We are currently working with a company to have a custom gear set build for the 5 speed transmission. We are very early into this project but designs and gear ratios are in prototype stages currently. The shift pattern will remain the same but will have a straight cut lift to shift gear set. Cad shows the gears should hold in excess of 800 fts of torque( im just hoping for better than stock at this point) I will keep everyone posted in next few weeks.
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Turbo Lab Straight cut Gears
- Thread starter TurboLab
- Start date
So it will be a dog-ring engagement with straight cut gears? What ratios are you going with?
Any way to make them helical, which are actually stronger than straight cut and quiet while straight cuts are VERY loud...?
Any way to make them helical, which are actually stronger than straight cut and quiet while straight cuts are VERY loud...?
Would have preferred dog engagement gears, so much time is lost lifting to shift. I suppose most of the interest would come from the guys with track cars where this would be ideal. Glad to see something is in the works
The ratios are still in the works but this gear set will be aimed at high hp/ torque road race cars, and i agree the straight cuts are "noisy" to say the least. I did get more info today that it looks like we will have first production mid January and we are leaving 1st , 2nd, and reverse gears oem to help with drive quality and costs. Ive never broken those gears so Im confident that the gear sets will be very strong just need to see if they will be street-able.
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These videos are what finally broke the camels back for me.
https://www.youtube.com/watch?v=LybfhlXuKek Winner but costly
https://www.youtube.com/watch?v=DH5mnEcw_Js DNF
https://www.youtube.com/watch?v=DvEehdI8GnQ DNF
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These videos are what finally broke the camels back for me.
https://www.youtube.com/watch?v=LybfhlXuKek Winner but costly
https://www.youtube.com/watch?v=DH5mnEcw_Js DNF
https://www.youtube.com/watch?v=DvEehdI8GnQ DNF
The stock 1.727 2nd gear is the strongest OEM gear while the JDM 1.952 is a much better ratio, but weaker. A stronger 2nd gear would be nice in that ratio as well as dog ring engagement from 2nd to 3rd, which is important on track and keeping that synchronized seems like a bit of a waste of you're going through all this trouble.
Can you make them all helical with dog rings?
Can you make them all helical with dog rings?
I can definitely ask. I'm never in 2nd gear...unless i dont have third 
I dont think it will be a problem but for testing i wanted to make sure this whole thing was going to work before i spend a bunch on a unproven concept. I actually would prefer a 4 speed than a 5 but first things first.
I did forget to mention that i switched to The new ATS all carbon differential and what a difference it made in the car! Completely eliminated understeer at corner exit and made a huge difference slow speed (Less than 70mph) corner exit. Im super happy with it and it is very quiet. Even after eating a 3rd gear it showed no signs of damage and is very high quality.
I dont think it will be a problem but for testing i wanted to make sure this whole thing was going to work before i spend a bunch on a unproven concept. I actually would prefer a 4 speed than a 5 but first things first.I did forget to mention that i switched to The new ATS all carbon differential and what a difference it made in the car! Completely eliminated understeer at corner exit and made a huge difference slow speed (Less than 70mph) corner exit. Im super happy with it and it is very quiet. Even after eating a 3rd gear it showed no signs of damage and is very high quality.
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You're never below 84mph (redline in 2nd gear)?
2nd gear is the biggest issue in the early model 5 speed in my opinion. Subscribed...
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- 10 August 2010
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I would expect it would only be 4 gears being made, and the stock 5th or a cuff if possible would be used?
Two reasons i dont like to go to 2nd gear is the oil temps start to fly the longer im at high rpms and i find i overbrake then try to compensate with throttle when i go for a lower gear. Driver flaw but one that im aware of. With the ats differential i need to run the type r final drive (wish i didnt have to) which makes 3rd gear pretty low when im making 550 ftbs on high boost.
So I followed up regarding gear designs and was educated that while helical gears are stronger on less noisy they put too much axial stress on the case and the shafts which causes the shafts to flex away from each other and also cause high oil temperatures from the shearing force on gears and bearing surfaces . They also provide less drag due to no thrust loads. The down side is the straight cut dog gears don't last nearly as long as helical and also require finesse at low speeds. Basically the quieter u can keep the gear change the longer they last. The gear vender said there is a lot of room for custom gear ratios. These will be noisy! Shooting for around January 15 to have gears . I bought a new dyno jet with the dual eddy current so I'll be able to load the transmission pretty heavy soon as it's ready . I'll record temperatures and video process along the way.
So they cannot make helical gears? The noise of straight cut will drown out the exhaust of a car with no cats or mufflers and I don't think that would be considered streetable by anyone.
There have been quite a few calls regarding gears so I'll update. The gears should be finished within next 30 days. It will be at least another month before I can test them. The gears will be sold only through our buisness once they have been tested. My buisness is slammed right now due to construction of new 4wheel dyno cell, but I'll do best to update everyone
I have two straight cut gears transmission from the ADAC GT Cup NSX back from the year 1994 when Honda R&D started racing with the NSX. The KREMER NSX had those trannys installed, those cars were the beginning of the LE MANS race cars. Maybe the thread-starter likes to buy it to start working from here? I have also lots of spare parts and a handwritten Honda R&D parts list. Comes with a special LSD also. Both trannys are plug and play with different gearing. Currently it is max top speed at 240kmh about with 8000rpm and 650mm rear tire diameter. Hit me an email if you like photos: [email protected]
I don't track my NSX, but have always wondered if there is a freeway/fuel savings 5th gear that allows the NSX to hit 65MPH at 2k RPMs......
Update on gear sets! We have 3rd 4th and 5th ready with designs for 1/2 coming soon. Current gear ratios 3rd gear 1.23 4th gear .97 5th gear .82. This combination will give a much better shift from 4th to 5th. We can cut pretty much what ever gear ratios you are looking for. Custom Final drives will also be available. This is a dog ring with removable face plate design that will be a lift and shift or you can setup a spark cut for flat shifting. Gears are made in ams-6265 which are then shot peened and Isotropicly finished. According to the manufacturer these should support in excess of 800 lbs torque. Price will be 5999.00 for the set of 3 gears with everything needed to install. Custom gear sets will be additional costs. I will have data and video up in about a month when the track is dry and we have our first event.
Maybe interested, just blew apart my transmission because of 700 ft/lbs.. Looking into options to prevent this from happening again.
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Dang, take my money!!!!!! I might need this before I max out ny turbo.
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