Lightening solid motor mounts on FC's
Zoom Zoom Boom!
Joined: Mar 2003
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From: San Francisco, CA
Originally Posted by 1987RX7guy
Well I am aware that the gain would be MINIMAL at best but pound per dollar I think that this is still better than say buying a composite hood/fenders/hatch etc.
Think about it:
~20 to drill ten holes in the mounts for a gain of maybe 1-2 pouns that is between 10-20 dollars per pound of redux.
Now 700 dollars or so to have a good quality hood made shipped and painted for you for 10-20 pounds of savings. That is around 35-70 dollars per pound.
Think about it:
~20 to drill ten holes in the mounts for a gain of maybe 1-2 pouns that is between 10-20 dollars per pound of redux.
Now 700 dollars or so to have a good quality hood made shipped and painted for you for 10-20 pounds of savings. That is around 35-70 dollars per pound.
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Joined: Sep 2001
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From: KY
Originally Posted by 1987RX7guy
I just got word from one of the manufacturers of the mounts. His weigh in at 24-25 ounces each!
That sums up to 1.5625 pounds! Damn!
That sums up to 1.5625 pounds! Damn!
Thread Starter
Joined: Nov 2002
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From: Laredo, Tx
well for the pair it is still a little over 3 pounds. But say we can shed 1 pound off the pair. That is about a 33% reduction in the added weight to the car.
Joined: Jun 2001
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From: London, Ontario, Canada
Originally Posted by 1987RX7guy
Can you tell the difference between you driving and you driving with a passenger? I can. That is more than 30 pounds but with some work you can make a noticable difference.
Thread Starter
Joined: Nov 2002
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From: Laredo, Tx
Originally Posted by Snrub
Yes of course I can feel a difference when there's a passenger in the car, but you are completely missing the point. You seem very insistant on doing it, and excited by the thought that you might be able to remove 1lbs. People actually make jokes where this topic is the punch line. I'm no longer going to read or post in this thread.
I wish I was driving!
Joined: Dec 2001
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From: BC, Canada
In a RACE CAR which I was prepping, I just took off the stock motor mounting plates (the cast aluminum right bracket and the steel left bracket) and welded some replacements, completely eliminating the "mount". This weighed the least combined weight out of stock or aluminum 3" x 1.85" mounts.
The mounts were then "swiss-cheezed" to further reduce their weight.
The mounts were then "swiss-cheezed" to further reduce their weight.
Joined: Dec 2001
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From: NY, MA, MI, OR, TX, and now LA or AZ!
Originally Posted by 1987RX7guy
Eh the point I made is valid. The trouble to have this done is less than the trouble to install new motor mounts so I deem it a reasonable amount of effort.
Joined: Feb 2001
Posts: 29,798
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From: London, Ontario, Canada
You know, a week ago I heard a story about Colin Chapman (founder of Lotus)...
Anyone who has ever driven a Lotus (or even leaned up against one...DON'T DO THIS!) knows how stupidly light those cars are. Every weight saving measure was taken, even with the production cars...So the story goes:
Colin Chapman always insisted on being there when the mechanics assembled thier race cars. He wanted to make sure things were done to his specifications (ie. right). So one race the mechanics decide to surprise Chapman and assemble the car before he arrived. When he actually was able to look over the car, he flew into a fit of anger and yelled that the mechanics did everything wrong. They were puzzled, because they had followed all the procedures exactly. They asked Colin "Sir, but what did we do wrong?". Colin popped off the body panels and pointed at every bolt and nut and yelled: "I'm not paying for washers to take a ride on the track!". He was so concerned about weight that he forced the mechanics to take the car apart, remove all the unnecessary washers, and reassemble the car....
My point is thus: Do you really, really want to go through the effort to remove 0.5LB from a set of 3 LB aluminium engine mounts? Even if it takes half an hour per mount (a decent estimate), it's certainly not worth it. Save the weight by not wearing a belt, or don't eat lunch before you drive on the track. You ARE tracking this car, right? Because if you aren't, then don't even bother with the solid mounts. Engine mounts not only try to isolate the shock of the drivetrain from the car, but they provide the necessary slack in the drivetrain to absorb the shocks from the road. Yes, many people use solid mounts...Personally I can't stand the damn things.
If you are going to do this, DO NOT dish the sides of the mount. Drill holes vertically instead. That way you at least retain (most of) the strength of the mount. If you dish the sides, they will crack laterally very quickly.
