Tamiya TA-04 SS Build tips and Race Review
In the inaugural IconicRC cup, the rules stipulate that no Tamiya cars post 2005 are allowed to compete. This is sort of a continuation o...
https://www.thercracer.com/2017/01/tamiya-ta-04-ss-build-tips-and-race.html
In the inaugural IconicRC cup, the rules stipulate that no Tamiya cars post 2005 are allowed to compete. This is sort of a continuation of the Tamiya eurocup that stopped in the UK around 2005. Although the top prize isn’t an all-expenses paid trip to Japan, it’s the chance to use the classic chassis that were allowed to compete in those days
In the debut season, I competed in the stock class with a TL01(Click here to see a detailed write up). Although I had a great level of success with it, the TA04 was generally regarded amongst the other drivers as a better car to use.
When competing in an R/C event, you want to have the best equipment available, to ensure that you have a the greatest opportunity to compete at the sharp end of the competition. So I was keen to take a closer look at what the TA04 could offer.
And when you compare it with a TL01, you can see that on paper at least it looks much more race worthy with these three key features differentiating it from my trusty TL01-LA
- Twin deck chassis, allowing a lower centre of gravity
- Belt drive transmission. Reduced drivetrain friction & a more efficient design
- More variable gear ratios available
Hunting for a TA-04
I wanted to experience building a TA-04 from new, and as this kit is long discontinued I had to do a few searches on eBay. However I was very lucky to find a brand new TA04-SS kit with the Toyota MR-S body sets at a very reasonable price.
The TA04-SS differs slightly to the standard standard TA04 chassis kits with the following key differences:
- Full turnbuckle set
- Full ball bearing set
- SS suspension arms. These give a 10mm shorter wheelbase
Chassis build
As I will be looking to use this in the stock class, I will be using a limited range of optional parts, as the rules are set to keep the costs low. However there are still a few things that you can do to get the most out of the stock kit to be a solid vintage race car.Differentials
The car is equipped with 3 gear bevel differentials front & rear. The rules don’t allow the diffs to be replaced with ball diffs, one ways or a spool. They must also function as originally designed so you cannot use a locker in the front diff to give you a spool.
I chose to use anti wear grease rather than the kit grease to allow a slightly heavier operation, allowing better power delivery
With the shorter arms, you are restricted to body shell choices. The SS was released with the following body sets. The Toyota MR-S (MR2 in the UK) & Audi TT-R DTM. These cars are shorter that most cars in real life, so Tamiya aimed to replicate this with the scale of body shell
I run a 3mm reamer in the arms just to make the suspension arm operation free in movement.
The rear assembly is built up with all the arms & rear drivetrain in place, then attached to the chassis. The differential is quickly removed from the top, but everything else requires removal of the rear end to replace anything
As you can see, I added blue aluminium ball ends all around. They are slightly lighter than kit, but they look nicer than the brass affairs!
As before, I fitted a set of TRF dampers. Teflon pistons, gold shock shafts and polished shock bodies make them one of the smoothest shocks on the market. Threaded bodies make precise ride height adjustments a breeze
The layshaft sits above the motor. This allows the motor to sit lower than previously possible. Compared to modern touring design, this allows the motor to sit as low as possible, lowering the centre of gravity. The belts run around the centre line of the chassis, eliminating torque steer
The rest of the car just screws to the bottom deck. The instructions are very clear & precise. Everything you expect from a Tamiya
I used a SRT CH7015 low profile servo, it sits in the car with plenty of room to move equipment around. I now favour the Hobbywing 1060 esc to power the vehicle. It’s a great unit, excellent value for money. Coupled with a Tamiya sport tuned motor, this should give me all the power required. The Vapex 3300mah lipo I use fitted with a small modification to the chassis. A quick chat with John Weston allowed me to do this. Please enquire to the organisers of the Iconic cup before you modify your own car
For the initial test, I will start with the Kit supplied MR-S body shell. The kit comes with a clear shell to paint as you see fit & a carbon printed one. I chose to use the carbon as a test until I am happy with the car, then may look to get it painted in my race colours
As the IconicRC championship is contested outdoors, I felt it would be fair to test the car outdoors. Strafford RCMCC is one of the tracks that will host one of the 4 rounds of the 2017 championship, so it will be an ideal test track!
Stafford currently hold a winter series at their outdoor track. Although many touring car racers prefer to race indoors in the winter, it’s nice to see a club using their club all year round. As they are hosting a round, they have a specific Iconic class, perfect to use your iconic car all year round. Judging by the level of entrants they regularly have, it certainly is popular!
I entered round 2. The ambient temperature was 6deg C, so was a chilly days racing.
As previously mentioned, I chose to test the car in the short wheelbase configuration. The MR-S was used for the practice session. Ride REX30 tyres were used for the day. I enjoyed these in the 2016 championship, I feel they may have been the wrong choice for the day. Maybe a colder tyre would have worked better
The car was set to track straight & was driven about to get a feel for the layout. The car was a little loose on the rear, so I adjusted the rear wing for more downforce & added a little more camber.
