4g61t.org

just a question... whos is useing oe rear driveshafts and who has had custom? id rather have one made anyone know of some est $. thanks

I don't see how a stock driveshaft would even work. My entire rear shaft/carrier bearing is gone, and the middle shaft was extended. It measured 39" or 40" exactly(i'd have to measure for varification) from weld to weld. I replaced all three U-joints, had it balanced and painted, a gorgeous piece for $250.

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1989 Dodge Colt Turbo w/ 4g63t swap
1999 Ford Contour SVT

I used the stock talon drive shaft, removed one u-joint, the overall total length was shortened. $50.00 for the welding. Three new u-joints I think they were about $100, so I guess about $150 in total for me.

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- Works in da bush

thanks guys, i dont have one to place up there so wasnt sure what you all were useing. ill see what i can get soon. thanks again

The thing I hate about the DSM drive shafts is that they are so darn heavy.

Coming in late here. I have the DSM driveshaft, but my guru suggests that instead of shortening and doing the carrier bracket mod, that we go with a single length shaft. He theorizes that there is power lost at each joint, and that the car is short enough to not need any joints. I agree. Are there any views? Talk to me Spinmasta.

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Age is a number; attitude counts.

thats what i was thinking the car is short so ill have one fitted, by the way bill your s looks like it coimg along well, but i placed the motor in the engine bay then took measurments and then tack weld test fitted then welded.

MIne was done at Cleveland custom clutch and joint here in...Cleveland. I asked them about a one piece unit. He suggested for the speeds the car saw (170+) that the driveshaft be 4 inch round. I did not have enough space for that. He also mentioned that since the car was not designed to have a one piece in it, that I should get a light wieght shaft as the bearing in the tranfer case was not designed to hold up that much weight.

Mine is whatever the stock sized shaft back about 2.5 feet then to a large carrier bearing. It then comes out 3 inch and goes to the rear end. I have had the car to 173 without issue.

I did break a U-joint that the driveshaft shop installed. They told me it was a nice spicer joint and should be strong. I broke it withing a montyh or so of having the car out. I talked to Shep about it and he said those joints are JUNK and to use a mitsu one. He said I would not break a mitsu one and guess what...I guess he knows a thing or two as I never broke one again.

My shaft was just under 600$

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89 Colt GT, T4 T61, 2.0L, .
http://videos.streetfire.net/search/...3300fc1b2f.htm
04 SRT-4, 3inch exhaust, Intake, Stage 2 W/toys
87 Conquest TSi, Coilover, huge sways
01 Dodge 2500 4wd cummins (tow rig)
91 Suzuki Samurai (Rock Crawler)

In order to do a single piece shaft with a DSM rear subframe mounted in the car you'd have to set up the motor and tcase first, then mount the rear in the correct height in order from having to cut some floorpan out, or notch the floorpan at the very rear. The reason is because the diff sits a little high in the car, higher than the tcase anyways, and one piece shaft on my car of stock driveshaft diameter would touch the rear part of the floorpan with my diff location. I personally would do a two piece shaft, three u-joints total. Mine is basically dead straight, maybe a hint of an upward angle towards the diff with the rear shaft.

Sorry to inform but the theory behind the u-joint power loss is most definitely flawed. The power lost through u-joints is 100% negligable at low shaft angles (though at extreme shaft angles (<15 degrees) the u-joint does follow a harmonicish angular frequency (rotational velocity)). That's like saying there is a noteworthy amount of power lost from FWD to AWD due to an increase in drivetrain mass. It just doesn't exists really to an amount that is worth worrying about. The only loss is through the friction of the extra bearings and gear faces, which on a 500whp car results in roughly an 8whp decrease from FWD to AWD. Now we've probably tripled the total motor driven drivetrain mass with an addition to AWD, but the energy losses only come through frictional areas, at least noticable losses. We're talking friction areas of tcase bearings/gears, differential bearings/gears, wheel bearings, u-joints, carrier bearing, the works. Claiming that a reduction in one or two u-joints in the driveshaft by running a one piece driveshaft will drastically reduce or noticably reduce whp output is scientifically/mathematically incorrect. I can gaurantee your shaft angles on a two piece driveshaft will be minimal, thus resulting in meaningless power loss through an increase in u-joints.

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1989 Dodge Colt Turbo w/ 4g63t swap
1999 Ford Contour SVT

Geeze, well stated guys. I'll see what goes. But "173"!!! Damn! and where were you at the time? Blows my mine. Anyway, interesting stuff.

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Age is a number; attitude counts.

I agree with SpinMasta11's statements about the driveshaft U-joint not having any affect on performance. But as for the drivetrain loss I don't disagree, but think it is worded improperly.

8whp loss at 500bhp would imply a 1.6% differance between a AWD and FWD with from everything I have ever read is incorrect and should be more like 4% "20hp" or more.

Also this is assuming a steady speed as each gear that is raod speed related will consume more energy (as friction) as the speed increases. Thats why a FWD will pull harder at 100mph that the same hp/lb AWD vehicle.

Also the higher the hp (it's really tourqe) the larger amount of friction created at each sheer point in the gear set. So the more power you make the more power it takes to turn it. I know this is not a linear ratio, but I am not sure wear it falls. As some rear ends are more efficient then others.

I am not trying to 1up spinmasta11 as he might just have not felt like typing this out.

As for the 173 thing. I was told be a punk arse vette guy that our drag cars might be good at acceleration from a stop, but they can't run to 170 like he can......LOL OMG LOL

We started at 60mph. I ran up to 8000 rpm in 5th then coasted down to about 60mph......then he finally caught up to me and passed. My car trapped 136 in the quarter so it is like 10-20 seconds from 60 to 173...

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89 Colt GT, T4 T61, 2.0L, .
http://videos.streetfire.net/search/...3300fc1b2f.htm
04 SRT-4, 3inch exhaust, Intake, Stage 2 W/toys
87 Conquest TSi, Coilover, huge sways
01 Dodge 2500 4wd cummins (tow rig)
91 Suzuki Samurai (Rock Crawler)

I'm digging the input from you guys. In the case where I stated 8whp, that was what was tested in back to back pulls on a 515whp AWD talon a buddy of mine owns. We converted to FWD via a dummy tcase and the car only picked up like 8-12whp during a few pulls in FWD, it was quite interesting, as I thought the same thing, roughly a 17% drop in power production through added drivetrain mass, though that didn't seem to be the case. So from there I started researching what was the actual cause of the power drop. The honda guys love busting on AWD being slow from a roll or topend because of the added drivetrain mass, but they have no clue what that additional mass is translated in to in terms of resistant force on the engine. All this can be applied to lightening flywheels, twin disk clutch setups, and unsprung weight.

Yeah dead right about the increase of friction on higher HP cars at shear points. Friction is nothing but a resistant force, and according to Newton a pressure felt over an area = a force. The shear points don't change in area, and pressure is increased as HP is increased, obviously resulting in greater force, or greater friction. Though how much of an increase in friction is really worth worrying about in terms of power being put to the ground. That I'm not sure of, I'd have to run the math. My gut says its probably not something you'd feel in power loss.

Got a vid of that vette run? GOD would I have loved to been there for that. Tell him the Dodge Colt with the Ford rear end is busting his ass with the mitsu power. He'd cringe, I know it.

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1989 Dodge Colt Turbo w/ 4g63t swap
1999 Ford Contour SVT

thanks spin and the rest of you, ill be useing the info soon i hope doing engine inturnals now