I'm about to have my e30 s50 turbo m3 tuned this coming Friday. Does anyone know the torque limit of the rear axles?
s50 bored to 86.5mm
GT35R .82
MS3Pro
JE pistons
Eagle Rods
2.93 diff
Tune will be on E85 first and I want to stay under the max torque limit of the axles.
96 M3, GT4094R, Arrow Rods, CP Pistons, Elring HG, cutring 87mm, 10 mm ARP studs,MS3pro, EMC Intercooler, n54 6 speed with Motiv twin disk, ZT-2 wideband, Zionsville Radiator, X-brace, H&R springs with bilstien shocks, QTP electronic cutout, Line Locks, stock exhaust 455rwtq, 453rwhp at 14 psi 91 octane.......684rwtq, 681rwhp at 24 psi running flex fuel E60 at time of dyno tune.
More importantly, what kind of tires are you running?
96 M3, GT4094R, Arrow Rods, CP Pistons, Elring HG, cutring 87mm, 10 mm ARP studs,MS3pro, EMC Intercooler, n54 6 speed with Motiv twin disk, ZT-2 wideband, Zionsville Radiator, X-brace, H&R springs with bilstien shocks, QTP electronic cutout, Line Locks, stock exhaust 455rwtq, 453rwhp at 14 psi 91 octane.......684rwtq, 681rwhp at 24 psi running flex fuel E60 at time of dyno tune.
Ive made 1080whp/800wtq factory axles, torque limit of the 188mm axle stub is really around 6-700wtq, if you dont have a 210 thats going to be your weakpoint
The OP has an E30. Does that change anything? DSS wants $1,800 to make 700 hp axles for the E30 versus $1000 to make 1000 hp axles for the E36, so I am guessing it takes more work to strengthen the E30 axles.
E30 axles are made of bamboo. Unfortunately the next weak point on them is the outer stub axle where it splines into the hub, so even if you make an indestructible axle shaft it eventually breaks the stub off. The best upgrade for an E30 is to get the entire rear subframe and diff out of a Z3 M coupe or M roadster. They came with a 210 diff, big axles, and bigger axle stubs and hubs. It all bolts right into an E30.
I think my friend with an M52 E30 is on his 3rd set of axles. He’s making around 400wtrq.
96 M3, GT4094R, Arrow Rods, CP Pistons, Elring HG, cutring 87mm, 10 mm ARP studs,MS3pro, EMC Intercooler, n54 6 speed with Motiv twin disk, ZT-2 wideband, Zionsville Radiator, X-brace, H&R springs with bilstien shocks, QTP electronic cutout, Line Locks, stock exhaust 455rwtq, 453rwhp at 14 psi 91 octane.......684rwtq, 681rwhp at 24 psi running flex fuel E60 at time of dyno tune.
M52 are smaller at the diff end and might not hold as much. Good stock M3 ones hold power as E36 HatR wrote, but they need rebuilding at 20-25 years old. And the diff stubs snap off the line if running drag radials at somewhere in the 500-600 lb rwtq range. 210 diff is the way to go, and you have to use the bigger M3 spec axles with it since the output stubs are larger.
Ah my fault, i saw e36 in the signature and got excited, i believe you need z3m axles/arms out back to handle the power.
E30 188mm axles bend in the wheel hub with aggressive driving around 450-500wtq
Didn’t they have ZF320 5 speeds as well? But if the axles are as strong as E36M3 axles, that helps the OP.
Last edited by pbonsalb; 01-16-2020 at 07:42 AM.
I thought I remember them being 210’s but I could be wrong. I know for certain the axles are stronger and they use a bigger wheel bearing to accommodate a bigger hub and stub shaft. If the Z3M isn’t a 210 you can get an E28 M5 diff which is a 210 and will fit in the E30/Z3 subframe. I think an E34 M5 diff might fit too. Donovan Marvin or Boris Skoblov would know, they both run this setup in their drag cars.
Also, the e30 is lighter than the e36, I'm shooting for 600rwhp so the zf320 should be able to handle it. My diff is 2.93
96 M3, GT4094R, Arrow Rods, CP Pistons, Elring HG, cutring 87mm, 10 mm ARP studs,MS3pro, EMC Intercooler, n54 6 speed with Motiv twin disk, ZT-2 wideband, Zionsville Radiator, X-brace, H&R springs with bilstien shocks, QTP electronic cutout, Line Locks, stock exhaust 455rwtq, 453rwhp at 14 psi 91 octane.......684rwtq, 681rwhp at 24 psi running flex fuel E60 at time of dyno tune.
I got 600 whp with 544 lbft torque on my e30 and I was fine ( although I v had alot of wheel spin )
Actually now I m shooting for 750 whp on stock axles with 3.25 lsd and will see how much would it hold :-)
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