Anyone who has ever driven a Lotus (or even leaned up against one...DON'T DO THIS!) knows how stupidly light those cars are. Every weight saving measure was taken, even with the production cars...So the story goes:
Colin Chapman always insisted on being there when the mechanics assembled thier race cars. He wanted to make sure things were done to his specifications (ie. right). So one race the mechanics decide to surprise Chapman and assemble the car before he arrived. When he actually was able to look over the car, he flew into a fit of anger and yelled that the mechanics did everything wrong. They were puzzled, because they had followed all the procedures exactly. They asked Colin "Sir, but what did we do wrong?". Colin popped off the body panels and pointed at every bolt and nut and yelled: "I'm not paying for washers to take a ride on the track!". He was so concerned about weight that he forced the mechanics to take the car apart, remove all the unnecessary washers, and reassemble the car....
My point is thus: Do you really, really want to go through the effort to remove 0.5LB from a set of 3 LB aluminium engine mounts? Even if it takes half an hour per mount (a decent estimate), it's certainly not worth it. Save the weight by not wearing a belt, or don't eat lunch before you drive on the track. You ARE tracking this car, right? Because if you aren't, then don't even bother with the solid mounts. Engine mounts not only try to isolate the shock of the drivetrain from the car, but they provide the necessary slack in the drivetrain to absorb the shocks from the road. Yes, many people use solid mounts...Personally I can't stand the damn things.
If you are going to do this, DO NOT dish the sides of the mount. Drill holes vertically instead. That way you at least retain (most of) the strength of the mount. If you dish the sides, they will crack laterally very quickly.
Thread Starter
Joined: Nov 2002
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From: Laredo, Tx
Yes this car is going to see the track(s), drag strip mainly but i hope to get to an auto cross or two if I get her running just right.
But you know me if its for performance it might aswell be done. Given you don' thave to go to the moon and back.
But you know me if its for performance it might aswell be done. Given you don' thave to go to the moon and back.
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Joined: Feb 2004
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From: NYC/Stony Brook Univ.
You know I have nothing against you santiago, i think youre a great source of info. BUT honestly I think you are sooo anti-rice, that you try to be too race oriented. You will never feel those 1.5 pounds (at most). Even if you addd up the weight redux, there are a lot of better things to do with your money/time. I understand what colin was doing, but I don't think you can do all of that. Remove every washer and nut that is. Especially if you drive this on the street.
Jahan
Jahan
Thread Starter
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From: Laredo, Tx
Originally Posted by Aaron Cake
*must bite my tongue* Shut up Aaron. Don't say a damn word....Go onto the next thread....
It's cool, I asked for comments and I got them on both sides. I personally think it is reasonable because it wouldn't take an enourmous amount of effort. Although I agree that it is a very small gain but it is a gain. Anyway i'm pretty much done with the thread for now. Hopefully i'll bump it up when I get them in and if I decide to do the drilling method.
Santiago
I purchased the Aluminum for my own Solid motor mounts and will lighten them a fraction. I'll try and post before and after shots/weights once they come off hte drill press.
WingmaN
Joined: Aug 2002
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From: Fort Worth Texas
The mounts weigh just under 1 lb each so unless you are obsessed with shaving weight they are not a problem as is. Instead of making a bunch of small holes or turning the middle down on a lathe to decrease the weight you could do a large recess on each side. I do one side on third gen mounts because one of the arms has a big bump it has to clear.
A recess will not effect the integrity as long as you leave at least a 1/2" shoulder.
But there are much easier ways of shaving weight.
My user name on Ebay is scalliwag_performance.
But www.scalliwag.com will get you to my PayPal shopping cart.
Here is what the recess looks like for the 3rd's
A recess will not effect the integrity as long as you leave at least a 1/2" shoulder.
But there are much easier ways of shaving weight.
My user name on Ebay is scalliwag_performance.
But www.scalliwag.com will get you to my PayPal shopping cart.
Here is what the recess looks like for the 3rd's
Meesto Spakaro
Joined: May 2001
Posts: 489
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From: Redondo Beach, CA
your car is anorexic
just go the bullimic route!
puke out some of the fluids like oil and gas. Gas is super heavy, one gallon should weigh a good five pounds, a quart of oil should be about a pound as well. This will cost you nothing, and you'll be .005 seconds faster in the quarter mile
just go the bullimic route!
puke out some of the fluids like oil and gas. Gas is super heavy, one gallon should weigh a good five pounds, a quart of oil should be about a pound as well. This will cost you nothing, and you'll be .005 seconds faster in the quarter mile