so I eventually backed off on the steering with the radio rather than mess with setup.
First round track was just misted after practice and the heats began. I set the tq, we ran in the 4th heat and the traction dropped off about half way through the qualifier. My fast lap was in the first 5 laps and was a 15.48 so it dropped a little bit more from practice that morning. I made a few mistakes that cost me about 8 seconds overall.
Second round we had a 45 minute break and were bumped back to the 5th heat due to the 2wd buggy class being split into another group. I ran a fast lap of a 15.67 in the first couple laps, made no mistakes and was still 2 seconds off my tq. We just didn't have the grip as the track dried out. The average lap also suffered hence the overall slow time.
3rd round we took a 25 minute break and were still in the 5th heat. I dropped my fast lap back down in the mid 15.5s and set a new tq but only by a few tenths in the whole 5 minutes. The track had a little more grip than the previous round at first but the traction just wasn't there. The truck didn't handle too bad, but like I said it just wanted to turn a bit too much for my liking even with the steering turned back to 96% on the radio. I felt like the truck was on edge and the back wanted to break loose. I stayed on power more and actually adjusted the radio to give me a little bit of throttle when I wasn't touching the throttle.
The main we were actually bumped up to the 3rd slot to split the b/a mains up for 2wd stock and mod buggy.
The track had grip and my lap time dropped to a low 15.3. The truck dove a little bit in the corners due to the increased traction and speed which made it a little harder to hang on to, but overall it handled pretty well. Second place was faster in the hot lap each round by a few tenths all day. He runs a 7.5 and used the speed/power to make up time down the straights and to drift around the corners. I run a 10.5 geared low and come off the track between 115 and 120 degrees. I plan to gear it up 1-2 teeth on the pinion because I am noticeably slower on the straight. I get caught on the straight/sweeper pretty easily, I just make up time through the rest of the track to make it not as noticeable in the overall lap time. In theory I can drop the time down if I am faster on the straight and sweeper and remain at the same speed everywhere else. Catch 22 is I don't want to add too much speed because I don't want to be out of control and make the truck harder to hang on to.
Next time out I will run a few laps to see if times have changed at all from the last time out. Then I will go up 1 tooth on the pinion and see how the lap time is. If that goes well I may stay there for a week and adjust to the speed or if it feels good I may go up another tooth out of curiosity. After that I will probably have to adjust the truck some, but first plan on saucing the fronts less or not at all and see how it goes. From there I can't say, maybe try a stiffer spring in the front if it still bites too much, maybe up 2.5 in oil, maybe adjust rear roll center to get more traction back there. I will just keep working at it and see how it goes. It is a new place to race for me and a different truck so I am learning a little more each time I go out.
I ran a few different buggy rear springs on the truck front and they were all too soft. Made the truck handle extremely well through the tight sections and the technical stuff, but was too soft for the sweeper and the jumps.
I was only able to get a 16.0 in the practice no matter how I set the truck up. Messed with roll centers, dropping the ride height and different pills. The 16.0 was my fast lap and that was it. There was a lot of consistent 16.2s and 16.3s but was only able to hit 16.0 every once in a while. I ran the track preferred proline prime in m4 compound with sauce each time and only made 1 change at a time to see the difference.
This past weekend I didn't change anything, went back to the setup I was running, threw the truck out there and again ran a 16.0 in the practice with the prime m4s. I thought I could get more grip out of different tires so I had a few prepped and ready to go. I tried the chainlinks in ultra soft sanded down to slicks and again ran a 16.0. The truck felt sluggish in the turns and pushed quite a bit with what felt like the same amount of forward bite. Then I threw on the tires in the picture above and it felt like there was a noticeable difference in the grip. First couple laps I was running 15.7s and 15.8s with only the occasional 16.0. That was the biggest change for me. I ran the same gearing and setup only difference was the tires. (About a month ago I gave these a shot and the back end was swinging around in the seweper and on the techical sections. The lap times were similar to what I was running at the time, it was just harder to drive so I went back to the other tires. In the mean time I scuffed the front some more and sanded the backs down to almost slicks and wanted to give that a go.)
Like I said, I instantly dropped time on my fast lap and was able to clear the middle doubles with no issue and didn't have to swing it wider or line it up just right like I did with the other tires. The truck had a lot more forward grip, but the truck turned/rotated too much for my liking so I eventually backed off on the steering with the radio rather than mess with setup.
First round track was just misted after practice and the heats began. I set the tq, we ran in the 4th heat and the traction dropped off about half way through the qualifier. My fast lap was in the first 5 laps and was a 15.48 so it dropped a little bit more from practice that morning. I made a few mistakes that cost me about 8 seconds overall.
Second round we had a 45 minute break and were bumped back to the 5th heat due to the 2wd buggy class being split into another group. I ran a fast lap of a 15.67 in the first couple laps, made no mistakes and was still 2 seconds off my tq. We just didn't have the grip as the track dried out. The average lap also suffered hence the overall slow time.
3rd round we took a 25 minute break and were still in the 5th heat. I dropped my fast lap back down in the mid 15.5s and set a new tq but only by a few tenths in the whole 5 minutes. The track had a little more grip than the previous round at first but the traction just wasn't there. The truck didn't handle too bad, but like I said it just wanted to turn a bit too much for my liking even with the steering turned back to 96% on the radio. I felt like the truck was on edge and the back wanted to break loose. I stayed on power more and actually adjusted the radio to give me a little bit of throttle when I wasn't touching the throttle.
The main we were actually bumped up to the 3rd slot to split the b/a mains up for 2wd stock and mod buggy.
The track had grip and my lap time dropped to a low 15.3. The truck dove a little bit in the corners due to the increased traction and speed which made it a little harder to hang on to, but overall it handled pretty well. Second place was faster in the hot lap each round by a few tenths all day. He runs a 7.5 and used the speed/power to make up time down the straights and to drift around the corners. I run a 10.5 geared low and come off the track between 115 and 120 degrees. I plan to gear it up 1-2 teeth on the pinion because I am noticeably slower on the straight. I get caught on the straight/sweeper pretty easily, I just make up time through the rest of the track to make it not as noticeable in the overall lap time. In theory I can drop the time down if I am faster on the straight and sweeper and remain at the same speed everywhere else. Catch 22 is I don't want to add too much speed because I don't want to be out of control and make the truck harder to hang on to.
Next time out I will run a few laps to see if times have changed at all from the last time out. Then I will go up 1 tooth on the pinion and see how the lap time is. If that goes well I may stay there for a week and adjust to the speed or if it feels good I may go up another tooth out of curiosity. After that I will probably have to adjust the truck some, but first plan on saucing the fronts less or not at all and see how it goes. From there I can't say, maybe try a stiffer spring in the front if it still bites too much, maybe up 2.5 in oil, maybe adjust rear roll center to get more traction back there. I will just keep working at it and see how it goes. It is a new place to race for me and a different truck so I am learning a little more each time I go out.
#138
#139

