TAV-30 Max speed limit?

[minikenny]

Teach me oh wise one.

I do have the ability to gear for 5:1 and theoretically go 60mph @ 6750RPM with 15" tires.

Then do it. Listen to people are telling you. Quit wasting time and money with taller gearing.

`I did notice the TAV-2 had the white spring and the TAV-30 doesn't. I wonder how much effort it would take to bend the other side of the White spring to make it fit the TAV-30.

The different springs change the shift points and affect acceleration but not top speed.

I was told by several people that 4:1 gearing wouldn't move anything. But i took it one step further and did 3:1 gearing and all of the torque was still there. Still waiting to do a top-speed comparison.

It seems like all you care about trying to prove yourself right or prove others wrong. Problem is, the others have the experience and good advice. You just have goofy ideas about how things work.

 

[Joe-405]

I have a barstool racer i built with a bsp engine and tav2 knockoff and i have been 58mph gps with my phone and it still had throttle left. I ran out of room cause i was in a church parking lot and had to let off. I was about 3/4 throttle or so.

11" shifter kart tire. 60 tooth #35 split sprocket. And i think a 10 tooth front.

 

[minikenny]

I have a barstool racer i built with a bsp engine and tav2 knockoff and i have been 58mph gps with my phone and it still had throttle left. I ran out of room cause i was in a church parking lot and had to let off. I was about 3/4 throttle or so.

11" shifter kart tire. 60 tooth #35 split sprocket. And i think a 10 tooth front.

There ya go. 6:1 gearing with 11" tires is the equivalent of 8:1 with 15" tires.

3:1 or even 4:1 is dumb.

 

[Twid]

275

 

[FirePowerMinis]

275

I was waiting... unk:

 

[xBrent92]

I'm going to add to the thread because i did it anyways..
i did a speed-run with the 3:1 gearing and i only got a 2mph difference.

4:1 got me 42mph and 3:1 got me 44mph.

And because of the gear ratio being too high and the TAV couldn't handle it, the belt burned,shredded, and ultimately broke in 2 pieces.
Right when it broke, i knew it because the revs went so much higher.

Lasted about 3 consecutive miles.

3:1 gearing is pointless for a go-kart/minibike Torque Converter setup. I will be trying 5:1 or 6:1. 4.8:1 would be the absolute highest i would go back to.

- Just Sharing -

 

[FirePowerMinis]

Sorry to see you waste time and money like that.
Some of the experienced members should have given you some idea of how stupid the 3:1 plan was.

 

[xBrent92]

Sorry to see you waste time and money like that.
Some of the experienced members should have given you some idea of how stupid the 3:1 plan was.

I was never told the specifics besides another forum saying "it wont even move".
Oh it moved all right. Just didn't gain anything out of it besides wisdom and experience.

Gives me the chance to say i have a kevlar belt. (will be purchasing tomorrow).


I would like to achieve at least 56mph with this TAV30 but like i said, i still have a few ratios to try. 4.8:1, 5:1, & 6:1. I remember when i did 6:1 with a clutch. It would RIP a line into the dirt:

I think the dirt was kinda damp after a sprinkle of rain though so..
But now i have a live axle 2 wheel drive kart, i wonder if it'd still throw a tail. But i'm going for speed so maybe a 5:1 or 4.8:1 will do since i dont have a 54tooth.

 

[xBrent92]

Just tested 4.8 : 1 Gearing

Still only 44 miles per hour.

3:1 , 4:1 , 4.8 : 1 Equals the same max speed with a TAV2-30 series

I think i need to use a clutch.

 

[minibikin']

Do you have a tach? What RPM were you at when it reached peak speed with each gear change? If the the RPM is the same you have a TAV issue. If has less RPM with a 3:1 gear than 4:1, you do t have enough power to pull the weight faster at that gear ratio.


Sent from my Texas Instruments Speak and Spell...[emoji2]

 

[xBrent92]

I don't have a tach but i do have a GPD speedometer. each gear ratio sounds about the same and gets up to speed rather quickly.

I did notice at max speed the TAV was in overdrive.
This is with the Yellow spring on hole #3. Hole #2 is as low as I can set it. On hole #1 the belt will sink straight down and barely move if it moves.

Also wanted to add:
When i'm going about 30mph and i open the throttle, it pulls. I can feel it. I think it is neat.

