Dana 36 & Dana 44 horsepower limits
01-11-2009, 10:08 PM
#21
Drifting
I've had no problems with my D44 so far in probably 100+ drag stip passes. I took it took the track today and cut a new best 60 foot time of 1.55 on the bottle (492rwhp/550rwtq). It will probably fail one day, but so far so good.
01-26-2009, 02:05 AM
#22
rear options
I prefer a solid axle for drag racing, & an independent for street & road racing. Cost can really help a person determine what they use, though.
Check out a bolt-in solid conversion here, (though not the cheapest way for a solid axle).
http://forums.corvetteforum.com/c4-t...sion-kits.html
I agree with the posts here on the different experiences. Listen to them.
The best advice I can give is: Build it as strong as you can realistically afford (Solid, 36, or 44)!
Check out a bolt-in solid conversion here, (though not the cheapest way for a solid axle).
http://forums.corvetteforum.com/c4-t...sion-kits.html
I agree with the posts here on the different experiences. Listen to them.
The best advice I can give is: Build it as strong as you can realistically afford (Solid, 36, or 44)!
01-26-2009, 12:26 PM
#23
Team Owner
I doesn't matter how much HP you make, it's all about how much of that HP you get to the ground. You can have 600hp but if your only running 1.6 60' times a 44 should last. A4 car are easer on rears than 6m. Get a 6m car to 60' is almost impossible without some chassis work and a great driver. There are alot of variables.
01-27-2009, 01:29 PM
#24
Team Owner
Member Since: Sep 2001
Location: Athens AL
Posts: 59,647
Received 1,400 Likes
on
1,016 Posts
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
12-11-2015, 10:04 AM
#25
Heel & Toe
Member Since: Aug 2015
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Dana 36 question
There is no definitive answer. I've probably broken more rear end parts than anyone on this board (the picture that rodj posted is of my parts) and I was only making about 275 RWHP/370 RWTQ on motor, 400/550 on the bottle.
Through all my trials and tribulations, I was pretty much forced to become knowledgeable about the D44 and independent rear in my car. This is the scoop, as I know it:
The most common initial failure is the outer stub axles, or as they are often referred to, the spindles. Inside the differential case, the most common failure is the spider gears. Usually, when a spider gear lets go gravity will pull the pieces to the bottom of the differential case. There is very little room between the ring gear and the bottom of the case, less than .07 of an inch; consequently the pieces of spider gear get shoved into (and sometimes completely through) the bottom of the case. Normally, this ruins the case. However, the spider gear failure really isn't that common. The outer stub axles are a MUCH more common first failure, in the neighborhood of 100:1, maybe more.
Cryo-treating hasn't helped me at all. I broke half a dozen cryo treated outer stub axles, a cryo treated half shaft, and a cryo treated ring and pinion.
The best solution is to get some larger spline outer stub axles from Summers Brothers Racing. They can also supply a rear hub bearing that has been broached to accept the larger spline count/OD stub axles.
Next, either chromoly or carbon fiber half shafts. Most people can find a local source for these things. For example, here in NC, there is a company that builds air plane propeller props out of chromoly. For $400-$500, they will build a set of C4 half shafts.
Build some snubber extenders for the rear snubbers. On my car, dropping the rear snubbers exactly 1 inch resulted in the half shafts being perfectly parallel to the ground at maximum squat. When I launch the car (and nothing breaks and everything works right) I'll ride the snubbers for the first few feet of the track because the car is squatting fairly hard. Without the snubber extenders the differential can go past parallel under extremely hard squat conditions.
If you just drag race the car, a spool is a great way to make the indy much stronger. I used one for awhile and liked it. I eventually took it out of the car, but it wouldn't kill me to put another one in. You'll lose some turning radius, but knowing that there are no spider gears in the case is a comforting feeling.
There's a ton more, but I've got to run. I'll come back in a day or two and write some more.
Good luck with your car.
Through all my trials and tribulations, I was pretty much forced to become knowledgeable about the D44 and independent rear in my car. This is the scoop, as I know it:
The most common initial failure is the outer stub axles, or as they are often referred to, the spindles. Inside the differential case, the most common failure is the spider gears. Usually, when a spider gear lets go gravity will pull the pieces to the bottom of the differential case. There is very little room between the ring gear and the bottom of the case, less than .07 of an inch; consequently the pieces of spider gear get shoved into (and sometimes completely through) the bottom of the case. Normally, this ruins the case. However, the spider gear failure really isn't that common. The outer stub axles are a MUCH more common first failure, in the neighborhood of 100:1, maybe more.
