Hybrid gearboxes. In search of the perfect gear ratios.

Between power and road surface lies a crucial step, transmission makes you go or not
hondaNickx
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by hondaNickx »

saxophonias wrote:So actually if you swap 2nd and 3rd gear from d14a4 gearbox to the d14a8 one then you have the gear ratios of d13b s20 tranny. Is this possible? I mean to swap only some gears?

1st and 2nd gear are solid with the primary shaft .You can't remove them ,you need to swap the shaft .But this is from S40 to S40 tranny so i don't think it would give problems to swap it out.To get the CRX gears in you need to take a little material off .If you popped open your first tranny you'll see it's not that difficult .I opened up 2 now and i now how it works.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

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saxophonias
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by saxophonias »

I see. What about the 3rd gear? Does it go along with 4rth? I can use 1-2-3 from a4 but i really want 4rth 5th and final from my a8 which are better. Any suggestions?

hondaNickx
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by hondaNickx »

saxophonias wrote:I see. What about the 3rd gear? Does it go along with 4rth? I can use 1-2-3 from a4 but i really want 4rth 5th and final from my a8 which are better. Any suggestions?

3th and 4th are somewhat the same gears you can switch 3th to 4th and 4th to thirth with minor modification.I don't really like a short 5th i don't want to drive 120Km/h at +4000rpm it's just a cruising gear anyway.But that's different for everyone offcourse.You can swap the 5th and FD out between transmissions ,it should fit without problems.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

Law_
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by Law_ »

sorry the answer but what is the Final Drive purpose?
final is not supposed to be the 5th?
Thanks

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saxophonias
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by saxophonias »

Nick actually i didn't want to ask you whether i can put 3rd gear to the place of 4rth and vice versa, but whether i could keep the 4rth gear of my a8 box without having to mess with the others (5,fd). I mean will have to move the entire axle or the gears can get out of the secondary axle and be replaced?
Something else as i have no experience on this. When open gearboxes will you have to use different flanges and other parts or can i reuse the same?

What is was thinking is to put 2nd and 3rd of my a4 box and keep 4rth 5th and FD of my a8.


Law have a look at this article
http://www.dur.ac.uk/r.g.bower/PoM/pom/node10.html
The effect of the gearing is to change the number of times the engine rotates for each rotation of the road wheel. In addition to the gearbox itself, the differential (or `final drive') may alter the gear ratio as well as dividing the torque between the two front wheels. The `drive train' is illustrated in Fig. 1.

hondaNickx
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by hondaNickx »

So you want 1-2-3 from A4 and 4th and 5th and FD from A8 .

You need to swap the Final drive And secundary shaft from A8 into your A4 .The small gear from Secundary shaft and the Big FD gear need to be together.Also you can change 4th and 5th from your A4 to A8 ,you need to pull off the top gears from the shaft on both secundary and primary shaft .Those 2 shafts work together too.

Here's a picture of a Z6 tranny inside

Image


The biggest gear is the Final Drive ,the tower of gears on the left is the secundary shaft and the tower on the right is the primary shaft.The top gear of the 2 towers is 5th .As you can see there's a 5th gear on the Secundary shaft and on the primary shaft.If you would count the tooth from both gears and divide them with each other you would get the 5th gear ratio of 0.771 from Z6.This works with all the other gears too.You can remove 5th from the secundary and primary shaft and replace them with 5th from a8 .It could be that either 5th gear from Primary or secundary shaft has the same amount of tooth and diameter as your A8 gears have,so you'll only need to swap out 1 gear.But most likely you'll need to swap both.

If you would buy a aftermarket Final drive you'll always get the big gear and the secundary shaft cause both gears have different tooth and diameter to adchieve that different ratio.Image
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

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SquirtAndSpark
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by SquirtAndSpark »

the "omniman's b16 91 oct 200whp b16a" is a good source of information about tranny modifications. and the gearbox's looks very similar!

watch the trailer:

http://www.youtube.com/watch?v=kqn9uepuVLk

cumps

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saxophonias
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by saxophonias »

Thanks Nick, you have been very helpful.

Law_
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by Law_ »

saxophonias wrote:Law have a look at this article
http://www.dur.ac.uk/r.g.bower/PoM/pom/node10.html
The effect of the gearing is to change the number of times the engine rotates for each rotation of the road wheel. In addition to the gearbox itself, the differential (or `final drive') may alter the gear ratio as well as dividing the torque between the two front wheels. The `drive train' is illustrated in Fig. 1.
thank you ! more clear now ;)

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saxophonias
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Re: Hybrid gearboxes. In search of the perfect gear ratios.

Post by saxophonias »

http://www.youtube.com/watch?v=IoS4lAC0K3k
check this hybrid pretty nice

http://www.youtube.com/watch?v=fR4xAJZK ... re=related
here is the comparison between the stock s40 and s20.even though the latter is shorter the distance of the gears is the same so the gains arent maximised. I think that if we manage to throw its gear at 5500rpms when shifting then the benefits in acceleration would be great
http://www.youtube.com/watch?v=DEObqqRlVR4
here another hybrid

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