Round 1 of qualifying got underway. I started last (car 6) so, just drove the circuit & looked to pass if I was faster than the car ahead of me. I made my up to 2nd place, but couldn’t catch car 1. I started round 2 in 2nd place. As I started behind car 1 without any traffic, I hoped I could catch him. As the session started, he was able to pull away through the corners, no difference down the straight. I noticed that he was able to drive a more consistent line through the corners, carrying more speed. I was feeling the short wheelbase would suit tight, technical tracks. It may work at Bedworth, but Stafford has longer sweeping corners. It may have been down to the body shell choice too. I enjoy using the Honda NSX on the TL01
Before the meeting, I decided to purchase a standard set of suspension arms. Between the heats, I decided to fit them. A bit of a tight squeeze in the time between heats! Removing the arms require removing the whole gearbox assemblies. The rear wasn’t so bad, but the front requires a lot more to be removed. Top tip, don’t fit the screw that holds the pivot blocks in place. The suspension arms are easier to replace if the screw isn’t fitted. The blocks can be removed easier without the whole assembly being removed from the car. I felt like I was going to bend the chassis in the rush. I made it just in time with the NSX body shell being fitted due to the new wheelbase
Round 3 got underway. Car 1 made a small mistake, allowing me to pass him on split times & win the round. The car felt like it was able to carry a lot more corner speed and was nicer to drive.
I went softer on shock oil for round 4. The car was quicker to turn in & felt quicker to change direction. I was able to pass car 1 to win the round.
If I took another round win, I would have the car on pole position for the finals. The qualifying after round 4, we were tied on points. Only my faster time separated us
For round 5, I fitted softer springs due to the low track temperatures. Unfortunately, I clipped a kerb & put it on its roof, requiring marshalling. The incident cost me the time to win the round (not the marshals fault, I shouldn’t of crashed!!!). As qualifying was sorted as round by round, I qualified in 2nd place. I had the potential to take pole position, but a driving error on my part cost me.
I changed additive to see how it fared. I was running the same tyres all day, the front looked very grained. I hoped they would last the finals as I didn’t bring any more with me.
The starting tone echoed out over the track and everyone launched away, with all of the cars racing around the 1st corner with no incidents. Unfortunately for me, we lapped at EXACTLY the same pace. I couldn’t close the gap, although the car that I was following could not increase his lead. They were so closely matched! As the race progressed, neither of use made any mistakes so, we crossed the line with a small gap between us. A marshal asked us after the race if our cars were fixed together as we were stuck at the same gap for the whole 5 minutes!
The tone went for final 2. I had a slightly better start & I was able to sit very close to car 1’s rear bumper. I saw a few small gaps, but not enough to make a clean pass. With a few laps to go, car 1 rolled on a kerb & I just snuck past as he was recovering. I was able to make my car very wide & was able to hold on for the win by less than 0.2 seconds!
We tied on final points, but the tie break was sorted by qualifying position, so I finished 2nd overall.
With more upgrades, the car could be a lot better. However, the car is built to the rules & we have to make the cars work with the rules set out.
If I wanted to add more upgrades, I would have to enter the GT class. For me, I think I prefer the TL01. I will carry out a back to back test to determine which car I will use for the 2017 season. Whichever car I use, I should have a good chance of trying to retain my 2016 title!
More info on the Iconic Cup is available here: (click)
Suspension arms
As stated earlier, the SS kit contains shorter than standard suspension. Each arm is 5mm shorter giving a total of 10mm shorter wheelbase. The theory behind this that it make the car more reactive, giving better handling. I bought some regular suspension arms just in case I prefer a longer car.With the shorter arms, you are restricted to body shell choices. The SS was released with the following body sets. The Toyota MR-S (MR2 in the UK) & Audi TT-R DTM. These cars are shorter that most cars in real life, so Tamiya aimed to replicate this with the scale of body shell
I run a 3mm reamer in the arms just to make the suspension arm operation free in movement.
The rear assembly is built up with all the arms & rear drivetrain in place, then attached to the chassis. The differential is quickly removed from the top, but everything else requires removal of the rear end to replace anything
As you can see, I added blue aluminium ball ends all around. They are slightly lighter than kit, but they look nicer than the brass affairs!
As before, I fitted a set of TRF dampers. Teflon pistons, gold shock shafts and polished shock bodies make them one of the smoothest shocks on the market. Threaded bodies make precise ride height adjustments a breeze
The layshaft sits above the motor. This allows the motor to sit lower than previously possible. Compared to modern touring design, this allows the motor to sit as low as possible, lowering the centre of gravity. The belts run around the centre line of the chassis, eliminating torque steer
The rest of the car just screws to the bottom deck. The instructions are very clear & precise. Everything you expect from a Tamiya
Electrics
As with the TL-01, I like to use the Tamiya Hi torque servo save with a 3Racing alloy horn. This improves the steering feel & prevents potential servo damage if the car takes a knock against a barrier.
