Did any of the cases need to be modified forr the new 1.04 gearing
or is it true drop in?
Did any of the cases need to be modified forr the new 1.04 gearing
or is it true drop in?
Ken Roberts
Supporter
John B at HFC Autosport, what are the actual ratios of the V10 graziano (for drop gear calculating)?
06 and up Gallardo V10 and Audi V10
Effective........... Actual
1-4.37................. 1-3.311
2-2.71................. 2-2.053
3-1.93................. 3-1.462
4-1.50................. 4-1.136
5-1.24.................. 5-.939
6-1.04.................. 6-.788
transfer-1.32
Final drive-3.08
06 and up Gallardo V10 and Audi V10
Effective........... Actual
1-4.37................. 1-3.311
2-2.71................. 2-2.053
3-1.93................. 3-1.462
4-1.50................. 4-1.136
5-1.24.................. 5-.939
6-1.04.................. 6-.788
transfer-1.32
Final drive-3.08
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Ken Roberts
Supporter
Here is a great video showing exactly where the drop gears are located in the box.
HCF - John
Gearbox / Brake Systems
Paul - the case needs a small amount of machining. We generally work with Ron McCall (McCall's Autoworks) on these. He's done about a dozen now - great feedback from customers.
Ken - those ratios are correct out to the thousanths. I'd use with confidence.
Ken Roberts
Supporter
Whose gears did you go with Johan?
HCF - John
Gearbox / Brake Systems
Ken - Johan has our drop gears. Two sets, actually!
Johan - I'm a little concerned about your installer not clearancing the boss. There have been 15+ sets installed now, and all I'm aware of required some machining. It's a lot more with the .76's, but the 1.04's need some as well.
When you do the second set, will you please double check that area? My gut tells me the first one is going to have to come apart.
Johan - I'm a little concerned about your installer not clearancing the boss. There have been 15+ sets installed now, and all I'm aware of required some machining. It's a lot more with the .76's, but the 1.04's need some as well.
When you do the second set, will you please double check that area? My gut tells me the first one is going to have to come apart.
Johan
Supporter
Hi John,
I was totally prepared for some clearencing when we istalled your transfer gear, but as it turned out it was not nessesary.
After your post here I called my friend doing the gear change and he is as certain as I am it was not needed.
Just to be certain I went out to my garage and checked it. When turning the input shaft when in gear (1 through 6) there is no resistance nor any strange noice.
Can’t remember now, but I believe we had about 1-1,5mm clearance to the casing.
This is an older transaxle (KVJ) so I wonder if the casting is a little different?
This will also explain the recessed gear. (You said they changed around 2014)
I was totally prepared for some clearencing when we istalled your transfer gear, but as it turned out it was not nessesary.
After your post here I called my friend doing the gear change and he is as certain as I am it was not needed.
Just to be certain I went out to my garage and checked it. When turning the input shaft when in gear (1 through 6) there is no resistance nor any strange noice.
Can’t remember now, but I believe we had about 1-1,5mm clearance to the casing.
This is an older transaxle (KVJ) so I wonder if the casting is a little different?
This will also explain the recessed gear. (You said they changed around 2014)
Ken Roberts
Supporter
I can confirm that my V10 Graziano (KVJ) also did not need to have a clearance machined in the case for the HCF 1.04 drop gears. Heffner Performance in Florida performed the install.
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HCF - John
Gearbox / Brake Systems
I stand corrected! Pulled the trans product guide and there is, in fact, a different part number for that particular housing. Very possible there's a difference in the casting that makes the 1.04's (but not the .76) not need any additional clearance.
Thanks Ken / Johan!
Thanks Ken / Johan!
Gents
I paid $1500 for a set of the .76 gear set. Just collecting dust....if interested make an offer.
I paid $1500 for a set of the .76 gear set. Just collecting dust....if interested make an offer.
Made a typo, paid 1700, but can still make a good deal for a good home in need.
Installing the Drop Gears...
I bought a set of John's gears a while back and put them in this week. I posted about this on the FB group ("Superlite SL-C Owners & Builders" for any Owners or Builders that want to join). Figured I'd include my comments and thoughts here since a lot more will probably see it here (hopefully without my phone typos).
My trans is a V10 unit. There is LOTs of clearance for these gears in the V10 case - no machining is necessary. V8 guys, YMMV. Pictures shows where these gears sit in the case to demonstrate.