anyone know what the spring rates are for the springs that come in the kit.
#141
#142
Tech Regular
iTrader: (7)

Update on issue with original kits with 89mm rear bones bottoming out in cups WAYYYYYYY prior to reaching maximum shock travel.
Updated kits come with 87.5mm bones (part # for the 87.5 dog bone is Z2-01075B) If you are located in NA and wanting parts from Amain they should have a listing for them in next 7-10 days.
A temporary (or long term if you like I suppose) fix is going to a 5x10x3 inner bearing. This works perfectly, I now have up travel to shock stopper without bone bottoming out in cup.
Cheers
Updated kits come with 87.5mm bones (part # for the 87.5 dog bone is Z2-01075B) If you are located in NA and wanting parts from Amain they should have a listing for them in next 7-10 days.
A temporary (or long term if you like I suppose) fix is going to a 5x10x3 inner bearing. This works perfectly, I now have up travel to shock stopper without bone bottoming out in cup.
Cheers
#144

Yeah they probably should fix it like any recall, but at least they made it a cheap fix. Under $25 for both I can live with that.
Hey has had anyone out there tried the shocks in the rear? If so what’s difference? What’s the truck feel like after? More rear grip or less? Haven’t been able to get to the track the last two weekends to try it out.
Hey has had anyone out there tried the shocks in the rear? If so what’s difference? What’s the truck feel like after? More rear grip or less? Haven’t been able to get to the track the last two weekends to try it out.
#145
Tech Master

As physics are the same for every car, shocks in the rear will put more weight to the far rear end. This will give you more grip, but e.g. in sweepers your rear end may step out earlier, corner speed will be lower. Anti-squat will cause rear-mounted shocks to have less droop unless you adjust them by removing spacers inside or lengthen the shock eyelets. You will have less steering and a less reactive truck overall. I'd rather buy the steel C-block and/or the Proline T6.1 body to have a less twitchy car, to be honest. After I drove the original YZ-2 for the first time, I never wanted to go back to a car or truck with so much weight hanging out on the rear end.
#146

As physics are the same for every car, shocks in the rear will put more weight to the far rear end. This will give you more grip, but e.g. in sweepers your rear end may step out earlier, corner speed will be lower. Anti-squat will cause rear-mounted shocks to have less droop unless you adjust them by removing spacers inside or lengthen the shock eyelets. You will have less steering and a less reactive truck overall. I'd rather buy the steel C-block and/or the Proline T6.1 body to have a less twitchy car, to be honest. After I drove the original YZ-2 for the first time, I never wanted to go back to a car or truck with so much weight hanging out on the rear end.
As of my last race and update I was planning on not messing with my setup and just trying to change the gearing to get some more speed for the straight and sweeper, get used to the faster speed then adjust, but I may throw the shocks in the back and see how it feels. For me, the more grip the better. I personally like that the car/truck is going to stick and go where I want it to rather than sliding around and correcting/anticipating the slide. I will be racing this weekend and am hoping for the same layout so I can compare the feel of the truck as well as my previous lap times.
#147
Tech Master

