Final Drive 4.4 or 4.7?

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Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

Quaife says they could manufacture the 4.4 final drive,not sure if there is enough interest here for it or probably Mr Goodwin could look into carrying them.This is an email from Quaife.


"The Tran-X range is based around Ford running gear, and is not a range we intend to broaden.

There are no Quaife branded crown wheel & pinion kits available, and neither is there a plan to introduce a range.

We do take on custom work though, so it is possible for us to manufacture what you are asking for, but it would need to be a minimum batch order of 50 units for us to consider the job.

If you have any further questions or I can be of any assistance in the future please don't hesitate to contact me."


Kind regards

Ben Ashton

Technical Sales
Brian
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Re: Final Drive 4.4 or 4.7?

Post by Brian »

Curious as to why you want this ratio?

Once we start adding power we usually go the other direction.

Brian
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

That is true as regards to adding more power (supercharger/turbo),which i have no intention on doing at this point.
I'm more focused on getting the most NA out of the car and keeping its balance.
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Re: Final Drive 4.4 or 4.7?

Post by Brian »

And you understand it might make the car really BUZZZZZ on a long freeway drive right?
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

Thats the only possible issue and could be slightly addressed with a larger set of daily driven wheels.
What about quicker acceleration,more tq to the wheels off the line,staying in rpm while downshifting.
I believe there are more pros than cons for autocrossing this setup.
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Re: Final Drive 4.4 or 4.7?

Post by Brian »

For autocross the short gearing you are contemplating will hurt your time if your courses are fast like here in San Diego. Lots of data available in the forums on this point. Our SCCA courses here are typically very TOP of 2nd gear for those with the 5speed. That actually puts the guys with NC 6Speeds at real disadvantage for STR class here as they are giving up lots of time shifting from 2nd to 3rd...and back down to 2nd...and back up to 3rd, etc. On our South East lot the courses tend to be tighter and the guys with 6 speeds may have slight advantage on that lot IF they don't have to grab 3rd....but on our faster west lot the 6speed guys typically get crushed (as do the S2000 guys in STR on our west lot), just too much time lost shifting up and down 3 times to 3rd gear per run, etc.

Similar results many years ago with Miata in CSP. It was the doctrine here for a few years that you ran wide 13 inch wheel/tire setups for CSP for gearing advantage...but once good wide 15 inch setups came along the data quickly showed when the course was fast enough to force the 13 inch guys to repeatedly grab 3rd gear, the 15 inch guys won more events because they could keep it on boil at top of 2nd gear and never lift. We did overlay of the data and that result was clear...yet it took a few years for some of the 13 inch guys getting beat at most (though not all) of the events to realize their effectively shorter gearing was not a good thing for autocross on our typically fast courses (they would win a slower South East lot course here and there, etc).

Thus, unless your local courses are slow enough to keep you in 2nd gear even with the shorter ratios you are contemplating....I predict a negative result vs your competitors in the same class. If you are running data what max speed do you typically hit now in 2nd gear? Do the math to figure out if you will need to grab 3rd to hit that speed with the alternative ratios ....and see if you can figure out how many times you will typically be grabbing third, etc. To sum it up...if your courses are so slow that you live in 2nd gear with your current ratio and shorter ratios won't change that fact...then your plan works. And if your local courses are so fast that you are already grabbing third gear and shorter ratios will mean you spend even more time in third, then I think your plan works. But if you are grabbing gears lots more often than your competitors, then I expect it is a bad plan and you merely repeat our local history here for both STR and CSP.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

Hey Brian,thanks for taking the time to lead me in the right direction.

I actually don't have any hard data to compare,just going on what i noticed from racing the car.I understand what you said about losing time by constantly shifthing from 2nd to 3rd.

Firstly,my car is an auto with paddles.We do a 2 lap course and i limit 2nd gear once each lap.Then there is a top corner onto a straight where my rpm is a little lower than where it should be(no clutch to kick).The straight,everyone uses 3rd.With my present setup i put 3rd in somewhere like 2/3 of the straight.

What i'm really looking for is that extra off the line being auto and to have more rpm coming out of corners.
Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

Hey everyone..
Is there a direct drop in 4.4 or 4.7 final drive for the nc as yet?
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Re: Final Drive 4.4 or 4.7?

Post by Brian »

Dubcity wrote:Hey everyone..
Is there a direct drop in 4.4 or 4.7 final drive for the nc as yet?
Search "Puddymod" on Miata.net forum for the guy that can set your NC up with just about any ratio you want.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Dubcity
Posts: 129
Joined: Sun Nov 13, 2011 8:46 pm

Re: Final Drive 4.4 or 4.7?

Post by Dubcity »

Hey,is there any direct drop in 4.4 or 4.7 final drive for the NC as yet?
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