If you do it yourself, expect 8 hours once you have it drained and on the bench if you really take your time. You will need 32/34/36mm sockets, some drifts/punches and one special tool (Audi T40210) or you can make one. I welded one up, but you could probably grind one out of the correct sized impact socket. You will also WANT a real 1/2" drive impact to remove the shaft nuts. And you will need a couple short 2x4 blocks or something to sit the trans on since the input shaft sticks out. If you are pulling the front drive, you need E-ring pliers and something to plug the hole.
You don't need the rest of the special tools in the manual and you do not have to disassemble the gear stack. The gear stack is heavy, so you may or may not need a hand lifting it out and putting it back in (the manual shows a special plate and a shop crane, but I did it by hand by myself with no issue).
I did not start with the manual, but did pause when I got to the point where you have to get the pinion out. Found the manual (attached here), and sure enough, you have to beat it out. The manual is not ideal because it covers way more than what you want, and has no complete parts picture for the trans. But all you need is there as long as you take pictures as you disassemble, or lay the parts out methodically.
A comment on John's gears...
I don’t know John other than buying the gears from him and I’m not a mechanical engineer. But we have been racing for a long time and do most our own work, so I've seen plenty. Given that background, take this however you want...
The OEM gears are such that at times only one tooth is taking the pressure. John’s are the same. However, John’s gears have a heavier root and a shape that keeps the tooth thicker until the next tooth engages. IMHO, materials and hardening being the same, I believe John’s gears are stronger. Given the fit and finish is miles better than OEM, likely the material and hardening surpasses OEM as well.
I've include pictures of both sets of gears together. You can see the tooth shape and size, as well as the rough edges (failures waiting to happen) on the OEM gears and the much better finish of John's. John's gears also fit better on the shafts - that is they were tighter but still went on by hand.
The attached pictures are LARGE so that folks can see the details on the gears.
I am going to try to attach the manual, but not sure it will let me as it's 11MB and it's a PDF
Frank
--------------
Fit in case
Old vs New
I bought a set of John's gears a while back and put them in this week. I posted about this on the FB group ("Superlite SL-C Owners & Builders" for any Owners or Builders that want to join). Figured I'd include my comments and thoughts here since a lot more will probably see it here (hopefully without my phone typos).
My trans is a V10 unit. There is LOTs of clearance for these gears in the V10 case - no machining is necessary. V8 guys, YMMV. Pictures shows where these gears sit in the case to demonstrate.
If you do it yourself, expect 8 hours once you have it drained and on the bench if you really take your time. You will need 32/34/36mm sockets, some drifts/punches and one special tool (Audi T40210) or you can make one. I welded one up, but you could probably grind one out of the correct sized impact socket. You will also WANT a real 1/2" drive impact to remove the shaft nuts. And you will need a couple short 2x4 blocks or something to sit the trans on since the input shaft sticks out. If you are pulling the front drive, you need E-ring pliers and something to plug the hole.
You don't need the rest of the special tools in the manual and you do not have to disassemble the gear stack. The gear stack is heavy, so you may or may not need a hand lifting it out and putting it back in (the manual shows a special plate and a shop crane, but I did it by hand by myself with no issue).
I did not start with the manual, but did pause when I got to the point where you have to get the pinion out. Found the manual (attached here), and sure enough, you have to beat it out. The manual is not ideal because it covers way more than what you want, and has no complete parts picture for the trans. But all you need is there as long as you take pictures as you disassemble, or lay the parts out methodically.
A comment on John's gears...
I don’t know John other than buying the gears from him and I’m not a mechanical engineer. But we have been racing for a long time and do most our own work, so I've seen plenty. Given that background, take this however you want...
The OEM gears are such that at times only one tooth is taking the pressure. John’s are the same. However, John’s gears have a heavier root and a shape that keeps the tooth thicker until the next tooth engages. IMHO, materials and hardening being the same, I believe John’s gears are stronger. Given the fit and finish is miles better than OEM, likely the material and hardening surpasses OEM as well.
I've include pictures of both sets of gears together. You can see the tooth shape and size, as well as the rough edges (failures waiting to happen) on the OEM gears and the much better finish of John's. John's gears also fit better on the shafts - that is they were tighter but still went on by hand.
The attached pictures are LARGE so that folks can see the details on the gears.
I am going to try to attach the manual, but not sure it will let me as it's 11MB and it's a PDF
Frank
--------------
Fit in case
Old vs New
Had the SLC out today. First time with the new drop gears.
Before I’ve had an LS7 and LS1 in the car. Now I have a 1UZ with a large turbo. This motor is only 244cid so MUCH less torque than an LS.
