To Weepow or not?

Jon Piper · Apr 21, 2017

Red97 said:
Ok had some time to figure this out.

Rated tq on my 05 engine is 102 ftlb @7100

137 hp in 1-3 gear with tq dropping each gear.

1st gear 265 ftlb @ 2730 rpm 4346 max converter rpm
2nd gear 193 ftlb @3736 rpm 5947 max converter rpm
3rd gear 153 ftlb @4733 rpm 7533 max converter rpm

So by those calculations the bike engine should be really comparable to a stock 3rz engine in 2nd gear.

1st gear should work well with the 205 for crawling around. WhIle 2nd gear should allow plenty of speed if needed.

Back on track ....

So, do you have much experience with busa's ? With that max rpm it'll be making less than 100 hp and be what ? 5-6 times heavier than a bike ?

muddinmetal · Apr 21, 2017

rednecklights said:
Back on track ....

So, do you have much experience with busa's ? With that max rpm it'll be making less than 100 hp and be what ? 5-6 times heavier than a bike ?

Exactly what I was thinging. Those motors make 10 ft lbs at 2500 rpm :wtflol:

Crawling with a motor that is weaker than a 5 hp briggs from idle to 1500rpm just isn't gonna happen

Red97 · Apr 21, 2017

rednecklights said:
Back on track ....

So, do you have much experience with busa's ? With that max rpm it'll be making less than 100 hp and be what ? 5-6 times heavier than a bike ?

Nope, talked with aw10 a bit and seen j Thomas buggy work ok.

It all goes back to gear ratios.

The bike in first gear the max rpm of the output shaft will be 4300 rpm. Engine bouncing off the limiter the output on the transmission will be spinning no faster than 4300.

Now peak tq on the engine is at 7100. Divide that by 2.6 (first gear in bike trans) = 2730rpm output shaft rpm is where peak tq will now be.

So 2730 rpm at the tq converter will be 265ft lb (bike engine will be spinning 7100)

So with a stall speed of 2000 rpm it will engage 730 rpm less than peak tq.

With the bike in first gear, the buggy will drive like a little diesel engine 265 ftlb @ 2730 with a max rpm of 4300 and 137 hp.

Now second gear in the bike should be like a 2rz/3rz 193 ftlb @3736 with a max rpm of 5947rpm still around 137hp.

The bike engine is still going to the rev limiter 11,300 but the output shaft is spinning the speeds above.

As for the bike trans holding up, I'm not sure. But an automatic should be a lot easier on it than the manual's the other guys run.

If it don't work, I can still put the engine in a go kart lol

Red97 · Apr 21, 2017

https://youtu.be/IpfPi0U3tAI

Aw10 buggy crawing.

4.10 gears 37 Treps 1st gear bike, 1st gear toy 151 4.x ratio? And stock toy t case in low.

With 5.12, 35's and an auto slow crawling shouldn't be too bad.

muddinmetal · Apr 21, 2017

Red97 said:
https://youtu.be/IpfPi0U3tAI

Aw10 buggy crawing.

4.10 gears 37 Treps 1st gear bike, 1st gear toy 151 4.x ratio? And stock toy t case in low.

With 5.12, 35's and an auto slow crawling shouldn't be too bad.

It should even crawl better than that one. I stand corrected

Jon Piper · Apr 21, 2017

Red97 said:
https://youtu.be/IpfPi0U3tAI

Aw10 buggy crawing.

4.10 gears 37 Treps 1st gear bike, 1st gear toy 151 4.x ratio? And stock toy t case in low.

With 5.12, 35's and an auto slow crawling shouldn't be too bad.

I'm aware of his buggy .... I've videoed his rig several times.

I'm not against this type of build. I think it's super cool BUT I'll bet if Austin had it all over to do again he'd start with an LS or another type engines I may be wrong :dunno:

Another thing I've wondered , how will an auto like being ran the wrong direction ? Or will you correct this ?

blacksheep10 · Apr 21, 2017

If the chain is on the left side of the bike, sitting where the auto trans would be and looking forward into the sprocket, I feel like the sprocket will be going CCW, just like looking at the back of an automotive engine, yes?

Red97 · Apr 21, 2017

rednecklights said:
I'm aware of his buggy .... I've videoed his rig several times.

I'm not against this type of build. I think it's super cool BUT I'll bet if Austin had it all over to do again he'd start with an LS or another type engines I may be wrong

Another thing I've wondered , how will an auto like being ran the wrong direction ? Or will you correct this ?

Wrong direction? Don't toyota spin the same direction as a v8?

Austin said his biggest issue was using the sami frame/body and not starting with a custom chassis.

I really like the idea of a small 4cy rig, figure this should compare to most of em. Even if I go tons and 37+ I know it's not gonna be a v8. But for something different, and mild trails it should be equivalent to most 4cyl buggies