Cryo-treating hasn't helped me at all. I broke half a dozen cryo treated outer stub axles, a cryo treated half shaft, and a cryo treated ring and pinion.
The best solution is to get some larger spline outer stub axles from Summers Brothers Racing. They can also supply a rear hub bearing that has been broached to accept the larger spline count/OD stub axles.
Next, either chromoly or carbon fiber half shafts. Most people can find a local source for these things. For example, here in NC, there is a company that builds air plane propeller props out of chromoly. For $400-$500, they will build a set of C4 half shafts.
Build some snubber extenders for the rear snubbers. On my car, dropping the rear snubbers exactly 1 inch resulted in the half shafts being perfectly parallel to the ground at maximum squat. When I launch the car (and nothing breaks and everything works right) I'll ride the snubbers for the first few feet of the track because the car is squatting fairly hard. Without the snubber extenders the differential can go past parallel under extremely hard squat conditions.
If you just drag race the car, a spool is a great way to make the indy much stronger. I used one for awhile and liked it. I eventually took it out of the car, but it wouldn't kill me to put another one in. You'll lose some turning radius, but knowing that there are no spider gears in the case is a comforting feeling.
There's a ton more, but I've got to run. I'll come back in a day or two and write some more.
Good luck with your car.
12-11-2015, 11:13 AM
#26
Team Owner
Pro Mechanic
Even if it's not...why not get full utility out of the rear that's in it...then get a D44?
12-11-2015, 11:25 AM
#27
Heel & Toe
Member Since: Aug 2015
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
I'm not against running the D36, however if I blow it up I don't have a core to trade in on a D44. Plus the D36 that's in it has 191000 miles on it.
12-11-2015, 12:15 PM
#28
Melting Slicks
Old thread................... New diff fluid would be a good idea. Hope you got some new u-joints with that mileage.
12-11-2015, 01:56 PM
#29
Team Owner
Member Since: Sep 2001
Location: Athens AL
Posts: 59,647
Received 1,400 Likes
on
1,016 Posts
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Hi I have a quick question about my dana 36 and you seem to be the guy to ask if you don't mind. I have an 85 vette street/strip project with and new motor going in come spring that makes 425 rwhp with no power adders. Here is the rest of the set up, automatic trans with 2100 stall, stock rear end gears and street tires. So my question is do you think my d36 will hold up for a while or should I not even wast my time with it and put a d44 in? I'm running the soft launch set up to keep tire spin down for consistency reasons but also to help with wear and tear on the drive train. Thanks!
If you stay with street tires you shouldn't really have to worry about it.
12-11-2015, 04:42 PM
#30
Heel & Toe
Member Since: Aug 2015
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
12-11-2015, 10:34 PM
#31
Team Owner
Why not? I can give you a few hundred reasons if you were the tow truck.
Like most things that break, the law is that it must break far away from home. Sometimes, you might get to play the banjo with the weird kid on the porch swing.
12-12-2015, 11:21 AM
#32
Melting Slicks
I'll add the 36 should have less drivetrain loss 
So 425 with a 36 maybe be like 410 with a 44?
Reducing vehicle weight by a lot helps lower the strain on a weaker rearend, I've done it in a few cars to try and maximize the efficiency. Also as mentioned earlier in the thread a highway gear helps. GL
edit: used the incorrect word
So 425 with a 36 maybe be like 410 with a 44? Reducing vehicle weight by a lot helps lower the strain on a weaker rearend, I've done it in a few cars to try and maximize the efficiency. Also as mentioned earlier in the thread a highway gear helps. GL
edit: used the incorrect word
Last edited by BOOT77; 12-12-2015 at 03:05 PM.
12-12-2015, 02:57 PM
#33
Team Owner
I'll add the 36 should have less valvetrain loss
So 425 with a 36 maybe be like 410 with a 44?
Reducing vehicle weight by a lot helps lower the strain on a weaker rearend, I've done it in a few cars to try and maximize the efficiency. Also as mentioned earlier in the thread a highway gear helps. GL
So 425 with a 36 maybe be like 410 with a 44?
Reducing vehicle weight by a lot helps lower the strain on a weaker rearend, I've done it in a few cars to try and maximize the efficiency. Also as mentioned earlier in the thread a highway gear helps. GL
So maybe by switching to the Dana 36 from my current Dana 44, I will dyno 15 more HP? Exactly how did you get this information? From your history, if I am not mistaken, you generally aren't very forthcoming about how you came about your numbers and 15 HP is a huge jump for such a simple change.