I used a SRT CH7015 low profile servo, it sits in the car with plenty of room to move equipment around. I now favour the Hobbywing 1060 esc to power the vehicle. It’s a great unit, excellent value for money. Coupled with a Tamiya sport tuned motor, this should give me all the power required. The Vapex 3300mah lipo I use fitted with a small modification to the chassis. A quick chat with John Weston allowed me to do this. Please enquire to the organisers of the Iconic cup before you modify your own car
For the initial test, I will start with the Kit supplied MR-S body shell. The kit comes with a clear shell to paint as you see fit & a carbon printed one. I chose to use the carbon as a test until I am happy with the car, then may look to get it painted in my race colours
Track test- Stafford
As the IconicRC championship is contested outdoors, I felt it would be fair to test the car outdoors. Strafford RCMCC is one of the tracks that will host one of the 4 rounds of the 2017 championship, so it will be an ideal test track!Stafford currently hold a winter series at their outdoor track. Although many touring car racers prefer to race indoors in the winter, it’s nice to see a club using their club all year round. As they are hosting a round, they have a specific Iconic class, perfect to use your iconic car all year round. Judging by the level of entrants they regularly have, it certainly is popular!
I entered round 2. The ambient temperature was 6deg C, so was a chilly days racing.
As previously mentioned, I chose to test the car in the short wheelbase configuration. The MR-S was used for the practice session. Ride REX30 tyres were used for the day. I enjoyed these in the 2016 championship, I feel they may have been the wrong choice for the day. Maybe a colder tyre would have worked better
The car was set to track straight & was driven about to get a feel for the layout. The car was a little loose on the rear, so I adjusted the rear wing for more downforce & added a little more camber.
Round 1 of qualifying got underway. I started last (car 6) so, just drove the circuit & looked to pass if I was faster than the car ahead of me. I made my up to 2nd place, but couldn’t catch car 1. I started round 2 in 2nd place. As I started behind car 1 without any traffic, I hoped I could catch him. As the session started, he was able to pull away through the corners, no difference down the straight. I noticed that he was able to drive a more consistent line through the corners, carrying more speed. I was feeling the short wheelbase would suit tight, technical tracks. It may work at Bedworth, but Stafford has longer sweeping corners. It may have been down to the body shell choice too. I enjoy using the Honda NSX on the TL01
Before the meeting, I decided to purchase a standard set of suspension arms. Between the heats, I decided to fit them. A bit of a tight squeeze in the time between heats! Removing the arms require removing the whole gearbox assemblies. The rear wasn’t so bad, but the front requires a lot more to be removed. Top tip, don’t fit the screw that holds the pivot blocks in place. The suspension arms are easier to replace if the screw isn’t fitted. The blocks can be removed easier without the whole assembly being removed from the car. I felt like I was going to bend the chassis in the rush. I made it just in time with the NSX body shell being fitted due to the new wheelbase
Round 3 got underway. Car 1 made a small mistake, allowing me to pass him on split times & win the round. The car felt like it was able to carry a lot more corner speed and was nicer to drive.
I went softer on shock oil for round 4. The car was quicker to turn in & felt quicker to change direction. I was able to pass car 1 to win the round.
If I took another round win, I would have the car on pole position for the finals. The qualifying after round 4, we were tied on points. Only my faster time separated us
For round 5, I fitted softer springs due to the low track temperatures. Unfortunately, I clipped a kerb & put it on its roof, requiring marshalling. The incident cost me the time to win the round (not the marshals fault, I shouldn’t of crashed!!!). As qualifying was sorted as round by round, I qualified in 2nd place. I had the potential to take pole position, but a driving error on my part cost me.
Finals
I lined up in 2nd place, ready to take the challenge to try for a win.I changed additive to see how it fared. I was running the same tyres all day, the front looked very grained. I hoped they would last the finals as I didn’t bring any more with me.
The starting tone echoed out over the track and everyone launched away, with all of the cars racing around the 1st corner with no incidents. Unfortunately for me, we lapped at EXACTLY the same pace. I couldn’t close the gap, although the car that I was following could not increase his lead. They were so closely matched! As the race progressed, neither of use made any mistakes so, we crossed the line with a small gap between us. A marshal asked us after the race if our cars were fixed together as we were stuck at the same gap for the whole 5 minutes!
The tone went for final 2. I had a slightly better start & I was able to sit very close to car 1’s rear bumper. I saw a few small gaps, but not enough to make a clean pass. With a few laps to go, car 1 rolled on a kerb & I just snuck past as he was recovering. I was able to make my car very wide & was able to hold on for the win by less than 0.2 seconds!
We tied on final points, but the tie break was sorted by qualifying position, so I finished 2nd overall.
Conclusion
The TA04 seems like a very good to use for the iconicRC cup. The car drove very well, but not as quick as I expected. It seemed like a good choice to enter the championship with. The car responds very well to setup change & there a lot mot more adjustments than the TL01
With more upgrades, the car could be a lot better. However, the car is built to the rules & we have to make the cars work with the rules set out.
If I wanted to add more upgrades, I would have to enter the GT class. For me, I think I prefer the TL01. I will carry out a back to back test to determine which car I will use for the 2017 season. Whichever car I use, I should have a good chance of trying to retain my 2016 title!
More info on the Iconic Cup is available here: (click)
