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Mower Building / Setup Help => Driveline => Topic started by: kb0323 on June 29, 2014, 05:01:36 PM

Title: need help with 700 tranny
Post by: kb0323 on June 29, 2014, 05:01:36 PM
I race a g/p I use the 700 tranny. I want to run 3rd gear but it is never enough. The tranny is a 5 speed. What do I need to do to it to run 3rd gear and compete.
Title: Re: need help with 700 tranny
Post by: more4les on June 30, 2014, 08:05:10 AM
Bigger front sprocket or smaller rear. It's about gear ratio. Understanding them is going to be your best friend.

Lester
Title: Re: need help with 700 tranny
Post by: kb0323 on June 30, 2014, 01:52:13 PM
I run a 17 on tranny 40 on axle. 5th gear I'm fast but wanna run 3rd.
Title: Re: need help with 700 tranny
Post by: bubba4trax on June 30, 2014, 02:14:22 PM
What pulleys are you running?
Title: Re: need help with 700 tranny
Post by: trbinrat on June 30, 2014, 06:45:18 PM
When you say never enough. Enough of what speed or power coming out of the corner? Are you on 6" rear tires or 8".

How big are the tracks that you run on.

On mine I run a 8 on the engine 5 on the tranny for pulleys and any where from 13 to 16 on the tranny and 40 to 46 on the axle. Now that I've gone to 6" rear tires I've gone as high as 18 tooth on the tranny.  This all depends on track size and what the track surface is made of.  This will also influence gearing.




 
Title: Re: need help with 700 tranny
Post by: kb0323 on July 04, 2014, 08:35:08 AM
I have 8" tires. I run 8 on motor and 5 on tranny for pulleys and I have a 17 sprocket on tranny and a 40 on axle.
Title: Re: need help with 700 tranny
Post by: PJG56 on July 04, 2014, 09:10:51 AM
Is your tranny 3rd gear set 25-25?
If it is with the pulley & gear ratios &tire size you stated,
that would equate to about 40 mph in 3rd!!
Title: Re: need help with 700 tranny
Post by: Jeff McKelroy on July 04, 2014, 11:36:53 AM
PJG56 is right.  If you have one of the 700's that has 23/27 in "3rd", your total drive ratio is 5.179.  Which is close, but an average for GP is 4.75-5.0:1 overall drive ratio.  If you had 25/25 gearset, your total drive ratio would be 4.4118:1.  That would mean you need to be somewhere in between those two numbers.

I am curious to know what the transmission's assembly number is?  We might can help you with what gears you have.  Next bet, which I would recommend anyway, is to split the case and count teeth.  Some transmissions didn't have the 25/25 set at all, and some had the 25/25 gearset in 5th.  There are literally hundreds of combinations.
Title: Re: need help with 700 tranny
Post by: trbinrat on July 04, 2014, 01:55:19 PM
Like Paul and Jeff said make sure it's on the 25 to 25 gear set. If you don't want to take it apart turn the pulley on the tranny 3 times and the out put should turn once.

I would drop that tranny gear down to a 15 and try it.
Title: Re: need help with 700 tranny
Post by: more4les on July 07, 2014, 09:43:07 AM
we run a bit higher (numerically lower) ratio on our Mod-XR. We are in the 4.50 range and at our last race was at 4.22. We do however run a Kawasaki 540 and keep it governed at closer to 3560. It makes more power there than if we push it up to 3650. Plus we never need to worry about failing post race tach check.

Lester
Title: Re: need help with 700 tranny
Post by: kb0323 on July 23, 2014, 07:36:58 AM
I split the case and the 25/25 is 5th gear. My complete setup is 8 on motor 5 on tranny for pulleys. 17 gear on tranny and 46 on axle.
Title: Re: need help with 700 tranny
Post by: docbro on July 23, 2014, 03:47:15 PM
Drop your axle sprocket to 44 and you will have a gear ratio of 4.85   Your ratio as it sits is 5.02:1 which might be a little steep.  Race in 5th gear, your 25/25 gear set, top speed about 35 MPH depending on tire size (16") and RPM of engine (3650)
Title: Re: need help with 700 tranny
Post by: kb0323 on July 23, 2014, 04:00:33 PM
Ok I will try it and post back after the race this weekend
Title: Re: need help with 700 tranny
Post by: westcoast racer on July 23, 2014, 04:29:09 PM
With ratios that high (4.75 to 5.0), how do any of you have any pull off the corners especially being governed?
Title: Re: need help with 700 tranny
Post by: Jeff McKelroy on July 23, 2014, 07:37:39 PM
With ratios that high (4.75 to 5.0), how do any of you have any pull off the corners especially being governed?

Easy: Don't slow down in the corners!!!   :omg: :D

It's not that I won't answer the question, but that's one of the things that makes the GP class fun.  It's playing chess to get the checkers.

FYI, with our ratios as they are, we were matching track times with the SP mowers at Carlisle.
Title: Re: need help with 700 tranny
Post by: Rooster on July 24, 2014, 03:48:36 PM
With ratios that high (4.75 to 5.0), how do any of you have any pull off the corners especially being governed?

NO