Define "a lot". How much weight is there to save? I can reuse my C beam, cutting a couple of holes from the 36 to the 44. What are the 4 extra holes worth? 5HP? I reuse pretty much the same stuff other than the differential. So what exactly is the weight differential? According to THIS, it is about 127 for the D36 and 140 for the D44. A whopping 13 pounds. Unless you are racing, I don't see how much effiencicy you are talking about. Maybe a little but "a lot", I don't see. With my jacket, cell, sidearm, shoes, clothes, I could drive naked and save 13 pounds.
The following users liked this post:
ACMX92 (01-21-2021)
12-12-2015, 03:15 PM
#34
Melting Slicks
LOL
For those who have to have it spelled out the question mark ???? meant it was a best guess and I do believe I said maybe????
It's well know a ford 8.8 is more efficient(less hp cost/loss) vs a 9inch, if you do not need the strength. But some are too closed minded to see the advantage of avoiding overkill to meet ones goals.
12-12-2015, 07:53 PM
#35
Team Owner
LOL
For those who have to have it spelled out the question mark ???? meant it was a best guess and I do believe I said maybe????
It's well know a ford 8.8 is more efficient(less hp cost/loss) vs a 9inch, if you do not need the strength. But some are too closed minded to see the advantage of avoiding overkill to meet ones goals.
For those who have to have it spelled out the question mark ???? meant it was a best guess and I do believe I said maybe????
It's well know a ford 8.8 is more efficient(less hp cost/loss) vs a 9inch, if you do not need the strength. But some are too closed minded to see the advantage of avoiding overkill to meet ones goals.
Please state the "advantage" just so we are clear. How much? In the race world, any bit helps and they have a mega wallet from the sponsors, as long as they are winning. In the real world, just enough is less money today and more tomorrow. But hey, if you are not just open minded but open wallet, I'll be more than happy to have just enough and charge your credit card when it breaks tomorrow. I have had "just enough" enough times to learn that it is cheaper in the long run to get a bit more to allow for growth tomorrow.
12-13-2015, 02:28 AM
#36
Safety Car
corvetteforum.com/forums/c4-general-discussion/3732196-too-much-power.html
Last edited by Hot Rod Roy; 12-13-2015 at 02:31 AM.
12-13-2015, 02:56 AM
#37
Team Owner
Do you realize you are asking a question of a guy that hasn't been on this forum since 12-5-2014? You should have started a new thread with your question, but it looks like you're getting some good response, anyway. Here's a link to "whalepirot", who has a 409 with an M6 trans and a cryo treated D36. He exploded a spider gear. On the street, not racing, no fat tires.
corvetteforum.com/forums/c4-general-discussion/3732196-too-much-power.html
corvetteforum.com/forums/c4-general-discussion/3732196-too-much-power.html
12-13-2015, 08:45 PM
#38
Team Owner
Pro Mechanic
Anyone can break anything....it really depends on YOU, and your track record. I made 100's of passes on a T5 transmission behind a SBC 400. Only broke a 3-4 shift fork, NEAT (earlier in this thread) had broken nearly every part in a D44 w/something like 250 RWHP, so...it really depends on you, and how you handle your stuff.
12-13-2015, 09:00 PM
#39
Heel & Toe
Member Since: Aug 2015
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
How is a D36 core, going to help you any on a "trade in on a D44"? A core means you rebuild it to provide "like new" version of the trade in/core. No amount of rebuilding, will turn a D36 into a D44.
Anyone can break anything....it really depends on YOU, and your track record. I made 100's of passes on a T5 transmission behind a SBC 400. Only broke a 3-4 shift fork, NEAT (earlier in this thread) had broken nearly every part in a D44 w/something like 250 RWHP, so...it really depends on you, and how you handle your stuff.
Anyone can break anything....it really depends on YOU, and your track record. I made 100's of passes on a T5 transmission behind a SBC 400. Only broke a 3-4 shift fork, NEAT (earlier in this thread) had broken nearly every part in a D44 w/something like 250 RWHP, so...it really depends on you, and how you handle your stuff.
12-13-2015, 10:20 PM
#40
I'm just thinking the D36 is worth something if it's in one piece, but anyways I'm running an easy launch set to help with wear and tear also with consistency at the drag strip. Auto trans, stock gear ratio, 2100 converter, and street tires. I'm just trying to figure out if I should give the D36 a shot or save myself the trouble later and just put a D44 in with the new motor and trans come spring.