1st is WONDERFUL!
Before, I’d start in 2nd. In fact I generally shifted 2-4-6 and just used only those gears.
Now shifting through all the gears is just right. With the car so light, I can still lug it down to 800rpm in 6th. Still just lights the tires up if taking off aggressively in 1st.
On track (TMS Infield), I only used 3rd gear once up to speed. If I was more comfortable on that track, I would have been using 4th on the front straight and 3rd on the remainder.
Before I’ve had an LS7 and LS1 in the car. Now I have a 1UZ with a large turbo. This motor is only 244cid so MUCH less torque than an LS.
1st is WONDERFUL!
Before, I’d start in 2nd. In fact I generally shifted 2-4-6 and just used only those gears.
Now shifting through all the gears is just right. With the car so light, I can still lug it down to 800rpm in 6th. Still just lights the tires up if taking off aggressively in 1st.
On track (TMS Infield), I only used 3rd gear once up to speed. If I was more comfortable on that track, I would have been using 4th on the front straight and 3rd on the remainder.
HCF - John
Gearbox / Brake Systems
Many thanks for the review, Frank! I'm glad you're happy with the gears and they've proven to be a good match for your use. That type of road course driving is exactly what the 1.04's were designed for!
HCF - John
Gearbox / Brake Systems
By the way, we offer transfer gear sets in a 1.04, 0.90 and .76 ratio depending on your intended use.
The ideal match for a street/road course car is the 1.04 combined with an overdrive 6th gear (which we are waiting on a part from Graziano to finalize). For those willing to sacrifice some acceleration, the .90s offer a similar overdrive rpm in 6th for the highway; the trade-off is some acceleration in gears 1-5 and a first gear that's a little on the tall side for clutch life/smooth engagement.
The ideal match for a street/road course car is the 1.04 combined with an overdrive 6th gear (which we are waiting on a part from Graziano to finalize). For those willing to sacrifice some acceleration, the .90s offer a similar overdrive rpm in 6th for the highway; the trade-off is some acceleration in gears 1-5 and a first gear that's a little on the tall side for clutch life/smooth engagement.
Gents
I bumped this drop gear topic back to the surface because I did an inventory of left-over build parts (ok actually I was cleaning the shop) and discovered I still have a set of .76 Graziano transfer gears just sitting around doing nothing. If interested PM me for a deal.
I bumped this drop gear topic back to the surface because I did an inventory of left-over build parts (ok actually I was cleaning the shop) and discovered I still have a set of .76 Graziano transfer gears just sitting around doing nothing. If interested PM me for a deal.
Reviving this thread for a couple reasons. First I’ve emailed HCF with no response. I’m trying to figure out my gearing. It has drop gears for sure but they were what was available 2017-18 or so. I have a LT4 with pulley swap and first and second are pretty useless. (First especially as I’m almost at redline at 40 mph). In 6th gear at 70 mph I’m at 2281 rpm’s. 5th at 65 mph I’m at 2577 rpm’s. Looking at the chart I’m posting below I assume I have the 1.038 gear set. I’m also trying to get my AIM MXS to show gearing. I’d like to use the precalculated math channel so I would have to know axle ratio and gear ratio. So IF I have the 1.038 gear set does that mean my axle ratio is 3.46 and the gear ratios are what’s in this table?? Thanks!! It appears what would be best for my engine set up would be the 0.76 set.
Attachments
Joel K
Supporter
I have an LT4 and chose a .904 drop gear set. Car not on the road yet, but essentially the same 1st gear ratio as the C6, and about 2100 RPM at 76 MPH. My hunch is the .76 is too tall for first gear.The Audi clutch is not known for it’s durability.
You may enjoy a video I did on this topic and reviewed some interesting gear ratio charts.This is just my opinion and my car is not on the road yet. It covers all the options except the .76.
Here is a link…
I’ve had a Viper where the custom first gear was too short, and a 2016 Hellcat where the stock first gear was too long. Had C4 and C5 Manual Trans Corvettes and their gearing always seemed spot on so got as close to the C6 gearing as I could.
You may enjoy a video I did on this topic and reviewed some interesting gear ratio charts.This is just my opinion and my car is not on the road yet. It covers all the options except the .76.
Here is a link…
I’ve had a Viper where the custom first gear was too short, and a 2016 Hellcat where the stock first gear was too long. Had C4 and C5 Manual Trans Corvettes and their gearing always seemed spot on so got as close to the C6 gearing as I could.