As long as there are more straights and 180s than sweepers, such a set-up should work pretty well. Many tracks with a focus on double and triple jumps are designed that way.
#148

Race update from the last time I was out... Short story is I tqd each round and won the main by multiple laps over 2nd place. I ran with the shocks in the rear, had a ton of rear grip and was extremely happy. Literally didn't change anything to set up, just flopped the shocks to the rear. Kit setup, shocks on the rear of the tower, gold shock shafts and no limiter in the front shocks. Even ran the kit oils in the shocks.
The track I run at is clay high bite and pretty flat. The jumps, tabletops and elevations are all made of wood so track changes can be done quickly so we have a new layout every month sometimes sooner. This time out the track was setup differently so no comparison on the times from before. This weekend was kind of a waste as far as info gathering went. Good because I had a ton of grip and was happy with the truck, but bummer because I couldn't make any changes to test see a difference because of the changes/issues with the track. Also somewhat of a bummer because there was a big blind spot on the left side before going up onto a tabletop.
We had an issue with the layout and loop being tripped. The loop isn't 1 lane, it is more like 1 lane and 2 feet due to them running oval in the past. The layout was changed to give us 6 lanes on the right side of the track instead of the usual 4. Even with the fast time being set at around 15/16 seconds we had some slower guys tripping the loop 2 times in one lap giving them 2 really fast laps to the normal 1 of around 17 seconds. After the first round the track was changed to keep this from happening. The track was 3 seconds faster. Half of my 2 races (2wd truck and 4wd buggy) the fast lap was not changed until halfway through that heat so most of the laps I had were clocking in at a little over 28 seconds. I did have some 14.0s in that round. The 3rd round changed because there was less time in between rounds due to no track change. Fast lap was 13.7 in the 2wd truck. The mains were flopped around and I ran 4wd buggy 2nd and truck 4th. I feel running in 6th and 7th heat of 10 was hurting the times. Track was a lot stickier in the first couple of races compared to running 6/7th. 4wd buggy was a 12.7 in the main and I was running 13.3s in the previous heat. Truck times dropped also in the main to 13.2s
I could have used a little more steering in the sweeper if I wanted to stay on power the whole time, but I was still able to keep speed around it and use the brakes to swing the back end around on the 180s/tight stuff.
If anyone out there is curious yes you will have a ton more rear grip just by flopping the rear shocks to the back of the tower. Next move for me will be to turn the steering up to 100 from 97, then move the battery forward or try a lighter battery to possibly get a hair more on power steering.
I will not be moving the shocks back in front of the tower. I am happy where it is at and will tune from here. As I said more grip made the truck feel more stable and was easier to drive for me.
The track I run at is clay high bite and pretty flat. The jumps, tabletops and elevations are all made of wood so track changes can be done quickly so we have a new layout every month sometimes sooner. This time out the track was setup differently so no comparison on the times from before. This weekend was kind of a waste as far as info gathering went. Good because I had a ton of grip and was happy with the truck, but bummer because I couldn't make any changes to test see a difference because of the changes/issues with the track. Also somewhat of a bummer because there was a big blind spot on the left side before going up onto a tabletop.
We had an issue with the layout and loop being tripped. The loop isn't 1 lane, it is more like 1 lane and 2 feet due to them running oval in the past. The layout was changed to give us 6 lanes on the right side of the track instead of the usual 4. Even with the fast time being set at around 15/16 seconds we had some slower guys tripping the loop 2 times in one lap giving them 2 really fast laps to the normal 1 of around 17 seconds. After the first round the track was changed to keep this from happening. The track was 3 seconds faster. Half of my 2 races (2wd truck and 4wd buggy) the fast lap was not changed until halfway through that heat so most of the laps I had were clocking in at a little over 28 seconds. I did have some 14.0s in that round. The 3rd round changed because there was less time in between rounds due to no track change. Fast lap was 13.7 in the 2wd truck. The mains were flopped around and I ran 4wd buggy 2nd and truck 4th. I feel running in 6th and 7th heat of 10 was hurting the times. Track was a lot stickier in the first couple of races compared to running 6/7th. 4wd buggy was a 12.7 in the main and I was running 13.3s in the previous heat. Truck times dropped also in the main to 13.2s
I could have used a little more steering in the sweeper if I wanted to stay on power the whole time, but I was still able to keep speed around it and use the brakes to swing the back end around on the 180s/tight stuff.
If anyone out there is curious yes you will have a ton more rear grip just by flopping the rear shocks to the back of the tower. Next move for me will be to turn the steering up to 100 from 97, then move the battery forward or try a lighter battery to possibly get a hair more on power steering.
I will not be moving the shocks back in front of the tower. I am happy where it is at and will tune from here. As I said more grip made the truck feel more stable and was easier to drive for me.
#149

