03-12-2007, 11:14 PM
I picked up a '91 m42 318 a month ago. Wanted to play with one. My silver track car is an '85 w/ m10 for those who don't know. The m42 is known to have ~135HP, the m10, ~102HP. I wanted to see if the m42 was really much faster.
My test was a small stretch of road with a mild incline near my house. Super scientific. :lol: Start in 2nd at 35MPH at the speed limit sign, wind out 2nd and shift to 3rd, see how fast I'm going by the end of this white line at an entry to some business.
Both are due for an engine oil change, both have synth fluids in the trans/diff.
The m42 is stock stock with ~148k on it, the m10 has been rebuilt and has no cat. Might have a couple more HP than it should, no more than that I would guess. The m42 makes great compression and seems to be running very well.
The m42 actually gets an edge in the gearing dept (it has a 4.10 while the m10 has a 3.64) as it's turning a bit over 4k at 35mph, and the m10 is at 3.5k. And the gear spacing is a bit tighter going into 3rd too. I would think this would be a BIG edge.
The m10 has the edge in weight, though I had about 100lbs of tools in the trunk to help. Both had about a half tank of gas. With me in it, the m10 318 was prob 2700lbs. The m42 318 test weight should be around 2850-2900.
Both have stock size tires, so the speedos shouldn't be too far off.
Test was all done within an hour on the same day, so same air temp and all that crap.
The results? After two passes with each car (after warming up of course), the m10 is going 62. The m42? Maybe 63. Came out the same way with each run, so I didn't bother doing more. And I didn't really need the cops/neighbors to notice.
Was my test run too short? Too many variables? Does the weight difference matter more than I'm giving it credit for? I would have thought the m42 would be going significantly faster. Is 1 MPH significant for such a short run?
Statistical error, drink more beer?
My test was a small stretch of road with a mild incline near my house. Super scientific. :lol: Start in 2nd at 35MPH at the speed limit sign, wind out 2nd and shift to 3rd, see how fast I'm going by the end of this white line at an entry to some business.
Both are due for an engine oil change, both have synth fluids in the trans/diff.
The m42 is stock stock with ~148k on it, the m10 has been rebuilt and has no cat. Might have a couple more HP than it should, no more than that I would guess. The m42 makes great compression and seems to be running very well.
The m42 actually gets an edge in the gearing dept (it has a 4.10 while the m10 has a 3.64) as it's turning a bit over 4k at 35mph, and the m10 is at 3.5k. And the gear spacing is a bit tighter going into 3rd too. I would think this would be a BIG edge.
The m10 has the edge in weight, though I had about 100lbs of tools in the trunk to help. Both had about a half tank of gas. With me in it, the m10 318 was prob 2700lbs. The m42 318 test weight should be around 2850-2900.
Both have stock size tires, so the speedos shouldn't be too far off.
Test was all done within an hour on the same day, so same air temp and all that crap.
The results? After two passes with each car (after warming up of course), the m10 is going 62. The m42? Maybe 63. Came out the same way with each run, so I didn't bother doing more. And I didn't really need the cops/neighbors to notice.
Was my test run too short? Too many variables? Does the weight difference matter more than I'm giving it credit for? I would have thought the m42 would be going significantly faster. Is 1 MPH significant for such a short run?
Statistical error, drink more beer?
The only thing that stops a bad guy with a van is a good guy with a van