I really think if I install a clutch it will go faster. I'm ready and willing to try it too.

edit2: Just noticed ... the gold driven spring someone tried on the 30series. (*_*)
It sounds exactly how the Yellow spring acts on hole#4 just without the coil bind.

 

[xBrent92]

The problem is definitely not my engine. I just went 58mph with a clutch on 4.8:1 gearing and that was because i let off to play with the acceleration and a hill slowed me down.

https://youtu.be/FZWPvAyQehk < partial video.

If only there was a cheap version of the big snowmobile CVT for more speed and torque and with a lower RPM engagement.

 

[xBrent92]

and i really dont think any of you have been faster than 45 mph with the tav-30. The driver will spin faster than the belt can grip which will slip and burn the belt.

Edit: unless going down a steep hill.

 

[Joe-405]

and i really dont think any of you have been faster than 45 mph with the tav-30. The driver will spin faster than the belt can grip which will slip and burn the belt.

Edit: unless going down a steep hill.

No incline not down hill.................Wanna Bet ?

wanna ride it yourself ? Your only a state away. If it doesnt hit 50+ i will pay your way here. If you get here and it does over that you just paid your own way. And i guarantee you im not paying up. Cause i have gps it multiple times.


Edit : AND i have used the exact same belt since it was built a few years ago. Never have had the cover off even yet. Only changed rpm springs is all.

 

[xBrent92]

I was just about to edit my post and say:
Sorry for calling y'all out. I am just frustrated that i've been limited to only 44 mph and need to use a clutch.

I wonder what the issue with my TAV is.


Okay, Joe
You sound serious enough for me to believe you.

I'm going to check if I wound the driven spring the wrong way. That's all I can think of for the mis-hap.

Added:
So I have it set like this..

edit2
I wish i showed that pic much earlier. I believe it is indeed wound backwards. If that is the case, at least i know what to tell the other people that have had this exact speed-limiting problem.

..such a helpful site this is. *sarcasm*

 

[xBrent92]

I have a barstool racer i built with a bsp engine and tav2 knockoff and i have been 58mph gps with my phone and it still had throttle left. I ran out of room cause i was in a church parking lot and had to let off. I was about 3/4 throttle or so.

11" shifter kart tire. 60 tooth #35 split sprocket. And i think a 10 tooth front

Wow that's a lot of revs. and i got worried hearing my kart at 6000+ for the first time.

 

[FirePowerMinis]

https://www.youtube.com/watch?v=kmGY0qsgW4Y

 

[yalipito]

I was just about to edit my post and say:
Sorry for calling y'all out. I am just frustrated that i've been limited to only 44 mph and need to use a clutch.

I wonder what the issue with my TAV is.


Okay, Joe
You sound serious enough for me to believe you.

I'm going to check if I wound the driven spring the wrong way. That's all I can think of for the mis-hap.

Added:
So I have it set like this..

edit2
I wish i showed that pic much earlier. I believe it is indeed wound backwards. If that is the case, at least i know what to tell the other people that have had this exact speed-limiting problem.

..such a helpful site this is. *sarcasm*

Post more pics for a better view. Wrong assembly will mess up the operation.

The wise one

 

[Joe-405]

And it's gonna matter on which way you have that driven on also. Cause mine is correct regular way on barstool. And it's turned around on the drag Minibike so the spring is wound backwards from normal.

And do you know your max rpm for that engine ? You kinda need to know to set the correct gear up


And I screen shot this from my other forum when I built the barstool. Forgot I had it...........

 

[xBrent92]

Post more pics for a better view. Wrong assembly will mess up the operation.

The wise one

Imagine the driver installed the way it is facing in this pic and that is how it was wound and installed. EXCEPT FOR THE BELT. the belt is installed correctly.

I pre-loaded the spring the other direction so i will be testing top speed tomorrow. Had to fix a fuel leak and new carb gasket.

And it's gonna matter on which way you have that driven on also. Cause mine is correct regular way on barstool. And it's turned around on the drag Minibike so the spring is wound backwards from normal.

And do you know your max rpm for that engine ? You kinda need to know to set the correct gear up


And I screen shot this from my other forum when I built the barstool. Forgot I had it...........

View attachment 88988

Hows 48 feel? Nowhere near your limit?? lol . I think my limit is between 65 and 70mph for this little thing.

max engine RPMs should be 8k i think? 26pound valve springs with Isky .290 cam 246duration @ 104LSA though.

Interesting how you say you've tried the driven on backwards..Sounds like it made it faster.
/
Can't wait for 60+ !