If it were me I'd ditch the overdrive and go to a good dog box.
Exactly what I plan to do with the Ambro. I like having the other
ratios, but I don't really find an overdrive useful in a racing
situation. You need to fiddle with it too much. If it were a five or
six speed gearbox you'd just be shifting, but too often I find myself
grabbing a lower gear and forgetting to switch the overdrive back so I
don't get the gear I want. You can get used to anything, and I could
probably come up with some automatic thing, like using a momentary
button for the overdrive that would switch back to straight drive when
I released it. But then I'd be getting used to that.
I find four gears are adequate for most of the tracks I drive given
the torquey TRactor motors we're using. A steel crank to let the
engine rev (even if it's not making more ponies) and a well chosen
rear end seem like a better choice. Might not be so with heavier cars,
but seems right for me.
At the price overdrives sell for these days you'd probably be most of
the way to a dog box trans by selling what you have. I'd definitely
want one in any street TR that I built as somewhat correct, so mine
will probably go into the Red TR3 in my shop (in other words, that I
wouldn't just stick a five or six speed trans into).
Sequential gearboxes are great, but you have to get used to them too.
When I was racing both a Radical and Peyote I had all kinds of goofy
problems caused by forgetting what car I was in--like not being able
to find the shift lever.
On Jul 20, 2008, at 10:39 AM, Jim Gray wrote:
> Greetings again,
> After 2.5 years the TR4 build is done ( for the most part) The car
> did well
> in it's first race but a few issues
> surfaced. The overdrive has never worked more than about ten shifts
> in any
> given stint.
> Once the car is completely cool it would function again for another
> ten or
> so shifts.
> It seems to go into free wheel or a neutral. I replaced the solenoid
> just
> yesterday
> with no change in symptoms. I regularly check the fluid level and
> I'm using
> Red Line
> 75-90 per John Esposito. I have heard the transmission pressure can be
> checked
> while the car is being driven. Any hot tips there would be
> appreciated. It
> seems like a good idea to do
> some daignostics before I pull the tranny. There is also a rotaional
> like
> clicking sound coming from the OD
> while staionary in neutral and goes away once it's moving. I rate it
> on a
> nasty clicking sound scale a 6 out of 10.
> I also have trouble with third gear. I think the syncro is going
> out. I have
> been told that third is troublesome anyway.
> It's pretty clear the tranny needs to come out before the next race.
> This is a stock tranny with no more than the layshaft and steel hat
> bushing
> upgrades to suit the J type OD.
> I am wondering, if you, the FOT, were building a new transmission for
> racing, what would you do ?
> The diff & gear is the 3.70 with a quaife. Any suggestions regarding
> ratio
> changes ?
> While doing a bit of research on dog boxes I ran across this incar
> race
> footage of a BMW with
> a sequential box. It's pretty good footage.
> http://www.youtube.com/watch?v=dmJH84FnQa8
> <http://www.youtube.com/watch?v=dmJH84FnQa8&feature=related>
> &feature=related
>
> Thanks again,
> Jim Gray
> RMVR
> _______________________________________________
> http://www.team.net/donate.html
>
> Fot mailing list
> Fot@autox.team.net
> http://autox.team.net/mailman/listinfo/fot
>
Bill Babcock
Babcock & Jenkins
Billb@bnj.com
503.936.7660
www.bnj.com
_______________________________________________
http://www.team.net/donate.html
Fot mailing list
Fot@autox.team.net
http://autox.team.net/mailman/listinfo/fot
|