Went to the dragstrip today. (protip: don't go to the dragstrip.)
#41
A 2.1 60' on street tires is not bad at all.
Looks like the exact same gears went on both of ours. One of those side gears went on mine, and two or three others split clean in half when the whole unit locked up. I wonder if cryo treating would help any?
And for the record, I wheel hopped for the first time the run before I broke mine too, so maybe that has something to do with it.
Looks like the exact same gears went on both of ours. One of those side gears went on mine, and two or three others split clean in half when the whole unit locked up. I wonder if cryo treating would help any?
And for the record, I wheel hopped for the first time the run before I broke mine too, so maybe that has something to do with it.
Cryo treating would help, but it's a band aid approach. The diff being weak isn't the problem. It's wheel hop that kills it. Kinda like knock on an engine. Dosn't matter what you have if you have knock, it will break your ****. If we didn't hop our rear ends would be much much better off.
FWIW, I think it needs a pair of frame rails that tie to the factor rails and the rear subframe, and then brace the diff off of these.
#42
Our 7" differential isn't the weak link IMO. Well, it sort of is. Wheel hop is what kills ****. Our diff winds up like a spring when you launch it. The front of the diff jumps up and nothing stops it. Look at how the RX7 diff is mounted. Ours needs to be supported just like that, with a brace between the frame rails holding the front of the diff. Stop wheel hop and the diff's would stop breaking.
I just sold a 1990 RX-7 TII with a LT-1 put 365hp to the wheels and had the worst wheel hop I have ever driven. I used poly on every point and welded the front of the diff to the mount to try and fix the hopping and nothing was fixing it. The RX-7 mount is NOT the answer.
#44
I don't know RX7's well, but something had to be giving for it to hop. On our miata's, the front of the diff is just not supported. What do you think was giving on the RX7 for it to hop? Again I've been under an RX7 twice, so not real farmiliar with them, but I know they have a brace that holds the front of the diff. Granted, it was all connected with bushings.
#45
Please elaborate. Sure it has something to do with it. You put down several hundred ft/lbs of torque to the rear wheels in first gear. The diff can lay down that torque, say 700 ft/lbs. But hop and it goes 700, then 200, then 1500, then 100, then 2100, etc. It beats on it and breaks stuff.
#47
It's when you weld up the spider gears in a stock open differential. This locks the differential so that both wheels ALWAYS turn the same speed. Great for drag racing. And that's about it. Sucks in the turns, dangerous as hell in the rain, makes the car push (understeer like a bitch), it's hell on axles, etc. But it will give incredibly predictable and consistent launches.
#51
Installing a larger diff. won't solve wheelhop, and that needs to be eradicated.
You all need to look at some of the V8-swap Miata guys and what they've done to reduce/eliminate wheelhop. A few of them have fabricated longitudinal links that connect the lower rear A-arms to the frame rails, and that seems to pretty much eliminate the problem.
You all need to look at some of the V8-swap Miata guys and what they've done to reduce/eliminate wheelhop. A few of them have fabricated longitudinal links that connect the lower rear A-arms to the frame rails, and that seems to pretty much eliminate the problem.
#55
Installing a larger diff. won't solve wheelhop, and that needs to be eradicated.
You all need to look at some of the V8-swap Miata guys and what they've done to reduce/eliminate wheelhop. A few of them have fabricated longitudinal links that connect the lower rear A-arms to the frame rails, and that seems to pretty much eliminate the problem.
You all need to look at some of the V8-swap Miata guys and what they've done to reduce/eliminate wheelhop. A few of them have fabricated longitudinal links that connect the lower rear A-arms to the frame rails, and that seems to pretty much eliminate the problem.
#59
Al Cooper was the first I remember seeing, but it looks like the pics are all broken on his cardomain site: http://www.cardomain.com/ride/291686/3
He does talk about it in post #4 here: http://forum.miata.net/vb/showthread...oper+wheel+hop
There's one other I've seen, but I can't think of the guy's name. I'll post when I find more.
#60
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Yes, V8Nutz's is probably the nicest example, as I recall: http://www.cardomain.com/ride/398122/3