Author Topic: LP 640 Autopro  (Read 211231 times)

RStaggs

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Re: LP 640 Autopro
« Reply #358 on: August 16, 2016, 10:27:10 PM »
Thanks 76 and Auto. Great clarity! I welded my shock mounts acourding to blue prints. I found several errors on the prints, such as the front shocks don't lined up straight. When I get my wheels and tires I'll do the same as you guys suggest. Thanks again, greatly appreciate it!

76mx

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Re: LP 640 Autopro
« Reply #357 on: August 16, 2016, 10:23:28 PM »
Pedro, I waited on you to answer so it would not interrupt. I am working on mine 10 hours a day and don't think I am making as much progress as you. Doesn't that bother you when all of the pieces have to be stripped off of the frame to paint it? My least favorite part of a build. Taking parts off seems so counterproductive. Here is a picture of 5" travel shocks with tires selected. It is at ride height and there is 2-1/2" of travel either way.

autopro

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Re: LP 640 Autopro
« Reply #356 on: August 16, 2016, 10:12:12 PM »
RStaggs, pay close attention to the fact that Pedro set everything at ride height with tires and wheels and THEN found his shock mount points, which centered the shock in the "Sweet Spot" center of its travel, absolutely critical with the very short 4" travel. Miss it by as little as 1/2" and now your shock only has 1-1/2" of travel in compression, not good and downright dangerous. With yours the way you described, with points already determined, a 5" travel shock is the only alternative. They will be about 11" compressed and about 16" extended, sweet spot at 13-1/2", and that is good. A 4" travel shock is completely extended at 14", where you say your sweet spot is. A 6" travel shock is fully compressed at 12" or 13", not leaving enough rebound stroke. Here is another thing that is absolutely critical. All of these assumptions were for tires and wheels that have not been selected yet. Change the tire diameter by 1" and it will change the sweet spot location by about 1/2". Now you only have 1-1/2" of compression and again this is dangerous. It is good to know what Pedro has used but because of the different tire combinations on the NAERC chassis, one size is definitely not a fits all. 

Wonderful explanation Charley, it really does make much better sense the way you explained it.  Thanks for chiming in  ::salute
Pedro

autopro

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Re: LP 640 Autopro
« Reply #355 on: August 16, 2016, 10:07:52 PM »
Bolting on bits that have already been fitted is very rewarding and I can do quite a bit in a little while.  Tonight I installed the fuel tank, pump and filter.  I glued rubber strip to the bottom of the tank and to the straps that hold it in place.





Pedro

76mx

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Re: LP 640 Autopro
« Reply #354 on: August 16, 2016, 10:07:15 PM »
RStaggs, pay close attention to the fact that Pedro set everything at ride height with tires and wheels and THEN found his shock mount points, which centered the shock in the "Sweet Spot" center of its travel, absolutely critical with the very short 4" travel. Miss it by as little as 1/2" and now your shock only has 1-1/2" of travel in compression, not good and downright dangerous. With yours the way you described, with points already determined, a 5" travel shock is the only alternative. They will be about 11" compressed and about 16" extended, sweet spot at 13-1/2", and that is good. A 4" travel shock is completely extended at 14", where you say your sweet spot is. A 6" travel shock is fully compressed at 12" or 13", not leaving enough rebound stroke. Here is another thing that is absolutely critical. All of these assumptions were for tires and wheels that have not been selected yet. Change the tire diameter by 1" and it will change the sweet spot location by about 1/2". Now you only have 1-1/2" of compression and again this is dangerous. It is good to know what Pedro has used but because of the different tire combinations on the NAERC chassis, one size is definitely not a fits all. 
« Last Edit: August 16, 2016, 10:09:28 PM by 76mx »

autopro

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Re: LP 640 Autopro
« Reply #353 on: August 16, 2016, 09:38:34 PM »
Hey Pedro - What size shocks and springs did you go with? Everything that I have read, indicates 12" shocks for front and rear? On my NAERC chassis, 12" shocks for the front will work fine, but... the rear, measures 14" (17" extended 12" compressed) . I don't have wheels and tires yet, in order to get a accurate measurement. I'm just wondering what you used?

According to the NAERC plans that I have it asks for 10" shocks all the way around with 10" springs on the back and 8" springs on the front.

I am using QA1 ALN4855B shocks that have compressed length of 10" and an extended length of 14.375".  I set the ride height of my chassis at 5.5" from the ground, then with the shock at the middle of its travel and bolted on the bottom to the suspension arm I was able to find the appropriate location of the top shock mount.  I hope this makes sense to you.  I didn't weld my top shock mounts until I had my shocks and springs and I did this set up.

Get your rims and tires and then set your chassis height off the ground, this will help you determine your shock size.  Did you already weld your top shock mounts?
Pedro

RStaggs

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Re: LP 640 Autopro
« Reply #352 on: August 16, 2016, 07:45:14 PM »
Hey Pedro - What size shocks and springs did you go with? Everything that I have read, indicates 12" shocks for front and rear? On my NAERC chassis, 12" shocks for the front will work fine, but... the rear, measures 14" (17" extended 12" compressed) . I don't have wheels and tires yet, in order to get a accurate measurement. I'm just wondering what you used?

autopro

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Re: LP 640 Autopro
« Reply #351 on: August 16, 2016, 08:48:27 AM »
Nick you just don't know, still a lot of work ahead but now I can finally see the light at the end of the tunnel.
Pedro

nickmkk

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Re: LP 640 Autopro
« Reply #350 on: August 16, 2016, 06:19:24 AM »
Looks awesome, I bet you can't wait to get it finished.

autopro

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Re: LP 640 Autopro
« Reply #349 on: August 15, 2016, 07:28:20 PM »
And finally for today, a rolling chassis  ::bounce






autopro

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Re: LP 640 Autopro
« Reply #348 on: August 15, 2016, 07:24:05 PM »
Honda civic radiators and Porsche 996/Boxster fans installed.



Pedro

autopro

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Re: LP 640 Autopro
« Reply #347 on: August 15, 2016, 07:22:06 PM »
So a little bit of progress on several parts, first off is the steering column has been installed and centered.   Made a hole in the front foot well area and installed all the passat components, even the seal and it worked out great.  The cutouts in the dash support will get boxed in once I double check the clearances for the gauge pod.





Pedro

autopro

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Re: LP 640 Autopro
« Reply #346 on: August 14, 2016, 12:25:35 AM »
I also started on the front suspension and got the steering rack installed.  Need to install the steering wheel but I'll do it sometime next week.






Pedro

autopro

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Re: LP 640 Autopro
« Reply #345 on: August 14, 2016, 12:19:36 AM »
Suspension work continues but at least the rear is under its own weight finally!







Pedro

autopro

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Re: LP 640 Autopro
« Reply #344 on: August 06, 2016, 10:23:00 PM »
And here's the right





« Last Edit: August 06, 2016, 10:50:35 PM by autopro »
Pedro